Equilibrium Moisture Content and Thermodynamic Properties of Garri

Gari, a widely consumed cassava product in West Africa, plays a vital role in the dietary needs of millions of people. Moisture content is a critical factor affecting its quality, texture, shelf life, and susceptibility to microbial contamination. This study investigates the equilibrium moisture content (EMC) of gari at varying temperatures (40°C, 45°C, 50°C, and 55°C) across different relative humidity (RH) levels. The static gravimetric method was employed to measure EMC, with data fitted to four sorption models: GAB, Modified Henderson, Modified Oswin, and Modified BET. The results demonstrated that EMC decreased as temperature increased, with the Modified Oswin model providing the best fit (R² = 0.968–0.983). The GAB model revealed a reduction in the monolayer moisture content (M<sub>0</sub>) from 3.988 to 3.640 as temperature rose, indicating a reduced water-binding capacity of the gari. Thermodynamic analysis showed exothermic enthalpy values ranging from -25.1 to -21.3 kJ/mol, and negative entropy values from -80.1 to -66.7 J/mol·K, suggesting strong interactions between water and starch molecules. These findings underscore the importance of controlling drying and storage conditions to maintain the quality and shelf life of gari, offering valuable insights for food processing, packaging, and storage solutsions.