Kinetics of β-Carotene Breakdown and Moisture Sorption Behavior of Yellow Cassava Flour during Storage

Abstract

β-Carotene is an important plant pigment with high vitamin A activity. The kinetics of β-carotene degradation and moisture sorption behavior of yellow cassava flour produced by different drying techniques was investigated during storage. The βcarotene degradation kinetics were described using a first-order kinetic model, while the moisture adsorption data was fitted to five mathematical equations using nonlinear regression. During storage, the reaction rate constant for β-carotene degradation, which increased with increasing temperature, ranged from 0.0045 to 0.0396, 0.0029 to 0.0309, and 0.0025 to 0.0349 per month for flour produced by solar drying, hot air oven drying, and drum drying, respectively. Flour produced by solar drying had the highest activation energy of 124.2 kJ/mol, whereas drum drying had the lowest activation energy of 85.8 kJ/mol. All the yellow cassava flours showed a type II sigmoidal sorption curve in which the equilibrium moisture content increased with increasing water activity. The GAB model was the best for describing the moisture sorption behavior of the product, with a predicted monolayer moisture ranging from 2.8 (for drum drying) to 8.0 g water/100 g of flour (for solar drying). Findings from this study are vital for establishing the packaging and storage requirements of yellow cassava flour.