Effect of frozen storage on the quality and amylopectin structure of Chinese steamed bread made from different wheat cultivars

Abstract

The physicochemical properties of wheat flour and the chain-length distributions of amylopectin from eleven cultivars were studied. Chinese steamed bread (CSB) was made by a one-step fermentation procedure using these flours to explore the effects of frozen storage on the qualities of CSB and starch molecular structures. The results indicated that the protein and wet gluten had significant effects on the fermentation rheological properties of wheat dough and CSB qualities. The amylose content and amylopectin structure had important influences on the pasting properties of wheat flour and the firming of CSB. Water loss and migration in CSB during freezing, accompanied by the starch retrogradation, depended on the amylose content and amylopectin structure. After 60-day of frozen storage at −18 °C, the amylopectin extracted from CSB showed decreased fractions of B1 and B2 chains while the long B3 chain and average chain length increased. Moreover, short amylopectin chains were negatively correlated with the hardness of CSB (P < 0.01). These results confirmed that the structure-property relationships of wheat flour have crucial influences on the qualities of CSB, which would benefit our selection of wheat materials for the frozen food industry and provide a reference for wheat breeding.