Physical and Chemical Constituets of Gossypium Hirsutum L
Subject: Chemistry | Topics:

Three varieties of Gossypium hirsutum L.(Cotton Seed); like Shimul Tula Seed, CB-09 and SK-05 Cotton Seed were collected from New market and Joydebpur, Gazipur for comparative study for their chemical and physical characteristics, and fatty oils compositions and nutrient contents of cakes (residues).

The Fatty oils from the samples were extracted by steam distillation and physical and chemical characteristics were determined by usual standard procedure.

There are varieties of cooking oil and fat available today and the claims made by them are, at best, confusing. On one side are the traditional ghee, mustard oil, coconut oil, and gingerly oil. Then, there are the used-for-decades vanaspati and groundnut oil, as well as the relatively newer kinds of vegetable oil ranging from Cottonseed, sunflower, safflower, corn, canola, soybean, and palm to various blends. Vegetable oils are in most of the processed foods we eat today everything from soups to crackers. Fats and oils contain fatty acids that can either be harmful or helpful to our health. Oils high in saturated fatty acids have been shown to raise blood serum cholesterol levels, which may lead to heart attacks in some people. Unsaturated oils have been shown to reduce serum cholesterol levels. Diet and health experts generally agree that reducing total fat and saturated fat intake would be beneficial for many people, especially those who should reduce their blood cholesterol levels. Managing our fat intake to get the most benefit for our bodies is the key. The right kinds of fats and oils are therefore important for good nutrition.  In particular, Cottonseed oil performs better than other oil as it lasts a long time and stores well by withstanding higher temperature for food items due to its high antioxidant content. Cottonseed oil brings out the flavor of foods. It is ideal for dressings and marinades and enhances vegetable and meat flavors. Many chefs prefer it for imparting a fresh taste to their “house” dressings. Also, Cottonseed oil’s light, non-oily consistency, plus its high smoke point, make it most desirable for oriental dishes and stir-fry vegetables. Cottonseed oil stays fresh longer in a fryer or in products on the shelf The flavor of Cottonseed oil does not deteriorate or “revert” as much as some other oils when it is used at high temperatures.  It is excellent for the finest baked goods. Besides, chips and snacks fried in Cottonseed oil may maintain a longer shelf life. It is a good option for preparing healthier foods. The purpose of this paper is to highlight the value of addition Cottonseed oil in the food industry and presents an insight into other contemporary edible oil. It is important to note that buying the right oil for health has become a big deal.

Cotton (Gossypium spp.) is an important fibre crop and plays a vital role as a cash crop in commerce of many countries. Cotton, also known as “King of fibres” plays a remarkable role in our economy. The cotton seed, which is byproduct, is an important source of edible oil and a protein concentrate feed for livestock. Moreover to flavor stability, cotton seed oil also has superior nutritive qualities; it has a 3:1 ratio of unsaturated to saturated fatty acids, which meets the recommendation of many health professionals. Cotton seed oil is rich in essential fatty acids such as palmitic and stearic (saturated), oleic and linoleic (unsaturated) acids. Cottonseed oil is cooking oil extracted from the seeds of cotton plant of various species, mainly Gossypium hirsutum L. and Gossypium hirsutum L. Cotton seed is the second largest source of vegetable oil in the world. The five largest producers (China, 27%; United states, 12% ; India, 11% former Soviet Union, 10%; Pakistan  9%) of cotton seed oil from 1995 to 2003 accounted for 70% of global output (Song and Zhang, 2007). The refined cotton seed oil is one of the best edible oil, which is used most of the world including USA, Uzbekistan, and China etc., Nowadays, the refined cotton seed oil was started to be used as an edible purposes in India and Pakistan. Cottonseed oil is typically composed of about 26% palmitic acid (C16:0), 15% oleic acid (C18:1), and 58% linoleic acid (C18:2) Liu et al. (2002). The relatively high level of palmitic acid provides a degree of stability to the oil that makes it suitable for high-temperature applications, but is nutritionally undesirable because of the low-density lipoprotein cholesterol-raising properties 038 Int. Res. J. Plant Sci. of this saturated fatty acid (Cox et al., 1995). Linoleic acid, which is the most important one, is present to the extent of 51 per cent (Shaikh et al., 1996). Although cottonseed oil has recently been shown to lower total serum cholesterol compared with corn (Zea mays) oil (Radcliffe et al., 2001), it ensured thus by lowering the level of the desirable high-density lipoprotein cholesterol without reducing the level of the undesirable low density lipoprotein cholesterol, presumably because of its significant content of palmitic acid. The processed cotton seed oil is the fifth leading vegetable oil in the world. Refined cotton seed oil is free from phenolic compound; gossypol and it can be directly used as cooking medium. Chemical analysis showed that by and large cotton seed oil and groundnut oil have similar physiochemical properties except free fatty acids which indicate the better keeping quality of cotton seed oil. Cotton seed oil is generally considered as healthy vegetable oil. It is cholesterol free and hence termed as “Heart oil”. In India nearly entire cotton seed oil being utilized for edible purposes and mostly for Vanaspati, only small quantity (5-10 %) is used for manufacturing soaps (Ashokkumar, 2006). It has high level of antioxidants (Vitamin E) that contribute to its long life in the cooking or on the shelf. Breeding for the improvement of cotton seed oil has not made much progress. Marked differences were observed in oil composition between varieties within the species. There is urgent need to utilize such improved varieties of cotton seed oil in cotton cultivated countries for edible purposes. If we use the extra quantity for edible oil, it may fulfill global need. Further it is essential to have varieties/ hybrids with more oil content (25%) for oil extraction. Cottonseed meal is left after oil extraction and used as a source of fodder protein in the livestock industry, but the sphere of its use in agriculture is limited. Constituting nearly half of a seed’s weight, the meal contains 23% high biological-value protein.

General Information:

*Cottonseed oil is edible vegetable oil extracted from the seeds of the cotton plant after the lint has been removed.

*It is solid at room temperature and does not need hydrogenation.

*Has a high smoking point and long shelf life and so is used in high heat cooking, like deep frying in the snack industries.

*It has a nutty buttery flavor but does not impart any color or odor to the fried foods. While unsaturated fats break down when used for repeated frying, cottonseed oil retains its nutritional value and keeps very well.

*Cheaper than other vegetable oils.

*Has a long shelf life without refrigeration when stored properly away from light and heat.

WHY IS THE COTTONSEED OIL HIGHLY ACCEPTABLE AS AN EDIBLE OIL?

Even though cottonseed oil is darker than soybean, peanut and other traditional oil types in colour, the impurities and pigments are readily removed by modern refining and bleaching techniques to produce lighter colour. It possesses properties that make it suitable for processing in salad oil. The proportion of highly saturated glycerides is such that when the oil is chilled slowly, the higher melting glycerides separate out and can be readily removed by filtration which does not get crystallized when held at 40o to 45°F. The high melting portion is generally utilized in blended oils for shortening or in hydrogenated products. It contains traces of fatty acids with instauration greater than linoleic acid. On hydrogenation, the instauration decreases and stability is further increased. Unlike soybean oil, cottonseed oil has greater resistance to flavour reversion. The stability is also due to the presence of antioxidants, namely tocopherols (Srinivasan, 2004).

Cottonseed oil is commonly used in manufacturing potato chips and other snack food. Along with soybean oil, it is very often partially or fully hydrogenated. The growing consensus is that in hydrogenated (trans fats) form, these oil types are very unhealthy. Cottonseed oil was the first oil to be hydrogenated in mass production, originally intended for candle production, and also as a food. In part because regulations apply differently to non-food crops, it has also been suggested that cottonseed oil may be highly contaminated with pesticide residues; however, insufficient testing has been done to prove this. Cotton (oil) is also one of the big four (soy, corn, rapeseed/canola, and cotton) genetically modified crops grown around the world. Fried foods and fast food chains commonly use cottonseed oil and vegetable oil blends to fry everything.

Health Benefits

1. Cottonseed oil has moderate amount of saturated fats, good amount of monounsaturated fats, high content of polyunsaturated fats and no cholesterol.

