Interaction mechanisms between caffeine and polyphenols in infusions of Camellia sinensis leaves

1H NMR-based metabolomic characterization during green tea (Camellia sinensis) fermentation

“…6). Most recently, variations in 1 H NMR chemical shifts of caffeine protons in black tea infusions of C. sinensis leaves were also reported in model solutions at different pH, which were induced by strong interaction with EGCG and EGC (Couzinet-Mossion et al, 2010). Therefore, the degradation of the interaction between caffeine and EGCG, EGC, or ECG may be responsible for the large chemical shift variations in 1 H NMR spectra of caffeine in fully fermented tea in the present study rather than pH variations among samples because pH values were carefully adjusted to 5.53 (±0.01, n = 10) in partially fermented tea, 5.52 (±0.01, n = 10) in fully fermented tea, and 5.53 (±0.02, n = 10) in green tea and because EGCG and EGC were also completely degraded in fully fermented teas.…”

The major factors influencing the formation of sediments in reconstituted green tea infusion

“…However, the removal of polyphenols also decreased total sugar, caffeine and protein participating in sediment formation. This indicates that polyphenols significantly influenced the other chemical components participating in sediment formation as the polyphenols could bind with caffeine and protein in the formation of tea sediment (Charlton et al, 2000;Couzinet-Mossion et al, 2010;Xu et al, 2013).…”

“…These results suggest that oxalic ion could easily combine with Ca 2+ although chelating agent Na 2 EDTA was present in the green tea infusion. As the pH of the tea infusion increased to 8.0, the turbidity of the tea infusion significantly decreased to 0.74 NTU because the polyphenols were oxidised under the alkaline conditions (Couzinet-Mossion et al, 2010). However, adding Ca 2+ could increase the turbidity to 81.08 NTU at pH 8.0.…”

“…The formation of tea sediment is influenced by various parameters, including the trace chemicals in the water used for its extraction (Couzinet-Mossion et al, 2010;Xu et al, 2013), extraction temperature (Liang & Xu, 2003), pH (Liang & Xu, 2001), the components of the tea leaves (Xu, Chen, Shen, & Yin, 2011) and the concentration of solids (Xu, Chen, Yuan, Tang, & Yin, 2012). Polyphenols and caffeine are the principal components of tea sediment (Chao & Chiang, 1999b;Yin et al, 2009).…”

Preparation of chitosan matrices with ferulic acid: physicochemical characterization and relationship on the growth ofAspergillus parasiticus

“…Furthermore, the increase in the fungistatic potential of the Mparticles/FA and Nparticles/FA, can also be attributed to the presence and release of FA (Free and linked FA in CS-TPP matrices). It has been reported that phenolic compounds exhibit antimicrobial effects against bacteria and fungi, due to their ability to interact via hydrogen bonds with proteins and amino acids from the cell wall and cell membrane, and even from cytoplasm, damaging cell permeability (Yi et al, 2014;Nakayama et al, 2013;Bossi et al, 2007;Couzinet-Mossion et al, 2010). It was also mentioned that these phenolic compounds decrease or inhibit the activity of essential enzymes for fungal growth (Bossi et al, 2007;Kandil, Li, Vasanthan, & Bressler, 2012;Yi et al, 2014).…”