Shelf-life Estimation Of HHP-treated Pickled Pepper

As an effective cold sterilization technology, High hydrostatic pressure technology can reduce some unexpected phenomenon like texture softening, color burn, which is an effective way to maintain the original taste of Sichuan pickles in sterilization process. During storage time, sensory quality of Sichuan pickles would decline influenced by changes of temperature, humidity, illumination intensity. Therefore, it is important to use of feasible means to explore the quality change rule and forecast shelf-life of Sichuan pickles.In this experiment, we analysis the changes of pickled pepper’s quality during storage time to set up Arrhenius equation, then to build the shelf-life prediction model of HHP-treated pickled peppers. We find the direction index in pH, total acid, color index and hardness data of HHP-treated pickled peppers, as pasteurized processing pickled peppers for comparison at20℃. Then the model parameters of Arrhenius equation confirmed by high temperature accelerated test at20℃,30℃,40℃,50℃and60℃. On this basis, shelf-life prediction model of HHP-treated pickled peppers can be deduced. Using this model the shelf life of HHP-treated pickled peppers storied at4℃can be forecasted.Test result as follows:During storage time, pH, total acid, color index and hardness data had all changed in different degrees. These changes of four index of HHP-treated pickled peppers and pasteurized processing pickled peppers had no significant difference (p<0.05). the CV of pH, total acid(TA), hardness data (HV), L*, AE and C*are-0.926,-0.005,-0.993,-0.998,0.977,0.986. Relative degree of variation are pH<HV<b*<TA<L*<a*. The CV of HHP-treated pickled peppers is3.92%, which means the stability of hardness data is very well.At20℃, the pH of pickled peppers on a declining curve, linear regression fitting equation of R2is less than0.9. Total acid fluctuating changed which can’t be obvious linear correlation with time. Hardness data of HHP-treated pickled peppers declined 6.75kg/cm2,falling range is63.8%, and pasteurized processing pickled peppers are5.89kg/cm2and59.0%, hardness data can be analysis by exponential equation, and both of the R2are greater than0.95,and the correlation index is-0.993. L*,a*,△a*,△E,C*also have a good linear correlation between storage time, all these regression coefficients are greater than0.95(p<0.01). L*is negative correlation with storage time,however a*,△a*,△E,C*are positive, b*and△b*have no correlation with storage time. Combine with CV of four index, hardness data chosen as direction index.High temperature accelerated test at20℃,30℃,40℃,50℃and60℃get the rate constants are-0.0179,-0.0262,-0.0645,-0.1144,-0.287. Using linear equation fitting Ink and1/T can get the Arrhenius curve (R2=0.9766), fitted equation is In and Ea=56.78J/mol; k0=1.95×108. The relationship between hardness variation and storage time can be described by an equation: k=1.95×108exp(-56.78/RT).Bo of HHP-treated pickled pepper is10.576kg/cm2,and the B is5.5kg/cm2which got from the consumer acceptance data. The logarithmic curve fitting equation of different storage temperature and storage time is y=72.24e-00702x, R2=0.9848, which is the shelf-life prediction model of HHP processing pickled peppers, x for storage temperature (℃), y for shelf life.Using the shelf-life prediction model of HHP-treated pickled peppers calculate the shelf-life of HHP-treated pickled peppers at4℃is130d and the real shelf life is132～136,and the error is3.65%.