Technology of fats and oil (B.Tech Food Technology)

Discover the intricate world of fats and oils in food technology with our comprehensive course. This presentation covers essential aspects of fats and oils, ideal for students, educators, and industry professionals. Topics include the chemistry and properties of fats and oils, sources and extraction methods, refining and processing techniques, functional roles in food products, nutritional aspects, health implications, and innovations in fat and oil technology. Gain in-depth knowledge on hydrogenation, interesterification, emulsification, and the development of low-fat and trans-fat alternatives. This course provides a thorough understanding of the technological advancements and applications of fats and oils in the food industry.

1. Technology of Fats and Oils BTech Food Technology Chirantan Sandip Saigaonkar FTS/2020/41

2. Fats protect internal organs from shock and injury, insulate the body, and promote healthy skin. Fats provide 9 calories per gram. Introduction

3. Oils are fats that are liquid at room temperature whereas fat is solid at room temperature. Oils come from different plants and from fish Lipids- A family of chemical compounds, which include fats and oils Cholesterol- a fat-like substance made of glucose or saturated fat (in our blood)

4. Food Pyramid

5. Classification of lipids Simple lipids

6. Compound lipids

7. Derived lipids

8. FUNCTION OF FAT Supplies heat (insulation) Carries Vitamin A,D,E,K (the fat soluble vitamins) Adds flavor to food Satisfies hunger, feel fuller longer Protects organs from shock and injury Promotes healthy skin

9. Visible Fat : Can be seen with eyes, like fats and oils after extraction Invisible Fat : Fats that are not immediately noticeable such as in egg yolk, cheese, cream, nuts , dry fruits etc.

10. Chemically fats and oils are known as Triglycerides

11. Fatty Acids Fatty Acids are the chemical chains that make up fats. They have 2 categories: The body needs fatty acids to transport other molecules such as fat-soluble vitamins (ADEK). Vitamins A,D,E & K- only dissolve in fatty acids not in water All other types of vitamins dissolve in water SATURATED UNSATURATED Saturated Polyunsaturated Monounsaturated

12. Types of fatty acids

13. Fatty Acids and their types Saturated Monounsaturated Polyunsaturated

14. Saturated Fatty Acids Fats that usually come from ANIMAL sources and fatty acid has no double bond in it Mono-unsaturated Fatty Acids Fat is usually semi-liquid at room temperature and sources are c anola, olive oil etc and fatty acid has one double bond

15. Poly-unsaturated Fatty Acids Fat is usually liquid at room temperature and sources are corn oil, soybean oil, fish oil, linseed oil etc. and fatty acid has two or more than two double bond.

16. Trans Fat Trans fat is an unsaturated fat molecule chemically changed to be a solid fat. It has longer shelf life and is less expensive Trans fats can cause HEART DISEASE.

17. Essential Fatty acids These fatty acids can not be synthesized by the body and must be obtained from the diet. Linoleic acid and linolenic acid are the two essential fatty acids. Non- essential fatty acids Can be synthesized by the body.

18. Antithrombotic effects of n-3 PUFAs and exercise Stupin et al, 2019: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC

19. Long chain fatty acids are made from Palmitate

20. Physical characteristics of fats and oils The analysis of the physical properties of oils and fats allows us to understand the behavior and characteristics given as below: Crystallization M elting point V iscosity Refractive index D ensity S olubility P lasticity Emulsifying capacity

21. Crystallization Fats differ from oils in their degree of solidification at room temperature, since in these conditions the oils are in a liquid state (not crystallized) while the fats are in the solid (crystallized) state. The proportion of crystals in fats have great importance in determining the physical properties of a product. Fats are considered solid when they have at least 10% of their crystallized components. The fat crystals have a size between 0.1 and 0.5 μm and can occasionally reach up to 100 μm . The crystals are maintained by Van der Walls forces forming a three-dimensional network that provides rigidity to the product. Fat can exist in different crystalline form and this phenomenon is called as polymorphism. An important feature of fat is its crystalline polymorphism since mono-di and triglyceride crystallize in different crystalline forms (α, β, β’)

