Enzymes in Minimally Processed Fruits and Vegetables

Abstract

Minimally processed fruits and vegetables are complex and more active systems than whole fruits and vegetables. Endogenous enzymes in fruits and vegetables play a vital role in the development of desired color, texture, flavor, nutritive value, and bioactivity of edible vegetable parts. Endogenous enzyme activities are controlled by “natural mechanisms” in whole fruits and vegetables. The natural control mechanisms over the enzymatic reactions are lost mainly during the various minimal processing. Some endogenous enzymes and microbial enzymes may cause deteriorative changes in fruits and vegetables and especially in minimally processed fruits and vegetables at the postharvest stage. Discoloration, loss of texture, off-flavor formation, lipid oxidation, and loss of nutritional value are the important detrimental changes in the quality of minimally processed fruits and vegetables. Such deleterious changes in the quality of fresh-cut fruits and vegetables can be diminished with several preserving technologies and techniques such as refrigeration, controlled atmosphere packaging and modified atmosphere packaging, high-pressure processing, and edible coating. However, each technology has some advantages and disadvantages, with the latter predominating. In this regard, novel technologies such as pulsed electric field, ultrasonication, UV irradiation, and alternative thermal-processing technologies such as microwave, radio frequency, and ohmic heating are being investigated.