Phenol profiles and antioxidant properties of white skinned grapes and their coloured genotypes during growth

Abstract

Anthocyanins are natural pigments that exhibit a wide range of protective effects with potential benefits for human health related to their antioxidant activities. Grape berries are rich anthocyanins, and these compounds have considerable influence on wine quality. However, these pigments are known to only be present in coloured grape berries. In the present study, we investigated three distinctive grapes, in which only a few reports of mutant strains on the skin colour of the grape berry were reported. Anthocyanin and non-anthocyanin phenolic profiles of grape berry skin, pulp, and seeds at different growth stages were analysed using high performance liquid chromatography of flight mass spectrometry (HPLC-ESI-MS/MS). Meanwhile, grape antioxidant properties were evaluated at growth stages, including the early stage, veraison, and mature stage. The results showed that some anthocyanins contents, such as malvidin 3-Oglucoside, are significantly different between white skin grapes and their corresponding coloured genotypes, with high content in coloured but not in white skin grapes. However, other anthocyanins, such as delphinidin 3-O-glucoside, showed no significant differences between white skin grapes and their corresponding coloured genotypes. Moreover, non-anthocyanin phenolic profiles and antioxidant properties, except cultivars Pinot Blanc and Pinot Noir, showed no significant differences between white skin grapes and their corresponding coloured genotypes at any growth stage, including the pulp and seeds. However, significant differences were noted between different cultivars, for example, white-ciputao and Pinot Noir, Pinot Blanc and Muscat Rouge, and coloured-ciputao and Muscat Blanc, showing that the antioxidant capacity was not always in correlation with skin colour of grape berries.

Voltammetric Behavior, Flavanol and Anthocyanin Contents, and Antioxidant Capacity of Grape Skins and Seeds during Ripening (Vitis vinifera var. Merlot, Tannat, and Syrah)

“…The results of this work confirm that the total phenolic content in skins were lower than in seeds [13]. In skins, the highest antioxidant capacity was found at the green stage but a previous study [48] found the highest TAC at maturity. This difference may depend on the extraction method used but also on the protocol of the test.…”

“…The content increased from 2 mg M3GE/g DW to 22 mg M3GE/g DW at maturity in skin Merlot extracts. A similar evolution was reported in the literature [41][42][43][47][48][49][50]. In the case of Syrah, the anthocyanins content decreased at maturity from 28 to 14 mg M3GE/g DW, this decline may be due to the degradation of anthocyanins by the peroxidases and glycosidases present in skins [47].…”

Evaluation of the potential astringency of the skins and seeds of different grape varieties based on polyphenol/protein binding

“…Grape skins and seeds contain high levels of functional compounds, which are known to play a beneficial role in human health (Karnopp et al, 2015;Niu et al, 2016;Pantelić et al, 2017;Trošt et al, 2016). These compounds can be transferred to wine during fermentation (Nogales-Bueno et al, 2017), further influencing the quality of the wine .…”

Anthocyanin profile, color and antioxidant activity of blueberry ( Vaccinium ashei ) juice as affected by thermal pretreatment

“…[1,2] Anthocyanins and other phenolic compounds in blueberries can protect organisms against oxidative stress induced by free radicals and exhibit a wide range of health-promoting effects. [3][4][5] To extend the fruit's commercial life, blueberries can be further processed into products such as jams and juices. Blueberry juice is increasingly promoted and consumed for its nutritional and health benefits.…”