有机和常规大米的品质与安全性分析

Quality and Safety of Rice( Oryza. sativa L. ) under Organic and Conventional Planting Methods

测定南北方大米的5个基本理化指标:直链淀粉、脂肪酸、水分、胶稠度与重金属(Cu、Cd、Pb)含量,分析并评价大米的品质及安全性。结果表明:供试大米样品的直链淀粉、脂肪酸、水分、胶稠度等指标均满足绿色食品标准(NY/T 419—2007);因为品种差异,北方粳米的含水率较高,南方籼米的直链淀粉、脂肪酸含量较高,所以北方大米的口感更好。有机和常规种植对大米的口感品质差异不明显;供试3种有机大米的Cu、Pb和Cd含量低,均满足绿色食品标准,2种常规种植大米Pb的含量超标,主要是受种植环境和种植方式的影响。

Basic physicochemial properties of 5 rice samples from north and south of China were determined to evaluate the quality and safety of rice in this paper. The property indexes are including amylose, fatty acids, moisture content, gel consistency and heavy metal （ Cu, Cd, Pb） content. The results showed that the contents of amylose, fatty acids, moisture content and gel consistency of the test rice samples were superior to the green food standard （NY/T 419-2007 ）. Moisture contents of northern japonica rice samples were higher than that of the south long-shaped rice samples, while amylose and fatty acid content of test samples were reversed due to the difference of varieties. There was no significant chewiness difference between rice samples under organic and conventional planting methods. On the other hand, metal （Cu, Pb,Cd） contents in 3 organic rice samples were lower than the green food standard, but the Pb contents in the conventional rice samples were higher than the standard, mainly because of the difference of the soil cnvironment and planting method.