22. Form α (vitreous state): appears when the fat solidifies by a quick method. the crystals formed are of the hexagonal type and are organized randomly in space. Form β: it occurs when the cooling is slow or if the tempering is carried out at a temperature slightly below the melting point, this form being the most stable of all. in the β form, tricyclic crystals are formed oriented in the same direction. the β form is typical of palm oil, peanut, corn, coconut, sunflower, olive and lard. Form β’: it is produced from the tempering above the melting point of the α form. in the β-form, orthorhombic crystals are formed which are oriented in opposite directions. the β’form is typical of modified partial cottonseed oil, fats, fats and modified lard. Both α, β and β’form have a melting point, an X-ray diffusion pattern and a refractive index.

23. Melting point The melting point of a fat corresponds to the melting point of the β form which is the most stable polymorphic form and is the temperature at which all the solids melt. When short chain or unsaturated acids are present, the melting point is reduced. The melting point is of great importance in the processing of animal fats. The melting points of pure fats are very precise, but since fats or oils are made up of a mixture of lipids with different melting points we have to refer to the melting zone which is defined as the melting point of the fat component. the fat that melts at a higher temperature.

24. Viscosity The viscosity of a fat is due to the internal friction between the lipids that constitute it. It is generally high due to the high number of molecules that make up a fat. By increasing the degree of unsaturation the viscosity decreases and when the length of the chain increases the fatty acids components also increases the viscosity.

25. Refractive index The refractive index of a substance is defined as the ratio between the speed of light in air and in matter (oil or fat) that is analyzed. Increasing the degree of unsaturation increases the refractive index and when the length of the chain increases, the refractive index also increases and that is why it is used to control the hydrogenation process. As the temperature increases, the refractive index decreases. The refractive index is characteristic of each oil and fat, which helps us to perform a quality control on them.

26. Density This physical property is of great importance when it comes to designing equipment to process grease. Density decreases when fats dilate when going from solid to liquid When the fats melt, their volume increases and therefore the density decreases. For the control of percentages of solid and liquid in commercial fat, dilatometric curves are used.

27. Solubility Solubility has great relevance in the processing of fats. Fats are fully soluble in non polar organic solvents (benzene, hexane etc.) Except for phospholipids, they are completely insoluble in polar solvents (water, acetonitrile). They are partially soluble in solvents of intermediate polarity (alcohol, acetone) The solubility of fats in organic solvents decreases with increasing chain length and degree of saturation. Phospholipids can interact with water because the phosphoric acid and the alcohols that compose them have hydrophilic groups. Generally the surface tension increases with the length of the chain and decreases with temperature. Surface tension and interfacial tension decrease with ease with the use of surfactant agents such as monoglycerides and phospholipids.

28. Plasticity It is the property that has a body to preserve its shape by resisting a certain pressure. The plasticity of a fat is caused by the presence of a three-dimensional network of crystals inside which liquid fat is immobilized. For a grease to be plastic and extensible there must be a ratio between the solid and liquid part (20 -40% solid state fat), the nets must not be tight and their crystals must be in α form. The plastic fats act as a solid until the deforming forces that are applied break the crystal lattice and the grease passes to behave like a viscous liquid and therefore can be smeared.

29. Emulsifying capacity The emulsifying capacity is the capacity in the water/ oil interface allowing the formation of emulsion

30. FACTORS AFFECTING PHYSICAL CHARACTERISTICS OF FATS AND OILS 1. Degree of Unsaturation of Fats and Oils Food fats and oils are made up of triglyceride molecules which may contain both saturated and unsaturated fatty acids. The fatty acids that combine to make up triglycerides will vary; therefore, triglycerides can contain all saturated fatty acids, all unsaturated fatty acids or a mixture of both saturated and unsaturated fatty acids. Depending on the type of fatty acids combined in the molecule, triglycerides can be classified as mono- or di -, -saturated (alternatively mono- or di - unsaturated), tri-saturated and tri-unsaturated

