人工模拟高温高湿过夏贮藏条件对大米总酸值的变化研究

Effect of Simulated Storage Condition on Acid Value of Rice

选用2003—2005年新收获的天津小站稻米为材料，将2004年稻米的含水量调为13％、14．2％、16．5％进行以室温条件贮藏和以恒温恒湿箱（35℃、80％）模拟过夏条件贮藏，定期测定大米中总酸值的变化。实验结果表明：小站稻米中总酸值随贮放时间延长而变化，储放一年以上大米出现陈化变质现象，品质下降。水分和储藏温度是影响大米总酸值含量的主要因素。经两年储藏后（2003年米）总酸值先稍有增加后急速下降，大米陈化程度已经很严重。

Rice materials harvested in 2003, 2004, and 2005, as well as rice materials with different moisture （ 13% , 14.2% , 16.5% , which was artificially adjusted from harvest in 2004） were used for this study. These rice materials were stored at simulated summer condition of temperature 35℃ and humidity 80%. Samples of the stored rice were taken regularly to determine the rice acid value. The results show that the rice acid value changes with extending storage time. Generally, the rice quality starts deterioration when the rice is stored for more than one year. Moisture and temperature are the main affecting factors for stored rice quality. The acid value of the rice material harvested in 2003 rises slightly first and then declines sharply during the storage period and the rice quality exhibits serious deterioration after two year＇s storage.