超声波联合紫外杀菌在椰子水中的应用

Application of Ultrasound Combined with Ultraviolet Sterilization to Coconut Water

摘要:

该研究探讨超声波和紫外联合处理对椰子水中微生物的杀灭效果以及对贮藏期椰子水品质的影响。以紫外、超声波单独处理作对比，探究联合处理对椰子水中大肠杆菌O157:H7的杀灭效果。同时对贮藏期椰子水中糖含量、酶活性和挥发性化合物进行检测和分析，探究联合处理对贮藏期椰子水品质的影响。实验结果表明，超声波与紫外联合处理杀菌效果最佳，采用该技术对椰子水处理180 s后（超声波，频率20 000 Hz，功率200 W；紫外，功率8 W，波长253.7 nm，照射距离6 cm），大肠杆菌O157:H7计数降低8.31个对数值。在贮藏实验中，29种挥发性化合物的峰值面积百分比未发生明显变化，理化指标保持稳定，且贮藏12 d后的椰子水总色差值不超过1。该研究证明联合处理180 s是椰子水杀菌的较优条件，因其协同效应大幅提升了杀菌效果，为超声波联合紫外杀菌技术的开发与应用提供科学的理论依据。

Abstract:

The sterilization effects of the ultrasound (US) and ultraviolet (UV) combined treatment on microorganisms in coconut water and on the quality of coconut water during storage were investigated in this study. The sterilization effect of the combined treatment on the Escherichia coli O157:H7 in coconut water was compared with those of UV alone and US alone. Meanwhile, the sugar content, enzyme activity and volatile compounds in the coconut water during storage were determined and analyzed to explore the effect of the combined treatment on the quality of coconut water over storage. The experimental results showed that the combination of US and UV treatment had the best sterilization effect. After the combined treatment on coconut water for 180 s (US, frequency 20 000 Hz, power 200 W; UV, power 8 W, wavelength 253.7 nm, distance 6 cm), the count of Escherichia coli O157:H7 decreased by 8.31 log10 CFU/mL. During storage t, the peak area percentages of 29 volatile compounds did not change significantly; the physicochemical indexes remained stable, and the total color difference value of the coconut water after 12 days of storage did not exceed one. The study demonstrated that the combined treatment for 180 s was a better approach for coconut water sterilization, because its synergistic effect greatly improved the sterilization effect, which provides a scientific theoretical basis for the development and application of the ultrasound and ultraviolet combined sterilization technology.