31. Generally speaking, fats that are liquid at room temperature tend to be more unsaturated than those that appear to be solid, but there are exceptions. For example, coconut oil has a high level of saturates, but many are of low molecular weight, hence this oil melts at or near room temperature. Thus, the physical state of the fat does not necessarily indicate the amount of un-saturation. The degree of un-saturation of a fat, i.e., the number of double bonds present, normally is expressed in terms of the iodine value (IV) of the fat. IV is the number of grams of iodine which will react with the double bonds in 100 grams of fat and may be calculated from the fatty acid composition. The typical IV for soybean oil is 123-139, for cottonseed oil 98-110, and for butterfat it is 25-42.

32. 2. Length of Carbon Chains in Fatty Acids The melting properties of triglycerides are related to those of their fatty acids. As the chain length of a saturated fatty acid increases, the melting point also increases. Thus, a short chain saturated fatty acid such as butyric acid has a lower melting point than saturated fatty acids with longer chains. This explains why coconut oil, which contains almost 90% saturated fatty acids but with a high proportion of relatively short chain low melting fatty acids, is a clear liquid at 80°F while lard, which contains only about 42% saturates, most with longer chains, is semi-solid at 80°F. Factors affecting physical properties of fats and oils- Continues

33. 3. Isomeric Forms of Fatty Acids For a given fatty acid chain length, saturated fatty acids will have higher melting points than those that are unsaturated. The melting points of unsaturated fatty acids are profoundly affected by the position and conformation of double bonds. For example, the monounsaturated fatty acid oleic acid and its geometric isomer elaidic acid have different melting points. Oleic acid is liquid at temperatures considerably below room temperature, whereas elaidic acid is solid even at temperatures above room temperature. Factors affecting physical properties of fats and oils- Continues

34. Factors affecting physical properties of fats and oils- Continues 4. Molecular Configuration of Triglycerides The molecular configuration of triglycerides can also affect the properties of fats. Melting points vary in sharpness depending on the number of different chemical entities present. Simple triglycerides have sharp melting points while triglyceride mixtures like lard and most vegetable shortenings have broad melting ranges. In cocoa butter, palmitic (P), stearic (S), and oleic (O) acids are combined in two predominant triglyceride forms (POS and SOS), giving cocoa butter its sharp melting point just slightly below body temperature. This melting pattern partially accounts for the pleasant eating quality of chocolate. A mixture of several triglycerides has a lower melting point than would be predicted for the mixture based on the melting points of the individual components and will have a broader melting range than any of its components. Monoglycerides and diglycerides have higher melting points than triglycerides with a similar fatty acid composition.

35. Factors affecting physical properties of fats and oils- Continues 5. Polymorphism of Fats Solidified fats often exhibit polymorphism, i.e., they can exist in several different crystalline forms, depending on the manner in which the molecules orient themselves in the solid state. The crystal form of the fat has a marked effect on the melting point and the performance of the fat in the various applications in which it is utilized. The crystal forms of fats can transform from lower melting to successively higher melting modifications. The order of this transformation is: Alpha ➝ Beta Prime ➝ Beta

36. Factors affecting physical properties of fats and oils- Continues The rate and extent of transformation are governed by the molecular composition and configuration of the fat, crystallization conditions, and the temperature and duration of storage. In general, fats containing diverse assortments of molecules with varying fatty acids or fatty acids locations tend to remain indefinitely in lower melting crystal forms (i.e. Beta Prime), whereas fats containing a relatively limited assortment of these types of molecules transform readily to higher melting crystal forms (i.e. Beta). Mechanical and thermal agitation during processing and storage at elevated temperatures tends to accelerate the rate of crystal transformation. 5. Polymorphism of Fats Continues……

37. Chemical properties of fats and oils

38. Chemical properties of fats and oils continues……. It may be defined as number of mg of KOH needed to saponify the 1 g of fat or oil

