Effect of Different Thawing Methods on the Quality and Antioxidant Activity of Frozen Actinidia arguta

This study investigated the effects of air thawing (AT), running water thawing (RWT), microwave thawing (MT), ultrasonic thawing (UT), and high-pressure processing thawing (HPPT) on the physicochemical properties, nutritional content, sensory quality, microstructure, and antioxidant capacity of frozen Actinidia arguta. Except for air thawing, the other four thawing methods significantly improved thawing efficiency. MT caused uneven heating and was prone to local overheating. HPPT enhanced color appearance and resulted in higher levels of chlorophyll, β-carotene, flavonoids, ascorbic acid, and polyphenols. However, HPPT reduced water-holding capacity and resulted in a softer texture. Moisture distribution, texture analysis, and scanning electron microscopy revealed that UT achieved uniform thawing without causing severe damage to fruit tissue structure. Consequently, UT-treated A. arguta exhibited firmer tissue structure, better water retention, and improved consumer palatability. Regarding antioxidant activity, both UT and HPPT demonstrated significant advantages. In summary, HPPT yields nutritionally enriched Actinidia arguta, while UT produces Actinidia arguta with superior textural quality. This study provides alternative strategies to conventional thawing methods for frozen Actinidia arguta.