2. Oleic acid, the monounsaturated fat, is good for the heart and it lowers the LDL cholesterol and total cholesterol in blood and maintains the HDL cholesterol.

3. Has good amounts of essential fatty acids, nearly 51% of linoleic acid (omega-6) and 0.2% of alpha-linolenic acid (omega-3), which are the precursors of prostaglandins, which are hormone like substances that have a variety of functions like contraction and relaxation of smooth muscles, control of blood pressure, pain and inflammatory response, etc in humans and animals.

4. Has high amounts of vitamin E (176%) and phytosterols, which fight against the free radicals in the body, preserve the integrity of the cell membranes and reduce the risk of heart diseases, cancers and other degenerative disorders.

5. Has no trans fats at all, but is semi-solid to solid at room temperature.

6. According to a recent study, researchers found gossypol, a compound derived from cottonseed oil and thought to be toxic, is used in Chinese medicine to help chemotherapy become more effective in patients with cancers of the head and neck. Usually chemotherapy or radiation does not respond very well in head and neck cancers.

Besides, Cottonseed oil enhances, rather than masks, the fresh natural flavors of foods. Its neutral taste makes it perfect for frying seafood, snack foods and oriental foods, especially stir-fry. In snack foods, where oil becomes part of the product, cottonseed oil is recognized as being superior because of its low flavor reversion especially when used at high temperatures. And, toward the end of its useful life, cottonseed oil won’t produce objectionable flavors as some oils do. Another of cottonseed oil’s benefits is the high level of antioxidants (Vitamin E) that contribute to its long life in the cooker or on the shelf. Studies show that these natural antioxidants are retained at high levels in fried products, creating longer shelf life.

NEGATIVE IMPACTS OF COTTONSEED OIL

The renowned nutrition expert, Dr. Andrew Weil, says cottonseed oil contains both naturally occurring toxins and pesticide contaminants. Cottonseed oil is generally extracted by using harsh chemical solvents and heat which may alter the chemistry of the oil. Most nutritionists are still uncertain about the long-term implications of these changes. Cottonseed oil is high in Vitamin E, which is an antioxidant. Antioxidants present in cottonseed oil work against the free radicals that cause cell damage aging. Nonetheless, it has very low amounts of heart-healthy omega-3 and mono-unsaturated fats.

In addition, cottonseed oil contains gossypol, a substance that has been shown to cause sterility in rats. For this reason, it has been used in parts of the world as a contraceptive and cottonseed oil has been seen as a threat to men’s fertility. A 2006 study done at the University of Lecce, Italy, ‘proteinaceous diet inhibits gossypol-induced spermatotoxicity” showed that gossypol in cottonseed oil is not an effective contraceptive, because if combined with most proteins, gossypol no longer causes infertility. Gossypol still has toxins that decrease spermatogenesis and sperm motility in men. This is a topic that should be brought up with fertility doctors because cottonseed oil is a very commonly used ingredient in many foods.

Chemical Composition

Its fatty acid profile generally consists of 70% unsaturated fatty acids including 18% (13% – 44%) monounsaturated (oleic), and 52% (33.1%-60.1%) polyunsaturated (linoleic & linolenic).

Cottonseed oil is described by scientists as being “naturally hydrogenated” because the saturated fatty acids it contains are the natural myristic, palmitic, and (predominantly) stearic acids. These fatty acids make it a stable frying oil without the need for additional processing or the formation of trans fatty acids. Cotton seed oil is not required to be as fully hydrogenated for many purposes as some of the more polyunsaturated oils. On partial hydrogenation, the amounts of monounsaturated fatty acids actually increase. When hydrogenated to a typical iodine value of about 80, for example, its fatty acid profile shifts to 50% monounsaturated, 21% polyunsaturated, and 29% saturated, which are all well within current diet/health guidelines.

Gossypol is a toxic yellow polyphenolic compound produced by cotton and other members of the order Malvaceae, such as okra. This coloured compound is found in tiny glands in the seeds, leaf, stem, tap root bark, and root of the cotton plant. The adaptive function of the compound is believed to be one of facilitating insect resistance. Further, gossypol acts as a male and female contraceptive. It may be used to treat gynaecological problems and viral infections. In addition, global cotton seed production can potentially provide the protein requirements for half a billion people per year. Work is under way to find a viable solution to the gossypol problem.

The three key steps of refining, bleaching and deodorization that are involved in producing finished oil act to reduce the gossypol level. Ferric chloride is often used to decolorize cotton seed oil.

1.7 Cottonseed Oil Fatty Acid Composition.

The specific fatty acid profile of the triglycerides in cottonseed is dependent on the variety of cotton grown, growing conditions such as temperature and rainfall, and the analytical method used to determine the profile. Table 5 summarizes the fatty acid composition observations of several research and commercial groups. Cottonseed oil is typical of the oleic– linoleic group of vegetable oils, because those two fatty acids comprise almost 75% of the total fatty acids. Although oleic acid makes up 22% and linoleic makes up 52%, less than 1% linolenic acid is present. Palmitic fatty acid makes up about 24% of the fatty acids. Minor amounts of other saturated fatty acids are also found. Bailey (23) noted that the composition of American cottonseed oils will rarely fall outside of these limits: 23–28% total saturated fatty acids, 22–28% oleic acid, and 44–53% linoleic acid. The Food and Agriculture Organization of the World Health Organization (FAO/WHO) has determined a range of fatty acid contents for commercial fats and oils. The acceptable range of fatty acids prescribed by Codex in 1997 for cottonseed oil is shown in Table 6 (77). Cherry et al. (78) examined the variation in cottonseed oil content and composition as part of a study of genetic and location effects on Texas cottonseed. Both factors were found to have a significant effect on oil quantity. The oil content of moisture and lint-free seeds ranged from 23.2% to 25.7% depending on location. The variation in the six key fatty acids of cottonseed oil was significant within both cultivars and location, and five of them had significant interactions between cultivar and location. Linoleic acid varied from 49.07% to 57.64% with a mean of 54.54%. Palmitic acid varied from 21.63% for an Acala variety grown in Lubbock to 26.18% for a Lockett variety grown in Corpus Christi, whereas the mean was 23.68%. The authors also indicated that agronomic practices as well as weather conditions at the specific location may play a part in the observed variation. Such variations in oil quantity are not well understood and have not

CodexFattyAcidRanges for Cottonseed Oil.

Fatty Acids, %            Typical            Range

Lauric C12:0               0–0.2

Myristic C14:0            0.7                  0.6–1.0

Palmitic C16:0            21.6               21.4–26.4

Palmitoleic C16:1        0.6                   0–1.2

Stearic C18:0 2.6       2.1–3.3

Oleic C18:1                 18.6                 14.7–21.7

Linoleic C18:2            54.4                46.7–58.3

Linolenic C18:3          0.7                  0–0.4

Arachidic C20:0          0.3                   0.2–0.5

Gadoleic C20:1                                   –0.1

Eicosadienoic C20:2               0–0.1

Behenic C22:0            0.2                  0–0.6

Erucic C22:1                           0–0.3

Docosadienoic C22:2             0–0.1

Lignoceric C24:0                   0–0.1

been carefully studied in cotton, and more work needs to be done. Cherry et al. (79) have provided a good review of the existing information.

AGRONOMICAL AND MORPHOLOGICAL CHARACTERS

The study of the genetics and evaluation of cotton (G. hirsutum) diversity is important for improvement, efficient management and utilisation of the existing gene pool (Altaf Khan et al., 2002). Cotton is the most important textile fibre crop (Cherry and Leffler, 1984). In Tanzania, cotton is grown by small-scale farmers in two growing areas known as the Western Cotton Growing Areas (WCGA’s) and Eastern Cotton Growing Areas (ECGA’s). Cotton varieties grown in these areas are adapted to the environment and tolerant to some diseases and insect pests (Jones and Kapingu, 1982; TCL and SB, 2002).

