Azuka C E, Nkama I, Asoiro F U
Department of Food Science and Technology, University of Nigeria, Nsukka, Nigeria.
Department of Agricultural and Bioresources Engineering, University of Nigeria, Nsukka, Nigeria.
J Food Sci Technol. 2021 May;58(5):1788-1796. doi: 10.1007/s13197-020-04690-1. Epub 2020 Aug 13.
Physical properties of rice grain is important for mechanisation and proper post-harvest handling operations to prevent post-harvest loss and achieve high head-rice grains. Knowledge on the physical properties of Nigeria's local rice is limited which has led to losses and production of low quality grains characterised by large amount of brokens and poor appearance. Physical properties of 18 local and 3 imported rice varieties (control), were evaluated using standard methods. The physical properties evaluated were grain dimensions, Arithmetic mean diameter, (AMD) geometric mean diameter (GMD), square mean diameter (SMD), sphericity, aspect ratio, surface area, general appearance, dockage and aroma. Most (77.78%) of the local rice varieties were long grain rice, 50% were slender grains and 50% were bold grains, 77.78% of the local rice varieties were heavy grains. The AMD, GMD and SMD of local rice grains ranged from 3.29-3.86 mm, 8.02-10.36 mm and 4.75-5.82 mm, respectively. The sphericity, aspect ratio and surface area were in the range of 51.25-59.23%, 0.31-0.46 and 21.87-29.44 mm, respectively. A significant percentage (50%) of the local rice were grey coloured and unappealing in appearance. All the local rice varieties had dockage (5-70%) while the imported rice varieties had no dockage and possessed translucent light-cream to yellow shades and were appealing in appearance. These data are important for correct coupling and adjustment of post-harvest processing machine to prevent losses and produce high head-rice with appealing appearance.
稻谷的物理特性对于机械化以及适当的收获后处理操作非常重要，有助于防止收获后损失并获得高整精米率。尼日利亚当地稻谷物理特性方面的知识有限，这导致了损失以及低质量稻谷的产出，其特点是碎米量大且外观不佳。使用标准方法对18个当地水稻品种和3个进口水稻品种（对照）的物理特性进行了评估。所评估的物理特性包括谷粒尺寸、算术平均直径（AMD）、几何平均直径（GMD）、平方平均直径（SMD）、球形度、长宽比、表面积、总体外观、杂质含量和香气。大多数（77.78%）当地水稻品种为长粒稻，50%为细长粒，50%为粗粒，77.78%的当地水稻品种为重粒。当地稻谷的AMD、GMD和SMD分别在3.29 - 3.86毫米、8.02 - 10.36毫米和4.75 - 5.82毫米范围内。球形度、长宽比和表面积分别在51.25 - 59.23%、0.31 - 0.46和21.87 - 29.44平方毫米范围内。相当大比例（50%）的当地水稻呈灰色，外观不佳。所有当地水稻品种都有杂质（5 - 70%），而进口水稻品种没有杂质，呈现半透明的浅米色至黄色色调，外观吸引人。这些数据对于正确连接和调整收获后加工机器以防止损失并生产出外观吸引人的高整精米率稻谷很重要。
