不同碾磨程度对糙米品质及相关性变化

Effect of Different Degrees of Milling on the Quality of Brown Rice and Their Correlation

摘要:

为了分析不同碾磨程度对糙米外观变化、营养物质含量、蒸煮及食味品质的影响，该文以空育131稻谷品种为原料进行研究，并采用斯皮尔曼方法分析碾磨程度与糙米品质之间的相关性，以获得口感与营养平衡的糙米。结果表明随着碾磨程度的增加（碾减率0%~7%，%均为质量分数），整糙米率下降1.20%，留皮度下降72.70%。营养组分含量呈显著下降，碾减率增加到7%时，蛋白质含量降低8.60%，粗纤维含量降低3.40%，淀粉含量升高11.00%，直链淀粉含量升高4.60%。Ca、Zn、Fe、Mn和Cu含量分别降低37.70%、19.21%、17.01%、37.52%、28.25%；VB1、VB2、VB3、VB5和VB6含量分别降低52.39%、25.00%、47.98%、35.36%、42.64%。蒸煮品质结果得出，碾减率从0%增加到7%时，吸水率、膨胀率、固形物损失率含量分别增加了50.88%、62.19%和5.27%。在碾减率4%时，崩解值最大（1 232.56 Pa.s），糊化温度最低（85.73 ℃），此时口感最佳。通过相关性分析得出影响糙米品质好坏程度的指标从大到小的排列顺序是：粗纤维>最终黏度>热焓值>VB3>Ca含量>硬度。综上，得出结论：糙米在碾减率4%、留皮度88.80%时的碾磨程度比较好，此时口感比相同品种的市售糙米更好，营养更均衡。

Abstract:

This study investigated the effects of varying different degrees of milling on the appearance changes, nutrient content, cooking, and taste quality of the brown rice variety Kongyu 131. Spearman’s method was employed to determine the correlation between the milling degree and brown rice quality, with the aim of obtaining brown rice with balanced taste and nutrition. The results showed that as the milling degree increased (milling rate 0%~7%, with all % indicating the mass fraction), the percentage of whole brown rice decreased by 1.20% and that of bran retention decreased by 72.70%. The content of nutritional components significantly decreased when the milling rate was increased to 7%: the protein content decreased by 8.60%, crude fiber content decreased by 3.40%, starch content increased by 11.00%, and amylose content increased by 4.60%. The contents of calcium, zinc, iron, manganese, and copper decreased by 37.70%, 19.21%, 17.01%, 37.52%, and 28.25%, respectively; the VB1, VB2, VB3, VB5, and VB6 contents decreased by 52.39%, 25.00%, 47.98%, 35.36%, and 42.64%, respectively. Analysis of cooking quality revealed that when the milling rate was increased from 0% to 7%, the water absorption, swelling, and solid loss rates increased by 50.88%, 62.19%, and 5.27%, respectively. The maximum disintegration value (1 232.56 Pa•s), minimum pasting temperature (85.73 ℃), and best taste were observed at a milling rate of 4%. Correlation analysis showed that the indices affecting the level of brown rice quality were, in descending order: crude fiber>final viscosity>enthalpy>VB3>calcium content>hardness. In summary, the optimal degree of milling for brown rice was 4%, at which bran retention was 88.80%; the taste of this rice was superior to that of commercially available brown rice of the same variety and exhibited more balanced nutrition.