大米的真空冷却研究

将微波处理后的大米进行真空冷却,对大米的温度、含水量、碘蓝值、游离脂肪酸、水溶性蛋白质等品质指标进行测定,研究不同微波处理条件下真空抽气冷却时间对大米品质的影响。结果表明:随着真空抽气时间的延长,大米的含水量、碘蓝值、游离脂肪酸含量降低,但水溶性蛋白质含量基本不变。微波处理条件会影响大米品质及大米真空冷却效果,以长时间低剂量微波处理对大米品质影响较小。大米经长时间低剂量微波处理后,真空抽气45 s,温度可降低到40℃以下,且爆腰率和碎米率较低,品质较好。

Effect of vacuum cooling on rice quality

Use vacuum cooling to reduce rice temperature after microwave treatment,and rice temperature,water content,blue value,free fatty acids and soluble-protein content were analyzed after different vacuum pumping times.The results showed that:with the extension of the vacuum pumping time,the moisture content,blue value,free fatty acid content were reduced,but the water-soluble protein content was basically unchanged.Microwave radiation will affect rice quality and vacuum cooling effects.Lower power with a longer treatment time has less effect on rice quality.After lower power with a longer treatment time by microwave,vacuum pumping for 45 s,the rice temperature can be reduced to below 40 ℃,and the rice have a better quality with lower kernel cracking rate and rice broken rate.