Biophenolic components of olives

The occurrence of biophenolic components in olives provides functional value to the Mediterranean food culture, owing to recognized antioxidant activities of these substances. The concentration of biophenolic compounds in olives are closely linked to texture and organoleptic characteristics of agrifood products, i.e. table olive and olive oil. The concentrations of di€erent biophenolic compounds in olives were investigated in order to develop appropriate procedures for determination of these compounds in fresh and processed table olives and in the olive drupes for olive oil production. Olives from Spain (Hojiblanca cv), Portugal (Douro cv), Greece (Thasos and Conservolia cvs) and Italy (Taggiasca and Cassanese cvs) were analysed. Four di€erent protocols were employed. The ®rst allows for an estimate of the total concentration of simple biophenolic compounds; the second, for soluble compounds and soluble esteri®ed derivatives of these compounds; the third, the qualitative determination of cytoplasmatic soluble biophenolic content; the fourth, determination of soluble, glucosidic, esteri®ed and cell-wall bound biophenols by means of a rapid, though more complex, sequential method, for their accurate evaluation on a structural and quantitative basis. Thus, the experimental procedures yield four di€erent fractions of the biophenolic components of the olive, checked by CC, HPLC and NMR. The experimental results depend on the procedure chosen, the degree of ripeness of the olives, and the environment of the olive cultivars. The composition of each of these fractions can be of valuable information, supporting for table olive growing and olive oil producers in maximising the competitive quality of their products by selecting olive materials whose concentrations of biophenolic compounds can be responsible for bene®cial e€ects on human health. # 2000 Published by Elsevier Science Ltd.