Determination of the total phenolic content of commercially available green teas using an in vitro gastrointestinal system: a preliminary study

Palamutoğlu M. İ., SİPAHİ S., Palamutoğlu R., Kasnak C.

Italian Journal of Food Science, cilt.38, sa.1, ss.298-307, 2026 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 38 Sayı: 1
  • Basım Tarihi: 2026
  • Doi Numarası: 10.15586/ijfs.v38i1.3356
  • Dergi Adı: Italian Journal of Food Science
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Compendex, Directory of Open Access Journals
  • Sayfa Sayıları: ss.298-307
  • Anahtar Kelimeler: catechin, green tea, HPLC, in vitro assays, phenolic compounds
  • Acıbadem Mehmet Ali Aydınlar Üniversitesi Adresli: Evet

Özet

This preliminary study evaluated changes in total phenolic content and catechin and epicatechin levels in commercially available green teas through an in vitro digestion. Samples (1.5% dry tea in 100 mL water at 80°C) were analyzed for total soluble solids, pH, and color. The initial total phenolic content ranged from 381.19–1779.50 µg gallic acid equivalent/mL, decreasing to 315.22–1266.37 µg/mL in the small intestine. Epicatechin decreased from 7.64–13.97 µg/mL to 4.53–9.19 µg/mL, while catechin dropped from 13.13–24.03 µg/mL to 5.43–14.03 µg/mL. Significant decreases occurred across digestion, indicating reduced bioaccessibility of green tea polyphenols that may influence antioxidant and health effects.