Key Factors Affecting the Quality of Milling Recovery in Rice Processing

Rice is the kernel of the grass ‘Oryza sativa’ L. Over 50 percent of the global population relies on this cereal grain as a staple food. This review aims to investigate and understand various rice processing techniques and machines, the causes of rice milling loss, and the remedies proposed by scholars. Rice processing refers to the extraction of edible grains from rice paddy. De-husking, de-hulling, and shelling are terms used to describe the removal of the husk, the outermost layer of the rice grain. This is typically accomplished using a de-husking machine, such as the Engelberg model (which uses a metal roller) or the SB type (which uses a rubber roller and a compacted rice mill). The next step is milling rice, which involves the removal of the bran, the innermost layer of the grain. This process is also known as polishing. In modern rice processing plants, polishing refers to shaping or smoothing the milled rice's surface. Rice grain-producing countries often experience high post-harvest processing losses due to poor physical qualities of rice varieties, inefficiencies in processing technologies, and equipment malfunctions. The percentage of postharvest loss is particularly high in developing countries where traditional and outdated processing methods are commonly used. As a result, rice processing requires careful attention and should be carried out by trained professionals. Therefore, this paper discusses the methods of rice processing and the factors that affect the quality of processed rice.