超高压及超高温瞬时灭菌对西瓜饮料品质的影响

Effect of Ultra High Pressure(UHP) and Ultra High Temperature(UHT) Sterilization Treatments on the Quality of Watermelon Beverage

研究400 MPa不同加压时间与超高温瞬时(ultra high-temperature,UHT)灭菌对调配西瓜饮料品质的影响。以未经灭菌的调配西瓜饮料为对照,运用流变仪、电子鼻等设备研究不同处理西瓜饮料菌落总数、内源酶、流体类型、黏度及风味的变化。结果表明:加压时间越长,对菌落总数抑制、多酚氧化酶及果胶甲酯酶钝化作用越强;西瓜汁假塑性越明显;且风味与对照组差异越明显;400 MPa、20 min超高压处理与UHT处理对调配西瓜饮料部分品质影响相似,但在保持西瓜饮料风味及色泽等方面优于UHT处理。

The effect of ultra high-temperature(UHT) sterilization and different ultra hydrostatic pressure treatments with a dwell time ranging from 20 to 60 min on the quality of watermelon beverage was investigated in this paper. All investigated treatments could significantly reduce total bacterial count, and PME and PPO activities compared with the control(P < 0.05).Longer treatment time resulted more inactivation of PME and PPO. The control was a typical non-Newtonian pseudoplastic fluid, and its flow behavior was not affected by dwell time. As the dwell time was extended, the viscosity increased, whilethe aroma became worse. UHT and high pressure treatment at 400 MPa for 20 min had the same effect on the quality, but the watermelon beverage treated at 400 MPa for 20 min had better flavor and color.