Optimization of the Compound Clarifying Agent to Clarify Yam Vinegar by Response Surface Methodology

Single and compound clarifiers which including glutin,pectinase,chitosan,celite were used to clarify the yam vinegar.Based on the method of response surface,a variety of clarifying agents were selected to investigate the effects of transmittance of fermented yam vinegar. The results showed that the establishment of the yam compound clarification response surface model was reliable and stable. The optimal compound clarification process conditions were 5∶2 (g∶g)ratio of diatomite and chitosan,the concentration of composite clarifier was 4 g/L,the clarification temperature was 36.5 ℃,and the clarification time was 83 min. Under the optimized conditions,the transmittance of yam vinegar was 95.8%,27% higher than that of the original vinegar. At the same time,it had no significant effect on other indicators of yam vinegar. Amino acid nitrogen was 0.27 g/100 mL,total acid was 5.29 g/100 mL,soluble solid was 8.74 °B_X.The appearance of processed yam vinegar was light yellow brown,transparent without suspended substance,and it had a supple texture.