Effects of ultrasonic-assisted maceration on flavor, metabolites and antioxidant properties of kiwi wine

Ultrasonic-assisted maceration offers a promising strategy to optimize flavor quality in fermented fruit wines, yet its application on kiwi wine (KW) remains unexplored. This study systematically investigated the impact of ultrasonic-assisted maceration on KW's metabolomics, flavoromics, sensory evaluation and antioxidant properties. 1H NMR identified 58 molecules in KW. Ultrasonic-assisted maceration significantly increased the concentrations of phenylalanine, acetoacetate, N,N-dimethylglycine, creatinine, and levulinate, while decreasing the levels of epicatechin, acetoin, cytidine, acetone, and hydroxyacetone. GC-IMS and GC-MS characterized 29 and 46 volatile molecules, respectively. The levels of esters and organic acids showed a direct proportionality to the intensity of the ultrasonic treatment, while an opposite trend was found for alcohols. Sensory scores of KW improved under the ultrasonic treatment. In detail, ultrasonic treatment for 40 min at 240 W led to the highest scores for taste-lasting and mouthfeel. A treatment of equal duration at 480 W led to the highest aroma score. E-tongue effectively discriminated taste features brought to KW by the treatments. Moreover, ultrasonic treatments significantly enhanced KW's scavenging activity of DPPH, hydroxyl and superoxide anion radicals. This study provides theoretical references and basis for the application of ultrasonic-assisted maceration as a technique to potentially enhance the flavor quality of KW.