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

Abstract

Whole grains consumption promotes health benefits, but demonstrates controversial impacts from phytic acid in meeting requirements of good health. Therefore, this study was aimed to determine the nutrient bioaccessibility and antioxidant properties of rice cultivars named "Adan" or "Bario" and deduce the nutritional impact of phytic acid. Majority of the dehusked rice in the collection showed an acceptable level of in-vitro starch digestibility and in-vitro protein digestibility, but were poor in antioxidant properties and bioaccessibility of minerals (Ca, Fe and Zn). The drawbacks identified in the rice cultivars were due to relatively high phytic acid content (2420.6 ± 94.6 mg/100 g) and low phenolic content (152.39 ± 18.84 μg GAE/g). The relationship between phytic acid content and mineral bioaccessibility was strongest in calcium (r = 0.60), followed by iron (r = 0.40) and zinc (r = 0.27). Phytic acid content did not significantly correlate with in-vitro starch digestibility and in-vitro protein digestibility but showed a weak relationship with antioxidant properties. These suggest that phytic acid could significantly impair the mineral bioaccessibility of dehusked rice, and also act as an important antioxidant in non-pigmented rice. Bario rice cultivars offered dehusked rice with wide range of in-vitro digestibility of starch and protein, and also pigmented rice as a good source of antioxidants. However, there is a need to reduce phytic acid content in dehusked rice for improved mineral bioaccessibility among Bario rice cultivars.

Bioavailability of iron and zinc as affected by phytic acid content in rice grain

“…After milling, the PA content was reduced up to 85%, while percent reduction was 58 and 80 in Bindli and PB267, respectively (Figure b). Lee, Loh, Bong, Sarbini, and Yiu () reported similar range of PA (0.826–3.235 g/100 g) in rice genotypes. Major amount of PA is present in the aleurone layer and can be removed by milling process (Itani, Tamaki, Arai, & Horino, ).…”

Phytate, iron, zinc, and calcium content of common Bolivian foods and their estimated mineral bioavailability

“…These results might be explained by the fact that minerals and phytate are not always found in the same part of the seeds or grains and that phytate can be linked to other elements such as magnesium or potassium or the variability of phytate depending of the maturity of the seeds or grains (Reddy & Sathe, ). Lee, Loh, Bong, Sarbini, and Yiu () reported no correlation between phytate and minerals in a study carried out with 30 samples of two rice cultivars from Malaysia. Masum Akond, Crawford, Berthold, Talukder, and Hossain () reported a negative correlation for phytate and iron, and calcium, and between phytate and zinc in 29 common bean genotypes.…”

Impact of phytic acid on nutrient bioaccessibility and antioxidant properties of chickpea genotypes

“…This include sesame (39.3–57.2 mg/g), soyabeans (12.2–19.3 mg/g), maize (9.8–21.3 mg/g), peanuts (9.2–19.7 mg/g), buckwheat (9.2–16.2 mg/g), rice (1.2–3.7 mg/g), wheat (1.1–3.3 mg/g) (Bilyeu et al, ; Greiner & Konietzny, ; Kim, Mullan, Selle, & Pluske, ). The relationship between phytic acid content and mineral bioavailability was investigated in rice by Lee, Loh, Bong, Sarbini, and Yiu (). They observed that phytic acid significantly impaired the mineral bio accessibility and contribute to antioxidant properties.…”

“…(1.1-3.3 mg/g) (Bilyeu et al, 2008;Greiner & Konietzny, 2006;Kim, Mullan, Selle, & Pluske, 2002). The relationship between phytic acid content and mineral bioavailability was investigated in rice by Lee, Loh, Bong, Sarbini, and Yiu (2015). They observed that phytic acid significantly impaired the mineral bio accessibility and contribute to antioxidant properties.…”