Detailed investigation of the composition and transformations of phenolic compounds in fresh and fermented Vaccinium floribundum berry extracts by high‐resolution mass spectrometry and bioinformatics

Abstract

Introduction Blueberries are known for their very high content of biologically active phenolic compounds; nonetheless, differently from the North American and European species of blueberries, Neotropical blueberries have not been extensively studied yet. Objectives In the present paper, the phenolic composition of Vaccinium floribundum Kunth, which is endemic to the Andean regions and grows 1,600 to 4,500 meters above sea level, was investigated by ultra‐high‐performance liquid chromatography coupled to high‐resolution mass spectrometry (UHPLC‐HRMS). Native and fermented berries were compared in terms of phenolic composition as well as antioxidant activity, total phenolic content, and total anthocyanin content. Materials and Methods V. floribundum native and fermented berries were extracted and analyzed by UHPLC‐HRMS. The acquired datasets were processed by Compound Discoverer 3.1 using a dedicated data analysis workflow that was specifically set up for phenolic compound identification. Results In total, 309 compounds were tentatively identified, including anthocyanins, flavonoids, phenolic acids, and proanthocyanidins. The molecular transformations of phenolic compounds during fermentation were comprehensively investigated for the first time, and by a customized data processing workflow, 13 quinones and quinone methides were tentatively identified in the fermented samples. Compared to other species of the genus Vaccinium, a peculiar phenolic profile is observed, with low abundance of highly methylated compounds. Conclusion Andean berries are a rich source of a wide variety of phenolic compounds. Untargeted MS analyses coupled to a dedicated data processing workflow allowed expanding the current knowledge on these berries, improving our understanding of the fate of phenolic compounds after fermentation.

Fermentation of Vaccinium floribundum Berries with Lactiplantibacillus plantarum Reduces Oxidative Stress in Endothelial Cells and Modulates Macrophages Function

“…The total phenolic content was determined by the Folin-Ciocalteu reagent method obtaining a similar polyphenols concentration in fermented and non-fermented Pushgay berries (P: 2.38 ± 0.01 and FP: 2.95 ± 0.14 µg GAE/µg lyophilized berry) (Table 1), in line with previous data [32].…”

“…Cerrato et al [32] showed that glyco-conjugations were mostly hydrolyzed following fermentation, and a higher concentration of free flavonols was found, mainly quercetin (97% of the total flavonol content) [32]. In the untargeted analysis, Cerrato et al also identified, for the first time, a large number of phenolic acids and their derivatives (≈145 compounds) in FP and P; furthermore, anthocyanins in P were almost completely degraded after fermentation in phenolic acids [32]. In this study, we performed a targeted/quantitative analysis of quercetin (both the aglycone and glycoconjugate forms) through HPLC-ESI MS/MS (Table 1).…”

“…Pushgay berries were collected between March and April 2019 in Cajamarca province (Cajamarca, Perú) and their taxonomy was certified by the Herbario San Marcos (National University of San Marcos, Lima, Peru) at the National University of San Marcos (Lima, Peru). Berries were crushed, freeze-dried by a Heto PowerDry LL1500 (Thermo Fisher Scientific, Waltham, MA, USA) finely ground in a mortar, and stored at −20 • C until use [32].…”

“…Quercetin glycoconjugates are the major flavonoid compounds in Pushgay berries [24,25] and the analysis of the phenolic profile of FP and P was obtained through untargeted characterization by ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) [32]. Cerrato et al [32] showed that glyco-conjugations were mostly hydrolyzed following fermentation, and a higher concentration of free flavonols was found, mainly quercetin (97% of the total flavonol content) [32].…”

“…Quercetin glycoconjugates are the major flavonoid compounds in Pushgay berries [24,25] and the analysis of the phenolic profile of FP and P was obtained through untargeted characterization by ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) [32]. Cerrato et al [32] showed that glyco-conjugations were mostly hydrolyzed following fermentation, and a higher concentration of free flavonols was found, mainly quercetin (97% of the total flavonol content) [32]. In the untargeted analysis, Cerrato et al also identified, for the first time, a large number of phenolic acids and their derivatives (≈145 compounds) in FP and P; furthermore, anthocyanins in P were almost completely degraded after fermentation in phenolic acids [32].…”