Effects of recombinant carrot antifreeze protein from Pichia pastoris GS115 on the physicochemical properties of hydrated gluten during freeze-thawed cycles

Abstract

The deterioration of gluten network caused by ice formation or recrystallization in frozen dough is one of the major factors causing the quality loss of bakery products. In this study, the effects of recombinant carrot antifreeze protein (rCaAFP) from Pichia pastoris GS115 on the physicochemical properties of hydrated gluten, including sodium dodecyl sulphate solubility, glutenin macropolymer (GMP) depolymerization, disulfide bonds content, secondary structure, rheological properties, and microstructure, were investigated during freeze-thawed cycles. The rCaAFP alleviated GMP depolymerization, weakened the damage of freeze-thawed cycles to disulfide bonds, secondary structure, and microstructure of hydrated gluten, and protected the rheological properties of hydrated gluten during freeze-thawed cycles. These results clearly demonstrate the utility of rCaAFP as a potent cryoprotectant in the preservation of hydrated gluten during frozen storage. This study may gain more insights into the deterioration process of wheat gluten during frozen storage and provide a theoretical basis for better preservation of frozen dough by rCaAFP from the perspectives of structure and functionality of gluten protein.