Application of plant-derived antifreeze protein in food

Plant-derived antifreeze proteins (AFPs) are a functional protein
produced by plants to protect cells from frost damage when the external environment changes.

AFPs have three properties, namely thermal hysteresis activity, modified growth morphological effects of ice crystals, and inhibition of ice crystal recrystallization
.

Plant-derived AFPs reduce mechanical damage caused by fluctuations in ambient temperature near sub-zero by inhibiting the recrystallization of ice crystals in solution, inhibiting the quality degradation caused by repeated freeze-thaw of food during refrigeration, and are more suitable for adding to refrigerated foods than AFPs from other sources
.

Food cold chain is very prone to temperature fluctuations in transportation, forming a freezing-thawing cycle, so the phenomenon of ice crystal recrystallization inevitably occurs, which in turn causes damage to cell tissues, resulting in changes in the physical and chemical properties and tissue morphology of
food.

At the same time, the recrystallization of water will also lead to changes in the internal components of cells, protein denaturation, starch regeneration and other phenomena
.

The formation and recrystallization of frozen sweet dairy ice crystals plays a vital role in the quality of the product, the formation process of ice crystals determines the growth of ice crystals during the hardening and storage process of frozen dairy products, and affects the cream state, roughness and moisture, hardness, ice refreshing taste and other sensory qualities of ice cream; Recrystallization determines the stability
of the texture and structure of the ice cream after the entire freezing operation.

By adding AFPs, the ice core size of ice crystals can be controlled from a mechanical point of view, the growth of ice crystals in sucrose solution can be inhibited, and the stability
under static storage conditions can be improved.

Plant-derived AFPs are also more
commonly used in frozen dough.

Quick-frozen fruits have high water content, and in the process of freezing and refrigeration, they are prone to sap loss and soft rotten deformation of fruits
.

The production of AFPs in plants is a complex process, the existence of which is closely related to the growth resistance of plants, changes in the external environment will directly affect their concentrations, and factors such as chemical induction will also stimulate plants to produce AFPs, of which the food field mostly uses cloning or transgenic pathways to obtain plant-derived AFPs
.

Plant-derived AFPs can not only inhibit the recrystallization phenomenon of food in the freezing and freezing process, reduce the reduction of nutrients and quality caused by the outflow of juice during thawing, but also non-toxic, add in a variety of foods will not have a negative impact, its functional characteristics are not associated with any toxic proteins, and it is expected that the future application prospects in the food field are very broad
.

At present, through the study of the mechanism of action of AFPs, a new direction of food antifreeze technology has been revealed, and it also provides a theoretical basis
for production practice.

(Source: Food Raw Materials Supply and Demand Service)

China Food News (2022-09-26 06 edition)

(Editor-in-charge: Yang Xiaojing)