Fat heating

Enzymes from these organisms find numerous applications beyond PCR. Certain ones can modify plant fibers or break down proteins or fats. Heat-stable enzymes with these digestive properties are very attractive to the food processing industry. Properly controlled, their action can make prepared foods more palatable, and they can be employed where ordinary enzymes fail. In food processing, all operations must be carried out under sterile conditions. Frequently, the easiest way to maintain sterility is to keep the... 

Deep-fat frying is one of the oldest and most common unit operations used for cooking foods by immersing them in an edible oil or fat heated above the boiling point of water (Farkas et al.. 

Different fractions from the extracts of pork fat were analyzed for volatile compounds by the GLC/MS method of Suzuki and Bailey (25). Fifty-six compounds consisting of 13 hydrocarbons, 15 aldehydes, 4 ketones, 3 alcohols, 6 phenols, 9 carbotylic adds, 1 ester and 5 heterocyclics were identified and quantified in extracts from pork fat heated at 160°C for 1 hr. 

Food Animal fats Heating coils in soaking... 

Low iodine value hard stocks can be controlled with quick titer determinations. There are many versions of this evaluation, but basically, the test involves dipping the bulb of a glass thermometer into liquid fat heated above the melting point, then rotating the thermometer stem to cool the fat. The end point is the temperature when the fat on the bulb clouds. Constants can be determined to add to the quick titer result to approximate real tier determined by AOCS Method Cc 12-59 (19). 

Murphy, J.J., McNeill, G.P., Connolly, J.F., and Gleeson, P.A. (1990) Effect on Cow Performance and Milk Fat Composition of Including Full Fat Soyabean and Rapeseed in the Concentrate Mixture for Lactating Dairy Cows, J. Dairy Res. 57, 295-306. Chouinard, P.Y., Girard, V., and Brisson, G.J. (1997) Performance and Profiles of Milk Fatty Acids Fed Full Fat, Heat-Treated Soybeans using Various Processing Methods, J. Dairy Sci. 80, 334-342. 

In saponification, a fat heated with a strong base produces glycerol and the salts of the fatty acids (soaps). 

When the fats are heated above 250"C they decompose with the production of acrolein, the intense smell of which is one of the best methods for detecting fats. The extraction of fats from tissues is most conveniently carried out by extraction with ether or some other solvent. 

SNG Substitute natural gas. soaps Sodium and potassium salts of fatty acids, particularly stearic, palmitic and oleic acids. Animal and vegetable oils and fats, from which soaps are prepared, consist essentially of the glyceryl esters of these acids. In soap manufacture the oil or fat is heated with dilute NaOH (less frequently KOH) solution in large vats. When hydrolysis is complete the soap is salted out , or precipitated from solution by addition of NaCl. The soap is then treated, as required, with perfumes, etc. and made into tablets. 

Spirit C 0.700 70-100 Fat extraction, vegetable oil mills, rubber industry, heating... 

If the original ester is a fat or oil and produces an odour of acrolein when heated, it may be a glyceride. Esters of ethylene glycol and of glycol with simple fatty acids are viscous and of high b.p. They are hydrolysed (method I) and the ethyl alcohol distilled ofl. The residue is diluted (a soap may be formed) and acidified with hydrochloric acid (Congo red paper). The acid is filtered or... 

Ester hydrolysis in base is called saponification, which means soap making Over 2000 years ago the Phoenicians made soap by heating animal fat with wood ashes Animal fat is rich m glycerol triesters and wood ashes are a source of potassium car bonate Basic hydrolysis of the fats produced a mixture of long chain carboxylic acids as their potassium salts... 

Saponification (Section 20 11) Hydrolysis of esters in basic solution The products are an alcohol and a carboxylate salt The term means soap making and denves from the process whereby animal fats were converted to soap by heating with wood ashes... 

A good compilation of the functions of fats in various food products is available (26). Some functions are quite subtle, eg, fats lend sheen, color, color development, and crystallinity. One of the principal roles is that of texture modification which includes viscosity, tenderness (shortening), control of ice crystals, elasticity, and flakiness, as in puff pastry. Fats also contribute to moisture retention, flavor in cultured dairy products, and heat transfer in deep fried foods. For the new technology of microwave cooking, fats assist in the distribution of the heating patterns of microwave cooking. 

The deleterious effect of some fat substitutes has been demonstrated in cake frosting (27) the result is an unacceptable frosting, filled with air bubbles. In another example, some low fat cheeses are quite acceptable when cold, but when heated result in a product texture that changes to a sticky, gummy mass. Attempts to replace fat must be viewed as a total systems approach (28,29). It is likely that no one material will replace fats in food rather, replacement will consist of mixtures with each ingredient addressing one or more of the roles played by fats in food. 

Each member of the N-Lite Series (National Starch) is aimed at a specific role ia fat replacemeat, ie, N-Lite L for soups and sandwich spreads N-Lite LP for use ia dressiags and dips. N-Lite LP is an iastant modified food starch which yields a very oily texture and is stable to heat, acid, and shear N-Oil is a tapioca dextria suggested for fat-like mouthfeel and the N-Elate and N-Oil Series are propriety mixtures of starches and other fat replacers. 

Theie aie only a few fat replacement products based on protein. LITA is a com protein—polysaccharide compound the role of the polysaccharide is to stabilize the protein (zein). The final product is 87% protein and 5% polysaccharide. The mixture, spray dried after processing, claims to look like cream on rehydration. It is low in viscosity, flavor, and lubricity, and is stable to mild heating. The protein particle size is 0.3—3 p.m (55). 

Specific heats of fats and oils may be calculated with some precision as a function of temperature, t, in °C hy) Uquid oils... 

When heated with small amounts of iodine, rosins, taU. oil, and other wood products are converted to more stable forms (135,136). Iodine has been used with some tin salts as a catalyst in the hydrogenation of coal (qv) and its distillation products (137,138), and has been recommended as a catalyst for the production of drying oils (qv) from unsaturated animal fats (139,140). 

Microwave Cooking Pads. A simple and effective method of reducing fat in meat products involves the use of microwavable heating pads. 

Pasteurization may be carried out by batch- or continuous-flow processes. In the batch process, each particle of milk must be heated to at least 63°C and held continuously at this temperature for at least 30 min. In the continuous process, milk is heated to at least 72°C for at least 15 s ia what is known as high temperature—short time (HTST) pasteurization, the primary method used for fluid milk. For milk products having a fat content above that of milk or that contain added sweeteners, 66°C is requited for the batch process and 75°C for the HTST process. For either method, foUowiag pasteurization the product should be cooled quickly to <7.2° C. Time—temperature relationships have been estabHshed for other products including ice cream mix, which is heated to 78°C for 15 s, and eggnog, which must be pasteurized at 69°C for 30 min or 80°C for 25 s. 

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