Effect Of Pretreatment Of Raw Materials On The Quality Of Bean Paste

Bean paste is a traditional fermented condiment in our country,and it enjoys popularity by consumers.The traditional process of pretreatment of raw materials is atmospheric pressure cooking process after soaking,and it has defects of low producing rate,high energy consumption,long period,high pollution and large space occupied.Therefor the manufacturers adopt the high pressure cooking process after running water of high temperture and short time,which learn the cooking process of soybean meal in soy brewing.Found in the actual production process that the total acid of bean paste of high pressure process are prone to higher than standard stipulated by the State in hot season, and product qualification rate is slightly lower. To solve this problem,this paper analyzed and improved production process, the quality of bean sauce has been improved,as follows:The conventional physical and chemical indicators of atmospheric pressure and high pressure cooking pressure during fermention were analyzed t.The results showed that water, total acid, ammonia nitrogen, reducing sugar of atmospheric pressure and high pressure cooking pressure were significantly different.Organic acids,free amino acids and volatile flavor compounds in bean paste of atmospheric pressure and high pressure cooking process were also tested during fermentation,and they are also different.Based on this ,the differences of two processes exist in the brewing process were analyzed.The main composition of clinker were difference between atmospheric pressure and high pressure cooking process,especially mositure,ash starch and protein.The results of experment of using soaking showed that effect of acid as tannin in bean to total acid of bean paste was negligible.The scanning electron microscope slices of bean flap in various stages of the pretreatment of raw materials showed that due to longer soaking time,water entered into the cell homogeneous,so that starch gelatinization and protein digestibility were moderate during atmospheric pressure cooking process.Because of time of running water was short and temperature of running water was high,protein denaterated and starch gelatinization has already begun;but the starch granules absorb water insufficiency and inhomogeneous in the phase of running water, so that starch gelatinization was insufficiency during high pressure cooking process.The mositure and enzyme activity of high pressure cooking process were lower than those of atmospheric pressure cooking process.The Maillard reaction and total number of microbial colonies were also slightly differences between two process.Finally in this paper,effect of running water content,running water temperature,running water time,cooking temperature and cooking time to starch gelatinization and apparent of clinker were invested.The high pressure cooking process was optimized by orthogonal experiments.The scanning electron microscope slices of bean flap in various stages of pretreatment of raw materials showed that starch gelatinization after optimization was prior to that before optimization.starch gelatinization and protein digestibility were improved,the mositure and enzyme activity of soy sauce koji were significantly increased. The conventional physical and chemical indicators show that the quality of bean paste was improved.