Studies On Bubbling Properties Of Barley Foam-active Protein By Maillard Reaction

Barley is the main raw material for beer production, the role foam-active proteins of barley play on the foaming capacity and foam stability of beer has been people’s concern. In this study, the foam-active proteins were used as the main material, and the purpose of this paper was to study the Maillard reaction to improve foaming capacity and foam stability of the proteins and to shed light on the foam improvement technology of beer for industry.First, the extent of the Maillard reaction of foam-active proteins was studied in the drying process. Statistics showed that along with the drying process, the reaction extent increased, while the foaming capacity and foam stability of the proteins improved obviously. The FTIR and SDS-PAGE characterization led to analyze and compare the structure and the molecular weight of the proteins. Based on the above assessment, it was evident Maillard reaction has occurred between the foam-active proteins and saccharide.Foam-active proteins were extracted from four barley cultivars grown in different geographic regions, which were subsequently quantified and analyzed by previous methods. It was discovered that the foaming capacity and foam stability of proteins were subject to increase during the drying process, for they were influenced by the Maillard reaction. Interestingly, the occasion differed from barleys of different regions, specifically when domestic and imported barleys were included in this research, the latter ones outclassed the domestic ones in foam quality. These results partially explained the quality gap between domestic and imported barleys.The optimal processing was investigated through single-factor experiment and orthogonal test, which led to the conclusion that the optimum graft reaction conditions were as follows:the weight ratio of glucose to protein1:2, pH9.5,60min. In this condition it would yield graft reaction products with DG23.89%and browning index0.179.Compared with unmodified sample, foaming capacity and foam stability of the foam-active proteins were increased1.3and3.5times respectively.