Enhanced Stability of Refined Soybean Oil Enriched with Phenolic Compounds of Olive Leaves

Abstract

S OYBEAN oil is a common vegetable oil, which is used for edible purposes. However, this oil is rich in unsaturated fatty acids that enhance oil deterioration by their oxidation. Such deterioration can be reduced using suitable antioxidants, preferably natural antioxidants. This work was made to assess the suitability of phenolic compounds that can be extracted from olive leaves to improve soybean oil stability against oxidation. Olive leaves extracts were tested for their content of phenolic compounds and have been then added to soybean oil which was subjected to accelerated oxidation. The oxidation stability was monitored following several technical methods commonly used for this purposes such as peroxide value, p-Anisidine value, as well as induction time by Rancimat method. The results have proved that the extracts of olive leaves can be used efficiently as a safe natural antioxidant in edible oils. However, the dose to be added should be adjusted as to achieve the activity of synthetic antioxidants.

Heterosis for seed, oil yield and quality of some different hybrids sunflower

“…Sunflower oil with high oleic acid content is nutritionally similar to olive oil which is considered superior to other types of seed oil (Doty, 1978;Hamed et al, 2020). Grundy (1986) and Soliman et al (2019) also suggested that a diet rich in monounsaturated fatty acids i. e. oleic acid reduces cholesterol in blood plasma (reducing the risk of coronary heart diseases), has a greater shelf life and a high degree of oxidative stability Zahran and Najafi, 2020;Farrag et al, 2020). The main breeding objective of sunflower is to develop high-yielding, diseaseresistant hybrids with high oil quality (Dudhe et al, 2009).…”

An Overview of Natural Extracts with Antioxidant Activity for the Improvement of the Oxidative Stability and Shelf Life of Edible Oils

“…Table 1 shows some examples of recent extraction procedures carried out in order to obtain natural extracts with antioxidant activity, for the presence of carotenoids and phenolics, subsequently used for the enrichment of vegetable oils. Phenols olive leaf powder extracted with ethanol (78%, v/v) at r.t. for 24 h, for three times olive fruit and olive pomace mixed with ethanol (78%, v/v) and stirred for 30 min [21] Phenols olive leaf powder extracted with methanol/water (80:20, v/v) at r.t. for 12 h under agitation in dark place [22] Phenols olive leaves extracted by MAE with methanol; while magnetic stirring, 6 min irradiation was performed (8 s power on and 15 s power off in order to prevent super-boiling of solvent).…”

“…In addition, ethanol is classified with the GRAS status, so it is suitable for the recovery of nutraceuticals [28]. Classical solid-liquid extraction technique at room temperature was used to obtain phenols from fresh olive leaves using ethanol or methanol [11,12], or from olive fruit and olive pomace using hydroalcoholic mixtures [21,22]. Sordini et al [24] extracted phenols from olive pomace homogenizing with 80% methanol, and then the aqueous extract was used for solid phase extraction (SPE) phenol separation by C18 cartridge and eluting with methanol.…”

“…Phenols from olive leaf extract (OLE) have been deeply analyzed, and it has been reported that OLE is a stronger antioxidant in respect to ascorbic acid. This result has been attributed to the synergistic effects among polyphenol compounds present in OLE [22]. Phenols from spinach and myrtle leaves have been also characterized, before addition to SFO and EVOO, respectively [25,34].…”

Antioxidant capacity, physicochemical properties, thermal behavior, and oxidative stability of nectarine (Prunus persica var. nucipersica) kernel oil

“…The kernel oil provides a viable source of essential FAs (predominantly the oleic acid) and chemical compounds while exhibiting appropriate physicochemical characteristics (Kamel & Kakuda, 1992). Recently, several methods have been used to extract oil from the kernel and seeds; examples include the ultrasound‐assisted extraction (UAE), microwave‐assisted extraction (MAE), and supercritical fluid extraction (SFE) and various classical procedures including mechanical (cold) and solvent (hot) extraction (Naeem et al., 2019; Rezvankhah et al, 2018; Sodeifian et al., 2016, 2018, 2019, Sodeifian, Sajadian, & Ardestani, 2017; Sodeifian, Sajadian, & Honarvar, 2017; Zahran & Najafi, 2020; Zahran & Tawfeuk, 2019).…”