Research On Production Process And New Product Development Of Mucor Douchi

Traditional douchi has long fermentation cycles and unstable quality,which seriously restricts its scale of production and the development of the industry.Therefore,mucor-type douchi process is being innovatively researched to shorten the production cycle,improve the quality,and develop a douchi-derived compound seasoning to expand the douchi product market.1.The effects of material-water ratio,soaking time,and soaking temperature on water absorption were researched with black beans as raw material.The best soaking process is the ratio of material-water is 1: 3,soaking temperature is 35?,soaking time is 4h.The effects of different cooking methods,cooking temperature,and cooking time on hardness and sensory were researched.Under the same conditions,the sensory score of dry steaming is higher than that of wet steaming,the most suitable duration for dry steaming at atmospheric pressure is 135 min,and the the most suitable duration for wet steaming at atmospheric pressure is 120 min,the best conditions for high-pressure cooking at 121?for 25 min,high-pressure has significantly shorter cooking time than normal-pressure.2.The effects of inoculation rate,koji-making time,koji-making temperature,and humidity on neutral protease activity were researched with neutral protease activity as an indicator.Three-factor and three-level response surface optimization experiment was designed based on single-factor experiments,it shows that the neutral protease activity reached the highest of 91.23U/g under the conditions of 4.20% inoculation rate,25?temperature,85% humidity and 65 h inoculation time.3.Amino nitrogen was used as an index to research the effects of salt,liquor,yeast,fermentation time,and fermentation temperature on amino nitrogen content.Further combined with orthogonal optimization experiments,the optimal fermentation process was determined as: 9.00% salt,4.00% wine,30?temperature and 54 d fermentation time.The physical and chemical indexes of douchi under the optimized conditions were tracked and monitored.The conclusions are as follows: the content of amino nitrogen increased with the increase of fermentation time,and stabilized at 54 days of fermentation;the content of reducing sugar increased rapidly in the early stage of fermentation,and showed a downward trend in the later stage of fermentation;the crude protein content decreased slightly during the post-fermentation process,while the water-soluble protein content increased with the increase of fermentation time until the end of fermentation;the browning intensity increased with the increase of fermentation time,and the browning intensity became stable when the douchi was mature;the content of free amino acids in the fermented stage of douchi continues to increase until the level of douchi reached 3.45%.4.Compare the organization state,color,flavor,and texture of the four kinds of douchi drying methods,and finally choose fried and dried.Douchi is pellet-shaped,crispy,tender on the outside,and has a good taste after being fried and dried.Then combin the single factor test and the orthogonal optimization test to optimize the amount of carbonyl amino material,paprika,secret spices,pepper powder,the recipe of douchi compound flavor beef sauce is: carboamino materials 7.50%,secret spices 0.80%,paprika powder 1.50%,pepper powder 0.60%,cooking oil 25.0%,douchi 50.00%,beef 9.00%,peanut 4.00%,salt 1.00%,MSG 0.40%,white sesame 0.20%.The beef sauce with douchi flavor produced under these conditions has a bright color,rich sauce flavor,as well as a spicy and refreshing taste.