低温等离子体处理对豆腐皮杀菌效果及其品质的影响

Effect of Cold Plasma Treatment on Sterilization and Quality of Thin Sheet of Bean Curd

豆腐皮作为中国传统的豆制品,因其营养丰富且易吸收的特点深受人们喜爱。然而豆腐皮在生产过程中易被外源微生物污染导致品质下降。低温等离子体杀菌技术作为一种新型非热的杀菌技术,具有杀菌效率高、无残留等优势。该文以等离子体的电源功率、处理时间及电极间距为试验因素,运用响应曲面试验方法探究各试验因素的交互作用机制,并优化杀菌工艺参数。结果表明:低温等离子体对豆腐皮杀菌的最优工艺为电源功率80 W、处理时间15 s、电极间距10 mm,菌落总数从4.56 lg(CFU/g)降低至3.85 lg(CFU/g);处理前后豆腐皮的感官评分、pH值无显著差异,而处理后的豆腐皮的弹性和咀嚼性有所提升。通过豆腐皮挥发性风味测定发现,低温等离子处理减少了豆腐皮中的豆腥味且增加了香味物质壬醛的含量。低温等离子体处理后的豆腐皮经真空包装后4℃下的货架期从3 d延长至6 d,具有较好的贮藏品质。

Thin sheet of bean curd,a traditional soybean product in China,is popular for its nutrition and eas-ily absorbed property.However,it is susceptible to contamination by exogenous microorganisms during the pro-duction,resulting in a deterioration in quality.As a new non-thermal sterilization technology,cold plasma ster-ilization has advantages such as high sterilization efficiency and no residue.In this paper,the treatment power,treatment time and electrode distance were used as the test factors to explore the interaction mecha-nism among various factors using response surface methodology.And the process conditions for cold plasma sterilization were optimized.The results showed that the optimal sterilization conditions for thin sheet of bean curd were treatment power 80 W,treatment time 15 s and electrode distance 10 mm.Under these conditions,the total bacterial count of thin sheet of bean curd decreased from 4.56 lg(CFU/g)to 3.85 lg(CFU/g).There were no significant differences in the sensory score and pH of thin sheet of bean curd before and after treat-ment.While the springiness and chewiness of thin sheet of bean curd treated by cold plasma were improved compared with the conditions before treament.Through the determination of the volatile flavor,it was found that cold plasma treatment reduced the bean odor in thin sheet of bean curd and increased the content of aro-matic substance nonanal.The shelf life of thin sheet of bean curd after vacuum packaging at 4℃was extended from 3 d to 6 d,resulting in an excellent storage quality.