ABSTRACT

Quality and sensory attributes of banana (Musa sapientum) peels, and their effect on wheat cakes were assessed. The proximate composition, antioxidant activity, mineral, vitamin and phytochemical content of the banana peel flour were evaluated using standard laboratory procedures. Afterwards, wheat flour and banana peel flour were blended into the following proportions: 90:10, 80:20, 70:30 and 50:50, respectively. The functional properties of the composite flour was evaluated prior to using them in cake production. Cake processed from 100% wheat flour served as the reference sample. The proximate composition, physical properties, microbial quality and sensory properties of the cake samples were also assessed using standard laboratory procedures. The data generated were statistically analysed by One Way Analysis of Variance (ANOVA) using Statistical Product of Service Solution (Version 22.0). The result of proximate composition showed that the banana peel flour possess dry matter (85.67), moisture content (13.34 %), crude protein (7.52 %), fat (9.36 %), crude fibre (10.87 %), ash (12.98 %), carbohydrate (45.14 %) and energy value (294.88 Kcal/100g). In terms of mineral content, the banana peel flour had their potassium, sodium, calcium, magnesium and phosphorus as 2.12 mg/100g, 210.82 mg/100g, 59.57 mg/100g, 14.27 mg/100g, 126.02 mg/100g, respectively. The result of phytochemical content showed that the banana peel flour had 1.58 mg/100g tannin, 1.83 mg/100g saponin, 0.73 mg/100g phenol and 2.05 mg/100g flavonoid. The vitamin content of the banana peel flour showed presence of vitamin A (1.23 µg/100g), vitamin C (47.96 mg/100g) and vitamin E (4.77 mg/100g). The result of antioxidant activity revealed that the banana peel flour had 1.26 mgGAE/100g, 28.93 % and 239.62 umol Trolox.eq for FRAP, DPPH and ABTS, respectively. The functional properties of the banana peel and wheat composite flour showed that bulk density, water absorption capacity, oil absorption capacity, swelling index and wettability of the composite flour ranged from 0.75 to 0.85 g/ml, 1.62 to 1.64 g/ml, 2.33 to 2.63 g/ml, 1.02 to 1.07 g/ml and 1.08 to 1.52 Sec, respectively. The proximate composition of the cake showed presence of moisture content (16.34 to 18.33 %), crude protein (8.23 to 8.43 %), crude fibre (19.76 to 20.94 %), fat (1.22 to 2.02 %), ash (1.42 to 1.56 %), carbohydrate (50.86 to 50.88 %) and energy value (414.39 to 425.59 Kcal/100g). In terms of the physical properties, volume, specific volume, density, width, height and weight of the cake samples ranged from 126.85 to 12.07 cm3, 0.71 to 0.75 g/cm3, 4.81 to 4.84 cm, 5.31 to 5.36 cm and 171.00 to 178.50 g, respectively. The result of microbial count ranged within 2.15x106 to 3.6x106 CFU/g with S. aureus and Bacillus Spp being the major isolated organisms. The result of sensory evaluation showed that cake processed with 100% wheat flour was more preferred by the panelists followed by cake substituted with 10% banana peel flour.