Targeted quantitative analysis of the effect of hawthorn leaves on volatiles and nonvolatile polyphenols and amino acids in hawthorn wine

This study investigates the effects of hawthorn leaves treatment and preheating on the physicochemical properties, aromatic profiles, and nutritional components of hawthorn wine. Three application strategies were implemented: (1) direct leaves addition to preheated/unheated pulp pre-fermentation, (2) leaves extract incorporation into preheated/unheated pulp pre-fermentation, and (3) post-fermentation leaves immersion in preheated/unheated wine. Results indicated that preheating combined with leaves treatment enhanced polyphenol content and antioxidant capacity. However, heat treatment led to a notable reduction in terpenes, aldehydes, and ketones, along with umami- and sweet-associated amino acids, while increasing certain bitter amino acids, ultimately diminishing sensory quality. Leaves supplementation significantly elevated polyphenol and amino acids levels as well as 16 characteristic aroma markers, including methyl octanoate, phenylethyl alcohol, and beta-damascenone. Strategy (2) had a superior improvement and promotion effect on all monitoring parameters and sensory evaluation of hawthorn wine compared to the other two strategies. Optimal sensory quality was achieved using unheated pulp with low-concentration leaves extract (2 g/L), which preserved aromatic complexity and amino acid balance. This study guides functional-flavor balance in hawthorn wine production, enhancing product diversity.