การประเมินคุณค่าทางโภชนาการในข้าวต่างสี

Abstract

Nutritional values of colored rice were evaluated by Phitsanulok Rice Research Center during wet season in 2002. The experiment was carried out at 2 sites, one was the farmers'field in Phitsanulok while the other was the private company's field in Sukhothai. The experimental design was RCB having 12 treatments with 4 replicates. Eight colored rice lines were compared to 4 standard varieties: 2 recommended white and 2 introduced colored ones. Recommended rate and type of fertilizer and chemical application were practiced at Phitsanulok site while organic farming strategy was practiced at Sukhothai site. Plant height, maturity and grain yield were recorded. The grain was sampled for nutritional analysis after harvest. Results revealed that all tested lines was rather short of 79-123 cm, wigh. Maturity was in the range of 95-140 days. Most lines provided a rather low yield except PSL00255-4-4-5R of which a similar grain yield to Chai Nat 2, a standard check variety. Rice lines having red to deep dark-red pericarp were more superior than those with white, yellow and light-red pericarp in dietary fiber, calcium, polyphenol and antioxidant contents. However, those with red to deep dark-red pericarp had lower level of vitaminB6 than the ones. Among the tested lines, there were 2 lines having higher nutritional values than the rest. The nutritional quality included the content of iron, polyphenol and antioxidative activity. They were designated as PSL00284-8-2-5R having deep dark-red pericarp and PSL00284-17-5-5R having dark red pericarp. In general, two different growing conditions provided similar nutritional values except the level of phytate. Organic rice had a higher phytate content than that grown normally.