Study On The Technology And Mechanism Of Key Aroma Compounds Retention In Tomato Juice

Tomato juice is rich in nutrition and unique in flavor,which is popular with consumers.However,the thermal treated sterilization is widely used in tomato juice on the market.Which limit the circulation of tomato juice because of flavor lost.In this study,the characteristic aroma components of tomato juice were screened out.And the aim of this research was to focusing flavor preservation technology on tomato juice.This paper mainly makes the following progress:1.In this study,aroma components of tomato juice were order by the value of OAV.It was found that five of the top ten aroma compounds in tomato juice came from the lipoxygenase?LOX?pathway.Therefore,there were 6 aroma compounds which come from LOX pathway as followed: hexanal,cis-3-hexenal,trans-2-hexenal,hexanol,cis-3-hexenol and tran-2-hexenol.And we defined these six as the key aroma components of tomato juice.2.To establish a rapid and simultaneous of GC method for key aroma compounds in tomato juice.The detection conditions of tomato juice by GC were selected through the single factor experiments.The effects of HP-5,DB-1MS,CP7511 and DB-WAX on the separation of characteristic flavor substances in tomato juice were compared.It was found that DB-WAX had the best separation of characteristic flavor components in tomato juice,and the separation degree of each peak was greater than 1.5.The standard curve of characteristic aroma components of tomato juice was established by external standard method.The R2 of the standard curve was greater than 0.99,and the linear fitting degree was good.The precision of GC as following,the intra-day precision was 2.13%,and the intra-day precision was 4.66%.3.To study the effects of hydrostatic high-pressure,p H,metal ions and linoleic acid maintenance technology on the key aroma components of tomato juice.The results showed that the flavor of tomato juice after hydrostatic high-pressure treatment was better than the control;p H7 treatment effectively maintained the key aroma components of tomato juice,the content of which was 5.98 times higher than control;ions of Fe³⁺ treatment effectively increased the key aroma components of tomato juice,the content of which was 7.12 times higher than control;linoleic acid and linoleic acid treatment increased the OAV of the key aroma components of tomato juice,among which linoleic acid and linoleic acid treatment increased the aroma activity.The addition of linoleic acid and linolenic acid increased the total amount of OAV of key components by 144% and 70.9%,respectively.Fe³⁺ and linoleic acid combined maintenance technology effectively maintained the key flavor components of tomato juice,and the sum of OAV of key characteristic flavor components increased by 10.4times compared with control.4.To study the effects of hydrostatic high-pressure,p H,metal ions and linoleic acid maintenance technology on key enzymes in flavor regulation of tomato juice.It was found that hydrostatic high-pressure,p H,metal ions and linoleic acid maintenance technology all affect the content of aroma components in tomato juice by regulating the activities of LOX,ADH and AAT,which were the key enzymes in LOX pathway.After ultra heat treated sterilization,the key enzymes in tomato juice were completely inactivated,but some enzymes were retained after hydrostatic high-pressure treatment;the activity of LOX was slightly decreased in p H7 + HHP group,and the activity of AAT was completely inactivated.There was no effect of the activity of LOX,but the activity of AAT was completely inactivated in the Fe³⁺ + HHP group.In order to increased the accumulation of C6 aldehyde/alcohol,the intermediate product of LOX pathway,by inactivating AAT.Linoleic acid as the substrate of LOX pathway,adding linoleic acid can naturally increase the amount of key aroma components in tomato juice.The combined treatment is a combination of Fe³⁺ and linoleic acid,which can improve the content of key aroma components in tomato juice by regulating substrate and enzyme activity.5.To evaluate the effect of combined preservation technology on storage stability of key aroma components in tomato juice.It was found that the proportion of key aroma components of tomato juice was well maintained with the prolongation of storage at 4?.In three months,compared with TP tomato juice,the OAV value of key aroma components in tomato juice treated with Fe³⁺ ion and linoleic acid was 9.8 times higher in the first month,9.2 times higher in the second month and 10.9 times higher in the third month.The key aroma components of tomato juice were obviously improved,and the flavor of tomato juice could be well maintained during storage.