Micronutrients and Macronutrients Contents of Whole Rice, Rifined Rice, and Bran Rice in Five Indonesia Cultivars of Black Rice (Oryza sativa L.)
Indonesia has a particularly high biodiversity of food crops, namely rice. Rice in Indonesia is divided into several types based on the aleurone pigment constituent, called rice with white rice, red and black. Black rice potential to developed as functional food because of its high micronutrients and macronutrients contents. This study was done to determine the contents of tocopherol, β-carotene, calcium (Ca), iron (Fe), zinc (Zn), carbohydrate, protein, and lipid in the whole rice, rice bran, and refined rice. Samples obtained from rice farmers are rice cultivars Wajolaka Nusa Tenggara Timur, Toraja from Lampung, Cempo Ireng from Sayegan, Melik from Bantul and Wedomartani from Sleman, Yogyakarta, Indonesia. Rice was separated into components, those are whole rice, rice bran, and refined rice. The method used to test the levels of tocopherol and β-carotene is spectrophotometry, Ca, Fe, and Zn tested by Absorption Spectrophotometer (AAS) and the carbohydrate, protein, and lipid contents tested by proximate analysis by different, micro-kjeldahl, and soxhletation method. Variance analysis performed through ANOVA test on SPSS-23 with a significance level of 5%. The results of the analysis showed tocopherol content of black rice cultivars Wajolaka, Toraja, Cempo Ireng, Melik and Wedomartani sequentially by 1,478; 0,862; 0.651; 1.617 and 1.618%, the content of β-Carotene in sequence at 912.93; 409.80; 1013.23; 1315.62; and 1463.88 μg/100g. The highest of mineral Ca content in cultivars Toraja is 244.4 μg/gram, the highest of mineral Fe and Zn is cultivar Wedomartani each 39.47 and 25.07 μg/gram. The carbohydrate, protein, and lipid of black rice in a series between 61.80 – 65.58 %, 7.13 – 9.10 %, and 1.98 – 3.23 %. The carbohydrate in refined rice between 62.71 – 67.89 %, in rice bran the protein and lipid contents 10.95 – 11.48 % and 5.70 – 6.86 %. Based on the data obtained, it can be concluded that tocopherol, β-carotene, Ca, Fe, Zn, carbohydrate, protein, and lipid contents are variated between black rice cultivars Wajolaka, Toraja, Cempo Ireng, Melik and Wedomartani. The highest tocopherol, β-carotene, Ca, Fe, Zn, protein dan lipid contents were found in the bran rice, whereas the highest carbohydrate content was found in refined rice.