39. Chemical properties of fats and oils continues…….

40. Nutritional properties of fats and oils

41. Functional properties of fats and oils

42. Types of changes in fats and oils

43. CHEMICAL REACTIONS OF FATS AND OILS 1 . Hydrolysis of Fats Like other esters, glycerides can be hydrolyzed readily. Partial hydrolysis of triglycerides will yield mono- and diglycerides and free fatty acids. When hydrolysis is carried to completion with water in the presence of an acid catalyst, the mono-, di-, and triglycerides will hydrolyze to yield glycerol and free fatty acids. With aqueous sodium hydroxide, glycerol and the sodium salts of the component fatty acids (soaps) are obtained. This process is also called saponification. In the digestive tracts of humans and animals and in bacteria, fats are hydrolyzed by enzymes (lipases). Lipolytic enzymes are present in some edible oil sources (i.e., palm fruit, coconut). Any residues of these lipolytic enzymes (present in some crude fats and oils) are deactivated by the elevated temperatures normally used in oil processing.

44. Hydrolysis by acid Hydrolysis by alkali

45. 2. Oxidation of Fats Autoxidation . Of particular interest in the food arena is the process of oxidation induced by air at room temperature referred to as “autoxidation”. Ordinarily, this is a slow process which occurs only to a limited degree. However, factors such as the presence of light can increase the rate of oxidation. In autoxidation, oxygen reacts with unsaturated fatty acids at the double bond site. Initially, peroxides are formed which may break down into secondary oxidation products (hydrocarbons, ketones, aldehydes, and smaller amounts of epoxides and alcohols). Metals, such as copper or iron, present at low levels in fats and oils can also promote autoxidation. Fats and oils are normally treated with chelating agents such as citric acid to complex these trace metals (thus inactivating their prooxidant effect).

46. The result of the autoxidation of fats and oils is the development of objectionable flavors and odors characteristic of the condition known as “oxidative rancidity”. Some fats resist this change to a remarkable extent while others are more susceptible depending on certain factors, such as the degree of unsaturation.

47. When rancidity has progressed significantly, it becomes readily apparent from the flavor and odor of the oil. Expert tasters are able to detect the development of rancidity in its early stages. The peroxide value determination, if used judiciously, is oftentimes helpful in measuring the degree to which oxidative rancidity in the fat has progressed.

48. Oxidation at Higher Temperatures Although the rate of oxidation is greatly accelerated at higher temperatures, oxidative reactions which occur at higher temperatures may not follow precisely the same routes and mechanisms as the reactions at room temperature. Thus, differences in the stability of fats and oils often become more apparent when the fats are used for frying or slow baking. The stability of a fat or oil may be predicted to some degree by determining the oxidative stability index (OSI). The more unsaturated the fat or oil, the greater will be its susceptibility to oxidative rancidity. Predominantly unsaturated oils (i.e., soybean, cottonseed, or corn) are less stable than predominantly saturated oils (i.e., coconut oil, palm oil). Dimethyl silicone is usually added to institutional frying fats and oils to reduce oxidation tendency and foaming at elevated temperatures. Historically, partial hydrogenation has often been employed in the processing of liquid vegetable oil to increase the stability and functionality of the oil. The trend of utilizing partial hydrogenation has been declining during the last decade due to developments in oils/fat processes and trans fat legislation.

49. Thermal degradation of triglycerides/fats/oils

50. Thermal degradation reaction of triglycerides/fats/oils

51. Photo-oxidation is an alternative mechanism that leads to formation of hydroperoxides as a result of excitation state of lipid electrons (type I photo-oxidation) or excitation state of oxygen electrons (type II photo-oxidation). Type I photo-oxidation – The reaction starts in the presence of light and some sensitizers, such as riboflavin. It is a process by which a hydrogen atom or an electron, transfer between an excited triplet sensitizer and a substrate, such as PUFA, producing free radicals or free radical ions. Type II photo-oxidation – Under this mechanism, environmental oxygen is normally in the triplet electronic state, 3O2. It can be excited by light to singlet oxygen in presence of a sensitizer, such as chlorophyll. Singlet oxygen is1,500 times faster in reacting with unsaturated lipids than triplet oxygen, which ultimately leads to forming hydroperoxides. Another important way in which unsaturated lipids can be oxidized involves exposure to light . In this process, oxygen becomes activated to the singlet state by transfer of energy from the photosensitizer.

