ABSTRACT

Cassava is an important staple consumed in various forms by humans. Information on glycemic index of staple foods are required for effective nutrition awareness creation. This study was designed to determine the glycemic index of commonly consumed cassava varieties in south-east Nigeria. The study was descriptive-crossectional and experimental in design. The samples were subjected to chemical (proximate) analysis using standard procedure. Twenty apparently healthy undergraduate students (fasting blood sugar: 71.50±10.73 mg/dl) assigned to four groups consumed 50g available carbohydrate portions of test foods. Blood samples were collected in the fasting state, 1 hourly, 1½  hourly  post-ingestion of the test food to determine plasma glucose concentrations, incremental area under the glucose curve, glycemic index and glycemic load. Results revealed that the moisture content was high in the two fufu varieties (52.20-53.75g/100g) while the white and pro-vitamin A garri were low in moisture (7.94-8.35g/100g). Ash content of the samples was highest in white garri (1.76 + 0.04 g/100g) followed by the pro-vit A garri (1.58 + 0.05 g/100g) and other fufu varieties (0.74-0.82g/100g). Yellow garri (1.16 + 0.04 g/100g) contained the highest fat value when compared to other samples (white garri -1.05 + 0.01 g/100g; white fufu -0.63 + 0.03 g/100g).  Crude protein content of the samples ranged from 2.54 + 0.09 to 0.79 + 0.09 g/100g. Carbohydrates levels of the two garri varieties (82.96 + 0.06-84.42 + 0.07 g/100g) was higher that observed for fufu samples (43.04-44.03g/100g). Energy content of the samples ranged from 352.32-353.74kcal in white garri and 181.02-187.95 kcal in yellow fufu. 50g available carbohydrate was obtained from 59.5g, 60.27g of raw garri and 116.17 and 113.56g of fufu. The GI and GL values obtained ranged from 80.6-96.0 and 40.3-48.0 which classified them as high GI and high GL foods. Results revealed that there was an increase in the post-prandial blood glucose after administration of the test foods at 60 minutes. At 90 minutes, all blood glucose level significantly dropped in all test foods except in pro vitamin A fufu and garri. Thus the mean blood sugar concentration was 96.0 + 18.64mmol/l, 80.6 + 11.28 mmol/l,   91.2 + 14.10 mmol/l, 89.4 + 12.62 mmol/l.  Therefore the introduction of pro Vitamin A biofortified cassava products to Nigeria households will assist in reducing the burden of diabetes and poor glycemic control.