Lipid-containing products, manufacturing

In the case of amorphous systems, absence of crystallinity upon tableting or over the shelf-life of the product must be ascertained to avoid potential slow down in dissolution, reduction in bioavailability, and loss of elegance. For lipid containing products, minimizing oxidation during manufacture and storage must be planned for by processing under inert conditions and incorporation of antioxidants in the formulation. ... 

Another application is in the manufacture of fats and oils containing nutritionally important PUFAs, such as EPA and DHA. For example, various vegetable and marine oils have been enriched with EPA and DHA using enzyme-catalyzed reactions (35, 51, 52). Use of this technique to produce structured lipids with MCEAs and PUEAs located specifically in either the sn-2 or sn-l,3 positions of the TAGs has been described. Enzymatic processes are particularly suitable for the production and modihcation of lipids containing PUFAs, because these unstable fatty acids are susceptible to damage under the more severe conditions used for chemical processing. 

Extensive lipolysis occurs in two families of cheese in which fatty acids and/or their degradation products are major contributors to flavour, i.e. certain Italian varieties (e.g. Romano and Provolone) and the Blue cheeses. Rennet paste, which contains pre-gastric esterase (PGE) rather than rennet extract, is used in the manufacture of these Italian cheeses. PGE is highly specific for the fatty acids on the sn-3 position of glycerol, which, in the case of milk lipids, are predominantly highly flavoured short-chain fatty acids (butanoic to decanoic). These acids are principally responsible for the characteristic piquant flavour of these Italian cheeses. 

Raw milk is a unique agricultural commodity. It contains emulsified globular lipids and colloidally dispersed proteins that may be easily modified, concentrated, or separated in relatively pure form from lactose and various salts that are in true solution. With these physical-chemical properties, an array of milk products and dairy-derived functional food ingredients has been developed and manufactured. Some, like cheese, butter, and certain fermented dairy foods, were developed in antiquity. Other dairy foods, like nonfat dry milk, ice cream, casein, and whey derivatives, are relatively recent products of science and technology. This chapter describes and explains the composition of traditional milk products, as well as that of some of the more recently developed or modified milk products designed to be competitive in the modern food industry. 

In general, workers involved in the manufacture of 2,4,5-TCP and subsequent products were exposed to far greater levels of 2,3,7,8-TCDD than those involved in the handling and application of chlorinated pesticides containing CDDs. Current serum lipid levels of 2,3,7,8-TCDD in a small number of U.S. Air Force veterans who were directly involved in the aerial spraying of herbicides (Agent Orange contaminated with 2,3,7,8-TCDD) in Vietnam as part of Operation Ranch Hand,... 

Another parameter that influences the overall properties of the bulk emulsion is the physical state of the lipid droplets in an emulsion (17, 19, 28-31). Crystallization of lipid droplets in emulsions can be either beneficial or detrimental to product quality. Margarine and butter, the most common water-in-oil emulsions in the food industry, are prepared by a controlled destabilization of oil-in-water emulsions containing partly crystalline droplets. The stability of dairy cream to mechanical agitation and temperature cycling depends on the nature and extent of crystallization in milk-fat globules. It should be noted that because the density of the phases can change as crystallization occurs, the rate at which milkfat droplets cream can be altered as droplets solidify. Emulsion manufacturers should therefore understand which factors influence the crystallization and melting of emulsified substances, and be aware of the effect that droplet phase transitions can have on the properties of emulsions. 

Unfortunately, the number of commercial formulations is very limited, primarily because of stability and manufacturing problems encountered during large-scale production. The list includes Sandimmune Neoral (cyclosporine A Novartis AG, Switzerland), which contains a microemulsion preconcentrate and is available as soft gels and solutions. Sandimmune (cyclosporine A Novartis AG, Switzerland), which contains an emulsion preconcentrate, and lipid soluble vitamins. Both formulations of cyclosporine have self-emulsifying properties and spontaneously form an o/w microemulsion (particle size <0.15 pm) and an o/w emulsion, respectively in the aqueous fluids of the GI tract. Although the discussion concerning potential of liposomes, niosomes, microemulsions, and solid dispersions for oral delivery is outside the scope of this chapter, the interested reader is referred to recently published reviews on these topics. " ... 

Cheese whey is an important by-product from the cheese manufacturing industry. Typically, 100 g of milk yields 10 g of cheese and 90 g of liquid whey. Cheese whey contains about 4.5-5% lactose, 0.6-0.8% soluble proteins, 0.4-0.5% (w/v) lipids, and varying concentrations of mineral salts [1]. Cheese whey disposal has long been a problem for the dairy industry. Most medium and small cheese producers still dispose of their whey or whey... 

Protein derivatives are generally composed of several different molecular species, as the result of the complex composition of source material and its processing to smaller peptides or condensates moreover, many different additives, impurities, by-products, and contaminants may be present. A hydrolyzed protein preparation can be composed of thousands of different peptides, inorganic ions, sugars, lipids, ammonia, preservatives, antioxidants, and a variety of other possible impurities. Fatty acid condensates of hydrolyzed protein can contain, in addition, soaps and acylamides. Furthermore, products with the same INCI name, prepared by different manufacturing processes or from different source materials, will probably differ, also significantly, in their chemical composition. 

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