Effect of Osmotic Dehydration in Tomato Juice on Microstructure of Garlic and on Drying Using Different Methods

Abstract

This study investigates the effects of osmotic dehydration on garlic clove halves using a low-pH osmotic solution with ascorbic acid, concentrated tomato juice, and basil extract (45° Brix). Samples, both dehydrated and fresh, were subjected to various drying methods. Physical properties, such as CT scan analysis, texture profile analysis (TPA), porosity, and density, were examined. Additional parameters like energy consumption, specific energy consumption, moisture content, water activity, and color change were evaluated. Osmotic dehydration reduced moisture content by over 7.5%. The specific energy consumption for microwave vacuum drying (MVD) was 95 kJ/g for osmotically dehydrated samples compared to 118 kJ/g for non-dehydrated samples. Drying times decreased by 24 min for MVD and 15% for microwave convective drying (MCD). The Weibull model best fit the drying kinetics, with R2 values above 0.99 and RMSE below 0.03 for all methods. TPA tests showed no significant impact of osmotic dehydration on hardness, though drying methods significantly affected hardness, ranging from 49 N to 707 N. Color change was higher for osmotically dehydrated samples, reaching 37.09 for OD-CD compared to 29.78 for CD.