EVALUATION OF POLYPHENOLS CONTENT AND ANTIOXIDANT ACTIVITY OF TWO TABLE GRAPE VARIETIES UNDER ENVIRONMENTAL CONDITIONS OF THESSALY

This paper examines the seeds, the skin and the flesh of two table grape varieties grown in Larissa, Greece, namely, the white variety Victoria and the colorful variety Muscat Hamburg, as to the content of total phenols (TP), non-flavonoid phenols (NFP), flavonoid phenols (FP), tannin flavonoids (TF), non-tannin phenols (NTP), total flavanols (F-3-ols), antiradical (DPPH center dot) and ferric reducing power (FRAP). The content of (TP) in the flesh, the skin and the seeds of grapes varied in a range from 0.64 mg (GAE)/g f.m. for the flesh of the variety Victoria to 11.14 mg (GAE)/g f.m. for the seeds of Muscat Hamburg variety. The (FP) and (TF) was the major phenolic fraction. The content of total F-3-ols which include catechin and epicatechin (monomers) and procyanidins (dimers, trimers and tetramers) is varying from 0.118 mg (CE)/g f.m. for the flesh of the variety Victoria to 2.40 mg (CE)/g f.m. for seeds of the variety Muscat Hamburg. The antiradical power (DPPH center dot) ranges from 0.61 mu mol DPPH center dot/g f.m. for the flesh of Victoria variety to 16.83 mu mol DPPH center dot/g for the seeds of the same variety and the antioxidant capacity ranges from 1.88 mu mol FRAP/g f.m. for the flesh of Victoria to 150.3 mu mol FRAP/g f.m. for the seeds of Muscat Hamburg.