| China is a major soybean producer and consumer in the world,and okara is a by-product of dried bean curd,soybean hulls,soybean milk and other bean products.Okara is rich in dietary fiber,which has the effects of lowering blood glucose,improving lipid metabolism,reducing calorie intake,anti-tumor,and promoting digestion.However,most of the dietary fiber is insoluble dietary fiber,which is difficult to be directly absorbed by the human body if not treated,so it is often used as feed,fertilizer,or directly discarded,resulting in a large amount of waste of resources.In this study,the content of soluble dietary fiber was increased by modification treatment using bean dregs as the raw material,which was added into the process of soybean curd with high fiber content and texture analysis by comparing its protein content,dietary fiber content and texture with those of traditional soybean curd with high fiber content.This study provided a theoretical basis for the high-value utilization of okara and the industrial production of high fiber sour soybean curd.With bean dregs as raw material and the content of soluble dietary fiber in bean dregs as the main index,through single factor and response surface analysis and comparison of the effects of high temperature cooking and cellulase hydrolysis on the modification effect,it was concluded that high temperature cooking was the better treatment.The optimum technological conditions of high temperature cooking were as follows:high temperature cooking temperature 115℃,solid-liquid ratio 1:15,and high temperature cooking time 26 min.Under these conditions,the soluble dietary fiber content in bean dregs was 19.97%.The optimal technological conditions for the treatment of soluble dietary fiber in bean dregs by enzymatic hydrolysis modification were as follows:enzyme addition 3.27%,enzymolysis temperature 46℃,and pH4.6.Under these conditions,the content of soluble dietary fiber in bean dregs was 18.03%.With gel strength and sensory score as the indicators,modified soybean dregs were added into the preparation process of soybean curd with high fiber content.The preparation conditions of soybean curd with high fiber content were determined by single factor analysis and response surface analysis,and the quality of soybean curd with high fiber content was compared with that of traditional soybean curd with high fiber content.The optimum condition of high fiber sour soybean dry was 21%sour soybean paste,1:4.6 ratio of soybean to water,85℃ of braising temperature and 14.5%of bean dregs.Under the optimal conditions,the yield of high fiber Physalis alkekengi Bunge was 135.8%,the water holding rate was 78.70%,the protein content was 45.16%,the fiber content was 2.15%,and the sensory score was 93.3.By comparison,the overall quality of high-fiber Physalis alkekengi is better than that of traditional Physalis alkekengi.The influencing factors on the texture of high fiber soybean curd were analyzed,and the structure was compared with that of traditional soybean curd with acid pulp.The results showed that the protein structure was degraded by the addition of okara.However,the addition of appropriate amount of TG enzyme could reduce the damage of okara to the protein structure and effectively improve the quality of high-fiber Physalis alkekengi Bunge.The crosslinking of high fiber Physalis alkekengi by TG enzyme was mainly reflected in the increase of β-sheet content in the secondary structure.The gel structure of high-fiber soybean dry protein crosslinked by TG enzyme was closer to the tertiary structure of soybean dry protein with acid pulp added from soybean dregs.The comparison of microstructures was analyzed,and it was found that the soybean stem with high fiber content exhibited a uniform,dense and ordered structure after the addition of TG enzyme. |
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