Study of the Phenolic Composition of Shiraz Red Grape Cultivar (Vitis vinifera L.) Cultivated in North-eastern Thailand and its Antioxidant and Antimicrobial Activity

Abstract

The seed, skin and whole grape extract of the red grape cultivar Shiraz, which is widely cultivated in Northeastern Thailand, were investigated. Total phenolic, total flavonoid and total monomeric anthocyanin content ranged from 48.04 to 116.73 g GAE/100g db (dry weight base), 74.82 to 258.69 mg CE/g db, and 5.06 to 55.45 mg/100g db, respectively. Dimeric procyanidin (119.56-484.08 mg/100g db), (+)-catechin (52.30-231.92 mg/100g db), (-)-epicatechin (27.92-174.10 mg/100g db), and gallic acid (4.42-27.80 mg/100g db) were found to be the main flavanols that were present in the seed. Rutin and trans-resveratrol were present in amounts of between 21.13 and 40.05 and 2.85 and 3.60 mg/100g db respectively. All extracts showed remarkable DPPH radical-scavenging activity (EC 50 ), ranging from 0.47 to 2.10 µg/mL. Methanolic extract from the seed and skin were also active against all Gram-positive bacteria, but these exerted less of an inhibiting effect on the growth of the tested Gram-negative bacteria. The activity of the methanolic extract of the seed was effective against B. cereus ATCC 11778, B. subtilis ATCC 6633 and S. faecalis TISTR 459.

Identification and Quantification of Flavonoids in Korean Wild Grape (Meoru grape, Vitis coignetiae) and Its Pomace

“…The amount of polyphenols and flavonoids was elevated in grape pomace and is ~2.30 time higher than that of whole grape, which is in agreement with Butkhup et al (2010). Unexpectedly, grape pomace posed high concentration of anthocyanins when exactly equal amount of whole grape and grape pomace were weighed and analyzed.…”

“…Naringenin which reduces plasma and hepatic cholesterol by suppressing HMG-CoA reductase activity Isovanillic acid, a non-flavonoid and a metabolized form of isovanillin by aldehyde dehydrogenase (Revilla and Ryan, 2000), was distinguished. Moreover, benzoic acid, caffeic acid, gallic acid, and rosmarinic acid, non-flavonoids, were found in either whole grape or grape pomace, which is similar to those found in the Vitis vinifera L. of Germany and USA and Shiraz red grape of Thailand (Lee et al, 2003;Kammerer et al, 2004;Butkhup et al, 2010).…”

“…The content of epicatechin and rutin of KWG was similar to those of whole Shiraz red grapes in Thailand (Butkhup et al, 2010) but lower than the Shiraz red grape when KWGs were pressed and turned to pomace.…”

The determination of bioactive ingredients of grape pomace (Vranac variety) for potential use in food and pharmaceutical industries

“…Grapes and wine are rich in phenolic compounds which are very important for human health as compounds with antioxidant, anti-cancer, anti-inflammatory and antimicrobial activities [1][2][3]. There are also studies on the beneficial effects of those compounds on the heart and other chronic diseases [4].…”

“…This waste was usually used for the production brandy and fertilizer. The phenol composition and antioxidant activity of grape extracts have been well documented [1][2][3][4]6], and there is less data about pomace [7][8][9]. Also, there were few reports about vegetable oils from grape seeds, and their health benefits, [10] but no reports about the whole grape pomace.…”