Research on the Influence of Carbon Diozide Content,Ezposure and Temperature on the Quality of Stored Paddy Rice with Different Moisture Contents
The determination of quality aspects of stored paddy rice was the subject of the presented study. After airing and drying in the sun and adjusting the moisture content of the rice at relative balance humidities of 60%,70%,80%, the rice was exposed into four different atmospheres at five different constant temperatures : 10℃, 15℃, 25℃, 35℃ and normal ambient temperature, which containing high contents of carbon dioxide. The atmospheres were applied by ventilation into the tested bulks of paddy after reduction of pressure and adjustment of the moisture. By periodic sampling, many performance indexes for quality were determined, such as viscosity, fatty acid value, germination rate, hydrogen peroxidase activity, taste panel scores,light transparency difference and alteration of microbes. It was shown by experimental data that the quality of stored paddy was degraded as grain storage temperature and grain moisture content and storage period increased. The rate of degrading was correlating to the storage temperature and moisture content of the rice. At a storage temperature of 15℃,paddy with high moisture content kept excellent palatability. At 25℃,except for paddy with high moisture content, the quality of paddy with lower moisture contents did not change. At 35℃, except for paddy with low moisture content, the performance of paddy decreased significantly, and paddy with high moisture content loosing its dietary property completely. Based on the research on paddy performance, alteration rules were developed for different storage conditions,such as different temperature, humidity and content of CO2 in the storage atmosphere,fatty acid value, taste panel scores and germination rate. The CO2 content influenced the quality performance of paddy,which had been stored for one year.However, it played obviously a role on grain storage pest control, and had a pronounced inhibition effect on the growth of grain microbes. When the volume content of CO2 was beyond 15% and the temperature at 35℃,it had some inhibition effects on increase of the fatty acids for paddy with high moisture content above 15%. The further increase of the CO2 content did not show a pronounced inhibition effect. When the moisture content was below 15% and the grain temperature below 15℃, the carbon dioxide inhibited excellently the growth of fungi, as well as with common paddy or paddy with lower performance. When the content of CO2 increased above 35% and the grain storage temperature above 25℃,growth of fungi was inhibited in shortly stored paddy with high moisture content above 15% to some extent. Modified atmospheres (MA)with increased carbon dioxide content reduced significantly the mass growth of grain fungi but it could played no roles on the variety of fungi occurring in the stored rice. When the moisture content and the temperature of the stored paddy were high, it could not be stored for long time even under MA.
carbon diozide gas content temperature moisture paddy quality
Fu Pengcheng Ye Zhenhong Li Rongtao
Chengdu Grain Storage Research Institute, State Administration of Grain Reserves 601131
国际会议
成都
英文
204-210
2008-09-21（万方平台首次上网日期，不代表论文的发表时间）