Effect of Lipid Content and Components on Cooking Quality and Their Responses to Nitrogen in Milled Japonica Rice

The objective of this study was to understand the relationship between cooking quality and lipid content and components in milled rice of different cultivars, and the regulation of nitrogen on lipid quality in japonica rice (Oryza sativa L.). Under 7 nitrogen conditions with 4 total nitrogen levels and 2 split ratios, the RVA parameters and contents of crude lipid, lipid components, and amylose were assayed in 6 cultivars. Genotype significantly affected the content and components of lipid in milled rice. The milled rice of small-panicle cultivars had higher contents of crude lipid and starch lipid and lower non-starch lipid in milled rice than that of the large-panicle cultivars. The effect of nitrogen on lipid content and components in milled rice was smaller than that of genotype, and varied among genotypes. The content of crude lipid was significantly and negatively correlated with breakdown value, and the content of starch lipid was significantly and negatively correlated with amylose content, setback value, and consistency viscosity. The results indicate that rice cooking quality can be promoted through cultivar improvement aiming at increasing starch lipid content in milled rice.

摘要选用6个穗型不同的粳稻品种, 采用7个氮肥处理, 研究了精米中脂肪含量和组分对稻米直链淀粉含量和RVA特征值的影响及其对氮素的响应。结果表明, 水稻精米中脂肪含量及组分存在显著的基因型差异。小穗型品种宁粳1号、早丰9号和武育粳3号精米中粗脂肪含量和淀粉脂含量分别大于或等于与之对应的大穗型品种宁粳2号、徐稻4号和武运粳7号; 精米中非淀粉脂含量小穗型品种宁粳1号、早丰9号和武育粳3号均小于或相近于与之对应的大穗型品种宁粳2号、徐稻4号和9522。氮素对精米脂肪含量及组分的影响小于基因型, 而且对于不同的基因型水稻氮素对脂肪的调控作用不同。精米中粗脂肪含量及各脂肪组分含量与直链淀粉含量及RVA特征值关系密切。精米中粗脂肪含量与脱脂前后的崩解值呈极显著负相关, 淀粉脂含量与直链淀粉含量、脱脂前后的消减值和回复值均呈显著或极显著负相关。因此, 精米中脂肪含量, 尤其是淀粉脂含量, 对稻米的蒸煮食味品质有显著影响, 提高精米中淀粉脂含量能够提高稻米的蒸煮食味品质。