超高压和热杀菌对草莓浊汁及清汁品质的影响

Effect of High Hydrostatic Pressure and Thermal Sterilization on Quality of Cloudy and Clear Strawberry Juice

研究超高压（常温下,550MPa,处理5min）、热处理（中心温度90℃,处理1min）及高温短时杀菌（110℃,处理8.6s）对草莓浊汁和清汁品质的影响。结果表明：（1）经超高压处理后,草莓浊汁的黏度、果胶含量和浊度无显著变化,悬浮稳定性显著增加;而热处理和高温短时杀菌处理后,浊汁的黏度和果胶含量显著减小,浊度增大,悬浮稳定性降低,但高温短时杀菌组好于热处理组;（2）草莓浊汁和清汁经超高压处理后Vc分别损失11.09%和13.59%,而热烫结合超高压处理后分别损失7.75%和10.73%;热处理和高温短时杀菌组浊汁和清汁中Vc的损失率高于超高压组,分别为28.86%～38.89%和20.38%～29.02%;（3）超高压处理对草莓浊汁和清汁的单体花色苷、聚合色度及总酚含量、DPPH和FRAP抗氧化活性没有显著影响;热处理和高温短时杀菌处理后草莓浊汁中的花色苷总量分别损失了3.89%～4.63%和7.46%～8.02%,而清汁中分别损失了5.97%～6.02%和8.09%～9.20%;聚合色度和聚合色度百分比增加,总酚含量无显著变化,抗氧化活性显著降低;（4）超高压处理对草莓浊汁和清汁的亮度L＊、红值a＊、黄值b＊、彩度C＊及色调角hab均没有显著影响;而热处理和高温短时杀菌处理使L＊值和a＊值均显著减小。

Effects of high hydrostatic pressure （550 MPa/5 min/ambient temperature）, thermal process （90 ℃/1 min） and high temperature with short time （110 ℃/8.6 s） treatment on the quality of cloud- y and clear strawberry juice were investigated. The viscosity, pectin, cloud and cloudy stability of cloudy juice showed no significant change after HHP treatment,while those of TP and HTST juice significantly decreased. Ascorbic acid in HHP cloudy and clear juice reduced by 11.09% and 13.59%, and it decresaed by 7.75% and 10.73% in juices treated by HHP combined with blanching. The loss rates of ascorbic acid in TP and HTST-treated cloudy and clear juice are higher,which are 28.86%-38. 89% and 20.38%-29.02% ,respectivity. Monomeric and polymeric anthocyanins,total phenols,DPPH and FRAP in HHP cloudy and clear juice well retain. The monomeric anthocyanins and antioxidant ac tivity of juices treated by TP and HTST significantly decrease,while the PC and PPC significantly in- crease, and total phenols do not change. The color parameters including L＊ ,a＊ ,b＊ ,C＊ and hab exhib ire no significant change,and the L＊ and a＊ values of TP and HTST juices significantly decrease.