.不同剂量率辐照对酵母抽提物自由基和挥发成分的影响.pdf

现代食品科技 Modern Food Science and Technology 2014, Vol.30, No.6 不同剂量率辐照对酵母抽提物自由基和 挥发成分的影响 耿胜荣，熊光权，夏和舟，廖涛，李新 （湖北省农业科学院农产品加工与核农技术研究所，湖北省农产品辐照加工中心，湖北武汉 430064） 摘要：酵母抽提物（Yeast extract ，YE）经60、480 Gy/min 剂量率钴源和12000 Gy/min 剂量率加速器辐照后，采用GC-MS 测 定挥发成分，并与五种目标氨基酸辐照挥发成分进行对比研究，探索酵母抽提物挥发物质的组成及氨基酸来源；通过ESR 技术测定 进一步分析自由基与剂量率的关系，研究剂量率对减少辐照损伤的作用和机理。结果表明，YE 辐照挥发成分6 种最主要的成分为丙 酮、乙酸、二甲基二硫、甲苯、2, 6-二甲基吡嗪和苯甲醛，并且随照后时间的延长呈先增加后减少趋势；挥发成分由甲硫氨酸、丙氨 酸和苯丙氨酸辐照降解生成；8 kGy 相同剂量辐照，三种处理的YE 挥发成分产生量：60 Gy/min480 Gy/min加速器。辐照YE 自由 基峰呈双连峰，峰型随剂量率和剂量的增加而变化；60 Gy/min 钴源辐照时，自由基浓度（A ）与吸收剂量（D ）的关系为： A=4363.5D+4873.9，R 2 0.9826 ；8 kGy 相同剂量辐照，三种处理的YE 自由基浓度：480 Gy/min加速器60 Gy/min 。可见， 高剂量率辐照可减少酵母抽提物自由基浓度，降低酵母抽提物辐解挥发成分的产生量。 关键词：酵母抽提物；剂量率；辐照；自由基；挥发成分 文章篇号：1673-9078(2014)6-168-173 Effect of Different Dosage Rates on Radical Content and Volatile Compounds of Irradiated Yeast Extract GENG Sheng-rong, XIONG Guang-quan, XIA He-zhou, LIAO Tao, LI Xin (Institute for Farm Products Processing and Nuclear-Agricultural Technology, Hubei Academy of Agricultural Sciences , Hubei Innovation Center of Agricultural Science and Technology, Wuhan 430064, China) Abstract: Yeast extract (YE) was irradiated respectively by γ-rays with dosage rate of 60 and 480 Gy/min and electron beams of 12000 Gy/min. The volatile compounds from irradiated YE and five kinds of target amino acid-water solutions were detected by gas chromatograph- mass spectrometer-computer (GC-MS), the composition of YE volatile compounds and their amino acid source were investigated. The radical characteristics of irradiation YE were researched by electron sin resonance (ESR) and the mechanism of dosage rate on reducing irradiation damage was studied. Result s showed that the six same volatile compounds from