浓缩苹果汁中微生物染菌的种类及防治研究

Research on Microbial Contamination and Precautionary Measures in Concentrated Apple Juice

浓缩苹果汁是饮料工业中常用的原料,其干物质量分数一般为40%~50%。然而在浓缩苹果汁的运输及贮藏过程中,因微生物染菌导致苹果汁发生腐败的现象时有发生。首先,从变质的苹果汁中进行微生物培养,结果表明其中数量最多的是酵母菌,占总菌落数的80%;霉菌数量次之,占15%;而细菌类数量最少,占5%。接下来采用焦亚硫酸钠和纳他霉素作为抑菌剂,分析比较了其对苹果汁中酵母菌的抑制作用。结果表明,焦亚硫酸钠对酵母菌的抑制作用较弱,使用量即使高达1 000×10^-(6)也不会影响酵母的增殖;而纳他霉素是一种效价极高的抑菌剂,只需使用量2×10^(-6)即能表现出对酵母菌的强烈抑制。研究结果不仅表明了苹果汁中染菌微生物的类型,更为果汁在运输及贮藏的保鲜提供了技术指导。

Concentrated apple juice is commonly used in beverage industry,which concentration is usually 40%~50%. However,in the process of the transportation and storage of apple juice,the occurrence of corruption caused by microbial contamination occurred frequently. In this study,the microbial kinds were first studied,and the results showed that the proportion of yeast,molds and bacteria in apple juice was 80%,15% and 5%,respectively. The inhibition of yeast was then compared using sodium pyrosulfite and natamycin as antibacterial agent. The results showed that sodium pyrosulfite had a weak inhibitory effect on yeast,and even the addition of 1 000×10^-6 would not work. While natamycin was a highly effective antibacterial agent, which only 2 ×10^-6 showed a strong inhibition on yeast. Result showed the types of bacterial microorganisms in apple juice,and also provided technical guidance for the preservation of apple juice in transportation and storage.