The Influence of Thawing Method on Bioactive Substances, Color, and Sensory Parameters in Frozen Strawberries from Retail Chains

Background: Freezing and thawing methods are critical to the final quality of food products. Methods: Our work focuses on evaluating the effect of five thawing protocols (in the refrigerator, at room temperature, in the microwave, and in a water bath at water temperatures of 20 and 40 °C) on the physicochemical properties, color, sensory properties, content of bioactive compounds, and antioxidant activity in frozen fruits of Fragaria spp. from different retail chains (n = 7) and from diverse countries of origin. Results: We found that although thawing at room temperature is a slow process, it best preserved the original quality of the strawberries when compared with other methods. Different thawing protocols had various effects on the color, sensory properties, polyphenol profile (TPC, TFC, TPA, and anthocyanins determined spectrophotometrically), and antioxidant activity (DPPH method) of strawberries. Our results indicate that each evaluated thawing method was viable. Conclusions: This study can provide a basis for selecting appropriate thawing processes in the strawberry processing industry based on the intended use of the food for further processing.