Review: Antifreeze proteins – an emerging technology for freezing foods

Although freezing is one of the traditional methods of food preservation, it can also significantly change the product characteristics. Large ice crystals cause changes in the texture and damage cell membranes and components. The quick freezing techniques form smaller ice crystals than the slow process, but temperature fluctuations during transport and distribution can promote crystal growth. This process is known as recrystallization and is a barrier to the use of freezing as a preservation method in many cases. The use of traditional cryoprotectants such as sucrose is a limited alternative since high concentrations are required. In the 70’s a cold water fish class of proteins was described that could interact and influence ice crystal growth even at low concentrations. They were denominated antifreeze proteins (AFPs) and are also found in plants, animals and microorganisms acclimatized to low temperatures. These proteins can interfere in the formation of the initial stable ice crystal nucleus, reduce the freezing point of water, or even inhibit the recrystallization process, especially in the case of plant AFPs. Several papers have been published and some patents registered on the use of antifreeze proteins in several foods such as dairy and meat products, pasta, fruits and vegetables, preserving the original characteristics of the products in a better way. Currently the cost is still a barrier to the commercial use of AFPs but the discovery of alternative sources could reduce the costs and make them an effective tool in the maintenance of the texture of frozen foods. Based on studies that evaluated the chemical aspects of antifreeze proteins and examples of their application, this review aims to present the general characteristics of AFPs and discuss their use.

Freezing proteins; Ice; Freezing; Recrystallization