Alternative Preservation Techniques to Address the Challenges of Postharvest Losses of Fruits: Osmotically Pretreatment on Colour Retention of Selected Fruits During Drying

Abstract

Post-harvest losses of fruits remain a major challenge in developing countries, especially in tropical regions, where high temperatures speed up deterioration. This study compared conventional solar drying and osmotic dehydration pretreatment for preserving the colour quality of apples, pin eapples, and tomatoes under the climatic conditions of BirninKebbi, Nigeria. Fruits were subjected to either direct solar drying or osmotic pretreatment followed by solar drying. Digital image analysis using ImageJ software was used to quantify colour changes through red, green and blue (RGB) pixel intensities during storage. Results indicated superior colour retention in osmotically treated samples, especially apples and pineapples. Analysis of variance showed significant differences in colour characteristics among treatment groups (F(6,35)=3.43, p=0.009). Regression analysis additionally showed that drying method markedly predicted colour quality (β=0.172, p=0.024). The results show that osmotic dehydration is a practical, low-cost technology able to reduce post-harvest losses while maintaining fruit market quality in resource-constrained environments.