Enzymes modified whipping proteins

Fig. 19.22. Process diagram for preparing enzyme-modified whipping proteins from soy protein isolate (Source Gunther, 1979).

Gunther, R.C. Chemistry and characteristics of enzyme-modified whipping proteins, ]. Am. Oil Chem. Soc. 1979, 5S, 345-349. 

Soya Proteins. Early attempts to make albumen substitutes from soya protein also ran into problems. A bean flavour tended to appear in the finished product. A solution to these problems has been found. Whipping agents based on enzyme modified soy proteins are now available. The advantage of enzymatic modification is that by appropriate choice of enzymes the protein can be modified in a very controlled way. Chemical treatment would be far less specific. In making these materials the manufacturer has control of the substrate and the enzyme, allowing the final product to be almost made to order. The substrates used are oil-free soy flakes or flour or soy protein concentrate or isolate. The enzymes to use are chosen from a combination of pepsin, papain, ficin, trypsin or bacterial proteases. The substrate will be treated with one or more enzymes under carefully controlled conditions. The finished product is then spray dried. 

Enzyme modified soy protein Whipping agent Protein Soy beans... 

Nougat can be made either in batches or continuously although the best nougat is made in batches. Various whipping agents can be used such as egg albumen, gelatine, milk protein and enzyme-modified soya protein. Starch or gum arabic can also be used in addition. The composition can be adjusted to give the desired texture. 

The effect of enzymic modification on the foaming and emulsification properties of fish proteins has been studied in several laboratories (8, 14, 28). Hermansson et al. (8) observed that solvent-extracted FPC modified with an alkaline bacterial protease yielded a whipped foam volume approximately 70% greater than untreated FPC. However, the stability of the foam from the enzyme-modified FPC was about 50% less than that of the untreated FPC. The foam volume of the enzyme-modified FPC was essentially equal to that of egg white, but the foam stability of the FPC hydrolysate was substantially less. 

In spite of the above limitations and the relatively small number of Studies involved, it is evident that the functionality of proteins as protein concentrates can be modified substantially by enzymes. Solubilities of proteins can be altered (generally increased) by hydrolytic reactions viscosities and gelation of protein solutions can be decreased dramatically by limited proteolysis the volume of foams of whipped hydrolysates is generally greater than that of the parent protein, but the foam stability is usually less. Emulsification properties of hydrolysates are affected in different ways depending on the protein. From the very limited number of studies on partial hydrolysis of food proteins it appears that water binding is increased as a result of proteolysis. ... 

Watanabe and Arai wrote an excellent review on the properties of enzymatically modified proteins and compared the chemical and enzymatic processes of various proteins [135]. Enzymatic processes can normally be carried out under milder and therefore safer experimental conditions than conventional chemical processes. Proteolytic enzymes have been used on proteins to improve their solubility soy protein, leaf protein concentrates, fish protein concentrates, meat proteins, egg proteins, milk proteins, and blood proteins. Special attention was given to caseins, gelatins, egg proteins, and cereals. Partial hydrolysis of these proteins under well-controlled conditions can produce emulsifying and whipping agents... 

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