碾磨精度对糙米营养及食用品质的影响

李金玲; 冷海静; 曹荣安; 王长远; 刁静静

doi:10.13386/j.issn1002-0306.2024050214

碾磨精度对糙米营养及食用品质的影响

Effect of Degree of Milling on the Nutrition and Eating Quality of Brown Rice

摘要

摘要: 为获得营养与口感平衡的高品质糙米，本文以绥粳18稻谷品种为原料，分析不同碾磨程度对糙米营养成分、食用品质的影响。本研究将脱壳的稻谷进行不同程度的碾磨，分别得到碾减率为0%、2%、4%、6%、8%、10%的糙米样品，以绥粳18精米作为对照，分析不同碾磨程度下，糙米的留皮度、维生素和氨基酸等营养组分，以及食味值等食用品质的变化，在此基础上，对碾减率与食味值、蛋白质、粗纤维等营养组分以及吸水率、硬度等食用品质指标进行Pearson相关性分析。结果表明：与绥粳18精米相比，糙米的留皮度显著高于精米（P<0.05），营养组分、食味值则逐渐下降。随着碾减率的增加，留皮度逐渐降低，当碾减率为4%，留皮度为60%，此时糙米的营养组分，如蛋白质、维生素B₁、赖氨酸等营养物质含量的保留率分别达到88.58%、80.03%、62.07%，食味值70分，且蒸煮后的米饭软硬适中、有米饭特有的香气；当碾减率达到10%，食味值达到80分，与精米的食味值差异不显著（P>0.05），但营养组分含量仍显著高于精米（P<0.05）。相关性分析结果得出，糙米碾减率与食味值吸水率、膨胀率、粘性、弹性呈正相关，且相关性大于0.95，碾减率与留皮度、蛋白质、硬度呈负相关，相关性不低于0.96。因此，改善留皮度、蛋白质等指标，可进一步提高糙米食用品质。

Abstract: To achieve high-quality brown rice with a balance of nutritional composition and eating quality, this study used the Suijing 18 rice variety as raw material to analyze the impact of different milling degrees on the nutritional composition and eating quality of brown rice. The dehulled rice was milled to varying degrees, yielding brown rice samples with milling degrees of 0%, 2%, 4%, 6%, 8%, and 10%, with Suijing 18 polished rice serving as the control, analyzing changes in the residual bran rate, vitamin, amino acid content, and eating quality, such as taste score, under different milling degrees. Based on this, Pearson correlation analysis between the eating quality of brown rice and its nutritional composition, cooking quality, and other indicators was conducted. The results indicated that, compared to Suijing 18 polished rice, the residual bran rate of brown rice was significantly higher (P<0.05), and both nutritional composition and taste scores gradually decreased. As the milling degree increased, the residual bran rate gradually decreased. When the milling degree was 4% and the residual bran rate was 60%, the retention rates of nutritional components in brown rice, such as protein, vitamin B₁, and lysine, were 88.58%, 80.03%, and 62.07%, respectively, with a taste score of 70, and the cooked rice had a moderate texture and the characteristic aroma of rice. When the milling degree reached 10%, the taste score reached 80, not significantly different from polished rice (P>0.05), but the content of nutritional components was still significantly higher than that of polished rice (P<0.05). Correlation analysis showed that the milling degree of brown rice was positively correlated with taste score, viscosity, elasticity, water absorption rate, and expansion rate, the correlation was greater than 0.95, and negatively correlated with residual bran rate and protein content, the correlation was not less than 0.96. Therefore, improving indicators such as residual bran rate and protein content can further enhance the eating quality of brown rice.