食品中肌醇的微生物检测方法研究

目的:建立测定食品中肌醇含量的微生物方法。方法:利用肌醇缺陷型菌种在不含肌醇培养基中的生长与肌醇浓度呈正相关的原理,对选取的葡萄汁酵母菌和酿酒酵母菌各三株进行筛选,并对目的菌株的培养基进行选择,采用四参数Logistic曲线拟合,根据吸光度计算出食品中肌醇的含量,并对此法进行了方法学验证。结果:筛选出肌醇缺陷型菌种葡萄汁酵母菌CICC 1465,使用市售青岛日水肌醇测定用培养基进行实验。该法检测肌醇的曲线范围为0.1~1.0μg/m L,强化食品与天然食品的精密度、重复性良好,回收率在90%~110%之间,检出限为0.375 mg/100 g。结论:该方法能够准确检测强化食品与天然食品中的肌醇含量,为食品安全国家标准中优化检测肌醇的微生物方法提供有效的参考。

Research on Determination of Inositol in Food by Microbiological Method

Objective: To develop a method for determination of inositol in food by microbiological method. Methods: In the culture medium without inositol,the growth of inositol deficient strain and the concentration of inositol were positively correlated with each other,which was reached by screening three strains of Saccharomyces uvarum and Saccharomyces cerevisiae,and selecting culture medium. The content of inositol in food was determined by using four-parameter logistic curve method according to absorbance.The methodology of this method had been verified.Results: The experiment had been done by inositol deficient strain-Saccharomyces uvarum( CICC 1465) and commercial culture medium for inositol determination of Qingdao rishui.The curve range of inositol content in natural food and enriched food was 0.1 ~ 1.0 μg/m L using this method. The precision,repeatability of this method were fairly good. The recovery was between 90%~ 110%. The detection limit was 0.375 mg/100 g. Conclusion: The method can accurately determinate inositol content in natural food and enriched food,as well as provide an efficient reference for the establishment and optimization of the microbiological method of inositol in the national food safety standard.