NUTRITIONAL QUALITY AND ACCEPTABILITY OF SELECTED MAIZE-BASED SNACKS FORTIFIED WITH KIDNEY BEANS (Phaseolus vulgaris) AND ALLIGATOR PEPPER (Aframomum melegueta)

Abstract

This work examined the nutritional quality and acceptability of selected maize-based snacks (aadun, kokoro and kango) fortified with kidney beans (Phaseolus vulgaris) and alligator pepper (Aframomum melegueta). The snacks are essentially traditional foods being consumed by all ages in southwestern part of Nigeria. Three varieties of maize were obtained from the Institute of Agricultural Research and Training (IAR&T), Ibadan, Nigeria, namely: ART-98-SW06-W, Br 9943-DMR-SR-W and SUWAN-1-SR-Y. Flour blends were obtained using the Response Surface Methodology (RSM) which resulted in appropriate blending ratios of maize, kidney beans and alligator pepper. A preliminary survey of some snack-producing centres, in southwestern Nigeria, was carried out to evaluate the characteristics of commercial practice peculiar to these traditional snacks. Aadun was produced by roasting the maize and then milled using a hammer mill. Palm oil, salt and dried pepper were added to the roasted maize flour proportionately and mixed thoroughly to obtain the product. Kokoro was produced by first gelling the maize flour using hot water, cooled, mixed with more maize flour, moulded to shape and finally deep fried at 140°C for 8 minutes. Kango was prepared by milling maize grain into flour; ingredients such as pepper, onion, salt and water were added to the maize flour, mixed together to make slurry. The slurry was fried in hot groundnut oil at temperature of 126°C for 8 minutes. Results from the preliminary survey revealed that 65% of the respondents believed that the business of snack production is not that capital intensive while 85% were of the opinion that aadun and kokoro in particular have a shelf life of not less than 2 days. All the respondents of kokoro recognised absence of moulding machine as an area of challenge while that of kango has to do with a shorter shelf life (12 h). The incorporation of kidney bean and alligator pepper in maize flour was observed to increase the water and oil absorption capacities of the resultant blends thereby giving 113.44 to 152.67 ml/mg and 104.97 to 136.67 ml/mg respectively for aadun; 109.07 to 156.11 ml/mg and 108.52 to 136.70 ml/mg respectively for kokoro; and 109.21 to 156.90 ml/mg and 110.68 to 136.67 ml/mg respectively for kango. The pasting properties of the maize flour blends were also enhanced due to the incorporation of kidney bean and alligator pepper. The peak viscosity of the flour blends ranged from 0.34 to 6.54 RVU (aadun), 3.25 to 7.65 RVU (kokoro) and 3.24 to 7.67 RVU (kango). The incorporation of kidney bean and alligator pepper in the production of the snacks increased the protein contents from 8.53 to 17.60% (aadun), 4.87 to 14.67% (kokoro) and 9.63 to 16.37% (kango). The mineral contents (sodium, potassium, calcium, magnesium, iron and zinc) of the snacks were equally increased due to the incorporation of kidney bean and alligator pepper. A general increase was observed for vitamin B1 (0.69- 1.25 mg/100g), B2 (0.09 - 0.46 mg/100g) and B3 (0.11 - 0.72 mg/100g) in the snacks due to the incorporation of kidney bean and alligator pepper. There was also a general increase in the anti-nutritional contents of the snacks containing kidney bean and alligator pepper and these include phytate (3.59 - 21.84 mg/g), oxalate (0.09 - 1.53 mg/g), tannin (0.82 to 6.71 mg/g and trypsin inhibitor (0.01 - 23.1%). However, the values were found to be within the acceptable levels. The sensory quality rating of the snacks revealed that aadun, kokoro and kango produced from (75.9% maize [ART2], 23.6% kidney bean and 0.5% alligator pepper); (75.9% maize [ART2], 23.6% kidney bean and 0.5% alligator pepper); and (82.7% maize [SUWAN3], 15.7% kidney bean and 1.6% alligator pepper), respectively were rated the highest in terms of texture, colour, taste and aroma. The lysine content of the snacks increased from 3.09 to 6.20 while the haematological parameters of rats fed with formulated snacks were higher than those fed with ordinary snacks. The histopathological examination showed that the liver and kidney of rats fed with improved snacks are healthy. This research work showed that aadun, kokoro and kango produced from the composited maize flour, kidney bean and alligator pepper had higher nutritional contents.