Diversity analysis and maintenance of crop genotypes are essential processes in identification of genetic relatedness of available genetic resources. It facilitates the selection of potential parents for subsequent crossing and selection of progenies up to the final utilisation of cultivars in production schemes

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Free fatty acids

Free fatty acids (FFA) (AOCS 1998, Ca 5qa-40) measures fatty acid changes that

occur in oils during deep-fat fiying. Free fatty acids are pro-oxidants and contribute to the decreased shelf life of oil (Frega and others 1999). In the initial stage of cooking, free fatty acids are produced by oxidative breakdown, but in later stages, hydrolysis of the fat caused by the presence of moisture in the food being fiied causes the increase in free fatty acids (Blumenthal 1996). In most deep fat fiying operations, the presence of FFA produced by hydrolysis is too small to affect the quality of the food, while the FFA formed by oxidation will adversely affect the product (Tyagi and Vasishtha 1996). Generation of up to 2% FFA from hydrolysis in oils that contain minute amounts of lauric acid, such as soybean and cottonseed oil, has no adverse effect on the odor or the flavor of foods (Tyagi and Vasishtha 1996). Oils high in lauric acid will produce a soapy flavor at ca. 0.5%) FFA content (Tyagi and Vasishtha 1996). When significant amounts of free fatty acids are present in the oil, smoking becomes excessive and the oil must be discarded (Blumenthal 1996). Detection of increases in FFA by titration is a poor measure of oil quality because it does not differentiate between acids formed by oxidation and those formed by hydrolysis. Free fatty acid levels are 0.05%) in fresh refined, bleached, and deodorized oils (Jones and King 1993).

Iodine value

Iodine value (AOCS 1998, Cd 1-25) is a simple test used in the oil industry which has a direct relationship to the deterioration of the quality of the oil. For the iodine value to be of any reasonable estimate, there must be an unheated reference sample in order todetermine the change in the values (Waltking et al. 1975). The iodine value indicates the number of unsaturated fatty acids (Jones and King 1993). The iodine value is a good estimate of lipid stability because fats v^th larger proportions of saturated fatty acids are less likely to undergo autoxidation (Jones and King 1993). The PUFA content in oils will undergo a steady increase in saturation as fiying time increases.

Peroxide value

Peroxide value (AOCS 1998, Cd 8b-90) is a test that measures primary oxidation in its early stage, however, it may not be a good measure of heat abuse in PUFA-rich oils. Hydroperoxides are the initial and primary products of lipid oxidation. They are transitory and are broken down by further reactions (Jackson 1981). Hydroperoxides can be quantitatively measured by determining the amount of iodine liberated by their reaction with potassium iodide (Blumenthal 1996). In PUFA-rich oils, peroxides are formed through the oxidation of free radicals obtained from abstraction of protons from methylene-intermpted fatty molecules (Tyagi and Vasishtha 1996). PUFA-rich oils decompose much faster than oils with less triene by means of labile hydrogen, obtained from the active methylene group of another molecule, which causes free radical polymerization (Tyagi and Vasishtha 1996). Tyagi and Vasishtha (1996) concluded that oils containing trans isomers could inhibit free radical polymerization by restricting the decomposition of peroxides. Peroxides quickly breakdovm to non-peroxide compounds, making their correlation with flavor variable (Jackson 1981). For a product to have acceptable shelf life, the peroxide value should be less than 1.0 meq/kg fat at the point of use (Blumenthal 1996).

Totox number

Totox number (AOCS 1998, Cd 18-90) is a test that con-elates well with oxidation and flavor in oils. The totox value is the anisidine value + 2 times the peroxide value. Using this combination of tests results in higher correlations with flavor than using the panisidine value alone (Jackson 1981). The p-anisidine value is primarily a measure of alpha-beta-unsaturated aldehydes (Jackson 1981). Aldehydes are secondary lipid oxidation products and account for 50% of the volatiles produced during oxidation (Tompkins and Perkins 1999). In particular, trans -2,trans -A decadianal (a precursor of linoleic acid) is associated with fiied food flavor, and its correlation with p-anisidine value is highly significant (Tompkins and Perkins 1999).

Fatty acid profiles

It is important to determine fatty acid profiles in both fresh and used oil because

the fatty acid composition in oils changes during deep-fat fiying. Thompson and Aust (1983) and Miller and White (1988) evaluated changes in the fatty acid composition of fiying oils after 40-100 hours of fiying. Both studies found that linoleic and Unolenic acid levels dropped, while amounts of saturated fatty acids increased. The decrease in unsaturation can be attributed to the destmction of double bonds by oxidation, scission, and polymerization (Tyagi and Vasishtha 1996). The amounts and types of fatty acids present in oil contribute to its fiinctional properties.

Cottonseed oil is known for its “nutty” flavor and is often used as the standard for which other oils are compared for pleasing aroma, flavor and performance (NCPA 1996). The sensory properties of oil are affected by frying time, temperature, oil type, whether the oil is fresh or has been replenished, fiying equipment, type of food being fried, and any additives in the oil.

Hydrogenation can affect the sensory quality of oil. Blumenthal et al. (1976) found

that the sensory quality of french fiies fried in hydrogenated soybean oil decreased as compared to non-hydrogenated soybean oil fried under the same conditions. Each type of oil will have its on flavor profile. Off-flavor compounds produced by polyunsaturated fats have been characterized by consumers as “grassy,” “fishy,” and “rancid” (Sinram and Hartman 1989). Min and Smouse (1989) described the two disadvantages of using hydrogenated oil. One disadvantage is that hydrogenated oil has a lower linoleic acid content, which causes less full and less pleasant flavors. Another disadvantage is that hydrogenated oil has different oxidation products as compared to natural fats. These peculiar products can produce unfamiliar off-flavors and odors to the oil and the product being fiied. In addition, appearance plays a role in the acceptance of a fiied product. French fries are expected to be light in color, with littie browning. During fiying, Maillard (nonenzymatic) browning can occur. This involves the reaction of sugars with free amino acids or free amino groups of proteins and peptides (Boskou and Elmadfa 1999). To avoid the development of dark colors while fiying, potatoes with lower sugar content are selected.

 Important characteristics in cotton improvement

Cotton cultivars may react differently to different production areas and have different characteristics but mainly are either hairy or non-hairy, normal or super okra leaf shaped, frego bract or normal bract, reddish or green coloured varieties. Hairy plant types are used to resist jassids in Africa and Asia. Cotton varieties without hairs (glabrous) offer resistance to Helioths spp. and pink bollworm by incurring decreased egg laying that is associated with decreased trash content of fibre (Thaxton and El-Zik, 1994). Super okra leaf shaped plants have a more open canopy, which permits 70% more light penetration. This reduces the numbers of boll weevil, pink bollworm, mite and boll rot. Super okra leaf shape is associated with accelerated fruiting rates, early maturity and production of fibre with less trash than normal leaf cultivars. Normal leaf cotton has taller plants than super okra leaf cotton and lower fruit loss at 43% compared to 59% for super okra leaf plants (Andries et al., 1969; Reddy, 1974).

The frego bract trait is associated with a high level of resistance to boll weevil and can reduce boll weevil damaged squares up to 50% compared with normal bract (Jones, 1972; Jenkins, 1976). Frego bract is associated with delayed fruiting in maturity in addition to reduced yield (Jones, 1972; Thaxton et al., 1985). Red plant colour confers significant degrees of non-preference to the boll weevil and cotton aphid damage. Varieties with the smooth-leaf trait generally give higher fibre grades than those with normal or densely hairy leaves (Thaxton and El-Zik, 1994).

Yield: Yield refers to the total seedcotton and lint yield. Yield is a composite of many other traits, each influenced by many genes that have variable effects and are modified by environmental conditions and cultural methods (Christidis and Harrison, 1955; Meredith, 1984). Cotton varieties vary in yield potential, therefore varieties producing high seedcotton and high lint yield are important to the client. Andries et al. (1971) reported lower yields with Super okra leaf cotton compared to normal leaf cotton. Lint and seed yield are highly significantly positively related. As one tends to increase, so does the other. Selections should not be based on seedcotton yield, instead selections should be based on lint yield as lint yield depends on seedcotton and ginning outturn (Thaxton and El-Zik, 1994).

