Targeted metabolomics analysis of the impact of co-pigment on the color of strawberry wine

The vibrant color of strawberry wine, primarily from anthocyanins, is susceptible to degradation during storage due to oxidation, temperature fluctuations, and enzymatic activity, diminishing visual appeal and value. Polyphenolic flavonoids offer potential for enhancing color stability through antioxidant effects and anthocyanin co-pigmentation. This study investigated gallic acid, rutin, and vanillic acid for improving strawberry wine color stability. Pre-fermentation rutin addition (Pre-Rutin) significantly enhanced stability, increasing redness, yellowness, and brightness, resulting in a more vibrant appearance. Post-pasteurization polyphenol content initially surged due to cellular disruption and biochemical reactions, later declining or stabilizing as microbial and chemical activities dominated. Anthocyanin content, sensitive to storage conditions, decreased over time from degradation factors, leading to color fading. Targeted metabolomics revealed that rutin profoundly facilitates the synthesis of specific anthocyanin derivatives: Pelargonidin-3-O-sophoroside content was 16.37 times higher, Cyanidin-3-O-(6″-O-succinyl) galactoside 7.9 times higher, and Cyanidin-3-O-arabinoside 4.3 times higher in the Rutin group versus the CK. This study demonstrates for the first time that pre-fermentation rutin addition significantly enhances strawberry wine color stability (ΔE<5) by catalyzing the formation of key anthocyanins. Crucially, rutin alters anthocyanin composition, inhibiting unstable non-acylated forms while promoting stable acylated and specifically glycosylated derivatives (notably Pelargonidin-3-O-sophoroside, Cyanidin-3-O-(6″-O-succinyl) galactoside and Cyanidin-3-O-arabinoside). This shift towards more stable anthocyanin structures significantly enhances overall color stability.