蓝莓复合果泥超高压和热杀菌的比较分析

Comparative Analysis of Ultra-high Pressure and Thermal Sterilization of A Blueberry-strawberry-apple Puree

以蓝莓、草莓和苹果为原料,通过感官评价分析,研制出一款蓝莓复合果泥。利用超高压(UHP)和热杀菌(TS)处理果泥,分析处理前后和4℃贮藏40 d内其微生物、理化指标、色泽、花青素、香气和流变特性的变化。结果表明,两种处理后果泥菌落总数、大肠菌群和霉菌均未检出,贮藏40 d时仍符合食品标准限量。pH值在处理后和贮藏期内都显著降低(P<0.05)。可溶性固形物在UHP处理后无显著变化(P>0.05),TS处理后显著增大(P<0.05),贮藏结束时均为7.80°Brix。TS处理后果泥花青素含量显著降低(P<0.05),UHP组无显著变化(P>0.05),贮藏期间,UHP组花色苷含量显著高于TS组。UHP和TS组果泥贮藏期间ΔE最大值分别为1.26和3.47,TS组果泥贮藏时出现明显颜色变化。电子鼻结果表明UHP比TS能更好地保留果泥的香气成分。流变仪结果表明UHP组果泥贮藏期间具有更好的稳定性。综上,UHP对蓝莓复合果泥的品质保存效果好,是一种适用于蓝莓复合果泥加工的杀菌方式。

Using blueberries,strawberries and apples as the raw materials,a blueberry-strawberry-apple compound puree was developed through sensory evaluation.The puree was treated by ultra-high pressure(UHP)and thermal sterilization(TS),respectively.The changes in microorganisms,physical and chemical indicators,color,content of anthocyanins,aroma and rheological properties of the puree before and after the treatment and during 40 days of storage at 4℃were analyzed.The results showed that the total number of bacterial colonies,coliform and mold were not detected in the purees immediately after the two treatments,and the counts of these microorganisms still met the food safety standard limit after 40 days of the storage.The pH decreased significantly after either treatment and during the storage(P<0.05).The total soluble solids did not change significantly after UHP(P>0.05),but increased significantly after TS(P<0.05),with both reaching 7.80°Brix at the end of storage.After TS,the anthocyanin content in the puree decreased significantly(P<0.05),with insignificant change in the UHP treated samples(P>0.05).During the storage,the anthocyanin content of the UHP treated puree was significantly higher than that of TS group(P<0.05).The maximumΔE values of UHP and TS were 1.26 and 3.47,respectively,indicating that TS could cause significant color changes in the puree during storage.The results of the electronic nose testing showed that UHP could better retain the aroma components of the puree than TS.The analysis by the rheometer showed that the puree after UHP had better stability during storage.In summary,UHP could better maintain the quality of the blueberry-strawberryapple puree,which was a proper sterilization method for the processing of the puree.