Institute of Chemical Industry of Forest Products, CAF, National Engineering Lab. for Biomass Chemical Utilization, Key and Open Lab. of Forest Chemical Engineering, SFA, Key Lab. of Biomass Energy and Material, Jiangsu Province, Nanjing 210042, China; Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China. Electronic address: [Email]
Chinese quince seed protein isolate (CPI) was extracted using aqueous extraction and the isoelectric precipitation method, and its physicochemical and functional properties were investigated. Results showed that CPI contained all essential amino acids with exception of methionine which met the minimum recommendations for adults (World Health Organization/Food and Agriculture Organization). The electrophoresis analysis of sodium dodecyl sulphate polyacrylamide gel indicated that the molecular weights of protein fractions were approximately 15-60 kDa. Differential scanning calorimetry analysis was conducted, and the denaturation temperature of CPI was 103.4 °C. The surface hydrophobicity of CPI was found to be 932.80. The experiments showed that CPI had high emulsifying capacity, foaming stability, water holding capacity and oil adsorption capacity. Moreover, CPI also had outstanding gel formation capacity since its least gelation concentration of CPI was only 8%. All these results implied that CPI could be a nutritional protein resource and functional ingredient in the food industry.