A triglyceride is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans and other vertebrates, as well as vegetable fat. They are also present in the blood to enable the bidirectional transference of adipose fat and blood glucose from the liver, and are a major component of human skin oils.
In organic chemistry, transesterification is the process of exchanging the organic group R″ of an ester with the organic group R′ of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. The reaction can also be accomplished with the help of enzymes (biocatalysts) particularly lipases (E.C.3.1.1.3).
Vegetable oils, or vegetable fats, are oils extracted from seeds, or less often, from other parts of fruits. Like animal fats, vegetable fats are mixtures of triglycerides. Soybean oil, rapeseed oil, and cocoa butter are examples of fats from seeds. Olive oil, palm oil, and rice bran oil are examples of fats from other parts of fruits. In common usage, vegetable oil may refer exclusively to vegetable fats which are liquid at room temperature. Vegetable oils are usually edible; non-edible oils derived mainly from petroleum are termed mineral oils.
Rancidity generally is the complete or incomplete oxidation or hydrolysis of fats and oils when exposed to air, light, or moisture or by bacterial action, resulting in unpleasant taste and odor. Specifically, it is the hydrolysis or autoxidation of fats into short-chain aldehydes and ketones, which are objectionable in taste and odor. When these processes occur in food, undesirable odors and flavors can result. In certain cases, however, the flavors can be desirable. In processed meats, these flavors are collectively known as warmed-over flavor. Rancidification can also detract from the nutritional value of food, as some vitamins are sensitive to oxidation. Similar to rancidification, oxidative degradation also occurs in other hydrocarbons, such as lubricating oils, fuels, and mechanical cutting fluids.
Biodiesel production is the process of producing the biofuel, biodiesel, through the chemical reactions of transesterification and esterification. This involves vegetable or animal fats and oils being reacted with short-chain alcohols. The alcohols used should be of low molecular weight. Ethanol is the most used because of its low cost, however, greater conversions into biodiesel can be reached using methanol. Although the transesterification reaction can be catalyzed by either acids or bases, the base-catalyzed reaction is more common. This path has lower reaction times and catalyst cost than those acid catalysis. However, alkaline catalysis has the disadvantage of high sensitivity to both water and free fatty acids present in the oils.
An alkyd is a polyester modified by the addition of fatty acids and other components. They are derived from polyols and a dicarboxylic acid or carboxylic acid anhydride. The term alkyd is a modification of the original name "alcid", reflecting the fact that they are derived from alcohol and organic acids. The inclusion of the fatty acid confers a tendency to form flexible coating. Alkyds are used in paints and in moulds for casting. They are the dominant resin or "binder" in most commercial "oil-based" coatings. Approximately 200,000 tons of alkyd resins are produced each year. The original alkyds were compounds of glycerol and phthalic acid sold under the name Glyptal. These were sold as substitutes for the darker-colored Copal resins, thus creating alkyd varnishes which were much paler in colour. From these, the alkyds we know today were developed.
Monoglycerides are a class of glycerides which are composed of a molecule of glycerol linked to a fatty acid via an ester bond. As glycerol contains both primary and secondary alcohol groups two different types of monoglycerides may be formed; 1-monoacylglycerols where the fatty acid is attached to a primary alcohol, or a 2-monoacylglycerols where the fatty acid is attached to the secondary alcohol.
Interesterified fat is a type of oil where the fatty acids have been moved from one triglyceride molecule to another. This is generally done to modify the melting point, slow rancidification and create an oil more suitable for deep frying or making margarine with good taste and low saturated fat content. It is not the same as partial hydrogenation which produces trans fatty acids, but interesterified fats used in the food industry can come from hydrogenated fat, for simplicity and frugality.
Fatty acid esters (FAEs) are a type of ester that result from the combination of a fatty acid with an alcohol. When the alcohol component is glycerol, the fatty acid esters produced can be monoglycerides, diglycerides, or triglycerides. Dietary fats are chemically triglycerides.
Oleochemistry is the study of vegetable oils and animal oils and fats, and oleochemicals derived from these fats and oils or from petrochemical feedstocks through physico-chemical modifications or transformation. First used in the making of soaps, oleochemistry is now part of our daily lives where it is found in a wide variety of sectors like food, cosmetics, pharmaceutical and industrial. The resulting product can be called Oleochemicals. They are analogous to petrochemicals derived from petroleum.
In enzymology, a monogalactosyldiacylglycerol synthase is an enzyme that catalyzes the chemical reaction
In enzymology, a CDP-diacylglycerol—inositol 3-phosphatidyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a CDP-diacylglycerol—serine O-phosphatidyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a diacylglycerol cholinephosphotransferase is an enzyme that catalyzes the chemical reaction
Glycerol monostearate, commonly known as GMS, is a monoglyceride commonly used as an emulsifier in foods. It takes the form of a white, odorless, and sweet-tasting flaky powder that is hygroscopic. Chemically it is the glycerol ester of stearic acid.
Mono- and diglycerides of fatty acids (E471) refers to a food additive composed of diglycerides and monoglycerides which is used as an emulsifier. This mixture is also sometimes referred to as partial glycerides.
Enzymatic Interesterification (EIE) is the catalytic reaction that occurs when an enzyme is introduced into oil and rearranges the fatty acids on the glycerol backbone of a triglyceride. Triglycerides are either liquid or solid at room temperature. The rearrangement of the fatty acids that occurs with enzymatic interesterification provides structure and functionality to triglycerides at room temperature. This process adjusts the melting properties, increasing functionality and plasticity in food production applications. One of five different ways of altering melting property profiles, enzymatic interesterification is unlike the more widely used partial hydrogenation method in that it produces no trans fatty acids and lowers saturated fat content.
A diglyceride, or diacylglycerol (DAG), is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages. Two possible forms exist, 1,2-diacylglycerols and 1,3-diacylglycerols. DAGs can act as surfactants and are commonly used as emulsifiers in processed foods. DAG-enriched oil has been investigated extensively as a fat substitute due to its ability to suppress the accumulation of body fat; with total annual sales of approximately USD 200 million in Japan since its introduction in the late 1990s till 2009.
Cooking oil is plant, animal, or synthetic fat used in frying, baking, and other types of cooking. It is also used in food preparation and flavouring not involving heat, such as salad dressings and bread dippings like bread dips, and may be called edible oil.
Sucrose esters or sucrose fatty acid esters are a group of surfactants chemically synthesized from esterification of sucrose and fatty acids. This group of substances is remarkable for the wide range of hydrophilic-lipophilic balance (HLB) that it covers. The polar sucrose moiety serves as a hydrophilic end of the molecule, while the long fatty acid chain serves as a lipophilic end of the molecule. Due to this amphipathic property, sucrose esters act as emulsifiers; i.e., they have the ability to bind both water and oil simultaneously. Depending on the HLB value, some can be used as water-in-oil emulsifiers, and some as oil-in-water emulsifiers. Sucrose esters are used in cosmetics, food preservatives, food additives, and other products. A class of sucrose esters with highly substituted hydroxyl groups, olestra, is also used as a fat replacer in food.
