Valorization of pineapple peels: Production of vinegar enriched with red-Jambo (Syzygium malaccense) leaf extract

Abstract

Pineapple peel vinegar was produced by the traditional system and enriched with the leaf extract of Syzygium malaccense (L.) Merr. & L.M. Perry. Appreciable phenolic contents and antioxidant potential were found in pulp and peel vinegar added of the extract. Catechin, epicatechin and caffeic, p-coumaric, ferulic, and gallic acids were the main phenolic compounds found in peel vinegar. The enrichment of the vinegar with the extract promoted an increase in the content of polyphenols (443.6-337.3 mg GAE/L) and antioxidant activity. Peel wines presented higher luminosity (L*) and higher saturation index (C*), and their color tended more towards yellow than pulp wines. Acetification reduced the saturation index (C*) and led to the intensification of the hue angle in the peels vinegar. All types of vinegar showed biocidal activity against different bacteria and yeast, and the addition of the extract potentiated the antimicrobial activity of peel vinegar, especially against S. aureus.