The structures of the condensed tannins from leaf, stem bark and root bark of Acacia confusa were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis, and their antioxidant activities were measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and ferric reducing/antioxidant power (FRAP) assays. The results s...

The effect of commercially available chestnut and mimosa tannins in vitro (experiment 1) or in vivo (experiment 2) on the growth or recovery of Escherichia coli O157:H7 or generic fecal E. coli was evaluated. In experiment 1, the mean growth rate of E. coli O157:H7, determined via the measurement of optical density at 600 nm during anaerobic culture in tryptic soy broth at 37 degrees C, was red...

CONTENTS INTRODUCTION . . 210 CHEMISTRY O F T A N N I N S . . . 210 OCCURRENCE O F T A N N I N S . . 211 G E N E R A L . . . 211 T A N N I N S IN CEREALS A N D LEGUME SEEDS . . 213 N A T U R A L FUNCTION O F T A N N I N S . . 215 T A N N I N ANALYSIS . . 215 COLORIMETRIC METHODS . . 215 Vanillin assay . . 215 Folin Denis assay . . 216 Prussian blue assay . . 216 Acid butanol assay . . 216 P R O...

Various tannin-complexing agents have been used to study the potential adverse effects of tannins on rumen metabolism. Using a method based on turbidity formation, the binding of various tannin-complexing agents (polyvinyl polypyrrolidone (PVPP), polyethylene glycol (PEG) of molecular weights 2000 to 35,000, and polyvinyl pyrrolidone (PVP) of molecular weight 10,000, 40,000 and 360,000) to tann...

The present study reports the effect of Emblica officinalis (EO) derived tannins on humoral immune responses and their protective efficacy against Eimeria infection in chickens. Tannins were extracted from EO and characterized by HPLC. EO derived tannins (EOT) and commercial tannins (CT) were orally administered in broiler chicks in graded doses for three consecutive days, that is, 5th-7th days...

Partially unacylated new oligomeric hydrolyzable tannins, nilotinin T2 (1, trimer) and nilotinin Q1 (2, tetramer), together with four known trimers, nilotinin T1 (3) and hirtellins T1-T3 (4-6), and a dimer, tamarixinin B (7), were isolated from the aqueous acetone extracts of leaves of Tamarix nilotica. Among them, the new trimer 1 and the known trimers 4 and 6, in addition to the partially una...

The tannin fractions isolated from hazelnuts, walnuts and almonds were characterised by colorimetric assays and by an SE-HPLC technique. The complexation of Cu(II) and Zn(II) was determined by the reaction with tetramethylmurexide, whereas for Fe(II), ferrozine was employed. The walnut tannins exhibited a significantly weaker reaction with the vanillin/HCl reagent than hazelnut and almond tanni...