Foods enzymes indigenous

Food-related enzymes indigenous to the food system are enzymes whose characteristics set them apart because of their individual impact on aspects of the food system that we can perceive. Thus, we are dealing here with only a few enzymes enzymes whose nature distinguishes them for us. 

It is essential for a successful assay that the vitamins be quantitatively extracted from the food matrix in a form that can be accurately measured by the particular HPLC technique to be used. An effective extraction procedure serves to homogenize and concentrate the sample, isolate the vitamin analyte from its association with protein, eliminate as far as possible known interfering substances, and destroy any indigenous enzyme activity. The vitamin-rich fraction thus obtained may require some form of cleanup before the vitamins can be measured, particularly when measuring the trace amounts of naturally occurring vitamins D and K. 

Olivecrona, T., Bengtsson-Olivecrona, G. 1991 Indigenous enzymes in milk.-II Lipase. In Food Enzymology (P.F. Fox, ed.), pp. 62-78, Elsevier Applied Science, London. 

Fox, P.F., Morrissey, P.A. 1981. Indigenous enzymes of bovine milk. In Enzymes and Food Processing (G.G. Birch, N. Blakebrough, K.J. Parker, eds.), pp. 213-238, Applied Science Publishers, London. 

Another source of enzyme changes in food stuflFs is related to enzyme systems indigenous to the microorganisms which are indigenous to the foods. They are too complex to deal with here. In the preceeding section, we have tried to indicate those enzymes whose impact is understood and to identify our adaptations to improve a food product or prevent its deterioration. 

There have been a limited number of studies on the effects of enzymic modification of protein concentrates on functional properties other than solubility. Studies on functional properties, as modified by enzymic treatments, emphasize foam formation and emulsifying characteristics of the hydrolysates. Treatment of chicken egg albumen alters the functional properties of the egg proteins in terms of foam volume and stability and the behavior of the proteins in angel food cakes (25). Various proteolytic enzymes were used to degrade the egg albumen partially. However, proteolytic enzyme inhibitors indigenous to the egg proteins repressed hydrolysis of the egg proteins compared with casein. 

Chivero ET, Mutukumira AN, Zvauyu R. (2001). Partial purification and characterization of a xylanase enzyme produced by a microorganism isolated from selected indigenous fruits of Zimbabwe. Food Chem, 72, 179-185. 

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