Evaluation of the glycemic index of some cooked variety of rice products in Nigeria

Abstract

The glycemic index (GI) is an important parameter of food quality which compares the hyperglycemic effect of a tested meal with pure glucose. The glycomic index of different varieties of rice (Oryza sativa) such as white rice, brown rice and parboiled rice were determined. A group of 22 participants with the mean age, weight, height and body mass index of 24 to 62 ± 1.43 years, 63.42 ± 10.50 kg, 1.70 ± 0.0 m and 21.90 ± 2.74 kgm^-2 were respectively selected for the study. The mean fasting blood glucose level of the participants was 84.81 ± 4.37 mgdl^-1. The mean blood glucose level at 30 and 60 min after the oral administration of 75 g glucose were 147.43 ± 11.67 and 125.95 ± 9.30 mgdl^-1, respectively. The mean glycemic response of pure glucose at 30 and 60 min were 62.62 ± 11.4 and 41.14 ± 8.932 mgdl^-1 respectively and hence, higher glycemic response for the pure glucose was obtained at 30 min. To the participants different varieties of cooked vice (white rice, brown rice and parboiled rice) boiled containing 75 g digestible carbohydrate were administered, the peak blood glucose response was obtained at 30 min. The mean glycemic response of white rice, brown rice and parboiled rice were 41.71 ± 6.17, 37.72 ± 5.11 and 35.05 ± 3.77 mgdl^-1, respectively. The glycemic responses after the consumption of cooked rice sample containing 75 g digestible carbohydrate, showed significant difference (P > 0.05) between cooked white rice and brown rice, cooked brown rice and parboiled rice and cooked white rice and parboiled rice. The mean GI values of cooked white rice, brown rice and parboiled rice were 66.61 ± 9.86, 60.24 ± 8.16 and 55.97 ± 6.01, respectively. Based on these GI values, it can be suggested that among the three varieties of cooked rice, the parboiled rice is a better choice for diabetes patients.

Keywords: Rice, blood glucose level, glycemic index, fiber, fasting, glucose.