THE EFFECTS OF VARIOUS TRADITIONAL PROCESSING METHODS ON THE GLYCEMIC INDEX AND GLYCEMIC LOAD OF COWPEAS (VIGNA UNGUICULATA)
ABSTRACT 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.PRACTICAL APPLICATIONSLegumes, 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.
- [Show abstract] [Hide abstract]
ABSTRACT: The kinetics of starch and protein digestion in hammer- and cryo-milled cowpea (70–370 μm) were investigated. The pH during the protein digestion reduced with time, and both the starch and protein digestion exhibited monophasic digestograms, which were suitably (r2 > 0.97, p < 0.001) described by a modified first-order kinetic model. The in vitro protein digestibility of the cowpea (>80%) was independent of the milling conditions. The hammer-milled cowpea digested more, but the reciprocal of its rate of protein digestion was independent of the square of the particle size. The rate of protein digestion in the cryo-milled cowpea inversely depended (p < 0.05) on the square of the particle size, with 67 × 10−7 cm2 s−1 as the diffusion coefficient. For the starch digestion, diffusion coefficients (cm2 s−1) were 0.6 × 10−7 (hammer-milled) and 0.3 × 10−7 (cryo-milled). The protein digestion proceeded at a much faster (100×) rate than the starch digestion.Journal of Food Engineering 11/2012; 113(2):254–264. DOI:10.1016/j.jfoodeng.2012.05.041 · 2.58 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Cowpea Bean belongs to the Vigna unguiculata species and arouses interest because it has great climate adaptation and nutritional qualities. It is frequently found in the African continent and in Brazilian North and Northeast regions. It is a legume that needs to be cooked for its usual consumption. The main purpose of this study was the investigation of the lipid profile and thermal behavior of the oil from raw and cooked cowpea beans. The fatty acid composition of this oil indicates that there is a predominance of polyunsaturated fatty acids with ~37 % linoleic acid and 24 % α-linolenic acid, against ~25 % of saturated fatty acids (mostly palmitic). Details concerning the thermal behavior of these oils were evaluated by thermogravimetry and differential scanning calorimetry (DSC), under nitrogen and synthetic air atmospheres. The kinetic parameters were evaluated from several heating rates with sample mass of 5 and 20 mg in open crucibles under synthetic air and nitrogen atmospheres. The obtained data were evaluated with the iso-conversional kinetic method, where the values of activation energy (E a/kJ mol−1) were evaluated in function of the conversion degree (a). The results indicate that the kinetic behavior of the cooked oil under nitrogen and synthetic air atmospheres are different, which was attributed to the several sample masses used. In addition, this oil also was evaluated by DSC from 25 to −60 °C, where it was verified a phase transition behavior.Journal of Thermal Analysis and Calorimetry 04/2014; 120(1). DOI:10.1007/s10973-014-4125-4 · 2.21 Impact Factor