Effects Of Cold Break Process And Hot Break Process On Quality Change Of Tomato Paste During Storage

Objective:At present,there are two major processing techniques for tomato pastes,namely,cold break process and hot break process.There are great differences in indexes of products obtained from different processing techniques.As for storage,non-enzymatic browning will occur during tomato pastes storage,resulting in discoloration of products,reduction of nutritional quality and flavor,and shortening of storage cycle.Therefore,it is quite necessary to solve the problem of non-enzymatic browning of tomato pastes during storage.Method:In this experiment,major reasons for the non-enzymatic browning of tomato pastes with hot break and cold break during storage were investigated by measuring the related indexes of non-enzymatic browning in hot break and cold break.Besides,the effect of hot break and cold break was also explored on non-enzymatic browning of tomato pastes.The present study provide a theoretical basis for improving the shelf life of tomato pastes products.In our study,tomato pastes were stored for 12 months at 20? and 35? to explore the effect of cold break and hot break on the non-enzymatic browning during storage.Consequently,by determining the changes of chemical substances that might cause color changes of tomato pastes with cold break and hot break during storage,the main reason for dark-colored tomato pastes was obtained.Conclusion:1.The parameters and variables related to browningand color changeswere analyzed intomatopastes with cold break and hot break during storage at 20? and 35?.Corresponding results showed that Maillard reaction and Vc oxidation decomposition were mainly responsible for the non-enzymatic browning of tomato pastes during storage.The color change of tomato pastes with composite aluminum foil under cold break and hot break was positively correlated with storage temperature and duration.Furthermore,values of chromatism and browning index were increased continuously,where as brightness(L*),redness(a*)and yellowness(b*)were decreased steadily with the prolongation of storage duration and the increase of storage temperature.Storage at 35? had a significant impact on the color change of tomato pastes,and the browning of tomato pastes with cold break was significantly higher than those with hot break.2.By measuring chemical composition changes of the two types of tomato pasteswithcold break and hot break under different temperature conditions,an exploration was made concerning reasons for non-enzymatic browning of the two tomato pastes.It was found that the main product of Maillard reaction was 5-HMF,which was the decisive factor affecting the browning index of tomato pastes during cold break and hot break.Maillard reaction and Vc oxidation decomposition were the major causes of non-enzymatic browning of tomato pastes during storage.However,lycopene had little contribution to the color change of two kinds of tomato pastes,which was not the predominant factor for color change of tomato pastes.3.The simulation system was constructed by the two tomato pastes with cold break and hot break,which was then detected every 10 days.It was further confirmed that Maillard reaction and Vc oxidation decomposition were the main causes of non-enzymatic browning of tomato pastes during storage.The contribution of glucose,fructose and sucrose was further determined in non-enzymatic browning of tomato pastes with composite aluminum foil under cold and hot break,with the order of glucose<sucrose<fructose.Therefore,the degradation of fructose was the main source of 5-HMF in cold break and hot break tomato pastes.Furthermore,tomato pastes with cold break produced more 5-HMF due to low processing temperature and more fructose than that with hot break,which was the direct cause of the rapid change of browning in tomato pastes with cold break.