Optimisation of onion bulb curing using a heat and mass transfer model

Improper curing of onion bulbs leads to high losses during storage. The aim is seal the by drying its outer scales and neck, limiting weight loss. A coupled heat mass transfer model was established for prediction moisture temperature distribution inside bulbs. finite element method used discretising governing equations transient transfer. predicted results were compared with experimental data profiles under controlled conditions at temperatures from 30 50 °C, relative humidity values 70%. simulation agreed well a small standard error estimate varying 0.06 0.042 (decimal, w.b.) 0.8 2 content temperature, respectively. revealed sharp gradients establishing near surface neck mostly uniform throughout curing. validated then optimise process targeting low overall loss, dehydration, skin diffusivity. Different time combinations found be optimal depending on harvesting stage size set target criteria. had more pronounced effect than other parameters. can serve as digital twin monitor control using measured inputs such humidity, air velocity.