不同储藏温度及储藏时间对稻米品质的影响

Influence of Different Storage Temperature and Time on Quality of Brown Rice

探讨短时间尺度储藏温度和时间与糙米品质的关系,为稻米安全储藏提供理论依据。选用两个典型籼稻品种IR110,IR124以及两个典型粳稻品种沈农265和辽粳294,将其糙米于-15,5,25,41℃条件下自然储藏180d,研究短时间尺度储藏温度和时间对糙米品质的的影响。结果表明:无论是籼稻还是粳稻,脂肪酸在不同温度下均随时间呈倒抛物线变化,但不同温度下波谷出现的早晚和幅度不同,温度越高波谷出现时间越早,波幅越大。表明高温条件下稻米内脂肪酸生化反应剧烈,高温不利于稻米安全储藏。从蛋白质含量上看,各温度条件下变化均不明显,表明稻米在储藏过程中,其品质变化与蛋白质含量关系不大。直链淀粉含量的增长率41℃时最大,5℃时最小。就食味值来说,不同温度下2个粳稻品种均优于2个籼稻品种,而无论籼粳稻品种,在-15℃和5℃低温条件下均表现为食味稳定,在25℃和41℃高温条件下食味变化剧烈。籼稻和粳稻的糙米随着储藏时间的延长品质都会发生改变,其中蛋白质含量随储藏温度和时间的变化较小,脂肪酸值随储藏温度的升高和储藏时间的延长呈倒抛物线趋势,直链淀粉含量随温度的升高增加,食味值随储藏温度的升高而下降。

The relationship between the quality of brown rice and the storage temperature and time in a short time was studied to offer theorial basis for the brown storage. The test adopted the respesentatives of two indica varieties and two japonica varieties in natural storage for 180 days under different temperature treatments（-15, -5, 25, 41℃）, and then the relationship between the quality of brown rice and the storage temperature and time was investigated in a short time. The results showed that for both indica varieties and japonica varieties, the fatty acid value appeared like a down parabolic curve, but the time for valley in the curve and the range were different, the higher temperature, the faster the time for valley in the curve and the bigger amplitude. This showed that fatty acid biochemistry reaction was intensity and had a disadvantage for the storage of the brown rice at high temperature. The storage temperature did not affect the protein contents. The highest and lowest growth rates of amlylose content were at 41℃, 5℃, respectively. As far as edible quality concerned, the two japonica varieties were superior to the two indica varieties under different temperature treatments. Both the two indica varieties and two japonica varieties edible quality maintained stable at low temperatures （-15℃, 5℃）, but the change of edible quality was conspicuous at high temperatures （25℃, 41℃）. The brown quality of indica and japonica varieties would be changed when the storage time was prolonged; the protein content was not significantly changed with the storage temperature and time; the fatty acid appeared like a down parabolic curve when the storage temperature and time increased; the amlylose content increased as the storage temperature, but the edible quality decreased.