 Number of bolls and boll size: The boll is the unit package of yield, thus high yield is achieved when the size and number of bolls per unit area is maximised. Kerr (1966) and Coyle and Smith (1997) suggested that prolificacy (boll number per plant or per unit area) is an important factor to consider during selection for yield improvement. Yield models described by Worley et al. (1976) supported this. Selection for boll size and seed size could positively influence lint yield, if a breeder selects for medium boll size, small seeds per boll and maintaining high ginning percentage (Coyle and Smith, 1997).

Plant height: Plant height is important as a contributor to yield and can determine vegetative and fruiting branches of the plant. Breeding for plant height variation is influenced by both yield potential and harvesting methods (Niles and Feaster, 1984). Kohel and Benedict (1987) observed plant heights between 0.95-1.07 m while Emeetai-Areke (1999) reported that the plant height of cotton ranged from 1.0-2.0 m. Generally plant height is highly affected by the environment.

Hairiness: Hairiness of the leaf and other parts of the plant is heritable and varies between varieties. Hairiness is important for insect pest (jassid) resistance. The hairs on leaves and stems interfere with the ovipostion and laying of eggs, thus reducing the rate of damage. Cotton leaf hairs are stellate and vary both in length and density from sparse to densely hairs (Munro, 1987).

 Ginning outturn (GOT): This is the percentage of lint obtained from a sample of seedcotton and varies between cotton varieties and for upland strains ranges between 30-40%. Christidis and Harrison (1955) and Munro (1987) reported that the range of varieties with regard to ginning percentages was shown to change little from year to year and from place to place. Singh and Singh (1980) and Carvalho and De-Carvalho (1995) studied genetic control of ginning outturn. Results indicated that ginning outturn is controlled by additive genetic effects. Singh et al. (1990) reported non additive effects controlling ginning outturn.

Seeds per boll: Munro (1987) reported that seeds per boll and the number of locules is a characteristic of the species or a variety. In G. hirsutum there is mainly eight seeds per locule and the locule per boll varies between three to five. Seeds are the units of production and fibres 27 grow from the outer cells of seed surfaces. The higher the number of seeds per boll, the more lint is produced because it increases the amount of surface area for lint production (Culp and Harrel, 1973). Therefore, breeding for increased bolls per unit land area, more seeds per boll, large seed surface area per unit seed weight and increased weight per unit seed surface are importanct (Smith and Coyle, 1999). Worley et al. (1976) reported that seeds per boll are the second largest contributor to yield.

Seed and lint index: Seed index refers to 100 seed weight. Seed index is important in determining yield, especially in seed cotton. It varies between varieties and is highly affected by population density. Cottonseed measures about 10×6 mm and weighs about 80 mg (5-10 g per 100 seed) (Munro, 1987). Each pure line has its own particular mean seed weight to which it breeds true. It is a characteristic subjected to great influence of boll size and number of seeds per locules (Sikka and Joshi, 1960).

Lint index represents the absolute weight of lint borne by a single seed (or more often 100 seeds). Lint index has a direct relationship with the yield potential of a genotype but is affected by population density (Munro, 1987). It is a compound characteristic being a function of mean number of hairs per seed and mean hair weight. Sikka and Joshi (1960) reported that lint index is governed by two genetic systems, a single pair of factors having pleiotropic effects and a complex of modifiers, which have minor effects on lint production. Lint index is controlled by additive genetic effects (Singh et al., 1990).

 Fibre strength: This fibre quality trait is useful for spinners and processors. The inherent strength of individual cotton fibres is an important factor in the strength of the thread spun from them. High tensile strength of fibres is necessary for good spinning properties, especially with modern fast spinning machines (Niles and Feaster, 1984; Munro, 1987). Fibre strength is affected by environmental fluctuations (Christidis and Harrison, 1955).

Fibre length: This is the staple length that is universally recognised as the premier fibre property, because it is closely associated with the processing efficiency in manufacturing and determining the quality of the yarn produced. Fibre length variation can occur from boll to boll and plant to plant. Even on a single seed the hairs are not of the same length (Munro, 1987).28

Fibre fineness (Micronaire): This is the measure of soft or silky feel. It is an important quality trait of cotton associated with long hairs and smaller cell diameter in combination with wall thickness. Fibre fineness determines the texture of cotton fibre into soft and silky or coarse and harsh and is affected by the environment (Sikka and Joshi, 1960). Christidis and Harrison (1955) reported that course lint is dominant over fine lint and is quantitatively inherited. Micronaire is acceptable anywhere within the base range of 3.5-4.9 units inclusive. The premium range is between 3.5-4.2, with values below 3.5 too fine and above 4.9 too coarse (Patil and Singh, 1994).

Uniformity of fibre length: It is an important fibre quality characteristic determining the maturity of fibres. The value is important in determining the spinning performance and utility of the lint. Higher values are an indication that the yarn spun from such fibres will be uniform in size and strength, with less wastage of fibres. Uniformity varies between varieties and is affected by environmental factors (Christidis and Harrison, 1955).

History and origin

Cotton is harvested from almost 32.4 million hectares in more than 40 nations of the temperate and tropic regions of the world (Anonymous, 1981). The crop is grown as far as 470 degrees N latitude in the Ukraine and 370 N latitude in the USA. In the Southern hemisphere production extends to about 320 S latitude (Niles and Feaster, 1984). Cotton grows at an optimum temperature of 300C, where 150C is the minimum temperature for cottonseed germination and growth (Munro, 1987).

Various theories have been advanced to explain the selective value of lint in the evolution of the species, but there is no convincing evidence that it is of any use to a cotton plant growing wild in its natural habitat (Munro, 1987). However, the primary centres of diversity for the genus are west central and southern Mexico (18 species), northeast Africa and Arabic (14 species) and Australia (17 species) (Brubaker et al., 1999). Brown et al. (1999) reported that Gossypium hirsutum L. and G. barbadense L. are natives of Mexico where they were domesticated originally.

In the light of increased knowledge of the distribution and relationships of primitive cottons, Santhanam and Hutchinson (1974) reported that the Asiatic species and races probably differentiated before domestication. Fryxell (1968) reported that cottonseeds can survive floating in seawater for at least a year with undiminished viability and can thus be distributed by ocean currents. Pursegloves (1968) agreed that the most likely explanation was that cottonseeds floated across the Atlantic from Africa to South America. The development of Old World cotton as a major raw material took place in Sind. This was found during excavation in Pakistan that was dated at approximately 3000 BC (Gulati and Turner, 1928). In Peru the New World tetraploid cottonseeds dated back to 2500 BC (Hutchinson, 1959). In Southern Mexico, cotton was dated around 3500 BC (Smith, 1968). Linted cotton species have been used for cotton fabrics between 4000 and 3000 BC (Munro, 1987). The oldest archaeological remains of G. hirsutum are from the Tehuacan Valley of Mexico, 4000 to 5000 years ago (Munro, 1987).

It is assumed that G. hirsutum was probably first domesticated by pre-Columbian people of the Yucatan peninsula

(Verhalen et al., 2002).  Variation determination for cotton varieties in Tanzania has been done morphologically using phenotypic descriptors. This knowledge has been important mainly for selecting parental material for crossing to improve available varieties

(Verhalen et al., 2002).  Variation determination for cotton varieties in Tanzania has been done morphologically using phenotypic descriptors. This knowledge has been important mainly for selecting parental material for crossing to improve available varieties

(Lukonge et al., 1999). Morphological properties mainly used were disease resistance, pest resistance, fibre quality, adaptability and yield components (boll size, boll number and branch number). Environment and cultivation practices had an effect on most of these morphological characteristics. Variation observed in farmers’ fields indicated a seed-mixing problem, but since the characters were unknown, it was difficult to identify individual varieties (Hau, 1997). Therefore, the objectives of this study were to characterise and quantify genetic diversity in 30 varieties collected from different areas using agronomical and morphological markers. Information obtained was compared with molecular markers in Chapter 6 to assess the relatedness between these two methods of characterisation.

