60Co-γ辐照对花生杀菌效果及其品质的影响

Effects of 60Co γ-irradiation on the Sterilization and Quality of Arachis hypogaea.L

摘要:

为减少有害微生物对花生的污染，本文研究了60Co-γ辐照对花生的杀菌效果以及对其感官品质、理化性质、质构特性和脂肪氧化酶的影响。结果表明：60Co-γ辐照处理可显著降低花生中微生物含量，且随着辐照剂量的增加，杀菌效果越显著；辐照剂量为1.50 kGy时，菌落总数、霉菌和酵母菌的灭菌率分别达到94.58%和95.63%，均达到90%以上；菌落总数、霉菌及酵母菌的辐照杀菌剂量D10分别为2.33 kGy和1.10 kGy；随着辐照剂量的增加感官评定得分越低，剂量≤1.50 kGy时，花生的感官品质在食用者可接受范围内。剂量为0.00~4.50 kGy时，辐照对花生水分、脂肪、蛋白及脂肪酸无明显影响，当剂量大于1.50 kGy时，仅粗纤维含量出现明显下降；辐照处理会在一定程度上增加花生的硬度，而对内聚性、弹性、胶黏性和咀嚼性则无明显影响；同时，辐照不会脂肪氧化酶产生明显影响。因此，60Co-γ辐照剂量不高于1.50 kGy时，能有效杀灭花生仁中微生物，且最大限度保持花生原有的食用品质。

Abstract:

To reduce microbial contamination in peanut, the bactericidal effect of 60Co γ-irradiation on the peanuts and the effects of 60Co γ-irradiation on the physicochemical properties and the texture characteristics and lipoxygenase of peanut were investigated. The results showed that 60Co γ-irradiation could significantly reduce the microbial content of peanut in a dose-dependent manner. The disinfection rates of total bacterial count, mold and yeast were 94.58% and 95.63%, respectively. The decimal reduction dose (D10) values of total bacterial count, mold and yeast were 2.33 kGy and 1.10 kGy, respectively. The sensory evaluation scores decreased with increasing irradiation doses, the sensory quality of peanuts was acceptable at the irradiation doses 1.5 kGy. At the range of dose of 0.00~4.50 kGy, irradiation had no significant effect on the moisture, fat, protein and fatty acids of peanuts, whereas, there was a significant decrease in the amount of coarse fiber when the irradiation dose was more than 1.50 kGy. Irradiation treatment could increase the hardness of peanuts to a certain extent, but had no obvious effect on the cohesiveness, elasticity, adhesiveness and chewiness of peanut. In addition, irradiation had no significant effect on lipoxygenase of peanuts. Therefore, when the dose of 60Co γ-irradiation dose was not more than 1.50 kGy, it could effectively kill the microbes in peanut and keep the maximal original edible quality of peanuts.