Abstract:The peptides and amino acids produced via the hydrolysis of rice protein are of very high nutritional value and functionality. In order to make full use of rice protein, comparative studies were made to study the interactive nature of rice protein and its hydrolysates with wheat flour upon mixing and the quality of the resulting crackers. Rice protein powders at different addition amounts (rice protein hydrolysate RPH, rice protein RP) were blended with wheat flour to investigate their effects on the dough mixing properties, dough textural characteristics, dough stretching features, and crackers’ textural and sensory properties, Also, structural analyses were carried out from he aspects of free sulfhydryl groups and disulphide bond content. The results showed that at the same addition amount (2.0 g/100 g), the stabilisation time for the dough with the added RPH (2.57 min) was significantly shorter than that with the added RP dough (3.05 min). The analyses of free sulfhydryl groups and disulfide bonds revealed that the free sulfhydryl groups increased by 0.29 and 0.17 μmol/g, respectively, with an increase in the addition amount of RPH or RP, whilst the corresponding disulfide bond contents decreased by 0.44 and 0.36 μmol/g, mrespectively, suggesting that both RPH and RP affected the structure of the gluten protein network. The experimental results of textural and sensory measurements showed that the breaking force of the crispy crackers fortified with 1.0 g of RPH (14.15 N) was significantly lower than that of cracker fortified with RP (20.27 N), and the highest sensory score was with the cracker fortified with 1.5 g of RPH (score: 85.67). In conclusion, this study provides a theoretical basis for the addition of RPH or RP to wheat flour to improve effectively the processing properties and product quality of dough.
