Bioactive compounds and antioxidant activity analysis during orange vinegar production

Abstract

Citrus fruits are significant sources of bioactive compounds, such as ascorbic acid, polyphenols and carotenoids, due to their antioxidant properties important for human nutrition. In addition, since oranges possess high sugar content (8-15%), making vinegars from alcoholic orange substrates, with functional characteristics is a possible development of novel products. The aim of this research work was to analyze changes in ascorbic acid, total phenolics, total carotenoids and antioxidant activity during orange vinegar processing. In order to analyze the influence of acetification and aging in these characteristics, samples were taken in three stages: orange alcoholic substrate for acetification (SNA), young orange vinegar or recently obtained (Vn0) and orange vinegar after six month-aging in bottles (Vn6). Statistically significant differences (p < 0.05) were found among bioactive compounds concentrations; antioxidant activity decreased along the process, but total phenolics and carotenoids remained constant during aging period (Vn0-Vn6). The highest reduction was recorded during the acetification stage, possibly due to components oxidation caused by continuous air flow to the system. A higher contribution (p < 0.05) to antioxidant activity was associated to ascorbic acid and phenolic compounds concentration.

Physicochemical characterization, antioxidant activity, and sensory analysis of beers brewed with cashew peduncle (Anacardium occidentale) and orange peel (Citrus sinensis)

“…These results suggest that there should be a threshold in the concentration of polyphenols content to promote a significant effect on antioxidant activity. The presence of phenolic compounds and antioxidant activity in orange peel (Kelebek et al, 2009;Hegazy & Obrahium, 2012;Park et al, 2014;Davies et al, 2017) and cashew peduncle (Lopes et al, 2012;Lima et al, 2013;Andrade et al, 2015) have been confirmed in others studies. Moreover, formulations presented antioxidant activity values (Table 5) higher than those found by Marques et al (2017) in craft beers.…”

Physical properties, resistant starch content and antioxidant profile of purple sweet potato powder after 12 months of storage

“…These findings are similar to works reporting on the antioxidant activities of different food products upon long-term storage. Tsai et al [39] observed a reduction in FRAP for mulberry wine stored for 12 months; Muzzaffar et al [40] observed a decrease in FRAP and DPPH scavenging activity for pumpkin candy stored for 3 months; while Davies et al [41] noticed a reduction in DPPH scavenging activity in orange vinegar after 6 months of storage. Based on these findings, it can be concluded that, the drop in antioxidant activity in food powders is inevitable after long-term storage, irrespective of storage temperatures.…”

Biotechnological Processes in Fruit Vinegar Production

“…On the other hand, it is also known that the concentration of ethanol could exert an inhibitory effect on acetic acid bacteria when it is above 50 g/L (approximately 6% v / v ), this being more pronounced in discontinuous processing [ 118 ]. For this reason, there are studies, such as the one by Davies et al [ 119 ] on the production of orange vinegar, where orange wine, which had an alcoholic content of 13–14%, was diluted in order to facilitate the action by acetic acid bacteria. The dilution caused a variation in the concentration of nutrients, and a solution with minerals and a source of nitrogen had to be added.…”

“…The investigations that have used the method of elaboration of fruit vinegars by means of submerged culture are also very numerous, of which orange has been the most commonly used fruit [ 28 , 42 , 119 ], followed by pomegranate [ 45 , 71 ]. Nevertheless, other research studies have been found on strawberries [ 62 ], persimmon [ 48 ], peach [ 109 ], tomato [ 132 ], lemon [ 80 ], apricot [ 76 ], and marula [ 129 ].…”