(Iqbal et al., 2001; Allen and Auld, 2002).  Improved cotton varieties are urgently needed to improve the cotton market through cotton yield, high ginning percentages and good cotton quality as these factors affect lint price on the world market. The success of a breeding programme is mainly due to knowledge on the available germplasm especially genetic diversity (Meredith and Bridge, 1984; Pillay and Myers, 1999). The above knowledge is important to a plant breeder.

(Farooq and Azam, 2002; Murtaza et al., 2005).  DNA fingerprinting involves the display of sets of fragments from specific DNA samples. It is an effective tool to increase the speed and quality of backcrossing conversion, thus reducing the time taken to produce crop varieties with desirable characteristics

Altaf Khan et al., 2002; Rana and Bhat, 2004. With the use of molecular techniques, it is now possible to hasten the transfer of desirable genes among varieties and to introgress novel genes from related species. Using DNA fingerprinting, polygenic characteristics can be easily tagged and genetic relationships between sexually incompatible crop plants can be established .

Bruce et al., 2001.AFLP analysis has been applied in cotton to identify genes for resistance to fungal wilt diseases. It showed a greater potential compared to conventional breeding since it reduced the selection time and used small numbers of plants for detection of resistance genes.

AUison et al. (1999) estimated the trans fatty acid intake of Americans by using food intake data from the 1989-1991 Continuing Survey of Food Intakes by Individuals (CSPII) and the trans fatty acid contents of foods contained in a database compiled by the USDA. It was found that the mean percentage of energy ingested as trans fatty acids was 2.6% and the mean percentage of total fat ingested as trans fatty acids was 7.4%o (5.3 grams of trans fatty acids per day). Of this value, only 20-25% of the trans fatty acid intake comes from naturally occurring sources (basically animal fats), where as the majority of the intake comes from altered fats.

Ascherio et al. 1999.Since the 1960s, levels of trans fatty acids in margarines have declined as softer margarines have arrived on the market due to health concerns.

Lichtenstein et al. 1999 In the mid 1980s, manufactures replaced partially hydrogenated vegetable oils used in household salad and cooking oils with unhydrogenated vegetable oils (ASCN 1995). The majority of trans fatty acids consumed today come from fiied foods, margarine, snacks and baked products (Table 6). For example, a large cake doughnut has 3 g of trans fatty acids and a large order of French fries has 5 grams of trans fatty acids (Lichtenstein et al. 1999). Trans fatty acids should be Umited to no more than 3 g/day).

(UPOV, 1991; Van Esbroeck et al., 1999; Murtaza et al., 2005). This knowledge is important for germplasm collection and conservation (Pillay and Myers, 1999). Accurate morphological characterisation of varieties is an important process in breeding as variety characteristics like resistance to insect pests and diseases can be determined. For example, hairy leaf or stem varieties are resistant to insects like jassids while smooth leaf varieties reduce the trash content in harvested cotton

(Gregory et al., 1990; Pillay and Myers, 1999).

Cotton is harvested as seedcotton, which is then ginned to separate the seed and lint. The long lint fibres are processed by spinning, to produce yarn that is knitted into fabrics. The short fibres (fuzz), covering the seeds are known as ‘linters’. Delinted cottonseed can be processed to produce oil, meal and hulls. Cottonseed oil has been in common use since the middle of the nineteenth century and achieved GRAS (Generally Recognised As Safe) status under the United States Federal Food Drug and Cosmetics Act because of its common use prior to 1958 (ANZFA, 2002). Cottonseed oil is used in a variety of products including edible vegetable oils and margarine, soap and plastics. Cottonseed cake, meal flour or hulls derived from it is used in food products and for animal feed as carbohydrate roughage, but is limited by the presence of natural toxicants in the seeds (gossypol and cyclopropenoid fatty acids) (Pillay and Myers, 1999).

Brubaker et al. 1999; Cotton belongs to the order Malvales, family Malvaceae and genus Gossypium. Gossypium includes about 45 diploid (2n=2x=26) species and five allotetraploid (2n=4x=52) species (cultivated and wild)

(Meredith et al., 1997). Utilising these morphological characteristics in breeding programmes help cotton growers to obtain high yields and good fibre quality with reduced dependence on pesticides. Meredith et al. (1997) reported a higher photosynthesis rate and improved fibre quality characteristics in varieties with subokra leaves compared to varieties with normal leaves.

Morphological markers can be monitored visually without specialised biochemical or molecular techniques. Although agronomical characterisation provides useful information to users, these characteristics are normally subjected to environmental influences and must be assessed during a fixed vegetative phase of the crop.  (Jackson et al., 1998).

Accumulation of tolerance to a number of stresses is the key to wideadaptation and consequently selection in multiple environments is the best way to breed stable genotypes (Romagosa and Fox, 1993). When the effects of environmental differences are large, it may be expected that the interaction of G x E will be large. As a result it is not only average performance that is important in genotype evaluation programmes, but also the magnitude of interactions (Gauch and Zobel, 1997).

Jixiang et al. (1996) and Hussain et al. (1998); observed that ginning outturn and lint index were positively and significantly correlated with each other. Fibre strength was correlated with seedcotton yield. Tang et al. (1996) observed a high positive genetic correlation for boll weight with lint percentages, fibre strength and micronaire. Lint yield showed a genetic correlation with fibre strength and boll weight. Dedaniya and Pethani (1994) and Carvalho et al. (1995) observed that seedcotton yield per plant was positively correlated with number of bolls, plant height, boll weight, lint weight per plant and bundle strength tenacity. Negative correlation was observed among fibre strength and earliness, fibre length and fibre fineness, fibre length and fibre percentage as well as fibre fineness and fibre percentage

Bunyecha and Tamminga, 1995; Ramadhani et al., 1998

Infrastructure shortcomings severely impede the development of the cotton sector. Firstly, because most cotton must be transported by rail, the quality of rail services is vital to sectoral performance. Greater efficiency in rail transport will lower costs to growers. Secondly the road network in the Mwanza region, where most cotton is produced, requires considerable upgrading. As with rail transport, road improvements will increase efficiency and reduce costs, thereby leading to higher producer prices (Baffes, 2002).

Declining input, caused by removal of input price subsidies at farmer level, (mainly insecticides and fertilizers) led to poor quality cotton and low yields. Any quality decline due to reduced input use reflects relative prices and hence market forces .

Following reforms, as cotton prices rose in the late 1990’s, price competition and overcapacity in ginning caused abandonment of zoning, leading to the mixing of infected and uninfected seed and ultimately reduction in cotton fibre quality. The northern and southern area varieties, which were released for specific agroclimatic conditions of the area, were mixed (Government of Tanzania, 1999a; TCL and SB, 2002).

Endrizzi et al., 1985; Pillay and Myers, 1999; Iqbal et al., 2001 The entire worldwide cotton production is from G. barbadense and G. hirsutum though G. hirsutum comprises 90-95% of the world cotton production.

In allotetraploid species, the D-genome has 13 small chromosomes and the A-genome has 13 moderately large chromosomes in the haploid complement of 26. D and A genomes differ in the amounts of moderately repetitive DNA sequences.

(Brubaker et al., 1999).; Mexican G. hirsutum types may have been grown in the Stephens Austin colony in Texas as early as 1821. Numerous introductions were probably made by soldiers returning from the Mexican-American war (1846-1848). These cultivars were subjected to strict selection to create varieties adapted to local conditions in various cotton growing regions of Northern America. Throughout these periods, outcrossing occurred between cultivars (Endrizzi et al., 1985), collectively known as American Upland cotton. The resulting high yielding and adaptable varieties were dispersed to Europe, Asia and Africa. The limited genetic diversity of cultivated upland G. hirsutum has been observed by several researchers (Multani and Lyon 1995; Iqbal et al., 1997; Iqbal et al., 2001; Lu and Myers, 2002). A hypothesis to explain this is that genetic bottlenecks occurred upon importation of small quantities of seed from Mexico to America in the 19th century. For example, Burling’s cotton in 1806 was smuggled out of Mexico in the stuffing of dolls. More bottlenecks may have occurred during the late stages of development of G. hirsutum Latifolium possibly as a result of rigorous selection (Lewis, 1962).

