CHARACTERIZATION OF A FIBRE-RICH POWDER PREPARED BY LIQUEFACTION OF UNRIPE BANANA FLOUR AND FORMULATION OF FIBRE-RICH BISCUITS

Abstract

Unripe banana flour is high in resistant starch and other essential chemicals, has recently been used to make a variety of innovative foodstuffs. The principle aim of this study was to evaluate some chemical and physicochemical properties of a fibre-rich powder prepared by liquefaction of unripe banana flour. Two flour samples prepared were subjected to analysis for determination of proximate composition, minerals composition, TS, RS, total phenolic content, antioxidant activity and total flavonoid content, water and oil holding capacity. Also experimental biscuits were formulated with partially substituting UBF and FRP with wheat flour in different proportions (18%, 29.9% w/w). These biscuits samples were evaluated for proximate composition and sensory attributes. UBF had higher amount of moisture content (6.7%) and ash content (2.6%). FRP had higher amount of carbohydrate content (86.1%). Formulated biscuit samples had highest value of crude fiber (1.7% in sample D), fat content (17.7% in sample B) and crude protein (10.1% in control sample) respectively. When comparing UBF and FRP to wheat flour, sodium, calcium, magnesium, potassium, and chloride were much greater significantly, but phosphorus, copper, zinc, and iron were significantly (p value < 0.05) lower. The two flour samples had antioxidant content that was more similar to each other. FRP had the highest levels of total phenolic content (1.04±0.06 mg GAE / 100 g) and total flavonoid content (7.5±0.04 mg QE / 100 g). The total starch content of UBF 45.8±0.03 (g/100g) was higher than FRP. Resistant starch content 19.13±0.01 (g/100g) was higher in UBF. The highest mean value of available starch 40.4±0.02 (g/100g) was found in FRP. Both WHC (2.6±04) g of water/g of dry sample and OHC (1.1±05) g of water/g of dry sample were higher in unripe banana flour. The consumer profiling of the biscuits made from a blend of UBF and FRP in comparison with that of wheat flour biscuits (control) revealed that cookies made with UBF and FRP attained higher overall acceptability scores than commercial or control biscuits. This finding showed that biscuits formulated from UBF and FRP could be of good consumer and market acceptability. All sensory attributes in the control biscuits were lower, with the exception of color. The sensory attributes of sample C (29.5% FRP) are the best of all the formulated biscuits. As a result, the findings of this study could be used in the bakery industry to fulfill consumer specifications and expectations.