Fat products processing

Contents v. 1. Edible oil and fat products chemistry, properties, and health effects - v. 2. Edible oil and fat products edible oils - v.3. Edible oil and fat products specially oils and oil products - v. 4. Edible oil and fat products products and apphcations - v. 5. Eidible oil and fat products processing technologies - v. 6. Industrial and nonedible products from oils and fats. 

Butter. In the United States about 10 wt % of edible fats used are butter. Butter is defined as a product that contains 80% milk fat with not more than 16% moisture. It is made of cream with 25—40% milk fat. The process is primarily a mechanical one in which the cream, an emulsion of fat-in-semm, is changed to butter, an emulsion of semm-in-fat. The process is accompHshed by churning or by a continuous operation with automatic controls. Some physical properties are given in Table 16 (see Emulsions). 

Food and kindred products Processing, packaging, shipping Meats, fats, oils, bones, offal, vegetables, fruits, nuts and shells, cereals... 

Mixtures of triglycerides, triglycerides plus free fatty adds or triglycerides plus fatty acid alkyl esters are used as reactants in fat modification processes. These mixtures are exposed to lipases supported on macroporous particles in the presence of a small amount of water. Liquid substrates (oils) can be reacted without use of a solvent, but with solid reactants (fats) it is necessary to add a solvent to ensure that the reactants and products are completely dissolved in the organic phase. Various water immisdble solvents can be used, but hexane is preferred for commercial operation because this solvent is already used industrially for the processing of oils and fats. 

Food products can generally be considered as a mixture of many components. For example, milk, cream and cheeses are primarily a mixture of water, fat globules and macromolecules. The concentrations of the components are important parameters in the food industry for the control of production processes, quality assurance and the development of new products. NMR has been used extensively to quantify the amount of each component, and also their states [59, 60]. For example, lipid crystallization has been studied in model systems and in actual food systems [61, 62]. Callaghan et al. [63] have shown that the fat in Cheddar cheese was diffusion-restricted and was most probably associated with small droplets. Many pioneering applications of NMR and MRI in food science and processing have been reviewed in Refs. [19, 20, 59]. 

One of the most important quality parameters of fried food is the amount of fat absorbed during the process, which is incompatible with recent consumer trends toward healthier food and low-fat products (Bouchon... 

The main current potential application of lipase-catalyzed fat-modification processes is in the production of valuable confectionery fats for instance, alternative methods of obtaining cocoa-butter equivalents by converting cheap palm-oil fats and stearic acid to cocoa-butter-like fats. The reaction is executed in a water-poor medium, such as hexane, to prevent hydrolysis. At least one commercial apphcation exists. Loders Croklaan (Unilever) has an enzymatic interesterification plant in Wormerveer, the Netherlands. Many other new potential applications of lipases have been proposed of which some will certainly be economically feasible. Examples and details can be found in chapter 9 of this book. 

MILK AND MILK PRODUCTS. Intricate chemical and microbiological problems arise in the production, processing, and distribution of milk products. Milk is a complex mixlure of fat (40 ). protein (3.5 3 I. carbohydrate (4.8rf) and mineral components t().7 ) and is an excellent hacleria growth medium hence the need for care and cleanliness in handling. 

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