The Effects Of Various Traditional Processing Methods On The Glycemic Index And Glycemic Load Of Cowpeas (Vigna Unguiculata)

Department of Medical Biochemistry College of Medicine School of Basic Medical Science University of Benin Benin City, Edo state 3000001, Nigeria
Journal of Food Biochemistry (Impact Factor: 0.74). 07/2010; 34(6):1332 - 1342. DOI: 10.1111/j.1745-4514.2010.00423.x


The glycemic index (GI) and glycemic load (GL) of processed brown cowpea (Vigna unguiculata) were determined. The whole seeds were dehulled, ground into a paste and steamed (“moin-moin” MM) or fried (“Akara” FB). Proximate analyses were done to determine the quantity containing 50 g available carbohydrate. Forty healthy volunteers were used for this study. The test groups consumed the processed cowpea while 50 g glucose was administered to the control group. The blood glucose response at 0, 30, 60,120 and 180 min was assessed for each individual of the different groups. The GI values for BB, MM and FB were 46.63 ± 9.0, 50.98 ± 5.74 and 53.42 ± 9.50, respectively. The GL values for the test foods were 5.51 ± 1.19, 6.92 ± 2.14 and 4.94 ± 1.88, respectively. The GI and GL values for the test foods did not differ significantly (P > 0.05). However, BB had the lowest GI and GL values.
Legumes, particularly cowpeas, are good sources of nutrients (protein, carbohydrate, fiber, vitamins and minerals). Recently, beans have been shown to be low glycemic index (GI) foods. They therefore have positive health benefits which include hypocholesterolemia, mitigation of diabetes and weight control.
Cowpeas are processed traditionally in Nigeria, by soaking, dehulling, grinding, frying steaming and boiling to form cooked beans. These methods are often combined by grinding to a paste and fried or steamed to form “Akara” (fried bean cakes) and “moin-moin” (steamed bean pudding), respectively. These processing methods generally alter the contents and nutritional quality of the seeds when consumed.
Diabetic Nigerians often eat these processed legumes because they help reduce hyperglycemic stress while providing satiety effects.
The determination of the glycemic indices and glycemic loads of these processed legumes will give useful information as to how best legumes can be processed for consumption by people with diabetes.

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