Research On Processing Technology And Quality Analysis Of Walnut Meal Fermented Beverage

Our country walnut resources are abundant.Walnut dregs as by-product of walnut oil extraction are usually used as fertilizers and feeds.The high-quality protein resources are wasted seriously and the added value of products is low.Lactic acid bacteria are a common class of probiotics which healthy for human body.The main raw material is walnut dregs in this paper.The walnut dregs fermented beverage is prepared by enzymatic hydrolysis of flavor protease and fermentation of lactic acid bacteria.This kind of beverage is not only improving the utilization rate of peony protein,but also increasing the variety of yogurt beverage.The main conclusions of the paper are as follows:1.Taking walnut dregs as the base material,drinking water as solvent,enzymatic hydrolysis with flavor protease,the optimal ratio of material to liquid is 1:12.Through orthogonal test,the order of influence of various factors on the content of peptide in enzymatic hydrolysate was as follows:enzymatic hydrolysis time>pH>addition enzyme amount>enzymatic hydrolysis temperature;optimal enzymatic hydrolysis process parameters are enzymatic hydrolysis temperature 50?,enzymatic hydrolysis time 5h,the amount of enzyme added 6%,pH6.0.The enzymatic hydrolysate obtained under this condition has a polypeptide content of 13.74 mg/m L,which has high nutritional value.2.The walnut protein enzymatic hydrolysate has a bitter taste and need to be debittered.The cross-linked starch as the debittering agent added amount is 0.4%.Through orthogonal test,the order of influence of various factors on the sensory score of walnut dregs fermented beverage are fermentation temperature>sucrose addition amount>inoculum amount>fermentation time>milk addition amount.The optimum process parameters are fermentation temperature 46 0 C,inoculum I%,fermentation time 7 h,milk addition 30%,sucrose addition 8%.The walnut dregs fermented beverage viscosity is 50.12 mPa·s-1,acidity is 87.34 °T and sensory score is 85.23 under these conditions.Taste good and has a good sweetness.3.Stabilizers for walnut dregs fermented beverages are sodium carboxymethyl cellulose(CMC-Na),high methoxyl pectin(HMP)and gum Arabic(GA).The effects of three stabilizers and their addition on the sensory,stability,viscosity and particle size of the walnut dregs fermented beverage are different.The overall performance is that after adding the stabilizer,the comprehensive score and viscosity increased significantly.When system showed the most stable state,the average particle size of the sample is significantly reduced contrast with no stabilizer added.The stabilizing effect is better than single stabilizer when CMC-Na,HMP and GA are used together,which can significantly improve the stability of walnut dregs fermented beverage and improve the taste.Adding 0.12%CMC-Na,0.09%HMP,0.7%GA works best.Rheological properties research of before and after adding stabilizer in walnut dregs fermented beverage shows that the walnut dregs fermented beverage changed from Newtonian fluid to non-Newtonian fluid after addition compound stabilizer.In addition,the viscosity is increasing and the protein flocculation is reduced which product stability increased.4.Shelf life test of walnut dregs fermented beverage shows that stored under low temperature condition(4?)for 16 days,the highest number of lactic acid bacteria live bacteria is 9.60 lg(CFU/mL).The total sugar content decreased and the peptide content first increased and then decreased and finally stabilized.The antioxidant capacity is maintained at high level.The SDS-PAGE gel electrophoresis test confirmed that the protein molecular weight gradually decreased during storage and the nutritional value increased.However,the sensory score of the sample decreases as the storage time increases.