Emulsified fats

The structure of cholic acid helps us understand how bile salts such as sodium tauro cholate promote the transport of lipids through a water rich environment The bot tom face of the molecule bears all of the polar groups and the top face is exclusively hydrocarbon like Bile salts emulsify fats by forming micelles m which the fats are on the inside and the bile salts are on the outside The hydrophobic face of the bile salt associates with the fat that is inside the micelle the hydrophilic face is m contact with water on the outside... 

Bile acids (Section 26 13) Steroid derivatives biosynthesized in the liver that aid digestion by emulsifying fats Bimolecular (Section 4 8) A process in which two particles re act in the same elementary step Biological isoprene unit (Section 26 8) Isopentenyl pyrophos phate the biological precursor to terpenes and steroids... 

Fig. 1. Effect of system components on emulsifier HLB. (------), fat—caseiaate-salts-water—emulsifier (—), fat—water—emulsifier (4).

Bile acids (Section 26.13) Steroid derivatives biosynthesized in the liver that aid digestion by emulsifying fats. 

Cliolestyramine (Questran) and colestipol (Colestid) are examples of bile acid sequestrants. Bile, which is manufactured and secreted by the liver and stored in the gallbladder, emulsifies fat and lipids as these products pass through the intestine Once emulsified, fats and lipids are readily absorbed in the intestine These drug bind to bile acids to form an insoluble substance that cannot be absorbed by the intestine, so it is secreted in the feces. With increased loss of bile acids, the liver uses cholesterol to manufacture more bile This is followed by a decrease in cholesterol levels. 

Ice cream is simultaneously both an emulsion and a partially solidified foam, so it comprises three phases at once. The ice cream would be too solid to eat without the air, and too cold to eat without discomfort. The air helps impart a smooth, creamy consistency. The solid structure is held together with a network of globules of emulsified fat and small ice crystals (where small in this context means about 50 xm diameter). 

Soy proteins are used extensively in meat and meat products by the military, the school lunch program and consumers to save money. Their ultimate acceptability is equally dependent upon the nutritional, chemical, sensory and shelf life changes which occur when they are added. Soy proteins in meat products such as ground beef inhibit rancidity, improve tenderness, increase moisture retention, decrease cooking shrink, fat dispersion during cooking and have no important effect on microbiological condition. Concomittantly, inordinate amounts of added soy protein may cause the meat product to be too soft, exhibit an undesirable flavor and may lead to a decreased PER and a deficiency in B-vitamins and trace minerals. In emulsified meat products, soy protein effectively binds water but does not emulsify fat as well as salt soluble muscle protein. Prudent incorporation of plant proteins can result in an improvement of the quality of the meat product with inconsequential adverse effects. 

The fat refining and bleaching operation is carried out to remove impurities that would cause color and odor in the finished soap. The wastewater from this source has a high soap concentration, treatment chemicals, fatty impurities, emulsified fats, and sulfuric acid solutions of fatty acids. Where steam is used for heating, the condensate may contain low-molecular-weight fatty acids, which are highly odorous, partially soluble materials. 

The approach is used to show the shape of cholic acid, one of the bile acids secreted into the gut to emulsify fats and encourage digestion. Cholic acid is characterized by a cis fusion of rings A and B. 

Proteins are important food components mainly due to their nutritional and functional value. Dietary proteins provide amino acids and nitrogen necessary for organisms. They also play a major role in determining the sensory and textural characteristics of food products. The functional properties are related to their ability to form viscoelastic networks, bind water, entrap flavors, emulsify fat and oil, and form stable foams [105]. 

Quil-A saponin toxicity. Mice fed Quil-A-supplemented diet (a saponin that emulsifies fats and potentiates the immune responses) showed higher level of docosa-pentaenoic acid in the liver. These changes were associated with a significant reduction in the plasma PGEl and PGE2 and thrombohane-B2 levels in response to an intraperitoneal injection of a lethal dose of lipopolysaccharide endotoxin, LDjf, 20 mg/ kg. The data suggest that sesame seed oil and Quil A, when present in the diet, exerted cumulative effects that resulted in a decrease in the levels of dienoic eicosanoids with a reduction in lL-1 P and a con-commitant elevation in the levels of lL-10 that were associated with a marked increase survival in mice . ... 

Condensed phosphates containing three- atoms of phosphorus are tripolyphosphates, the most important of which is sodium tripolyphosphate (.STPP). This compound reacts with the protein in meat, fish, and poultry to prevent denaturing or loss of fluids. This properly is sometimes called "moisture binding. STPP also solubilizes protein, which aids in binding diced cured meat, fish, and poultry. It also emulsifies fat to prevent separation. 

Swift, C.E., Lockett, C.. and Fryer, P.J. 1961. Comminuted meat emulsions—The capacity of meat for emulsifying fat. Food Technology 15 468-472. 

Bile salts emulsify fats in the intestine. The hydrophobic side or surface of the bile salt associates with triacylglycerols to form a complex. These complexes aggregate to form a micelle, with the hydrophilic side of the bile salt facing outward. Pancreatic lipase also associates with this micelle. The action of the lipase releases free... 

Figure 13. Photomicrographs of lamellae formed from O/W food emulsions containing 20 wt% emulsified fat, illuminated by transmitted light.

Figure 15. Intensity profile of light back-scattered from a food emulsion containing 20 wt% emulsified fat, at 5 °C, using green light (543 nm).

In this chapter the physical methods for analyzing whippable emulsions are divided into analyses of 1) the emulsified fat phase 2) the fat-water interface and air-water interface, and 3) the continuous water phase. The descriptive tests are mentioned at the end of the chapter as it is easier to explain the meaning of these tests after the fundamental mechanisms have been described. 

Figure 1 Melting enthalpy of bulk fat and emulsified fat of ice cream mix with (+E) and without (-E) emulsifier after cooling at 5°C measured by DSC.

Explain, with the aid of a diagram, how a soap emulsifies fats and oils. 

Shimizu, M., Kamiya, T., and Yamauchi, K. 1981. The adsorption of whey proteins on the surface of emulsified fat. Agric. Biol. Chem. 45, 2491-2496. 

Buchheim, W., Schiitt, M., Frede, E. 1996. High pressure effects on emulsified fats. In High Pressure Bioscience and Biotechnology (R. Hayashi, C. Balny, eds.), pp. 331-336, Elsevier Science B.V., Amsterdam. 

Differences in nucleation explain the differences observed between crystallization in the bulk and emulsified states. In bulk fats, only a small number of nuclei are needed to induce crystallization. However, when the same fat is emulsified, each fat droplet must contain a nucleus or impurity in order to crystallize, the probability of which is low. As a result, the emulsified fat requires more supercooling (i.e., to a lower temperature) in order to nucleate (Walstra et al., 1994). 

The interaction of para-casein-covered emulsified fat particles (which may be considered as pseudo-protein particles) with the casein matrix of the cheese, and... 

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