Combination of 3’,4’,5,7-tetrahydroxy isoflavone and active modified atmosphere packaging inhibits yellowing, maintains quality, and prolongs shelf life of fresh peeled water chestnuts (Eleocharis dulcis)

Abstract

Yellowing and quality loss shorten the shelf life of fresh peeled water chestnuts (FPWCs). The purpose of this study was to elucidate the mechanism by which the combination of 3’,4’,5,7-tetrahydroxy isoflavone (3’,4’,5,7-THIF) and active modified atmosphere packaging (AMAP) prolonged the shelf life of FPWCs. FPWCs were treated with 1.0% 3’,4’,5,7-THIF, AMAP (18.3% O2, 81.7% N2), and a combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2). The yellowing extent, mass loss rate, enzymatic activities, yellowing substance concentrations, quality, and microorganisms of FPWCs were analyzed. The results showed that the three treatments all inhibited the increase in the mass loss rate and activity of peroxidase and lowered the eriodictyol concentration. AMAP (18.3% O2, 81.7% N2) and the combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) inhibited the respiration of FPWCs and increased the total soluble solids, titratable acidity, and ascorbic acid concentrations. The three treatments had no significant effects on the activities of polyphenol oxidase and phenylalanine lyase and naringenin concentration. 3’,4’,5,7-THIF (1.0%), AMAP (18.3% O2, 81.7% N2), and the combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) prolonged the shelf life of FPWCs by 6, 6, and 12 d, respectively. The combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) was optimal among the three treatment methods. These results suggested that the combination of 1.0% 3’,4’,5,7-THIF and AMAP (18.3% O2, 81.7% N2) might be used to extend the shelf life of FPWCs in practice.