Effect of African Yam Bean and Sprouted Maize Incorporation on Proximate Composition Functional, Pasting and Sensory Properties of Gari

Abstract

Background: Gari, a fermented and toasted product from cassava (Manihot esculenta Crantz) serves as a major staple food in Nigeria and many West African countries. Standard gari despite its popularity and economic importance is deficient in protein and micronutrient composition, necessitating incorporation with other locally available produce. This study investigated the effect of African yam bean (Sphenostylis stenocarpa) and sprouted maize (Zea mays) incorporation on proximate composition, functional, pasting and sensory properties of gari.

Methodology: Cassava, African yam bean and sprouted maize were processed into mash and blended in varying ratios (100:0:0), (97:1.5:1.5), (95:2.5:2.5), (90:5:5), (87:6.5:6.5), (85:7.5:7.5), (80:10:10), (77:11.5:11.5), (75:12.5:12.5), (70:15:15), (67:16.5:16.5), (65:17.5:17.5), (60:20:20), (57:21.5:21.5), (55:22.5:22.5), (50:25:25), (47:26.5:26.5), (45:27.5:27.5), (40:30:30), (35:32.5:32.5) respectively prior to fermentation and toasting and represented as samples A to T. Standard analytical methods were used to determine the proximate composition. Functional, pasting and sensory properties were evaluated using established procedures.

Results: Proximate composition shows moisture content value range of (7.43 to 10.40%), ash (1.95 to 3.75%), fat (0.75 to 2.65%), fibre (2.02 to 4.31%), protein (2.95 to 20.98%) and carbohydrate (60.88 to 81.93%). Bulk density, water absorption capacity, oil absorption capacity, swelling index, emulsion capacity and foam capacity values ranged from (0.508 to 0.775g/cm3), (3.05 to 5.85g/ml), (2.15 to 4.52g/g), (1.52 to 2.58), (23.33 to 32.99%) and (5.21 to 9.89%) respectively. Pasting viscosities (peak, trough, breakdown and set back) varied significantly (p<0.05) with range of values (338.16 to 387.25RVU), (121.42 to 141.74RVU), (212.26 to 246.21RVU), (390.21 to 435.36RVU) and (252.77 to 305.06RVU), respectively. Peak time and pasting temperature ranged from (4.53 to 6.12 Minutes) and (79.14 to 87.50 0C) respectively. Sensory properties revealed that gari produced from 100% cassava which served as control was the most preferred by a 30 man semi trained panelist with an overall acceptability score of 7.48 followed by sample C (97% cassava mash+1.5% African yam bean +1.5% sprouted maize mash) with score 7.36.

Conclusion: The incorporation of sprouted maize and African yam bean significantly (p<0.05) improved the nutritional, functional and pasting qualities of gari.