Comparative Study of Drying Kinetics of Plantain Slices Using Solar, Oven, and Open-Air Methods in Cross River State

Plantain (Musa paradisiaca) is an important staple food in Cross River State, South South Nigeria, where post-harvest losses of up to 40 percent have been reported due to inadequate preservation infrastructure. This study compares the drying kinetics of plantain slices subjected to three drying methods: indirect solar drying, forced-air oven drying at 60 degrees Celsius, and traditional open-air sun drying. Ripe plantain slices of uniform 5 mm thickness were used for each drying method, with mass recorded at one-hour intervals until equilibrium moisture content was achieved. Drying data were fitted to six thin-layer drying models including Newton, Page, Modified Page, Henderson and Pabis, Logarithmic, and Two-term models. Model selection was based on chi-square, root mean square error, and coefficient of determination criteria. The Page model provided the best fit across all three methods. Solar drying achieved target moisture content (12 percent wet basis) in 38 hours, compared to 16 hours for oven drying and 72 hours for open-air sun drying. Quality evaluation of dried products included colour, texture, and microbial load. Solar-dried samples had the lowest microbial count and best colour retention compared to open-air samples. The study contributes to drying kinetics literature for tropical starchy crops. Findings are relevant to plantain processors, rural energy practitioners, and agricultural extension services in Cross River State. Keywords: plantain, drying kinetics, solar drying, thin-layer models, Cross River State