Functionality enzymatic food

The ultimate goal of all researchers in this area has been to relate precisely the macroscopic manifestations of protein functionality in its utilization with its molecular properties. Great progress recently has been made in relating particular molecular structure to enzymatic activity. However, in the area of food functionality, the advance has been less rapid. The obvious difficulties are attributable to the mixed nature of food systems. The macroscopic manifestation in these products is usually the result of many interactions between different proteins and between these and nonprotein components. The multiplicity of the reactions under the conditions of food preparation or processing bears little resemblance to the clean-cut, precise reactions of pure proteins in solution. All extrapolations from the latter to the former have met with little success. In absence of this direct approach, we have resorted to various indirect approaches. 

In the past ten years, protein modification has been the subject of many excellent publications and reviews [4,5,6,7,59]. Chemical or enzymatic food protein modification is theoretically feasible [8,9,10,175], Modification of proteins may alter their net charge, hy-drophobicity, structure, and furthermore their surface activity and thus the functional properties of the proteins. [11,12],... 

Soy protein is a low-cost food protein with good nutritional value, but its uses in foods are limited because of inferior functional properties as compared to those of commonly used animal proteins such as casein and albumin (1.2). Therefore, modifications are often required to make soy protein more suitable for food use. Improved functional properties, particularly in the pH range of 3 to 7 where most food systems belong, have been achieved by non-enzymatic methods, including succinylation (3-5), deamidation (6.7), and phosphorylation (8.9). 

Ohba, R., Deguchi, T., Kishikawa, M., Arsyad, F., Morimura, S., and Kida, K. (2003). Physiological functions of enzymatic hydrolysates of collagen or keratin contained in livestock and fish waste. Food Sci. Technol. Res. 9, 91-93. 

Panyam, D., Kilara, A. (1996). Enhancing the functionality of food proteins by enzymatic modification. Trends in Food Science and Technology, 7, 120-125. 

TThe primary function of D-amino acid oxidase, present at high levels in the kidney, is thought to be the detoxification of ingested D-amino acids derived from bacterial cell walls and from cooked foodstuffs (heat causes some spontaneous racemization of the l-amino acids in proteins). Oxalate, whether obtained in foods or produced enzymatically in the kidneys, has medical significance. Crystals of calcium oxalate account for up to 75% of all kidney stones. ... 

Protein hydrolysates are usually produced by limited enzymatic hydrolysis of protein molecules in foodstuff, yielding polypeptides that are smaller in molecular mass. Protein hydrolysis has several aims. The most common is to make the protein moiety of afoodstuff soluble by reducing the size of the peptides. Solubilization simplifies isolation of the protein moiety by physical means. Protein hydrolysis has also been applied to improve the functional, organoleptic, and nutritional value of a foodstuff. Advances in the technology of protein hydrolysate production has allowed the use of unconventional protein sources for animal and human food. 

Enzymatic hydrolysis of food proteins yields peptides that are of great interest to the food industry and are utilized for various purposes, e.g., improving the functional properties of foods, parenteral feeding (casein hydrolyzates), or milk protein substitutes in cases of intolerance. 

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