Study On Debittering And Temperature-Pressure Synergistic Sterilization Of Lonicera Caerulea Berry Juice

Lonicera caerulea is rich in nutrients and has a high juice yield.It is a good raw material for making berry juice,but it has not been well developed and utilized because of its bitter taste.At present,there is no domestic research on debittering of Lonicera caerulea berry juice.Adsorption debittering is a commonly used debittering method with simple operation and low cost,but improper debittering parameters will lead to poor debittering effect and reduce the content of nutrients in berry juice.Therefore,the optimization of the debittering process should not only consider the effect of debittering,but also minimize the loss of nutrients.The berry juice after debittering only guarantees deliciousness,and its safety in eating depends on good sterilization technology.Ultra-high pressure sterilization is a popular sterilization technology,but it has the disadvantages of incomplete sterilization and high requirements for sterilization equipment.The temperature-pressure synergistic sterilization technology is a new type of combined sterilization technology based on ultra-high pressure sterilization,which can be effective kill the microorganisms in the juice,and maintain the original nutrition and flavor of the juice,reduce the loss of the instrument and reduce the cost.Consequently,in this study,HPLC-MS/MS and activated carbon were used to analyze and adsorb the bitter substances in the Lonicera caerulea berry juice,and combined with the temperature-pressure synergistic sterilization technology,we are committed to preparing a delicious and safe berry juice,so as to promote the development and utilization of Lonicera caerulea resources.The main results are as follows:(1)By HPLC-MS/MS,three bitter substances in Lonicera caerulea berry juice were detected and analyzed,including loganin acid,loganin and secologanin,all of which belong to iridoid terpenoids.The total peak area in the HPLC was 5.03×10~5.(2)Taking active carbon as the debittering agent,the debittering effect was positive related to the amount of debittering agent(4%,5%,6%,7%,8%).The amount of debittering agent had no obvious influence on the total phenol content and anthocyanin content.When the debittering temperature was40?,the debittering effect was obvious,under this condition,the anthocyanin content and total phenol content were slightly decreased.The debittering effect was positively correlated with the debittering time(20 min,35 min,50 min,65 min,80 min),and the total phenol content and anthocyanin content were negatively correlated with the debittering time.The results of orthogonal experiment showed that the best debittering effect was achieved by adding 6%debittering agent,debittering 65 minutes and45?,under this condition,the total peak area of the bitter substance was 3.08×10~5.After debittering,the p H of berry juice increased,but the anthocyanin content,polyphenol content,Brix and color did not change significantly.(3)The results of heat treatment at 60?for 30 min showed that the microbial lethality was 1.5 lg;Ultra-high pressure treatment achieved the best sterilization effect at 600 MP and 3 min,and the lethal rate of microorganism was 1.95 lg When the temperature-pressure cooperative sterilization treatment conditions were 300 MP 3 min-60?5 min/8 min,400 MP 3 min-50?5 min/8 min and 400 MP 3min-60?3 min/5 min/8 min,the same best sterilization effect was achieved,and the microbial lethal rate reached 2.78 lg.(4)Under the storage conditions of 4?and 25?,the heat sterilization group and 300 MP 3min-60?5 min/8 min sterilization group did not reach the storage period of 35 days.Under the condition of 400 MP 3 min-50?5 min/8 min,400 MP 3 min-60?2 min/5 min/8 min,the temperature-pressure synergistic sterilization group could reach 35 days of food safety storage period.(5)Different storage temperature(4?,25?)had no significant effect on the content of total phenols,p H and Brix,but low temperature was beneficial to the stability of anthocyanin and the inhibition of browning.There was no significant effect on the total phenol,anthocyanin,p H,Brix and browning degree of juice under different temperature-pressure synergistic sterilization conditions(400MP 3 min-50?5 min/8 min,400 MP 3 min-60?2 min/5 min/8 min).(6)During the storage period,the total phenol content increased first and then decreased.The anthocyanin content decreased first and then increased at 4?,and decreased first and then maintained stable at 25?.The browning degree first increased and then stabilized.The p H and Brix of berry juice did not change during storage.