Physicochemical properties, phytochemicals, and biological activities of heat-treated Elaeagnus multiflora juice and vinegar

Abstract

In this study, vineger was produced after heat treatment of Elaeagnus multiflora juice and its fermentative characteristics were investigated. The heat-treated juice and vinegar of E. multiflora were similar in fruit color, with b values (redness) of 39.48 (juice) and 37.56 (vinegar). After 10 days of fermentation of E. multiflora fruit, the acetic acid bacteria viable cell number, pH, acidity, reducing sugar content, and alcohol content were 4.59-4.62 log CFU/mL, 3.14-3.45, 0.2-2.12%, 0.69-35.24 mg/mL, and 0.2%, respectively. The heat-treated juice and vinegar showed significantly higher radical scavenging and digestive enzyme inhibitory activities than untreated samples, and the levels of soluble phenolics, soluble flavonoids, flavan-3-ol derivatives, and phenolic and derivatives were increased. Additioinally, the heat-treated vinegar contained major organic acids, such as acetic acid (21.82 mg/mL), and major flavan-3-ols and phenolic acids, such as catechin (72.24 μg/mL), catechin gallate (273.36 μg/mL), epigallocatechin gallate (68.35 μg/mL), protocatechuic acid (12.84 μg/mL), and salicylic acid (42.29 μg/mL). At 25 μL/mL treatment, DPPH and ABTS radical scavenging activities and α-glucosidase and pancreatic lipase inhibitory activities were 79.66%, 93.99%, 90.12%, and 64.85%, respectively. This result suggested that it is possible to produce new types of vinegar and beverages, using heat-treated E. multiflora juice. ? The Korean Society of Food Preservation. All rights reserved.