52. Edible oil is oxidized during processing and storage via autoxidation and photosensitized oxidation, in which triplet oxygen (3O2) and singlet oxygen (1O2) react with the oil, respectively. Autoxidation of oils requires radical forms of acylglycerols , whereas photosensitized oxidation does not require lipid radicals since 1O2 reacts directly with double bonds. Lipid hydroperoxides formed by 3O2 are conjugated dienes, whereas 1O2 produces both conjugated and nonconjugated dienes. The hydroperoxides are decomposed to produce off-flavor compounds and the oil quality decreases. Autoxidation of oil is accelerated by the presence of free fatty acids, mono- and diacylglycerols, metals such as iron, and thermally oxidized compounds. Chlorophylls and phenolic compounds decrease the autoxidation of oil in the dark, and carotenoids, tocopherols, and phospholipids demonstrate both antioxidant and prooxidant activity depending on the oil system. In photosensitized oxidation chlorophyll acts as a photosensitizer for the formation of 1O2; however, carotenoids and tocopherols decrease the oxidation through 1O2 quenching. Temperature, light, oxygen concentration, oil processing, and fatty acid composition also affect the oxidative stability of edible oil.

53. Autoxidation of oils, free radical chain reaction, includes initiation, propagation, and termination steps: Initiation RH → R· + H· Propagation R· + 3O 2 → ROO· ROO· + RH → ROOH + R· Termination ROO· + R· → ROOR R· + R· → RR (R : lipid alkyl)

54. 3. Polymerization of Fats All commonly used fats and particularly those high in polyunsaturated fatty acids tend to form larger molecules (known broadly as polymers) when heated under extreme conditions of temperature and time. Under normal processing and cooking conditions, polymers are formed. It is believed that polymers in fats and oils arise by formation of either carbon-to-carbon bonds or oxygen bridges between molecules. When an appreciable amount of polymer is present, there is a marked increase in viscosity.

55. 4. Reactions during Heating and Cooking Glycerides are subject to chemical reactions (oxidation, hydrolysis, and polymerization) which can occur particularly during deep fat frying. The extent of these reactions, which may be reflected by a decrease in iodine value of the fat and an increase in free fatty acids, depends on the frying conditions (principally the temperature, aeration, moisture, and duration). The composition of a frying medium also may be affected by the kind of food being fried. For example, when frying foods such as chicken, some fat from the food will be rendered and blended with the frying medium while some of the frying medium will be absorbed by the food. In this manner the fatty acid composition of the frying medium will change as frying progresses. Since absorption of frying medium into the food may be extensive, it is often necessary to replenish the fryer with fresh frying medium. Obviously, this replacement with fresh medium tends to dilute overall compositional changes of the fat that would have taken place during prolonged frying.

56. The  smoke ,  flash , and  fire   points  of a fatty material are standard measures of its thermal stability when heated in contact with air. The “smoke point” is the temperature at which smoke is first detected in a laboratory apparatus protected from drafts and provided with special illumination. The temperature at which the fat smokes freely is usually somewhat higher. The “flash point” is the temperature at which the volatile products are evolved at such a rate that they are capable of being ignited but not capable of supporting combustion. The “fire point” is the temperature at which the volatile products will support continued combustion. For typical non-lauric oils with a free fatty acid content of about 0.05%, the “smoke”, “flash”, and “fire” points are around 420°F, 620°F, and 670°F respectively.

57. The degree of unsaturation of an oil has little, if any, effect on its smoke, flash, or fire points. Oils containing fatty acids of low molecular weight such as coconut oil, however, have lower smoke, flash, and fire points than other animal or vegetable fats of comparable free fatty acid content. Oils subjected to extended use will have increased free fatty acid contents resulting in a lowering of the smoke, flash, and fire points. Accordingly, used oil freshened with new oil will show increased smoke, flash, and fire points.

