Effect of Storage on Physical, Chemical, Microbial and Sensory Properties of a Formulated Biscuit Prepared from Sweetpotato- Pigeonpea-Banana Flour Blend

Biscuit is gaining increasing prominence in the diet of Nigerians since most of them have adopted the western lifestyle. It is therefore a veritable vehicle to improve the nutritional well being of Nigerians. Storage is known to affect the quality attributes of biscuit. A nutritionally improved biscuit had been formulated from optimised sweetpotato, pigeonpea and banana flour blend. This study therefore evaluated the some quality attributes of the nutritionally improved biscuit stored at room temperature of 85% relative humidity. The moisture, colour, textural properties, rancidity, microbial load and sensory properties of the biscuit packed in high density polyethylene pouches (HDPE) and low density polyethylene pouch (LDPE) were investigated at 2 weeks interval. The water vapour transmission rate of the high density polyethylene pack and low density polyethylene pack were 4.052 x 10-13 g/mm/day/mmHg and 6.566x 10-13 g/mm/day/mmHg, respectively. The moisture content, free fatty acid and peroxide values which increased during storage varied from 6.75 to 13.2%, 1.48 to 3.77% and 1.6 to 2.43 meqO2/kg, respectively in LDPE, while the values increased from 6.75 to 10.35%, 1.48 to 2.83% and 1.6 to 2.37 meqO2/kg, respectively in HDPE. The L*, a*, b*, hardness, springiness, adhesiveness, cohesiveness and overall acceptability of the biscuit decreased in both LDPE and HDPE during storage. The biscuits stored in LDPE and HDPE were acceptable till 4 and 6 weeks, respectively.