Fragaria viridis Fruit Metabolites: Variation of LC-MS Profile and Antioxidant Potential during Ripening and Storage

Abstract

Fragaria viridis Weston or creamy strawberry is one of the less-known species of the Fragaria genus (Rosaceae family) with a wide distribution in Eurasia and is still in the shadow of more popular relatives F. ananassa (garden strawberry) or F. vesca (wild strawberry). Importantly, there is a lack of scientific knowledge on F. viridis compounds, their stability in the postharvest period, and bioactivity. In this study, metabolites of F. viridis fruits in three ripening stages were characterized with high-performance liquid chromatography with photodiode array and electrospray ionization triple quadrupole mass spectrometric detection (HPLC-PAD-ESI-tQ-MS). In total, 95 compounds of various groups including carbohydrates, organic acids, phenolics, and triterpenes, were identified for the first time. The quantitative content of the compounds varied differently during the ripening progress; some of them increased (anthocyanins, organic acids, and carbohydrates), while others demonstrated a decrease (ellagitannins, flavonols, etc.). The most abundant secondary metabolites of F. viridis fruits were ellagitannins (5.97–7.54 mg/g of fresh weight), with agrimoniin (1.41–2.63 mg/g) and lambertianin C (1.20–1.86 mg/g) as major components. Antioxidant properties estimated by in vitro assays (2,2-diphenyl-1-picrylhydrazyl radical (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical (ABTS), ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC)) showed good antioxidant potential in all ripening stages of F. viridis fruits. The pilot human experiment on the effect of F. viridis fruit consumption on the serum total antioxidant capacity confirmed the effectiveness of this kind of strawberry. Postharvest storage of ripe fruits at 4 °C and 20 °C lead to declining content in the majority of compounds particularly ascorbic acid, ellagitannins, and flavonols, with the most significant loss at room temperature storage. These results suggest that F. viridis fruits are a prospective source of numerous metabolites that have potential health benefits.

Water-Soluble Melanoidin Pigment as a New Antioxidant Component of Fermented Willowherb Leaves (Epilobium angustifolium)

“…The changes of low-molecular-weight phenolics before and after the fermentation of E. angustifolium leaves were precisely analysed by high-performance liquid chromatography with photodiode array detection and electrospray ionization triple quadrupole mass spectrometric detection (HPLC-PDA–ESI-tQ-MS). Finally, 59 compounds were identified after comparison of their chromatographic behaviour, ultraviolet, and mass spectra with reference substances (28 compounds) and literature data [ 27 , 28 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ] ( Figure 2 , Table 2 ). Only 23 of the compounds had been found in E. angustifolium previously [ 43 , 45 , 54 ]; 36 compounds were detected for the first time.…”

“…The antioxidant potential of E. angustifolium melanoidin, oenothein B and trolox was studied using the known in vitro microplate spectrophotometric assays: scavenging activity against 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH • ) [ 24 ], 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radicals (ABTS • + ) [ 25 ], N , N -dimethyl- p -phenylenediamine radicals (DMPD •+ ) [ 26 ], superoxide anion radicals (O 2 • − ) [ 27 ], hydroxyl radicals ( • OH) [ 27 ], and chloride radicals (Cl • ) [ 28 ]. The nitric oxide (II) scavenging potential was studied in a spectrophotometric assay with sodium nitroprusside as a source of NO [ 29 ].…”

“…The trolox equivalent content in the oenothein B and E. angustifolium melanoidin solutions and the E. angustifolium decoctions was found by a coulometric titration method with electrogenerated bromine radicals [ 28 ] using the potentiostat Expert-006 (Econics Expert Ltd., Moscow, Russia) with a four-electrode two-compartment electrochemical cell. All measurements were carried out three times.…”

Metabolites of Siberian Raspberries: LC-MS Profile, Seasonal Variation, Antioxidant Activity and, Thermal Stability of Rubus matsumuranus Phenolome

“…In R. matsumuranus leaves, 21 compounds were determined to be flavonols in glycoside form. By comparing their mass spectral data with those reported previously [25][26][27][28][29] and with reference standards, these flavonols were identified as derivatives of quercetin (12 compounds) and kaempferol (9 compounds). The quercetin group of flavonols was the largest with non-acylated and acylated fragments linked with carbohydrate fragments.…”

“…Another ellagitannin of the hexahydroxydiphenoylgalloyl-glucose type, potentillin (22), was detected previously in R. arcticus leaves [48] and R. idaeus shoots [38]. Okuda et al [47] suggested using the compounds sanguiin H6 (29) and sanguiim H11 (33) as chemotaxonomic markers of the genus Rubus. This statement applies to the considered plant object.…”