Stabilization of refined olive oil by enrichment with chlorophyll pigments extracted from Chemlali olive leaves

Abstract

This paper presents the first investigation on the effect of enrichment refined olive oil by chlorophyll pigment extracted from Chemlali olive leaves during storage (6 months). The changes that occurred in the quality indices, fatty acids, sterol, and phenolic content were investigated during the storage of refined olive oil under RT (208C) and accelerated conditions (508C) in the dark. Additionally, the pigments (chlorophyll and carotene) changes during 6 months of oil storage were evaluated. At the end of the storage, more than 90% of chlorophyll pigments decomposed in all samples, while, carotene pigment loss was lower showing up to 60 and 85% loss for oil stored at 20 and 508C, respectively, at the end of storage. The reduction of total phenolic compounds exhibited similar degradation profiles, being reduced by 5% and up to 60% for the enriched refined olive oil stored at 20 and 508C in 6 months, respectively. In the fatty acid composition, an increase in oleic acid and a decrease in linoleic and linolenic acids were less significant in enriched than non-enriched refined olive oil. On the other hand, sterol composition was less affected by storage in enriched oil samples. However, the sterol concentration of the oil samples showed an increase in b-sitosterol, 24-methylene cholesterol, stigmasterol, and a decrease in cholesterol, D5, 24-stigmastadienol percentage at the end of storage. Based on the Rancimat method, the oils with added leaf pigment extract had the lowest peroxide value and the highest stability. After 6 months of storage, the oxidative resistance of refined olive oil fell to 0.2 and to zero for enriched refined olive oil stored at 20 and 508C, respectively.

Oxidative Stability of Extra Virgin Olive Oil with Natural Plant Extracts during Microwave Heating

“…While in olive oil enriched with olive leaves and basil extracts, the losses of carotenoid content was 57 and 55 %, respectively, from the initial content. The results of the present study are in accordance with Jaber et al [19] who studied the stabilization of refined olive oil by enrichment with chlorophyll pigments extracted from Chemlali olive leaves. In addition, these results were in agreement with those founded by Malheiro et al [17] and Yahyaoui et al [2] who reported that microwave heating time decreased the total chlorophylls and carotenoids contents as long as the exposure time increases.…”

Thermal Stability of Chlorophyll Pigments in Virgin Olive Oil

“…These results are in good agreement with Ayadi and Grati-Kamun (2009), Malheiro et al (2009) and Jaber et al (2012) who reported more than 90% chlorophyll loss in olive oil samples.…”

Effect of Storage on Refined Olive Oil Composition: Stabilization by Addition of Chlorophyll Pigments and Squalene

“…As it can be observed in Fig. 2 18 , which reported that enrichment of refined olive oil with phenolic compounds and chlorophyll pigments rich extract recovered from Chemlali olive leaves resulted in an appreciable resistance to oxidative deterioration. In addition, Psomiadou, & Tsimidou 19 claimed that squalene had a protective effect on the oxidative stability of olive oil due to the products of squalene oxidation are quite stable and would not be further involved in propagation reactions.…”

“…Additionally, it was mentioned that the products of squalene oxidation remain unchanged over a substantial range of oxygen uptake, so that they may not strongly participate in propagation reactions. Recent work in our laboratory has shown that chlorophyll pigment recovered from Chemlali olive oil increased the oxidative stability of refined oils at the beginning of the study to attend 6 h 20 min 18 . This low stability of oils enriched with chlorophyll extract was attributed to the latter s low antioxidant capacity as reported by LanferMarquez, et al 24 Therefore, added with squalene 800 mg kg 1 could be responsible for the increase of oxidative stability of studied oils.…”