Study On The Production Technology Of Peanut Meal Natto

Natto is a kind of nutritious fermented food,which contains rich nutrients and functional ingredients.It has been popular in recent years because it can dissolve thrombus,lower blood pressure,regulat stomach,and prevent cancer.In this paper,a new taste and new formula of peanut meal natto was developed,and the high activity bacillus natto was screened out.The optimum fermentation technology and preservation technology of peanut meal natto were studied.The development of peanut meal natto not only improves the taste of traditional natto,improves the quality of natto,but also makes full use of China's abundant peanut meal resources and saves costs,which can provide more benefits for enterprises.Bacillus natto was extracted from four groups of natto and screened by casein plate method.It was found that the BN-1 activity of the strain was the highest,and the ratio of the transparent circle formed on the casein plate to the diameter of its own colony was up to 4.5.Then the physiological and biochemical identification of strain BN-1 was carried out.The results showed that all the indexes of strain BN-1 were consistent with those of Bacillus subtilis and were reliable strains for fermentation.Peanut meal and soybean were used as raw materials to ferment peanut meal natto with high activity Bacillus natto?BN-1?,and the optimum fermentation technology was studied.The effects of peanut meal content,fermentation time and fermentation temperature on the quality of peanut meal were significant,but inoculation was not.Based on the comprehensive score of peanut meal,the fermentation process was optimized by response surface method.The optimum results were as follows:peanut meal content was21.67%,fermentation time was 23.07 h,fermentation temperature was 39.47?.Under these conditions,all indexes of peanut meal were good,the activity of nattokinase reached1267 U,and the highest sensory score was 45.9%.The content of daidzin in peanut meal was also determined.It was found that the content of daidzin in peanut meal was 0.062mg/g,which was 0.0208 mg/g higher than that of common natto,which indicated that the fermented peanut meal natto had certain nutritional value.When the storage temperature of peanut meal natto was less than 4?,the minimum number of live Bacillus natto was 7.257.25×10¹⁰CFU/g after 20 days.Over time,there was no significant change in the number of live strains of Bacillus natto.When the temperature was above 4?,the number of live Bacillus natto began to decrease obviously from the third day.On the 20th day,it decreased to 1.91×1010CFU/g,and when the storage time was longer than 12 days,the number of live Bacillus natto decreased at any temperature,and with time,the higher the temperature,the faster the decrease.The storage temperature of peanut meal natto was about 2?and the shelf life was 12 days.Under this condition,the peanut meal natto can still maintain a high sensory evaluation,and the survival rate of Bacillus natto could reach 98.2%.