Profiling the physicochemical characteristics of Indonesian freeze-dried strawberries with various pre-treatment

Strawberries are a commodity with high economic value due to their bioactive compounds. Consuming strawberries has been shown to offer health benefits, including antioxidant, anti-inflammatory, anticancer properties, and cardiovascular protection. This study aims to compare the physicochemical properties of freeze-dried strawberries subjected to different pre-treatments: blanching, soaking in hypochlorite solution, and soaking in hot (60 °C) hypochlorite solution. The strawberries were then freeze-dried and stored at 45 °C for 8 weeks to evaluate changes in their physicochemical characteristics. Pre-treatment methods significantly influenced the bioactive compounds. Scanning Electron Microscopy (SEM) of the freeze-dried samples showed that blanching caused the most severe tissue damage. FTIR and LC-HRMS chromatograms suggested that hypochlorite treatments may trigger oxidation or other chemical reactions, resulting in changes in functional groups. The main compounds identified across all pre-treatment methods were ellagic acid (C 14 H 6 O 8 ), kaempferol (C 15 H 10 O 6 ), quercetin (C 15 H 10 O 7 ), benzofuranone (C 15 H 12 O 6 ), catechin (C 15 H 14 O 6 ), some phenolic acid and glycoside. After 8 weeks of storage, antioxidant activity and total flavonoid content declined, while pH increased, color darkened, and brightness and redness decreased. These findings provide a foundation for determining optimal drying duration and offer insights into bioactive compound transformations during the drying process. • Blanching and hypochlorite treatments affect tissue damage and bioactive compounds. • FTIR and LC-HRMS chromatograms showed some changes in the functional groups. • Storage at 45 °C results in a decrease in antioxidant activity and flavonoid content.