Wine by-Products: Phenolic Characterization and Antioxidant Activity Evaluation of Grapes and Grape Pomaces from Six Different French Grape Varieties

Abstract

Grenache, Syrah, Carignan Noir, Mourvèdre, Counoise and Alicante Bouchet grape seeds and skins, harvested in 2009 and 2010 in the Rhône valley area of France, and their respective pomaces remaining after vinification, were analyzed for their phenolic composition and antioxidant activity. The polyphenol content was quantified by HPLC and the Folin-Ciocalteu assay. The antioxidant potential was measured with four different assays: ORAC, FRAP, ABTS and DPPH. Seeds contained higher amounts of total polyphenols, up to 44.5 mg of gallic acid equivalent [GAE]/g dry weight in Alicante pomace, than skin extracts. The maximum total phenolic in skins was 31.6 mg GAE/g dry weight detected in 2010 Alicante pomace. Seeds also had the highest antioxidant capacity. HPLC analysis revealed that, despite the vinification process, pomaces still contained an appreciable amount of proanthocyanidins as well as several anthocyanin glycosides. Alicante and Syrah proved to be the varieties of most interest in terms of their potential development for nutraceutical purposes.

Determination of Bioactive Compounds and Mineral Contents of Seedless Parts and Seeds of Grapes

“…Concerning the results, the grape seeds contained rich bioactive substances. According to Ky et al (2014), the total phenolic content of grape seed extracts varied from 36.6 to 49.7 mg GAE/g, and the antioxidant activity of the seed extract of grape varieties using DPPH ranged from 117.4 to 536.2 µmol Trolox/g (dry weight). The total phenolic contents of the grape seeds (825.80 to 3 313.5 mg GAE/100 g) were higher than that of the pulp (50.79 to 141.72 mg GAE/100 g) (Anastasiadi et al, 2010).…”

Influence of Acidity and Extraction Time on the Recovery of Flavonoids from Grape Skin Pomace Optimized by Response Surface Methodology

“…Comparing the contents of polymeric procyanidins from literature of 13.4 mg g -1 d.m. 45 , the grape skin pomace from this study represents a potentially valuable source of phenolic compounds. 47 .…”

Antioxidant comparative effects of two grape pomace Mexican extracts from vineyards on erythrocytes

“…The information obtained could be used to generate further evidence design and development of food and other products (e.g. nutraceuticals) with health benefits (Ky, Lorrain, Kolbas, Crozier, & Teissedre, 2014).…”