Effects of household cooking processes on mineral, vitamin B, and phytic acid contents and mineral bioaccessibility in rice

The effects of washing, soaking, and cooking (ordinary cooking, high-pressure cooking, and microwave cooking) on thiamine, riboflavin, phytic acid (PA), and mineral contents (Mg, Ca, Mn, Zn, and Fe) of different cultivars rice, Xinfeng 2 and T-You 15, were investigated. Washing caused a significant loss in vitamin B, PA, and mineral contents, whereas, soaking only decreased the thiamine content. Moreover, cooking decreased the vitamin B and PA contents, and high-pressure cooking exerted more remarkable effects than those of ordinary and microwave cooking. Furthermore, washing and soaking increased the Zn and Ca bioaccessibilities, however, cooking improved the bioaccessibilities of Mg, Fe, and Ca, but decrease those of Zn and Mn. Therefore, vitamin and mineral losses caused by excessive washing should be given attention. Cooking processes in relatively low temperature may also be beneficial to the nutritive properties of vitamins and minerals.