常压低温等离子体对鲜切胡萝卜表面金黄色葡萄球菌的杀菌效果及品质影响

Effect of atmospheric Pressure low-temperature plasma on sterilization rate of staphylococcus aureus on sliced carrot surface and quality attributes

为了解决鲜切胡萝卜微生物安全问题,采用常压低温等离子体(APLTP)对鲜切胡萝卜表面进行杀菌处理,研究ATLTP对鲜切胡萝卜表面金黄色葡萄球菌的杀菌效果。在单因素实验的基础上,利用响应面分析方法建立金黄色葡萄球菌杀菌率的二次项数学模型,利用模型对处理电压、处理时间和处理极距及其相互作用进行分析。结果表明:ATLTP能有效杀死鲜切胡萝卜表面的金黄色葡萄球菌,各因子对杀菌率的影响大小依次是处理电压>处理极距>处理时间,最佳工艺条件为处理电压170 V,处理时间5 min,处理极距2.5 cm,此时杀菌率高达92.35%,与预测值92.26%接近,提高了鲜切胡萝卜食用安全性。APLTP处理前后胡萝卜的水分含量、可溶性固形物、p H值、色泽、相对电导率、丙二醛及Vc含量变化均不显著(P>0.05),较好的保持了胡萝卜的水分、糖度、酸度和颜色,同时维持了细胞膜的通透性及抗氧化能力。

In order to solve the problem of microbial safety on the cut surface of fresh carrot,the surface was sterilized by atmospheric pressure low-temperature plasma（ ATLTP） to study sterilization effect on staphylococcus aureus. On the basis of single factor test,a quadratic polynomial mathematical model for the sterilization rate of staphylococcus aureus was established by response surface methodology to analyze the effects of processing voltage,processing time and processing pole distance,and their pairwise interactions. The experimental results showed that staphylococcus aureus on the fresh cut carrot surface could be effectively killed by ATLTP. Factors influencing the sterilization rate were in order as processing voltage processing pole distance processing time. The conditions were optimized as follows： processing voltage 170 V,processing time 5 min,processing pole distance 2. 5 cm. The sterilization rate reached to92. 35% under these conditions,which closed to the predicted value of 92. 26%,and improves the edible safety of fresh sliced carrot. The water content,soluble solids,p H value,color,relative conductivity,malondialdehyde and Vc content of carrot were not significantly changed（ P 0. 05）. It is better to maintain the moisture,sugar,acidity and color of carrot,while maintaining the cell membrane permeability and antioxidant capacity.