Meredith et al. (1997) stated that cotton yield has greatly increased since 1935 because of improved crop management and breeding. In South Africa, cotton is one of the five major crops produced commercially in the country and makes a significant contribution to the economy (Dippenaar-Schoeman, 1999).

In Tanzania, cotton is of great economical importance as it is the second most important cash crop after coffee, representing 15% of the country’s total exports and almost 40% of agricultural exports (Bunyecha and Tamminga, 1995; Baffes, 2002). Following liberalisation of the cotton industry, strong competition from village to market level resulted in the deterioration of cotton quality. Furthermore, mixing of different types of cotton varieties led to poor cotton properties (TCL and SB, 2002). Available varieties have medium yields (1200 kg/ha at research level and 300-500 kg/ha at farmers level), medium ginning percentages (36.8-39.6%) and medium fibre strength (22-25g/tex). Based on improved spinning machines, a fibre strength above 28 g/tex is recommended for international cotton fibre markets (Deussen, 1992; Hau, 1997).

(Meredith et al., 1997). Utilising these morphological characteristics in breeding programmes help cotton growers to obtain high yields and good fibre quality with reduced dependence on pesticides. Meredith et al. (1997) reported a higher photosynthesis rate and improved fibre quality characteristics in varieties with subokra leaves compared to varieties with normal leaves.

Morphological markers can be monitored visually without specialised biochemical or molecular techniques. Although agronomical characterisation provides useful information to users, these characteristics are normally subjected to environmental influences and must be assessed during a fixed vegetative phase of the crop (Swanepoel, 1999).

(Powell et al., 1996; Rana and Bhat, 2004).

Molecular markers are becoming increasingly attractive markers in molecular breeding and diversity assessment

Tang et al. (1993a), and Baloch et al. (1996) observed positive and negative GCA effects exerted by parents on boll weight, boll number, lint yield and lint percentage. SCA effects for lint percentage observed were significant and consistent across the environment. Theoretically the presence of significant GCA and SCA in the F1 generation is a consequence of fluctuations in additive and dominance relationships among parents (Tang et al., 1993a).

Zock et al. (1995).; It has been known for years that dietary fat and cholesterol influence blood cholesterol concentrations. Extensive research has been done not only on fats as a class, but on individual fatty acids and their effects on blood lipid levels and lipoprotein concentration. The length of the chain and the degree of unsaturation of a particular fatty acid molecule contribute to the ability of the fatty acid to promote or delay the development of atherosclerosis. Scientists now agree that total dietary fat intake itself is a poor predictor of CHD risk (Nelson 1998). Small differences in fatty acid stmctures may have huge influences on their metabolic effect (Pederson 2001). For example, myristic acid (14:0) and palmitic acid (16:0) are potent cholesterol increasing fatty acids, while stearic acid (18:0) and oleic acid (cis 18:1) have no effect on semm cholesterol, and linoleic acid (18:2) decreases semm cholesterol (Pederson 2001). Laurate, myristate, and palmitate constitute the majority of saturated fatty acids consumed in the Westem diet (Nelson 1998). Trans fatty acids are metabolized in the same manner as saturated fatty acids. A study by Mensink and Katan (1990) found that consumption of trans fatty acids increases blood cholesterol levels. Other studies have shovm that saturated fatty acids and trans fatty acids are equal in their effects on blood cholesterol. Large scale epidemiological surveys and resuhs from human feeding studies all point to the same conclusion, that an increased risk from coronary heart disease is associated v^th dietary intake of trans fatty acids (Nelson 1998).

(Carvalho et al., 1995). Ibragimov (1989) observed close genetic correlation between relatively short fibre and high fibre outturn and high yield. Chen et al. (1991) observed that days from sowing to standard flowering date, days from sowing to practical flowering date, plant height and sympodia per plant were significantly positively correlated with each other and negatively correlated with first peak in cotton harvest.

Zock et al., 1994.; Polyunsaturated oils can, however, be converted into stable cooking oils by hydrogenation in which the carbon double bonds (unsaturated) are reduced to single bonds (saturated). However, partial hydrogenation results in the breakdown of naturally occurring cis carbon bonds and occasional reformation in trans configuration (Ray and Carr, 1985), forming trans-fatty acids (the two hydrogen constituents are on opposite sites) (Gurr and Harwood, 1991). In contrast to cis-unsaturated fatty acids, trans-fatty acids are known to be as potent as palmitic fatty acid in raising plasma LDL cholesterol levels (Noakes and Clifton, 1998) and lowering plasma high density lipoprotein (HDL) cholesterol

Although cotton is grown mostly for fibre, the seeds are an important source of oil. The estimated world production of cottonseed oil in 1985 was 3.57 million metric tons ranking fifth in vegetable oil production after soybean, palm, rapeseed and sunflower (Hatje, 1989). World production of cottonseed oil was about 4 million metric tons in both 1997 and 1998 (Jones and Kersey, 2002).

Brubaker et al., 1994 The wild G. hirsutum variety is ‘Yucatanense’, a sprawling perennial shrub with reproductive development controlled by photoperiod flowering under short day conditions. Variety ‘Punctatum’ arose from ‘Yucatanense’. These early-domesticated varieties dispersed to the rest of Mesoamerica, northern South America and the Caribbean basin. Ethno botanical evidence suggested that landrace ‘Latifolium’ arose from this germplasm. Some accessions classified as ‘Latifolium’ show photoperiodic flowering while others are photoperiodic independent. In Guatemala, cotton was traditionally intercropped with pepper (Capsicum spp.). Cotton plants were removed as soon as first bolls began to open in order to prevent competition with the developing pepper. This practice would have eliminated late maturing genotypes. Selection for early maturity would have reduced seed dormancy and possibly photoperiod dependent flowering. The early maturing Latifolium genotypes diffused into the highlands of southern central Mexico

Kapoor (1994) and Turner et al. (1976) indicated that epistasis for seedcotton yield per plant, boll weight and ginning outturn was of duplicate type, thus additive and dominance gene effects have been found to be important in upland cotton. However, it varied from characteristic to characteristic. Gad et al. (1974) and Singh and Singh (1980) reported additive genetic variation for seedcotton yield, number of bolls, ginning outturn and lint index. Sayal and Sulemani (1996) reported over-dominance on lint percentage, seed index, lint index and staple length from a 8 x 8 diallel cross and additive effects for seedcotton yield. Carvalho and De-Carvalho (1995) studied fibre percentage and boll size in four varieties of G. hirsutum and 12 hybrids from a complete diallel set of crosses. Both traits showed incomplete dominance. Additive gene effects predominated in the control of both traits. Ahmad et al. (1997) observed additive gene action with partial dominance for bolls per plant, boll weight, seedcotton yield and seed index. Epistatic effects were involved in the expression of all characteristics except for boll weight.

Mensink and Katan, 1992; Zock et al., 1994). However, it was revealed that stearic acid (C18:0) does not raise LDL-cholesterol like other saturates and may lower the total cholesterol, thus is considered to be neutral with respect to risk of cardiovascular disease (Dougherty et al., 1995; Liu et al., 2002). On the other hand, unsaturated fatty acids, such as monounsaturated oleic acid (C18:1) and polyunsaturated linoleic acid (C18:2) and α-linolenic acid (C18:3), have the beneficial property of lowering LDL-cholesterol, thus reducing the risk of cardiovascular disease (Mensink and Katan, 1992).

Wang et al., 1989; Stanton et al., 1994.; Gossypium arboreum (A2 genome) is still grown in Pakistan and India on marginal land for use in non-woven material and is helpful in breeding programmes as a donor of host-plant resistance genes. The A-genome cotton enhances genetic diversity of tetraploid cotton breeding programmes (Stanton et al., 1994), especially with the development of techniques for introgressing A-genome germplasm into AD-genome cultivars (Stewart, 1992). Hybrids between G. hirsutum and G. arboreum have led to the selection of genotypes with earlier maturity and an increased range of fibre traits

Poehlman, 1987; Abdalla et al., 2001.;  Cotton is primarily a self-pollinated crop but there is about 1-32% natural outcrossing during field cultivation that depends mainly on location and pollinator availability.

