| A new kind of peptides beverage was manufactured with fresh papaya and soybeans as main materials which can be used for deep processing and application of Hainan tropical fruit. After papaya and soybeans pulped and filtered, the protein in soybean milk was hydrolyzed by protease of fresh papaya. The main goal of the present work was to optimize the hydrolysis conditions for fresh papaya pulp hydrolyzed soy milk by using single factor experiment and Response Surface Methodology. Compare the reducing capacity, clearing DPPH radical ability, eliminating ABTS radical, hydroxyl free radical and superoxide anion radical ability of the peptides during different hydrolyzing time, which Vc and BHT and gallic acid as control. With the method of response surface experiment and sensory evaluation values, the optimum formulations of peptides beverage were determined. The effect of stabilizers, emulsifiers and sterilization on stability and retention period of papaya-soybean peptides beverage have been investigated in this paper. Eventually, a new kind of peptides beverage, certain physiological functions, tastes good and stable, can be manufactured.By single factor experiment and response surface method to optimize the hydrolysis conditions, peptide concentration in solution as the index, the optimum hydrolyzing conditions determined in order to maximize the combined responses were56.4?,5.22h,6.53pH and0.4(v/v) papaya-to-soybean milk ratio. The polypeptides content produced under these conditions was1.230g/L. Degree of hydrolysis and amino nitrogen content changing with time was measured under the hydrolyzing conditions. The results showed that degree of hydrolysis was2.46%when hydrolyzing time was5.5h, under these conditions the average peptide chain length (PCL) was41. In addition, amino nitrogen content was0.078%when hydrolyzing time was5h. Those results suggest that fresh papaya has certain ability to hydrolyzed soybean milk.Through testing papaya soybean hydrolyzate of reducing power and the DPPH· ABTS+·,· OH and O2·· and observing antioxidant properties of product of fresh papaya milk hydrolysis,the results showed that papaya soy peptides all have strong clearing DPPH radical ability, eliminating ABTS radical, hydroxyl free radical, superoxide anion radical ability getting from different hydrolyzing time, however, the same ability of a mixture of fresh papaya pulp and soy milk was not significant, but their reducing ability and DPPH radical eradication were equivalent, it proved that soy protein without hydrolysis had a certain antioxidant ability. Hydrolyzing time has strong influence on eliminating ABTS free radical, hydroxyl free radical, superoxide anion free radical, but little effect on reducing capacity and eliminating DPPH free radical.We assessed the effect of citric acid, hydrolysate and surge on the sensory score and consumer acceptability of papaya-soybean polypeptide beverage by response surface methodology. Flavor, smell, color, taste and other sensory score were taken into consideration. The most suitable formulation found was:surge6.18%, hydrolysate23.21%, citric acid0.19%.Stabilizer was conducted having effect on the stability of the beverage by the response surface methodology. Furthermore research on composite stabilizer and composite emulsifier impacted of the stability of the papaya soybean polypeptide beverage. The optimal formulation of stability were CMC-Na0.157%, xanthan gum0.121%, sodium alginate0.087%, monoglyceride0.09%, sugar esters0.09%. At this time, the stability and sensory evaluation of the beverage was best.Finally, we found the sensory qualities and microbial indicators in accordance with the GB by testing the finished product of three months, half of year. |
PDF Full Text Request