不同灭菌处理对蓝莓汁品质的影响

以蓝莓汁为原料,研究目前果汁饮料生产较多的巴氏、超高温瞬时和微波3种灭菌方式对蓝莓原汁微生物和理化性质及感官评价的影响。研究表明:3种灭菌方式均能达到商业无菌的要求,对蓝莓汁的pH、可溶性固形物和总酸含量无影响;巴氏灭菌能有效保持蓝莓汁的悬浮稳定性、色泽和花色苷含量,但巴氏灭菌样的DPPH自由基清除率低于微波灭菌样,微波灭菌蓝莓汁的DPPH自由基清除率高达88.24%,仅比对照样低0.6%;采用定量描述分析法对灭菌样进行感官评价,巴氏灭菌一定程度上抑制了蓝莓汁酶促褐变,但破坏了天然色泽、香味,产生不宜的蒸煮味,后感明显减弱。微波灭菌则最大限度地保持了食品的色泽、香、味。因此,微波灭菌处理对蓝莓汁的灭菌效果最好,能够较好保留蓝莓汁的理化特性、感官品质和抗氧化活力。

Effect of Sterilization Treatments on the Quality of Blueberry Juice

Microorganisms, physical-chemical properties and sensory evaluation of blueberry juice by pasteurization, UHT and microwave treatment were investigated . Results indicated that the three treatments all met thecommercial sterilization requirements. The pH value, total soluble solid and total acid content of blueberry juice had no changes for the samples treated by the three methods. Pasteurization effectively maintained the suspension stability, color and anthocyanins content of blueberry juice. And the free radical scavenging ability against DPPH of the Pasteuring samples was lower than that of the microwave treatment, where the free radical scavenging ability against DPPH of microwave treatment was up to 88.24%. The sensory evaluation showed that the blueberry juice by microwave treatment was closest to the control sample than the other treatments, especially in color and aroma. Therefore, microwave treatment can effectively inactivate the microorganisms and keep the physical-chemical properties, sensory evaluation and antioxidant activity of blueberry juice.