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

  • L. Butkhup Laboratory Equipment Center, Division of Research Supporting and Extension Services, Mahasarakham University, Mahasarakham 44000, Thailand
  • S. Chowtivannakul Division of Research Supporting and Extension Services, Mahasarakham University, Mahasarakham 44150, Thailand
  • R. Gaensakoo Department of Biotechnology, Faculty of Technology, Mahasarakham University, Mahasarakham 44000, Thailand
  • P. Prathepha Department of Biotechnology, Faculty of Technology, Mahasarakham University, Mahasarakham 44000, Thailand
  • S. Samappito Department of Biotechnology, Faculty of Technology, Mahasarakham University, Mahasarakham 44000, Thailand

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
(EC50), 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.
Published
2016-12-12
Section
Articles