Comparison of Chemical Composition, Bioactive Compounds and Antioxidant Activity of Three Olive-Waste Cakes

Abstract

The objectives of this study were to determine the physicochemical composition, phenolic, tocopherol, flavonoid, flavanol, dietary fiber and β-carotene contents, as well as the antioxidant activity of three olive-waste cakes from varieties Picual, Frantoio and Arbequina. Frantoio presented the highest dietary fiber content and Arbequina showed the highest β-carotene content. Results indicated that total phenolic content followed the sequence (Frantoio > Picual > Arbequina). Picual presented the highest free phenolic and flavonoid contents (3499.11 mg gallic acid equivalent/100 g dry weight (DW) and 1331.45 mg CTE/100 g DW, respectively) showing the highest antioxidant capacity. The identified free phenolic compounds of the three varieties were gallic acid, 3-hydroxytyrosol, rutin hydrate, tyrosol and p-coumaric acids. The α-tocopherol was the predominant for the three varieties.