电子束辐照对大米营养和蒸煮品质的影响

Effect of electron beam irradiation on nutritive and cooking qualities of rice

为进一步发展、完善辐照杀虫灭菌技术应用于储粮方面的理论研究,该研究采用0、0.83、1.56、2.30、4.93kGy不同剂量的电子束辐照大米样品,考察其对大米品质的影响。结果表明:不同剂量的电子束辐照对大米的蛋白质含量、氨基酸的含量与组成无明显影响(p>0.05);随着辐照剂量的增加,大米的脂肪酸值、胶稠度升高(p<0.05),吸水率、膨胀率下降(p<0.05);电子束辐照对大米糊化温度的影响不明显(p>0.05),但显著降低大米的峰值黏度、衰减值、回生值(p<0.05),明显影响米饭的蒸煮品质(p<0.05),剂量为4.93kGy时蒸煮米饭出现明显的褐变。电子束辐照大米的剂量不宜超过2.30kGy,以0.83kGy的辐照剂量较佳,该研究结果将为储藏和进出口检疫中对大米进行辐照杀虫、灭菌时的剂量选择提供参考。

To further consummate and improve the theory about application of ionizing irradiation disinfection and sterilization to stored-grain, rice samples were exposed to electron beam with dosage levels of 0, 0.83, 1.56, 2.30, 4.93 kGy to evaluate the effect of electron beam irradiation on nutritive quality, pasting property, cooking and eating qualities of rice. The results showed that the protein content and amino acid composition of rice were not significantly influenced by irradiation （p〉0.05）, fatty acid value and gel consistency raised while water absorption and swelling degree reduced with the increasing irradiation dosage （p〈0.05）. No significant change in pasting temperature was observed between irradiated and non-irradiated samples （p〈0.05）, but peak viscosity, breakdown, setback of rapid visco analyzer were significantly decreased with dosage increasing （p〈0.05）. The cooking quality was significatnly lowered by irradiation with the increasing dosage （p〈0.05）, and the cooked rice browned at 4.93 kGy dosage level. Thus, the adequate electron beam irradiation dose for rice should be less than 2.30 kGy, and the best qualities of rice will be kept when irradiated with 0.83 kGy. The experimental results can provide a theoretical evidence for the choice of irradiation dosage for the application of low-energy electron beam irradiation in sterilization as well as insect disinfection of rice.