Lin et al., 1986; Becker and Léon, 1988).; Eberhart and Russell (1966) proposed the use of two stability parameters to describe the performance of a variety over an array of environments. They proposed the regression of each cultivar on an environmental index as a function of the squared deviation. Breeders search for genotypes that show a stable high yield over years and locations. In general a genotype is considered stable when its performance across environments does not deviate from the average performance of a group of standard genotypes. Eberhart and Russell (1966) proposed pooling the sum of squares for environments and G x E interactions and subdividing it into a linear effect between environments [with 1 degree of freedom (df)], a linear effect for G x E (with G-1 df) and a deviation from regression for each genotype (with E-2 df). The residual mean squares from the regression model across environments is used as an index of stability and a stable genotype is one in which the deviation from regression mean squares (S2di) is small.

Chang et al., 1978

Highly unsaturated oils are unstable when exposed to high temperatures and oxidative conditions for long periods of time. This results in the development of short chain aldehyde, hydroperoxide and keto derivatives, imparting undesirable flavours and reducing the frying performance of the oil by raising the total level of polar compounds .

Andries et al. (1971) reported that row spacing affects plant height. For such characteristics, conclusive results are obtained by repeats over years and/or locations. However, other traits like leaf colour, leaf shape and boll shape are consistent over environments and data from one or two tests normally give a good indication of relative performance

Hutchinson et al., 1947 Cotton improvement has always been directed towards yield and yield components like locules, boll size, number of bolls per plant, seeds per boll, seed size, lint index, seed index and ginning outturn. Therefore, breeders applied different breeding methods for improvement like pedigree breeding (Munro, 1987), bulk population breeding (Allard, 1960), backcross breeding (Sikka and Joshi, 1960) and interspecific and intraspecific breeding for hybrid vigour or heterosis that is found in F1 crosses within and between species

 AAS(Atomic Absorption Spectrometry)

Discussion on mineral elemental Analysis of Gossypium hirsutum L.(cotton seed ):

The mineral content was determined by AAS(Atomic Absorption Spectrometry). Model no: SpectrAA 55B, made by Australia. Instrument type: wave length dispersive AAs (WDXRF) with SC and PC type detector, AAS equipped with an X-ray tube anode Rh tube, and also five filters, the AAS instrument was fully” automatic. And P10 gas was used and mineral element concentration was detected on dry matter basis. Which have described in Section-6.3

Mineral contents of:

Mineral content such as Mg, P,Zn S, K, Ca, Cr, Mn, Fe,Ni,B,Pb,Cd etc. were determined in its fresh seed powder. Plants and its seed were collected from Newmarket and Gazipur. The result of element analysis of its seed was determined by AAS (Atomic absorption Spectrometry )method in g/l00g dry weight basis of the sample. The element analysis of Gossypium hirsutum L.(cotton seed  )seed can be compared with

different countries. The result of minerals content of cotton seed of Newmarket and Gazipur  appeared as element basis in Table-7.15

The total concentration of macro and.micro elements were measured in cotton seed from three different places of Newmarket and Gazipur by AAS (Atomic Absorption  spectrometry) for the first time in Bangladesh by the authors. Precision of the measurements was taken by analysis of three samples of Newmarket and Gazipur.

So far we aware till now the elemental composition of Gossypium hirsutum L.(cotton seed )seed have not been investigated on elemental analysis in Bangladesh by using modern analytical techniques such as AAS analysis anywhere and were not reported earlier.

Table-: Elemental analysis in percent comparatively (on dry matter basis) of  different regions of Bangladesh (g/l00g).

Sl. No.

Component as Element

Name of the region

Shimul Tula

CB-09

SK-05

1

Ca

1.59

1.76

1.64

2

Mg

0.655

0.934

0.783

3

S

0.438

0.656

0.576

4

K

0.94

0.76

0.80

5

P

1.25

0.48

0.54

6

Zn

99

65

68

7

B

39

42

32

8

Mn

7.60

16.70

18.40

9

Fe

89.8

161.1

115.5

10

Ni

2.50

4.10

4.20

11

Pb

7.40

2.10

2.80

12

Cd

1.10

1.20

1.30

13

              Cr

Trace

Trace

Trace

Results and discussion

On the basis of information found in the literature, we have planned and formulated the schemes of the research works (Scheme-1.1) on Gossypium hirsutum L.(cotton seed  ) seed. The experimental results, data, found on the basis of the conducted experiments are tabulated and discussed as follows in the comparison with the previous reported values of Newmarket and Gazipur

6.1 Proximate Analysis of Gossypium hirsutum L.(cotton seed  ) seeds:

The proximate analysis like moisture, dry matter, ash, crude fiber, protein, carbohydrates, food energy, index of Gossypium hirsutum L.(cotton seed ) Newmarket and Gazipur were determined by the conventional methods described in Section-3.1 to 3.7.

6.1.1 Discussion on proximate analysis of Gossypium hirsutum L. (cotton seed) seed of Newmarket and Gazipur.

The proximate analysis of Gossypium hirsutum L.(cotton seed ) can be compared with different countries. The comparative result of the proximate analysis of seed of Newmarket and Gazipur appears in Table -5.8

In our study some variation is observed in our data. These variation may be due to on such factors as type of genetic variety, maturity, collection time, climatic condition in geographical location, composition of the soil, water, fertilizer used as well as permissibility, selectivity and absorbility of plants for the uptake of these parameter. All the effects caused the final level of proximate analysis in a plant. So far we aware till now the proximate analysis of Gossypium hirsutum L.(cotton seed )  seed have not been investigated in Bangladesh by using modern analytical techniques and anywhere and were not reported earlier

Table-: Comparative study on the Proximate Analysis of

Gossypium hirsutum L.(cotton seed ) of Newmarket and Gazipur.

Parameter of proximate analysis (g/l00g)

Sample collected from

Shimul Tula

CB-09

SK-05

Month of collection

November,2010

December,2010

December,2010

Maturity

mature

mature

mature

Moisture

12.99

0.0077

0.014

Dry Matter

87.01

99.99

99.98

Total ash

6.67

8.4

8.3

Acid soluble ash

82.4

79.6

79.75

Acid insoluble ash

17.5

20.39

20.25

Organic matter

93.33

91.57

91.70

Crude fiber

19.53

34.49

36.54

‘   Nitrogen

6.68

4.53

4.54

Protein

41.75

28.31

28.35

Carbohydrates

3.45

14.91

18.21

Food energy, (cal/gm)

315.17

296.72

267.96

Discussion on the fatty oil of Gossypium hirsutum L.(cotton seed ):

The fatty oil of Gossypium hirsutum L.(cotton seed ) was extracted by steam distillation according to the procedures described in Section-4.5 And Scheme-4.1. It was found that the cotton seed contained 0.202% to 2.6% of fatty oil was determined (Table-4.2) on the fresh weight basis (g/l00g), whereas Guenther found no reports of Fatty oil from the Gossypium hirsutum L.(cotton seed ) but in Wealth of china found up to 0.203% of fatty oil .

 Discussion on the physical properties of the fatty oil of Gossypium hirsutum L.(cotton seed ): The physical  characteristics  such as  colour,  appearance,  specific  gravity,  optical rotation, solubility, refractive index of the fatty oil were determined by conventional methods described in Section-4.5. The result of the physical properties of Gossypium hirsutum L.(cotton seed ) seed Fatty oil of Newmarket and Gazipur appeared in Table-5.9

The slight variation of this oil content and the composition of the fatty oil depend on several  factors such as genotype,  stage of maturity, cultivation peculiarities,  soil composition and climatic differences in various geographical locations. Fluctuation of the oil composition can impart change in the organoleptic properties of the plant belonging to the botanical species and variety. So far we aware till now no systematic investigation on the Chemical composition of the fatty oil of Gossypium hirsutum L.(cotton seed ) seed have not been investigated in Bangladesh by using modern analytical techniques.

