Antifreeze proteins in foods

Abstract

Antifreeze proteins (AFPs) are polypeptides produced by plants, animals, and microorganisms that allow them to survive at temperatures below zero. These compounds were first identified in 1969 by DeVries in the blood of fishes living in frozen sea areas and were named antifreeze proteins because they lowered the freezing point of the fish’s blood below the freezing point of sea water without significantly increasing the osmotic pressure. Antifreeze proteins can halt the formation of large ice crystals associated with recrystallization during frozen storage and thawing, and their potential as a food additive have been investigated in the recent years. Initially the use of AFPs was limited to ice cream products, but now meat, frozen dough, fruit, and vegetables are also among the products investigated. There are many research results about the successful application of AFPs in the freezing and thawing of food. However, in the future commercial use of these proteins will most likely be influenced by various factors such as isolation and purification, thermal stability, price, chemical synthesis, and development in molecular biology. This chapter describes the studies on the use of AFPs in food, as well as the dietary sources of these proteins, their use in foods, their toxicity, and the factors that influence their use.