Enhancing the Nutritional Value and Preservation Quality of Strawberries through an Optimized Osmotic Dehydration Process

Abstract

This study aimed to optimize the osmotic dehydration process of strawberry slices by examining the effects of glycerol concentration, immersion time, and temperature on water loss and solid gain. Additionally, the study explored the use of chokeberry infusion to enhance the total phenolic content of the strawberries, thereby increasing their nutritional value. Using the Box–Behnken design and response surface methodology, the study identified optimal conditions to maximize water loss and solid gain. The findings revealed that high glycerol concentration (60% w/w) and temperature (50 °C), combined with optimal immersion times, significantly influenced water loss and solid gain. Experimental validations confirmed the model’s predictions, showing high prediction accuracy (87.37% to 87.69%) for water loss determination but moderate prediction accuracy (42.80% to 64.72%) for solid gain. The immersion of strawberry slices in a hypertonic osmotic chokeberry infusion for 170–220 min maximized the migration of natural antioxidants. Moreover, the osmotic dehydration process effectively reduced water activity and moisture content, enhancing the strawberries’ shelf stability. Furthermore, the addition of calcium chloride (CaCl2) helped maintain the strawberries’ firmness and color during dehydration. Overall, the optimized osmotic dehydration process preserved the structural integrity and improved the nutritional profile and preservation quality of the strawberries, suitable for preparation of various fruit-based products.

Keywords

• osmotic dehydration
• strawberry
• process optimization
• response surface methodology
• total phenolic content (TPC)
• physicochemical characteristics