ISOLATED SOYBEAN PROTEINS

Isolated soybean proteins, or soybean protein isolates as they are also called, are the most concentrated form of commercially available soybean protein products. They contain over 90% protein, on a moisture free basis.
The basic principles of ISP production are simple. Using defatted soy flour or flakes as the starting material, the protein is first solubilized in water. The solution is separated from the solid residue. Finally, the protein is precipitated from the solution, separated and dried. In the production of ISP for food use, in contrast to ISP for industrial use, care is taken to minimize chemical modification of the proteins during processing. Obviously,the sanitary requirements are also much more demanding.
Being almost pure protein, ISP can be made to be practically free of objectionable odour, flavour, colour, anti-nutritional factors and flatulence. Furthermore, the high protein concentration provides maximum formulation flexibility when ISP’s are incorporated into food products.

Meat Industry
In emulsion type sausages, such as frankfurters and bologna, ISP and proteinates are used for their moisture and fat binding properties and as emulsion stabilizers. Typical usage levels are 1% to 4% on a prehydrated basis. The use of ISP in these products permits reducing the proportion of expensive meat in the formulation, without reducing the protein content or sacrificing eating quality.
Methods for incorporating soy protein products into whole muscle meat have been developed recently. Isolated soybean protein is dispersed in specially formulated meat curing brines and injected into whole muscle using stitch pumps. It is also possible to incorporate the protein by surface application of the protein containing brine, followed by massaging or tumbling, as practised in the cured meat industry. Typical brine formulations contain salt, sugars, phosphates, nitrite and/or ascorbic acid.

Cereal products
ISP is sometimes used instead of, or in combination with isolates and soy flour, in the formulation of milk replacer mixtures in bakery products. ISP has been used for protein fortification of pasta and specialty bread. In these applications, the high protein content and blandness of ISP are clear advantages.

Dairy-type products
Soybean protein isolates are used in non-dairy coffee whiteners, liquid whipped toppings, emulsified sour cream or cheese dressings, non dairy frozen deserts etc. The basis for these applications is, demand for non-non-dairy (all-vegetarian, cholesterol-free, allergen-free) food products, as well as economy.
Imitation cheeses have been produced from isolated soy proteins, with or without milk whey components. The types of cheeses which can be produced include soft, semi-soft, surface-cultured (imitation Camembert) and ripened hard cheeses.