Table -: Comparative studies on Physical properties of fatty oil from different of Bangladesh :

Physical CharacteristicsSample collected from 
Oil yield (%) g/l000gShimul TulaCB-09SK-05
Organol-OdorLike Butter OilyOily
EpticColourYellowish DarkDark
 Appearance

at room

temperature 30°C

Appearance

at room

temperature 28°C

Appearance

at room

temperature 30°C

Appearance

at room

temperature 30°C

Specific gravity at 30°C0.8980.9010.899
Refractive index [r|]30°c1.48591.45251.4525
Optical rotation [cc]D26 c-39.4OC-38.2OC-38.2OC
Solubility inAlcoholPartial SolublePartial SolublePartial Soluble
 Distilled waterInsoluble Insoluble Insoluble
 ChloroformSoluble Soluble Soluble
 CCl4Soluble Soluble Soluble
 Diethyle ether Soluble Soluble Soluble
 n-HexaneSoluble Soluble Soluble

Comparative study of the chemical characteristics of  fatty oil of Gazipur & New Market:

Chemical characteristics of the fatty oil such as acid value, ester value, saponification

value, iodine value, unsaponifable matter, peroxide value,  were determined by the conventional methods described in Section-5.6.

The result of the chemical characteristics of Gossypium hirsutum L (cotton seed)

Table-: Chemical characteristics of fatty oil Gossypium hirsutum L (cotton seed):

Chemical Characteristics

Sample Collected From Gazipur & Newmarket

 

Shimul Tula

CB-09

SK-05

Acid value

 9.59.6

Iodine value

47.7693.8689.82

Saponification value

248.358205.38188.50

Peroxide Value

32.6028.9328.93

Discussion on GC-MS analysis of the Fatty oil:

In the present study, Fatty oil Gossypium hirsutum L (cotton seed) has been extracted from  and isolated 4th compounds from the Fatty oil of two different regions in Gazipur & New Market they were identified and quantified by GC-MS were represented in Table-4.28 & 4.30. Structures of the identified compounds obtained from the library of GC-MS instrument were given in Table-4.29.& 4.31. The main GC-MS spectrum of the Fatty oil from Cotton Seed was shown in Figure-4.4 & 4.6. Information regarding the main peak analysis collected from GC-MS NIST 107 library was shown to be in the Figure-4.5 & 4.7.

The chemical constituents of the Fatty oil of Cotton Seed were identified by the above mentioned techniques consist of 11 The GC-MS analysis showed that Shimul Tula contained Palmitic acid, Oleic acid, Linoleic acid.

The CB-09 contained The chemical constituents of the Fatty oil of Cotton Seed were identified by the above mentioned techniques consist of 11 The GC-MS analysis showed that Shimul Tula contained Palmitic acid, Stcearic acid  Oleic acid, Linoleic acid.

The SK-05 contained The chemical constituents of the Fatty oil of Cotton Seed were identified by the above mentioned techniques consist of 11 The GC-MS analysis showed that Shimul Tula contained Palmitic acid, Stcearic acid  Oleic acid, Linoleic acid.

This was not reported earlier.The GC-MS methods which were determined in Section-  

 The GC-MS analysis was done to ensure better identification and quantification    of different components of Fatty oil. The percentages of various components have been determined from their peak areas. In this investigation, 3 peaks were found for 4 compounds in Shimul Tula sample & 4th peaks were found for 4th compounds in CB-09 & SK-05 sample. The major components of Gossypium hirsutum L (cotton seed  Fatty oil were found as  Shimul tula Palmitic acid, Oleic acid, Linoleic acid  .The major components of Gossypium hirsutum Fatty oil were found as  CB-09  Palmitic acid, Stcearic acid  Oleic acid, Linoleic acid. The major components of Gossypium hirsutum Fatty oil were found as  SK-05  Palmitic acid, Stcearic acid  Oleic acid, Linoleic acid.

Results show that both the two countries oils are a complex mixture of numerous compounds, many of which are found in trace amounts. It is worth mentioning that there is a great variation in the chemical composition of these two regions oil of   . This confirms that the reported variation in oil is due to geographic divergence and ecological conditions.

On the basis of the above fact it may be concluded that Gossypium hirsutum L. (Cotton Seed) grown widely in Bangladesh. Their high concentration in seeds, oil makes it potentially useful in medicine because they exhibit antibacterial activities3‘.The oil has been known to be used in folk medicine in the treatment of dyspepsia, hiccough, vomiting and pain in bladder. Gossypium hirsutum plant oils and extracts have been used for a wide variety of purposes for many thousands of years 27. In particular, the antimicrobial activity of plant oils and extracts has formed the basis of many applications, e.g. in raw and processed food preservation, pharmaceuticals, alternative medicine and natural therapies.

Discussion on mineral elemental Analysis of Gossypium hirsutum L.(cotton seed ):

The mineral content was determined by AAS(Atomic Absorption Spectrometry). Model no: SpectrAA 55B, made by Australia. Instrument type: wave length dispersive AAs (WDXRF) with SC and PC type detector, AAS equipped with an X-ray tube anode Rh tube, and also five filters, the AAS instrument was fully” automatic. And P10 gas was used and mineral element concentration was detected on dry matter basis. Which have described in Section-6.3

Mineral contents of:

By the authors. Precision of the measurements was taken by analysis of three samples of Newmarket and Gazipur. So far we aware till now the elemental composition of Gossypium hirsutum L.(cotton seed )seed have not been investigated on Mineral content such as Mg, P,Zn S, K, Ca, Cr, Mn, Fe,Ni,B,Pb,Cd etc. were determined in its fresh seed powder. Plants and its seed were collected from Newmarket and Gazipur. The result of element analysis of its seed was determined by AAS(Atomic absorption Spectrometry )method in g/l00g dry weight basis of the sample. The element analysis of Gossypium hirsutum L.(cotton seed  )seed can be compared with different countries. The result of minerals content of cotton seed of Newmarket and Gazipur  appeared as element basis in Table-7.15

The total concentration of macro and.micro elements were measured in cotton seed from three different places of Newmarket and Gazipur by AAS(Atomic Absorption  spectrometry) for the first time in Bangladesh elemental analysis in Bangladesh by using modern analytical techniques such as AAS analysis anywhere and were not reported earlier

Table-: Elemental analysis in percent comparatively (on dry matter basis) of different regions of Bangladesh (g/l00g).

Sl. No.

Component as Element

Name of the region

Shimul Tula

CB-09

SK-05

1

Ca

1.59

1.76

1.64

2

Mg

0.655

0.934

0.783

3

S

0.438

0.656

0.576

4

K

0.94

0.76

0.80

5

P

1.25

0.48

0.54

6

Zn

99

65

68

7

B

39

42

32

8

Mn

7.60

16.70

18.40

9

Fe

89.8

161.1

115.5

10

Ni

2.50

4.10

4.20

11

Pb

7.40

2.10

2.80

12

Cd

1.10

1.20

1.30

13

              Cr

Trace

Trace

Trace

CONCLUSIONS

The utilization of cottonseed oil for human consumption should receive immediate attention in India for meeting the shortage of edible oil (Mehta, 2006). It contains more than 50% of poly-unsaturated fatty acids and is very ideal in human diets. Cottonseed oil is very popular in USA (Young and Westcott, 2000). However, in India, it is used to a very small extent. Therefore, efforts are to be made on a war footing to popularize its use in our country, which can eventually result in stoppage of import of other edible oil, at least to some extent. Efforts are also needed to popularize cultivation of varieties of cotton with high percentage of oil. Nonetheless, most of the people need to curb the total amount of fat in their diet (Morris, 2002). A combination of oil ensures a healthy intake of all important fatty acids. Therefore, use mustard, sesame, canola or olive oil (extra light or refined) for cooking, groundnut oil for frying, and olive oil (extra virgin) for salads and pasta. With cooking oil, less is more.

The effects of seed size are pure effects of size and are not confounded by other effects such as genotypic factors, which is common in these studies that previously performed. Overall, results of this study showed that oil content, germination and emergence of cotton seed was largely affected by size of seeds. This findings helps cotton breeders that commonly, does not look for the genetic improvement of isolated traits, but for the genetic improvement of a set of traits, since, it is interesting for the breeder to know the intervention in one trait can cause alteration in others.

Cotton Seed

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