Chemical Composition of Amurca Generated from Jordanian Olive Oil

Sana M Janakat

doi:10.4172/2155-9600.1000186

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-5-methyl phenol and luteolin.

Highlights

Olive oil is the major product of pressed olive fruits
Some inconsistency is found in the literature concerning the use of the term amurca; in this article the term amurca refers to watery bitter tasting and dark colored sediment that settles at the bottom of crude olive oil container over time [1,2]
Soaking amurca samples in hexane (1:3) over night, the mixture was centrifuged at 3000 rpm (723xg) for 20 minutes and the supernatant was collected, and hexane was evaporated using rotary evaporator, free fatty acid and peroxide values were determined according to the official EU method [8,12]

Summary

Introduction

Olive oil is the major product of pressed olive fruits. Mechanical extraction of oil involves crushing whole olive fruits, kneading the resulting paste, pressing, separating, collecting free flow oil and separating amurca from olive oil via centrifugation and filtration [1].Amurca is known as olive oil lees in english [2] and Turtub in Jordan. This study was designed to 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.

Results

Conclusion