TECHNOLOGICAL, ANTIOXIDANT, ANTIMICROBIAL AND SENSORY PROFILES OF SELECTED KINDS OF GRAPE OILS

Abstract

The aim of this study was to determine technological (fat content, acid number, peroxide value, oxidation stability, fatty acid profiles), antioxidant (DPPH method), antimicrobial activity (antibacterial and antifungal) and sensory profiles of 4 kinds of Slovak grape seed oils (commercial, oil from white grape variety, oil from blue grape variety and oil made from grape after alcoholic fermentation). The fat content ranged from 95.86 % (blue grape variety oil) to 98.23 % (commercial oil). The values of acid number ranged from 0.15 mg KOH. g-1 (blue grape variety oil) to 0.90 mg KOH. g-1 (commercial oil) and of peroxide number from 2.75 mmol O2. kg-1 (blue grape variety oil) to 8.91 mmol O2. kg-1 (commercial oil). Values of antioxidant activity (DPPH method) ranged from 47.61 mg TEAC. l-1 (commercial oil) to 75.30 mg TEAC. l-1 (blue grape variety oil) and oxidation stability from 2.75 h (commercial oil) to 8.91 h (blue grape variety oil). The predominant acid in all samples was essential omega-6 fatty acid linoleic acid, which can decrease the cholesterol levels and it is necessary for the activity of cell membranes. Its content differed from 69.43± 0.00 % in commercial oil to 72.75± 0.04 % in blue grape variety oil. Grape oils inhibited microscopic fungi (Candida albicans), gramnegative G- (Yersinia enterocolitica, Salmonella enterica subs. enterica) and grampositive G+ (Bacillus cereus, Staphylococcus aureus subs. aureus) bacteria. Sensory analysis of tested oils was evaluated good, with the best results in commercial oil, especially consistency and overall appearance. The results of this work characterize and accentuate the qualities of edible grape oils, as a nutritionally valuable food for the nutrition of the human organism.