基于电子鼻分析鱼油储藏过程中酸败程度的研究

鱼油的酸败往往伴随着气味的变化,利用电子鼻对储藏过程中金枪鱼油的挥发性气味进行研究,每5 d测定1次,运用主成分分析(PCA)、线性判别分析(LDA)区分不同储藏时间的鱼油样品,并通过偏最小二乘法(PLS)建立酸价、过氧化值的预测模型。结果表明:随着储藏时间的延长,金枪鱼油整体气味呈增加趋势,这种气味变化趋势与酸价、过氧化值的变化趋势基本一致;不同储藏时间的金枪鱼油样品可以区分开来,LDA分析方法明显优于PCA分析方法;利用PLS偏最小二乘法(PLS)预测金枪鱼油酸价和过氧化值,得到线性模拟方程,验证试验表明,酸价、过氧化值预测值与实测值的平均相对偏差分别为10.60%、12.04%,准确性较好,可作为酸价、过氧化值预测的辅助手段。

三种加热方式对油脂品质影响的比较

采用电磁炉、微波炉、常规加热对大豆油、花生油进行处理,测定其酸价和过氧化值,以比较三种加热方式对油脂品质的影响。结果表明,电磁炉加热对油脂品质的影响最大,微波炉加热对油脂品质的影响次之,常规加热的影响最小;花生油、豆油依次对热效应的敏感程度增加;间歇加热、加新油加热有利于油脂品质的保护。

Oxidation Stability of Camellia Oil During Refining

In this paper, the crude camellia oil extracted by cold pressing and deacidified oil, decolorized oil, dewaxed oil and finished tea oil obtained in different refining stages were studied. The changes of acid value, peroxide value and free radical scavenging ability of camellia oil in each stage were compared and analyzed.The results showed that the total phenol content of crude oil was the highest, and the total phenol content of alkali refined crude oil decreased significantly. After dewaxing, the total phenol concentration of camellia oil increased by 63.5%. The reason may be that low temperature conditions contributed to the recovery of phenolic structure in camellia oil, and without the influence of alkaline solution, the damage degree of phenolic substances was greatly reduced, thus elevating the total phenol content. The lowest peroxide value of camellia oil was observed in the alkali-refining deacidification stage, which decreased by 29.3%. Crude oil had the highest acid value and concentration of antioxidant substances. After alkali-refining deacidification,the acid value and the concentration of antioxidant substances dropped by 85.3%and 88.9%, respectively. Total phenols had the strongest correlation with acid value,followed by free radical scavenging ability, and the correlation with peroxide value was not obvious.

一起食物中毒的检测与分析

2009年12月21日,我市疾控中心卫生科接到举报电话,说有三个年轻男孩当天中午在市西环路边体育场附近的＂重庆鸡公堡＂饭店吃饭后,下午均出现不同程序的呕吐、腹泄症状。怀疑是食物中毒,请求市疾控中心派人采样、检测。经林州市疾控中心检验科所采样品中食用植物油油样的检测、分析,现将检测结果汇报整理如下：