| Frozen rabbiteye blueberries (Vaccinium ashei) were processed into juice (BJ), wines, and vinegars. Two wines were produced by using fermentation without (BW1) or with (BW2) skin contact. Rabbiteye blueberry vinegars were made from BW1 (JV) or BW2 (WV) or blueberries (BV). Total phenolics, total anthocyanins, antioxidant activities (beta-carotene bleaching assay and ferric thiocyanate assay), and antiradical activity (DPPH-radical scavenging method) of these fluid products and their by-products (pomaces) were determined. The BW2 had the highest content of anthocyanins and polyphenols and the highest beta-carotene bleaching activity and antiradical activity. Among the by-products, WP had higher total anthocyanin content, total polyphenol content, and antioxidant activities. Acetification decreased total anthocyanin content, total polyphenols and antioxidant activities.; Aroma-active components of rabbiteye blueberry vinegars (JV, WV, and BV) were evaluated. Direct solvent extraction (DSE) and solid-phase microextraction (SPME) were used to collect aroma components. Key aroma components were determined by gas chromatography-olfactometry (GCO) based on Osme analysis. Of 48 aroma components detected, 26, 29, and 36 components in JV, WV, and BV were aroma-active components, respectively. The most potent odorants included acetic acid (vinegar), 2/3-methyl-butanoic acid (sweaty), phenethyl acetate (sweet, honey), 2-phenylethenol (rosy), octanoic acid (sweaty), eugenol (clove), and phenylacetic acid. The contributions of these compounds to each sample were different. |
