Studies on in vitro bioavailability and starch hydrolysis in zinc fortified ready-to-eat parboiled rice (komal chawal)

Zinc fortified parboiled rice (komal chawal) was produced from a low amylose variety of rice by applying 'brown rice parboiling' method. In addition to the effect of milling on fortification, the effectiveness of fortification upon the amount of bioaccessible (in vitro digest) and bioavailable (cellular uptake) form of Zn was tested. The effect on glycaemic index was also assessed by employing an in vitro starch hydrolysis assay. The bioaccessible form of Zn in the unmilled fortified rice were ranged in between 4.24 and 11.07 mg/100 g, which was significantly higher (p < 0.05) than the milled and unfortified parboiled rice. Similarly, the % absorption of bioavailable Zn was negligible in the unfortified parboiled rice as compared to the fortified rice (14.5-24.5%). The estimated GI of fortified parboiled rice samples was in the range of 50.97-59.79, which was lower than the unfortified parboiled rice (58.80-62.53) and raw rice (78.71-84.64). The results thus demonstrated that Zn fortified komal chawal can be a novel and rapidly produced micronutrient enhanced ready-to-eat rice.