电子束辐照对美国红鱼肉营养成分的影响

Effect of electron beam irradiation on the nutritional ingredient of Sciaenops ocellatus meat

采用不同剂量(0、1、3、5、7和9 kGy)的电子束处理普通和真空包装的美国红鱼肉,研究电子束辐照对红鱼肉营养成分的影响。(1)辐照剂量对红鱼肉的水分含量影响显著,对灰分、蛋白质、脂肪、总糖含量无显著影响,包装形式对辐照红鱼肉一般营养成分的影响均不显著。(2)包装形式和辐照剂量对红鱼肉的氨基酸总量、呈味氨基酸及必需氨基酸与总氨基酸比(Essential amino acid/total amino acid,EAA/TAA)和必需氨基酸与非必需氨基酸比(Essential amino acid/nonessential amino acid,EAA/NEAA)均无显著影响,辐照后红鱼肉的第一限制性氨基酸由蛋氨酸+半胱氨酸变成缬氨酸。(3)辐照剂量、包装形式对红鱼肉中脂肪酸总量影响不显著。辐照剂量对红鱼肉的不饱和脂肪酸、多不饱和脂肪酸、二十二碳六烯酸(Docosahexaenoic acid,DHA)的相对含量均有显著影响,真空包装鱼肉的DHA损失率低于普通包装,低剂量组鱼肉的DHA损失率低于高剂量组。结合电子束辐照对美国红鱼肉的杀菌效果,辐照剂量控制在3-5 kGy为宜。

The influences of electron beam irradiation and package pattern （vacuum or ordinary） on the nutritional ingredient of Sciaenops ocellatus meat were investigated. The results were summarized as follows： （1） Electron-beam irradiation dose had notable effect on the moisture content, but no significant impact on the content of ash, protein, lipid and total carbohydrate. The package pattern had no significant effect on the common nutrional composition of Sciaenops ocellatus meat. （2） Either package pattern or irradiation dose showed little influence on the total amino acids, delicious amino acid, EAA/TAA and EAA/NEAA of Sciaenops ocellatus meat. The first limiting amino acid of Sciaenops ocellatus meat changed from Met plus Cys to Val in virtue of electron beam irradiation. （3） Both irradiation dose and package pattern showed no difference to the total fatty acid content. But the irradiation dose had notable effect on the relative content of unsaturated fatty acid, polyunsaturated fatty acid and DHA. The vac- uum-packaged group had less DHA loss than the ordinary-packaged group with the same absorbed dose, and low dose groups had less DHA loss than the high groups. As conclusion, combining with the bactericidal effect of electron beam irradiation to sciaenops ocellatus meat, the recommended dose has been proposed to be 3--5 kGy.