脂类在稻米陈化过程中的变化及与稻米糊化特性的关系

Chang of Rice Lipids During Storage and It'sEffects on Rice Gelatinization

糙米分别在３８℃和８℃条件下储藏６个月，非淀粉脂脂肪酸变化较大，其中软脂酸和亚油酸相对含量减少，油酸相对含量增加。淀粉脂脂肪酸变化很小。淀粉脂和非淀粉脂中的糖脂和磷脂含量下降，糖脂下降速度较快，磷脂下降速度较慢。用粘度仪、差分扫描量热仪对不同条件下储藏的糙米粉、脱脂糙米粉进行分析，结果表明，脱去非淀粉脂的样品与对照相比，糊化特性值均降低，说明脂类对稻米的糊化特性确有影响。脱非淀粉脂能改善糙米储藏稳定性。

Brown rice was stored under various temperatures (38℃ and 8℃)for 6 months.During the storage,the content of fatty acids in nonstarch lipids changed more greatly,with the relative content of palmitic acid and linoleic acid decreased while the oleic acid increased.The content of fatty acids in starch lipids changed slightly.The quantity of phospholpids and glyoclipids in starch lipids or nonstarch lipids both decreased,glycolipids decreased more rapidly than phospholipids.Gelatinization characteristics of brown rice flour and defatted brown rice flour were also determined with a Brabender viscography and Dsc.The results showed that the parameters of geliniztion characteristics of defatted brown rice flour were lower than the whole brown rice flour,suggesting that lipids do have effects on rice gelatinization.