Effect of alcoholic and acetous fermentations on the phenolic acids of Kei‐apple (Dovyalis caffra L.) fruit

Abstract

BACKGROUND The Kei apple is a tree found on the African continent. Limited information exists on the effect of alcoholic and acetous fermentation on the phytochemicals of Kei apple. The fruit has increased concentrations of l‐malic, ascorbic, and phenolic acids among other compounds. Juice was co‐inoculated with Schizosaccharomyces pombe (Sp) and Saccharomyces cerevisiae (Sc) to induce alcoholic fermentation (AF). Acetous fermentation followed AF, using an acetic acid bacteria (AAB) consortium. RESULTS Saccharomyces cerevisiae + Sp wines and vinegars had the highest pH. Total acidity, soluble solids and l‐malic acid decreased during AF and acetous fermentation, and was highest in Sc wines and vinegars. Volatile acidity (VA) concentration was highest in Sp vinegars but was not significantly different from Sc and Sc + Sp vinegars. Gallic acid was highest in Sp wines and vinegars, whereas syringic acid was highest in Sc wines and vinegars. The Sc + Sp wines were highest in caffeic, p‐coumaric, and protocatechuic acids. Schizosaccharomyces pombe vinegars were highest in caffeic and p‐coumaric acids. Highest concentrations of ferulic and sinapic acids were found in Sp and Sc wines, respectively. Chlorogenic acid was most abundant phenolic acid in both wines and vinegars. CONCLUSION Saccharomyces cerevisiae + Sp and Sc fermentation had a positive effect on most phenolic acids; Sc + AAB had an increased effect on syringic and chlorogenic acids, whereas Sp + AAB resulted in an increase in gallic, caffeic, and p‐coumaric acids. The AAB selected had minimal performance with respect to VA production in comparison to commercial vinegars. Acetic acid bacteria selection for acetous fermentation should therefore be reconsidered and the decrease of certain phenolic acids during acetous fermentation needs to be investigated. © 2021 Society of Chemical Industry

Analysis of Antioxidant Capacity and Antimicrobial Properties of Selected Polish Grape Vinegars Obtained by Spontaneous Fermentation

“…Research shows that yeasts act in two ways during the fermentation process: They can capture polyphenols and release antioxidant compounds other than polyphenols from inside the cells and from the cell wall [ 39 ], i.e., by the release of bound and conjugated phenolic acids to their free form after cell wall degradation [ 71 ]. It was observed that the strain of yeast involved in alcoholic fermentation affected the profile of organic acids [ 72 ] as well as TCP and antioxidant potential [ 73 ].…”

The role of fruit vinegar in food science: perspectives among consumers, the scientific community and patent holders

“…Thus, the keywords found in the scientific articles are presented in the form of a word cloud (Figure 1b). It was noted that the most mentioned keyword was "phenolic" (n = 31), which shows that the characterization of the phenolic profile of vinegars was evident in the documents retrieved (Fernandes et al, 2019;Kim et al, 2020;Minnaar et al, 2021;Zou et al, 2017), followed by the words "vinegar" (n = 23), "antioxidant activity" (n = 14) and "fermentation" (n = 14). Moreover, it was possible to classify the scientific articles retrieved into subject areas (Table 1), where most studies were attributed to the areas of Agricultural and Biological Sciences (n = 57), and Biochemistry, Genetics and Molecular Biology (n = 34).…”

“…The study revealed that sea buckthorn vinegar is a source of organic acids, in particular acetic acid (39.65 g/L), and of polyphenols such as gallic acid (763.89 mg/L) (Özdemir et al, 2022a). On the other hand, in the vinegar made with fruits of Dovyalis caffra L., the predominant polyphenol was chlorogenic acid, which showed mean values between 1,910.98 and 1,958.75 mg/L (Minnaar et al, 2021). In addition, Özdemir et al (2022a) reported that the major polyphenol found in vinegar made from fruits of Rosa canina L. was catechin (5.66 mg/L).…”

“…Moreover, it was possible to classify the scientific articles retrieved into subject areas (Table 1), where most studies were attributed to the areas of Agricultural and Biological Sciences (n = 57), and Biochemistry, Genetics and Molecular Biology (n = 34). Studies related to vinegars classified under the area of Agricultural and Biological Sciences focused on the production of new types of vinegars and their chemical, bioactive, and sensory characterization (Minnaar et al, 2021;Özdemir et al, 2022a, b;Siqueira et al, 2021;Zou et al, 2022).…”