No abstract

Rice (Oryza sativa) is the foremost cereal crop in Southeast Asia. It serves as staple food, thus has a major contribution to the calorie intake. In addition, rice contains melatonin which is beneficial for human health. It is, therefore, essential to retain this compound by appropriate rice production processes. Melatonin profile during rice production was monitored for three varieties (IR64, umbulumbul and pandan wangi) from conventional farming and four varieties (batang lembang, pandan wangi, black and red rice) from organic farming. The effect of polishing degree on melatonin content in rice was also evaluated. Melatonin level decreased throughout rice production and then remained steady at roughly 25-40% in final product. The most influential factor was polishing which led to melatonin losses of up to 50%. The results for organically cultivated varieties were similar. However, melatonin in black rice appeared to be persistent in the matrix during rice production. 

Information on expiration time of rice on packaging labels is needed to provide quality assurance to consumers. The research aimed to find out the expiration time of rice from the microbiological aspect of rice. Rice samples used was Ciherang varieties. Rice was packed using 3 types of packaging, sacks, non-vacuum plastic and vacuum plastic. Rice was stored in two different places, air-conditioned rooms and room temperature. The results showed that mold and yeast contamination in Ciherang Rice up to 8 months’ storage are still below the required standard.

The decline of rice quality will occur during storage. One of the quality parameters of rice is the cooking quality. The study was conducted to determine the cooking quality characteristics of Ciherang rice for eight months storage. Rice was stored in several types of packaging, namely plastic sacks, vacuum plastic packaging and non-vacuum plastic. While the storage temperature was air conditioner temperature and room temperature. The cooking quality of rice observed in this study included the cooking time, the water absorption ratio, the volume expansion ratio, and gel consistency. The results showed that the cooking time of rice with vacuum polypropylene plastic packaging did not change during eight months storage. However, the water absorption ratio and the volume expansion ratio of rice had increased during eight months storage. Rice that was stored at room temperature had a higher water absorption ratio and volume expansion ratio than rice stored at air conditioner temperature. Meanwhile, the gel consistency of rice after eight months of storage showed a significant decreased in all treatments. In general, the gel consistency of rice after eight months storage showed the harder texture than initial rice before storage.