Chemical Composition of Amurca Generated from Jordanian Olive Oil

Abstract

Amurca (olive oil lees) is one of olive oil byproducts which is a watery bitter tasting and dark colored sediment that settles at the bottom of crude olive oil containers over time. In this study, gross composition, total phenolic compounds, antioxidant activity, HPLC profile of phenolic compounds, lipid peroxidation inhibitory activity, free fatty acid and peroxide values of amurca were determined. The gross composition of Jordanian amurca was as follows: carbohydrates 0.74 ± 0.02%, proteins 0.7 ± 0.02%, fats 49.43 ± 0.29%, moisture 47.33 ± 0.30%, ash 0.89 ± 0.05% and fiber 0. 92 ± 0.03%. Total phenolic compounds content was 289 mg GAE/100 g of amurca and antioxidant activity was 22.3 ± 0.21 mg vitamin E equivalent/100 g. Peroxide value was 1.78 ± 0.03 meqO2/kg amurca, free fatty acid value was 1.62 ± 0.029 (oleic acid%) and LPO inhibition was 95.7%. The most abundant phenolic compounds detected by HPLC were oleuropen, gallic acid, 3-hydroxyphenol, sinapic acid, kaempherol, isopropyl-5methyl phenol and luteolin.