电子束辐照对细点圆趾蟹肉营养及滋味成分的影响

以细点圆趾蟹蟹肉为材料,研究电子束辐照对蟹肉营养和滋味成分的影响,为电子束辐照技术在水产品加工中的应用提供依据。结果表明:辐照处理后7 kGy及以上剂量组蟹肉总氨基酸和非必需氨基酸含量下降比较明显;辐照没有改变蟹肉的第1和第2限制性氨基酸种类,各组蟹肉必需氨基酸与总氨基酸之比和必需氨基酸与非必需氨基酸之比均分别超过40%和60%,为质量较好的蛋白质;脂肪酸分析结果显示,电子束辐照对蟹肉饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸总量均无显著影响;随着辐照剂量增加,蟹肉中的游离氨基酸总量呈下降趋势,但呈鲜、甜鲜味的游离氨基酸含量有所增加,说明适当的辐照剂量对蟹肉氨基酸的呈味有改善作用;蟹肉中的主要呈味核苷酸是5’-肌苷酸二钠,辐照后蟹肉5’-腺苷酸和5’-肌苷酸二钠含量有所上升,而5’-鸟苷酸二钠含量有所下降,辐照对蟹肉鲜味有提升作用;结合鲜味氨基酸和呈味核苷酸的鲜味协同效应,各辐照组味精当量值均高于对照组,其中1 kGy组蟹肉的味精当量值最高,达到17.92%。综合蟹肉氨基酸、脂肪酸组成和滋味成分的变化规律分析,认为1～9 kGy剂量电子束辐照对蟹肉营养和滋味没有明显的负面影响,可用于对蟹肉进行前处理。

Effects of Electron Beam Irradiation on Nutritional and Taste Components of Ovalipes punctatus Meat

Ovalipes punctatus meat was used to investigate the effects of electron beam (EB) irradiation on its nutritional and taste components in order to provide a basis for scientific application of EB irradiation. The results showed that the contents of total amino acids and non-essential amino acids in crab meat irradiated with doses equal to or greater than 7 kGy decreased obviously. Irradiation did not change the first or second limiting amino acids of crab meat. The ratio of essential amino acids to total amino acids (EAA/TAA) and the ratio of essential amino acids to non-essential amino acids (EAA/NEAA) in both unirradiated and irradiated groups exceeded 40% and 60%, respectively, indicating good protein quality. The results of fatty acid composition showed that EB irradiation had no significant effect on the content of saturated or unsaturated fatty acids. With the increase of irradiation dose, the total amount of free amino acids in crab meat showed a downward trend, whereas the contents of umami and sweet-umami free amino acid increased, which indicates that the appropriate irradiation dose could improve the taste of amino acids in crab meat. The main flavor nucleotide in crab meat was IMP. After EB irradiation, the contents of AMP and IMP while GMP content decreased thereby enhancing the umami taste of crab meat. Based on the synergistic effects of umami amino acids and flavor nucleotides, equivalent umami concentration (EUC) value in each irradiation group was higher than in the control group. The 1 kGy irradiation group had the highest EUC value of 17.92%. Collectively, EB irradiation at doses of 1–9 kGy had no obvious negative effect on the nutrition or taste of crab meat and it could be suitable for the pretreatment of crab meat.