Study On Production Process Control And Antioxidant Activity Of Rice Dreg Sauce

Rice dreg protein（RDP）was used as main material of fermented sauce,which shows that the method is feasible by preliminary studies.In the thesis,production process control and antioxidant activity of RDP sauce were investigated further.The main contents and results were as follows:When amino acid nitrogen,total nitrogen,soluble protein and conversion rate of total nitrogen were used as main indicators,It has been confirmed that factors of fermentation temperature,salt concentration of the moromi and addition of brine significantly affect the quality of RDP sauce during the fermentation period,and the conditions of its fermentation were optimized.The results show that the optimized technological conditions were as follows:RDP sauce was fermented in brine of 2.8times volume at below 35℃,and salt concentrations of the moromi was 11%.RDP sauce with the higher raw material utilization ratio and quality could be obtained under the fermentation conditions.Using the DPPH radical scavenging activity,reducing power,metal ions chelation and anti-lipid peroxidation as indices,the antioxidant activity and active ingredients of RDP sauce fermenting at different temperatures and the effects of RDP sauce on antioxidant activity during storage of fresh pork were studied.The results show that the reducing power,metal ions chelation and anti-lipid peroxidation of RDP sauce increased as the fermentation temperature increased in vitro antioxidant experiment,and DPPH radical scavenging activity from highness to lowliness in turn was 50℃,20℃,35℃.The active ingredients（free phenolics,antioxidant amino acids,5-HMF）of RDP sauce increased as the fermentation temperature increased during the fermentation period,50℃ was in favor to accumulate the active ingredients.RDP sauce,which fermenting at50℃ is the best among them,can increase total antioxidation of fresh pork and inhibit lipid oxidation to a certain extent.Using the DPPH radical scavenging activity,reducing power as indices,the antioxidative stability of RDP sauce was studied.The results show that alkaline environment had more negative influence on the antioxidant activity of RDP sauce than acidic environment,the antioxidant activity was quick to lose in alkaline environment.Metal ions in varying degrees reduced the antioxidant activity of RDP sauce,among them,Cu²⁺,Fe³⁺and Zn²⁺could cause large damage to the antioxidant activity.Sucrose,glucose and fructose although for the antioxidant activity of RDP sauce had some umaging effects,but the antioxidant activity remained at the high standard.Sodium benzoate and potassium sorbate at different levels reduced the antioxidant activity of RDP sauce.Using reducing sugar and amino nitrogen,total nitrogen,sensory evaluation,DPPH radical scavenging activity,reducing power as evaluation index,the different sterilization temperature for the influence of antioxidant activity and quality of RDP sauce was compared.Considering the effect of sterilization temperature on RDP sauce quality stability,the optimum sterilization temperature was selected.The combinations of food additives were selected scientifically and reasonably.Using sensory evaluation as index,the optimum formulation process parameter was determined.The results show that the optimized sterilization temperature was 70⁷5oC,the optimizing recipe of variety sauce was 2.0%monosodium glutamaet,0.3%citric acid,0.4%high fructose corn syrup and 0.03%ethyl-maltol.