Effect Of Two Different Cold Shock Treatments On Quality Of Hupingzao Jujuba With Different Maturity Levels During Storage

In this experiment,three maturity levels hupingzao jujuba were used as test materials.Cold-shocked hupingzao jujuba at white ripening,mid-red and full red stages were used with 0 ~ 1 ? distilled water and acidic electrolyzed functional water(AEW).Screen for appropriate cold shock conditions.Treat the date fruits with the selected cold shock conditions,and then store them in an environment of normal temperature,and periodically measure their quality and physiological and biochemical indicators(including: hardness,weight loss,peel color index,pulp color difference,vitamin C content,respiratory rate,MDA content,TSS content,TA content,SOD activity,PPO activity,POD and amylase activity),in which the hupingzao jujuba in the full red stage did not involve the peel color index and pulp color difference.Finally,the cold-shock treatment conditions with the best storage quality of the three maturity levels hupingzao jujuba in the white maturity stage,mid-red stage and full red stage were obtained.It provides a certain theoretical basis for the cold-shock treatment on the storage and freshness of hupingzao jujuba with different maturity,and also provides a certain theoretical basis for the fresh-keeping of fresh hupingzao jujuba by electrolyzed functional water cold shock treatment.The results showed that:1.Used 0 ~ 1 ? AEW and distilled water to cold shock three maturity levels hupingzao jujuba at different times.The results showed that the optimal cold-shock treatment time of the white ripening hupingzao jujuba under two kinds of cold shock treatment was 60 minutes;the optimal cold-shock treatment time of the mid-red hupingzao jujuba under two kinds of cold shock treatment respectively,AEW cold shock treatment for 80 minutes,distilled water cold-shocked for 60 minutes;the optimal cold-shock treatment time of the full-red hupingzao jujuba under two kinds of cold-shock treatments are AEW cold shock treatment for 100 minutes,and distilled water for 80 minutes.2.By using two different cold-shock treatment methods of AEW and distilled water to treat hupingzao jujuba with different maturity levels,it was found that cold-shock treatment could delay the post-maturity changes of hupingzao jujuba with different maturity levels.The effect of AEW cold shock treatment on the white ripening period of hupingzao jujuba was most significant.Among them,the peak of respiration was delayed by nearly 20 days,the peak of PPO activity was 20% lower than that of the control group,and the antioxidant enzyme activity was higher and better.It maintains the hardness and nutritional content of hupingzao jujuba in the white ripening period,has a certain inhibitory effect on the post-ripening senescence of hupingzao jujuba in the white ripening period.The cold shock treatment effect of distilled water on white ripening hupingzao jujuba is inferior to AEW,but it also has a certain fresh preservation effect.3.The two groups of cold shock treatment could extend the storage time of hupingzao jujuba in the mid-red period and full red period to a certain extent.At the end of storage,acidic electrolyzed functional water cold shock treatment inhibited the respiration rate of the hupingzao jujuba in the mid-red period by11.8%,the relative reduction in MDA content was 17.1%,the SOD activity increased by 13.8%,and the amylase activity decreased by 20.2% The respiration rate of hupingzao jujuba in the whole red period was suppressed by 10.2%,weight loss was reduced by 7.6%,and POD activity was increased by 12.3%.The cold shock treatment of distilled water inhibited the respiration rate of the jujube jujube in the half-red period by 11.0%,the relative reduction of MDA content by 15.2%,the SOD activity increased by 8.8%,and the amylase activity decreased by 13.3%.Respiratory rate was suppressed by 5.3%,weight loss was reduced by 5.4%,and POD activity was increased by 7.4%.