QUALITY CHARACTERIZATION OF SNACK BAR FROM ORANGE-FLESHED SWEET POTATO PUREE, PEANUT PASTE AND SESAME SEED FLOUR

Abstract

ABSTRACT The problem of malnutrition in sub-Saharan Africa is one that has longed plagued the continent. To solve this, there has been a focus on finding low-cost plant protein sources for inclusion in food formulations which at the same time solves the twin problem of food wastage. The objective of this study was to formulate and characterize snack bar made from indigenous crops namely; Orange Fleshed Sweet Potato (OFSP), peanut and sesame seed while ginger was added as a spice and also to increase the functionality of the snack bar. Simplex centroid mixture design for three-component was used to generate fourteen experimental runs to investigate the effect of ingredient combination (60- 65% OFSP, 25-30% peanut paste (P) and 10-15% sesame flour (SF)). The snack bar was analysed for proximate, minerals, vitamins, physical and sensory properties. Data from experimental runs were analysed using one-way ANOVA, regression model and numerical optimization. Proximate, vitamin, minerals, amino-acid profile, anti-oxidant, physical and sensory properties were carried out on the optimized snack bar samples. The mean range for each of the proximate were moisture (12.39 to 21.19%), fat (19.62 to 22.79%), fat (1.68 to 5.89%), fibre (3.48 to 11.93%), protein (18.99 to 35.89%) and carbohydrate (15.64 to 40.56%); vitamins were Vitamin E (2.99 to 3.46mg/g) and β-carotene (0.67 to 2.11mg/g); minerals were phosphorous (12.96 to 19.10mg/g), sodium (35.93 to 44.48mg/g), potassium (55.75 to 85.10mg/g), zinc (1.78 to 3.52ppm) and calcium (30.50 to 43.00mg/g) and for consumer overall acceptability was (5.56 to 7.88). Numerical optimization technique were used to obtain the optimum mixture blend of O64.93P25S10 and O60P27.07S12.94 with a desirability level of 0.571 and 0.557 respectively. The qualities of optimized snack bars were amino acid profile (valine (4.37, 4.05g/100g), threonine (2.82, 2.97g/100g), isoleucine (4.36, 4.07g/100g), leucine (6.46, 7.36g/100g), lysine of (3.19, 3.26g/100g), methionine (1.22, 1.37g/100g), phenylalanine (3.20, 3.65g/100g), histidine (2.09, 2.64g/100g) and tryptophan (0.98, 1.09g/100g), glycine (3.17, 3.28g/100g), alanine (4.76, 5.09g/100g), serine (3.47, 3.70g/100g), proline (3.73, 3.66g/100g), aspartic acid (7.94, 8.42g/100g), arginine (5.00, 5.46g/100g), tyrosine (3.08, 3.06g/100g) and cysteine (0.84, 0.94g/100g) and glutamic (11.87, 12.09g/100g) respectively. Vitamin E, B1, B3, B6, B9 and C were (6.00, 0.39mg/g), (0.84, 0.18mg/g), (1.47, 0.57mg/g), (1.04, 1.49mg/100g), 5.56, 13.82mg/g), (7.73, 11.71mg/100g) respectively; DPPH and TPC were (61.33, 57.39%) and (15.79, 11.96 mg GAE/100g) respectively; colour was Lightness (26.28, 25.29), redness (8.22, 7.61) and yellowness (19.88 and 16.43) respectively; Texture were hardness (187 and 245N), chewiness (184 and 281N), adhesiveness (57.70 and 54.87J), stringiness (7.92, 7.15mm), gumminess (190.5, 281mm) and cohesiveness (1.09, 1.36). The optimized samples had an overall acceptability of (7.03, 6.94) respectively. In conclusion, the optimized snack bars had a high sensory acceptance and it’s nutritional and anti-oxidants properties makes it suitable to be consumed as a healthy snack.