2450MHz频率微波加热条件下番茄汁杀菌特性的研究

Study on Characters of Sterilization of 2450-MHz Microwave Heating for Tomato Juice

本研究选用番茄汁作为研究对象,使用频率为2450MHz的微波进行加热,以时间、功率以及样品的含糖、含盐浓度作为参数,考察样品的升温模式、杀菌效果以及番茄汁的品质指标。本研究中,热效应为微波致死微生物的主要原因。添加糖和盐的样品,经微波处理后,微生物的致死率发生显著变化。微波处理后的样品,L*(亮度)增加,a*(红度)下降,番茄红素测得值增加,较传统巴氏杀菌更好的保留了VC。

As a representative of liquid foods, tomato juice was heated by 2450-MHz microwave. Effect of microwave power on heating rate on tomato juice sample was intestigated, as well as sterilization effects of different microwave powers and time and concentrations of sucrose and NaCl in the sample, and the physicochemical indexes of the tomato juice sterilized by different heating methods were determined. It was found that thermal effect is the most important cause of microwave sterilization. The sterilization effect of microwave heating is greatly impacted by the addition of sucrose and NaC1 in the sample. More microbes survive in the tomato juice which contains sucrose and NaCl. After microwave heating, the L＊ value of the tomato juice increases notably while the a＊ value decreases. Compared with traditional heating method, the microwave heating method can retain contents lycopene and vitamin C better.