Efect Of Thermos-Sonication Sterilization On The Quality Of NFC Orange Juice During Low-Temperature Storage

NFC Juice(Not from Concentrate Juice)is a product that is directly sterilized and canned after the fruit is squeezed.It has a rich and refreshing taste with a wide consumer group.NFC juice must go throμgh the important link of sterilization in the processing process,and traditional pasteurization is usually used.However,pasteurization destroys fruit juice quality to a certain extent,such as the destruction of nutrients and the increase in browning.Therefore,the development of new sterilization technology can not only meet the sterilization requirements,and ensure product storage,but also reduce the damage to the quality of juice products,and even improve the quality of juice products,which is of great significance and has great application prospects.Thermo-sonication Sterilization(TS)can achieve a better sterilization effect at a lower temperature and improve the quality of the juice in terms of perception,aroma,and nutritional quality.In this paper,NFC orange juice was taken as the research object,S.typhimurium,Escherichia coli,and Listeria monocytogenes were the most representative and most representative in food safety issues selected.Bacteria with public safety significance are the reference objects for sterilization strength.First,the sterilization parameters of Thermo-sonication Sterilization are optimized,and then the impact of optimized Thermosonication Sterilization on the conventional physical and chemical properties,aroma,flavor,and nutritional indicators in NFC orange juice processing and storage has studied.The main results are as follows:(1)In NFC orange juice,with the increase of ultrasonic time,power,and temperature,the sterilization effect on S.typhimurium,Escherichia coli,and Listeria monocytogenes was continuously enhanced,and the temperature had the greatest impact on the inactivation effect.Among them,Listeria monocytogenes was the most resistant to temperature and ultrasound.To ensure food safety,the inactivation effect of pathogenic bacteria recommended by the US FDA must be greater than 5 log CFU/m L.With this as the goal,the optimal sterilization conditions for S.typhimurium recommended by response surface analysis were 7 minutes,600 W,57℃;The best sterilization conditions for Escherichia coli were 7 minutes,600 W,57℃;the best sterilization conditions for Listeria monocytogenes were 12.3 minutes,600 W,60℃.Finally,13 min,600 W,and60°C were selected as the processing parameters for combined Thermo-sonication sterilization.(2)Compared with traditional pasteurization,there was no significant difference in p H,SSC,and TA of NFC orange juice treated by thermos-sonication sterilization during storage.However,there were significant differences in color difference and browning index,and the color was brighter yellow in appearance;limonin and the formation of bitter substances such as nomilin had been well controlled;NFC orange juice had a high content of total phenols,flavonoids,and Vc,and has strong antioxidant activity.Therefore,thermos-sonication sterilization was beneficial for maintaining and improving the quality of NFC orange juice during cold storage.(3)PCA principal component analysis found that the aroma and flavor of thermossonication sterilization NFC orange juice was very different from pasteurized NFC orange juice,and got more scores from the tasters.Both sterilization methods of NFC orange juice are rich in odorous substances through GC-MS.Compared with pasteurization,the juice products produced by sound and heat combined sterilization have a more natural flavor and less degradation of nutrients.(4)The in vitro simulated digestion of NFC orange juice showed that pepsin and gastric acid can promote the release of phenols,flavonoids,and antioxidant substances.Trypsin and bile could further promote the release of phenolics and antioxidants,but degrade flavonoids.Compared to traditional pasteurized NFC orange juice,the thermossonication sterilization NFC orange juice samples released more phenols,flavonoids,and antioxidant substances after reaching the intestinal tract,which was more nutritional for healthy.