Genotypic, grain morphological and locality variation in rice phytate content and phytase activity

Abstract

Phytate complexes in whole grain rice are indigestible by human but can be broken down by endogenous phytase enzyme. The inherent phytate content and phytase activity could influence the nutritional quality of whole grain rice. This work aims to determine and identify their variability with genotypes, growing areas and grain morphology. It was found that the whole rice grain was largely high in phytate content (18.20 to 32.36 g/kg) but low in phytase activity (4.77 to 102.65 U/kg), with significant variation among cultivars. Phytate content was marginally different between growing locations but, with no significant difference among their genotypes and grain morphology. This variation could be due to locality factors such as cropping and fertilization practices in the cultivation site. Meanwhile, phytase activity appeared to be determined by genotype, grain width and grain length-to-width ratio. A relatively high phytase activity could be selected from the whole grain rice based on rounded grain and in the genotypic category of L. These types of rice cultivars could reduce the inherent phytate level and improve the nutritional quality of the whole grain rice.

Impact of phytic acid on nutrient bioaccessibility and antioxidant properties of dehusked rice

“…These samples are generally referred to Bario rice cultivars in this study, due to potential distribution of the original Bario rice from the Bario highlands. Genotypic and grain morphological information of these rice cultivars were obtained from previous study (Lee et al 2014). Rice bran colors ( Fig.…”

“…Bario rice cultivars collected from Bario highlands are a good source of protein and thiamine, moderate in glycemic index and also low in fat content (Nicholas et al 2014). Nevertheless, no information is available on the bioaccessibility of nutrients and antioxidant properties of Bario rice cultivars in relation to their high phytic acid content (18.20 to 32.36 g/kg) (Lee et al 2014). Nutrient bioaccessibility refers to the nutrient fraction released from the food matrix, in contrast to nutrient bioavailability that refers to nutrients available for utilization under physiological conditions (Parada and Aguilera 2007).…”

Phytic acid, inorganic phosphorus, antioxidants in bread and durum wheat and their associations with agronomic traits

“…Ficco et al (2009) using the principal component analysis and the Pearson's correlation found a negative association of P i and TGW (-0.31 p < 0.01) and of P i and YLD (-0.27 p < 0.05) in durum wheat, while similar findings were confirmed by other studies (Monasterio and . According to Lee at al. (2014) phytase activity affecting the PA content in wheat appeared to be determined by the grain length to width ratio.…”