58. Lipid oxidation is a highly complex set of free radical reactions between fatty acids and oxygen, which results in oxidative degradation of lipids, also known as rancidity. Lipid oxidation intermediate products (free radicals) and end products (reactive aldehydes) may interact with other food constituents, such as proteins, sugars, pigments, and vitamins, and negatively modify their properties. The reaction mechanisms and the rate of lipid oxidation depend on many factors , such as fatty acid composition, the presence of prooxidants and antioxidants, type of lipid (triacylglycerols, phospholipids, and others), and storage conditions, for example, temperature, light, oxygen availability, and water activity. LIPID OXIDATION

59. STEPS OF LIPID OXIDATION

60. Factors affecting development of oxidation Fatty acid compositions- SFA, MUFA or PUFA Oxygen, free radicals Pro-oxidants Antioxidants and additives Processing conditions Storage time and conditions

61. Rancidity

62. Hydrolytic rancidity

63. Active sites

64. Lipolysis

65. Blood

66. The first carbon following the carboxyl carbon is the alpha carbon The second carbon following the carboxyl carbon is the beta carbon. The last carbon in the chain, farthest from the carboxyl group, is the omega carbon.  

67. Salient features of Beta oxidation

68. Specialty of Beta oxidation

69. Stages of Beta oxidation

70. Inhibition of oxidation reactions

71. Synthetic antioxidants

72. Natural Antioxidants

73. Oil based antioxidants Bioactive minor components present in Edible oils tocopherols – almost all vegetable oil tocotrienols- palm oil, rice bran oil, wheat germ oil Omega-3 fatty acids- linseed oil, canola oil, soybean oil Carotenoids- palm oil lecithin- soybean oil Oryzanols- rice bran oil lignans - linseed oil, sesame oil phytosterols and phytostanols - olive oil, canola oil, sesame oil, rice bran oil

74. Ideal antioxidants

75. Mechanism of antioxidants

76. Measurement methods of oxidative rancidity

77. LIPIDS AND HEALTH

78. A variety of fatty acids exists in the diet of humans, in the bloodstream of humans, and in cells and tissues of humans Fatty acids are energy sources and membrane constituents. They have biological activities that act to influence cell and tissue metabolism, function, and responsiveness to hormonal and other signals. The biological activities may be grouped as regulation of membrane structure and function; regulation of intracellular signaling pathways, transcription factor activity, and gene expression; and regulation of the production of bioactive lipid mediators. Fatty acids influence health, well-being, and disease risk through various biological activities

79. Although traditionally most interest in the health impact of fatty acids related to cardiovascular disease and clear that fatty acids influence a range of other diseases however its evident through various studies that fats play important role in metabolic diseases such as type 2 diabetes, inflammatory diseases, and cancer. Scientists, regulators, and communicators have described the biological effects and the health impacts of fatty acids according to type of fatty acid. However, it is now obvious that within any fatty acid class, different fatty acids have different actions and effects.

80. Palm oil, coconut oil, cocoa butter, and animal-derived fats such as lard, tallow, and butter are rich sources of saturated fatty acids, although the amounts of individual saturated fatty acids present vary among these sources. Many plant oils contain a significant amount of saturated fatty acids, particularly palmitic acid. Saturated fatty acids are also synthesized de novo in humans, the precursor being acetyl-CoA produced from carbohydrate or amino acid metabolism. Effects of Saturated Fatty Acids on Human Health

81. Many cell membrane phospholipids contain significant proportions of palmitic and stearic acids; neural cell membrane phospholipids contain some longer chain saturated fatty acids. Ceramides and sphingolipids can be rich in saturated fatty acids, while gangliosides are often very rich in stearic acid. Stearic acid shares some but not all properties with myristic and palmitic acids, while the milk fat–derived odd-chain saturated fatty acids (pentadecanoic and heptadecanoic) are associated with lower risk of type 2 diabetes, CHD, and CVD. It becomes evident when considering these findings that not all saturated fatty acids have the same effects on human health, most likely because each type of saturated fatty acid has unique effects on cells and tissues.

