Effect Of High-pressure Pretreatment On Quality And Safety Of Fermented Ruditapes Philippinarum Sauce

In the fermentation of shellfish,the microbial contamination of shellfish will affect the food safety of fermented products,but the use of traditional heat treatment for pre sterilization will change the quality of shellfish,thus changing the quality of fermented products.As a nonthermal sterilization technology,high-pressure technology has little effect on the quality of shellfish.Therefore,this paper compared and explored the effects of high-pressure pretreatment,heat pretreatment and manual shelling on ruditapes philippinarum shelling effect,sterilization effect and quality,explored the rapid fermentation technology of ruditapes philippinarum,and explored the effects of different pretreatments on the safety and quality of fermented ruditapes philippinarum sauce.The main results were as follows:(1)The effects of high-pressure treatment,heat treatment and manual shelling on shelling effect,germicidal efficacy,water content,pH value,color difference,texture and appearance of clam were studied,and the optimal high-pressure pretreatment parameters were determined.The results showed that 400 MPa and 6 min were selected as the parameters of high-pressure treatment,which had better germicidal effect on ruditapes philippinarum,and the yield was significantly higher than that of heat treatment(P < 0.05).The results showed that the total bacterial count of clam meat decreased from 4.54 lg CFU/g to the detection limit(< 1.0 lg CFU/g)under 400 MPa for 6 min,the yield increased from 23.89% to 36.8%,and the yield of heat treatment was 28.42%.After heat treatment,the moisture content decreased significantly(P < 0.05),while the high-pressure treatment had no significant effect on moisture content(P >0.05),and had little effect on appearance and pH value.(2)The ruditapes philippinarum pretreated by high-pressure was hydrolyzed by papain and flavor protease,and then fermented by pediococcus pentosaceus.The fermentation technology was optimized by orthogonal experiment,which was based on sensory evaluation and free amino acid content.Based on the results of single factor experiment,the sensory evaluation and the content of amino acid nitrogen were used as indexes to carry out the orthogonal experiment.The results showed that the optimal solution was 6% inoculum,6% salt,36 h fermentation time and 35 ? fermentation temperature.(3)The effects of high-pressure sterilization pretreatment,heat pretreatment and manual shelling on the total acid,pH value,volatile basic nitrogen,putrescine and cadaverine of fermented ruditapes philippinarum sauce were compared.The results showed that the contents of volatile basic nitrogen,putrescine and cadaverine were decreased by high-pressure pretreatment and heat pretreatment.The total acid content of the fermented sauce was increased gradually and the pH value was decreased rapidly in the early stage of fermentation,which ensured the safety of fermentation.At 36 h,the contents of volatile basic nitrogen in highpressure group,heat treatment group and control group were 65.15 ± 2.71,43.73 ± 2.54 and79.43 ± 2.81 g/100 mL respectively;the putrescine content in high-pressure group and heat treatment group were decreased from 0.64 mg/L of control group to the detection limit,and the cadaverine content were decreased from 140.96 mg/L of control group to 0.83 and 0.79 mg/L.(4)The effects of high-pressure sterilization pretreatment,heat sterilization pretreatment and manual shelling on amino acid nitrogen,nutritional components,sensory evaluation and antioxidant activity of fermented ruditapes philippinarum sauce were compared.The results showed that high-pressure pretreatment had no significant effect on the content of amino acid nitrogen in fermented sauce,and could improve the sensory evaluation.Heat pretreatment slowed down the increase of amino acid nitrogen,and different pretreatment methods of fermented sauce had strong antioxidant capacity.At 36 h,the content of amino acid nitrogen in high-pressure group,control group and heat treatment group was 0.68 ± 0.01,0.68 ± 0.01,0.42± 0.02 g/100 mL;after high-pressure pretreatment,the total score of sensory evaluation was increased from 13.20 ± 1.10 to 18.20 ± 1.48;when the mass concentration was 10 g/100 mL,The DPPH free radical scavenging rates of high-pressure group,heat treatment group and control group were 92.20 ± 0.82%,95.61 ± 0.21% and 93.24 ± 0.63%,respectively.