Effects of cyclodextrins on phenolic acids biotransformation and color and volatile substances stabilization in sequentially fermented apple juice

Exogenous additions and storage time affect the nutritional and sensory properties of fermented products. This study investigated the effect of natural cyclodextrin on the nutritional indicators and overall quality of Saccharomyces cerevisiae and Lactiplantibacillus plantarum sequentially fermented apple juice, and further studied the quality changes during the shelf life. Results showed that the cyclodextrin significantly affected the quality of apple juice during sequential fermentation and storage, especially β-cyclodextrin increased the total polyphenols and flavonoids of apple juice after sequential fermentation reached 0.67 g/L and 0.42 g/L; DPPH and ABTS radical scavenging rate increased to 76.33% and 77.55%; increased the organic acids and monomeric phenols. β-CD has a positive effect on the generation and protection of higher alcohols and esters, especially ethyl acetate and heptyl acetate. Compared with other groups, the addition of β-CD before fermentation showed superior color retention in terms of lightness (L*) and yellow (b*) index under 4 °C and 25 °C. Additionally, the aroma and sensory qualities of the product were improved and preserved. Therefore, the addition of cyclodextrin before fermentation not only improved the nutritional quality and antioxidant activity of fermented juice, retained and improved the aroma and color, but also stabilized the comprehensive quality during storage.