82. Effects of cis MUFAs on Human Health Oleic acid (18:1ω-9) is the most prevalent cis MUFA in the human diet, and in many individuals, it is the most prevalent dietary fatty acid. It is widespread in foods. Olive oil is an especially rich source, with oleic acid typically contributing about 70% of fatty acids present. Low–erucic acid rapeseed oil (aka canola oil) typically contains about 60% of fatty acids as oleic acid, while “high oleic” varieties of normally linoleic acid–rich oils such as sunflower oil are now available. Dairy fats contain oleic acid and also vaccenic acid (18:1ω-7). Both palmitoleic and oleic acids can be synthesized de novo in humans, by Δ9-desaturation of palmitic and stearic acids, respectively. Many cell membrane phospholipids contain significant proportions of oleic acid and some palmitoleic acid.

83. Effects of cis MUFAs on Human Health Studies have reported that replacing saturated fatty acids with oleic acid has a small cholesterol and LDL cholesterol–lowering effect with an inconsistent effect on HDL cholesterol. Decreased peroxidizability of lipoprotein and cell membrane oleic acid compared with PUFAs would be expected to limit inflammation, because oxidative stress is proinflammatory.

84. Coconut oil is 100% fat, 80-90% of which is saturated fat. This gives it a firm texture at cold or room temperatures. Fat is made up of smaller molecules called fatty acids, and there are several types of saturated fatty acids in coconut oil. The predominant type is lauric acid (47%), with myristic and palmitic acids present in smaller amounts, which have been shown in research to raise harmful LDL levels. Also present in trace amounts are Monounsaturated and polyunsaturated fats.

85. Coconut oil contains no cholesterol, no fiber, and only traces of vitamins, minerals, and plant sterols. Plant sterols have a chemical structure that mimics blood cholesterol, and may help to block the absorption of cholesterol in the body. However, the amount found in a few tablespoons of coconut oil is too small to produce a beneficial effect. coconut oil made of 100% medium-chain triglycerides (MCTs) MCTs have a shorter chemical structure than other fats, and so are quickly absorbed and used by the body. After digestion, MCTs travel to the liver where they are immediately used for energy.

86. Virgin or Extra Virgin (interchangeable terms): If using a “dry” method, the fresh coconut meat of mature coconuts is dried quickly with a small amount of heat, and then pressed with a machine to remove the oil. If using a “wet” method, a machine presses fresh coconut meat to yield milk and oil. The milk is separated from the oil by fermentation, enzymes, or centrifuge machines. The resulting oil has a smoke point of about 350 degrees Fahrenheit (F), which can be used for quick sautéing or baking but is not appropriate for very high heat such as deep-frying.  Expeller-pressed—A machine presses the oil from coconut flesh, often with the use of steam or heat. Cold-pressed—The oil is pressed without use of heat. The temperature remains below 120 degrees F this is believed to help retain more nutrients.

87. Virgin coconut oil is defined as oil extracted from fresh coconut meat and processed using physical and natural processes (Codex alimentarius , 1999). There is no prior drying (e.g., use of copra), refining or chemical reactions before the oil is extracted from coconut meal by mechanical means (expelling, pressing, heating, washing, settling, filtration, and centrifugation). aqueous extraction of coconut oil with added exogenous enzymes (proteases, amylases, polyglacturonases , cellulases, pectinases or combinations of enzymes) achieving oil yields ranging from 12–80% from fresh or dried coconut meat.

