Does a Freeze-thaw Pretreatment Enhance the Quality of Dried Foods? A Meta-Analysis

Based on the results of several studies, it's questionable if freeze-thaw pretreatment can improve dried product qualities. To answer this question, a meta-analysis was conducted to explain the effect of freeze-thaw pretreatment on the quality of dried products. This research aimed to determine the impact of freeze-thaw pretreatment on the quality of dried plant-based foods. The data was sourced from the Scopus database, and the selection criteria were based on the PRISMA protocol. All meta-analysis calculations were performed using OpenMEE Software. The results revealed that freeze-thaw pretreatment significantly affected ΔE, TFC, and TPC. However, freeze-thaw pretreatment does not significantly affect shrinkage and hardness. Based on the analysis subgroup found, the best freezing temperatures are -20 °C and -196 °C because both temperatures favourably impact TFC and hardness. Moreover, freeze-thaw pretreatment is suitable for infrared hot air, near-infrared, and hot air–microwave vacuum drying. The freeze-thaw pretreatment has also been effective in enhancing the quality of lotus roots, cranberries, and red dragons