VARIATION OF TANNINS IN OAK LEAVES

Tannin content (as total phenols), condensed tannins and protein precipitation capacity were estimated in the young and old leaves of five oak species. The tannin content and protein precipitation capacity was in the order Quercus semecarpifolia > Q. serrata > Q. leucotrichophora > Q. glauca > Q. baloot. Tannin level was highest in young leaves and declined in old leaves. Protein precipitation capacity had a trend similar to that of total phenols. Conversely, in all the species examined, condensed tannins were minimum in the young but maximum in old leaves.