88. Refined: The copra is machine-pressed to release the oil. The oil is then steamed or heated to deodorize the oil and “bleached” by filtering through clays to remove impurities and any remaining bacteria. Sometimes chemical solvents such as hexane may be used to extract oil from the copra. The resulting oil has a higher smoke point at about 400-450 degrees F, and is flavorless and odorless. Partially Hydrogenated: The small amount of unsaturated fats in coconut oil is hydrogenated or partially hydrogenated to extend shelf life and help maintain its solid texture in warm temperatures. This process creates  trans fats , which should be avoided.

89. Common name Fatty acid Percentage Caproic acid 6:0 0.2–0.5 Caprylic acid 8:0 5.4–9.5 Capric acid 10:0 4.5–9.7 Lauric acid 12:0 44.1–51 Myristic acid 14:0 13.1–18.5 Palmitic acid 16:0 7.5–10.5 Stearic acid 18:0 1.0–3.2 Arachidic acid 20:0 0.2–1.5 Oleic acid 18:1 n -9 5.0–8.2 Linoleic acid 18:2 n -6 1.0–2.6

90. Products Canned coconut milk (light and nonlight, with and without added emulsifiers) may be the basis of some savory sauces, especially those that are Asian-based. Coconut cream is coconut “milk” with more fat, less water and generally a greater coconut taste. Coconut “milk” is produced when the “meat” of a coconut is cooked, and then the meat is strained. Coconut water is the “juice” that flows from a newly cracked coconut. Coconut “meat” is the interior of the coconut that is often shredded and sweetened; however, unsweetened varieties may be available. Coconut powder (dried coconut milk) and coconut extract may also help to boost the coconut flavor in some recipes.

91. The use of these coconut products also adds some texture to some formulations and recipes due to the fat in the coconuts, and to the dried, shredded consistency of the coconut meat. So for taste, texture and interest, a small amount of coconut and/or its products may be helpful additions.

92. Cottonseed contains hull and kernel. The hull produces fibre and linters. The kernel contains oil, protein, carbohydrate and other constituents such as vitamins, minerals, lecithin, sterols etc. Cottonseed oil is extracted from cottonseed kernel. Cottonseed oil, also termed as "Heart Oil" is among the most unsaturated edible oils. Cottonseed oil quality utilization and processing Refined and deodorised cottonseed oil is considered as one of the purest cooking medium available. An additional benefit that accrues from Cottonseed Oil is its high level of antioxidants - tocopherols.

93. Fatty acid composition of different cotton seed oil

94. Tocopherol content of various oils

95. Various processes involved in deterioration

96. Toxic elements- cottonseed pigments Cottonseed contains gassypurpurin , gossycaerulin , gossyfulivin , gossyverdurin and gossypol. Gossypol is yellow, gossypurpurin - purple, gossyfulvin - orange, gossycaerulin -blue and gossyverduin - green. The gossypol content is greater in raw material than in cooked cottonseed, whereas gossypupurin and gossyfulvin are found in higher proportion in cooked seed. Gossypol.is the most important pigment present in the cottonseed and create enormous problem of seed processing and utilisation of cottonseed as by-product. Gossypol is located all over in plant. It gives undesirable colour to the oil and reacts with protein to reduce the nutritive value of cottonseed product. It is toxic to non-ruminant animal. Several new processes and solvents have been tried to remove the pigment from cottonseed so that it can be used for edible purposes without any adverse effect. Gossypol is in the free state in the whole seed and on cooking of cottonseed forms "bound gossypol" as a result of gossypol combining with either free amino or free carboxy groups of cottonseed protein. Bound gossypol decreases the nutritive value of protein and availability of lysine, an essential amino acid.

97. In India entire cottonseed oil produced is utilised for edible purposes, mostly for vanaspati, only small quantity (5-10%) is used for manufacturing soaps.

98. Central Institute for Research on Cotton Technology (CIRCOT), Mumbai to develop efficient oil extraction protocols and also to test their techno-economic feasibility. Efforts are being made to identify suitable antifoaming agent along with its optimum concentration for preserving quality of frying oil for longer duration under Indian cooking habits. To create awareness and to promote widespread consumption, work is being carried out towards exploring novel culinary applications also.

99. Steps involved in processing of cottonseed oils