Antioxidant Activity of Oregano, Parsley, and Olive Mill Wastewaters in Bulk Oils and Oil-in-Water Emulsions Enriched in Fish Oil

Abstract

The antioxidant activity of oregano, parsley, olive mill wastewaters (OMWW), Trolox, and ethylenediaminetetraacetic acid (EDTA) was evaluated in bulk oils and oil-in-water (o/w) emulsions enriched with 5% tuna oil by monitoring the formation of hydroperoxides, hexanal, and t-t-2,4-heptadienal in samples stored at 37 degrees C for 14 days. In bulk oil, the order of antioxidant activity was, in decreasing order (p < 0.05), OMWW > oregano > parsley > EDTA > Trolox. The antioxidant activity in o/w emulsion followed the same order except that EDTA was as efficient an antioxidant as OMWW. In addition, the total phenolic content, the radical scavenging properties, the reducing capacity, and the iron chelating activity of OMWW, parsley, and oregano extracts were determined by the Folin-Ciocalteau, oxygen radical absorbance capacity, ferric reducing antioxidant power, and iron(II) chelating activity assays, respectively. The antioxidant activity of OMWW, parsley, and oregano in food systems was related to their total phenolic content and radical scavenging capacity but not to their ability to chelate iron in vitro. OMWW was identified as a promising source of antioxidants to retard lipid oxidation in fish oil-enriched food products.

Effects of parsley supplementation on the seminal quality, blood lipid profile and oxidant status of young and old male rabbits

“…A high level of parsley (0.6%) decreased serum LDL compared with un-supplemented bucks. These results support that parsley exerts an antioxidant activity (Ahsan et al,1990;Kery et al, 2001;Jimenez-Alvarez et al, 2008).…”

Oxidative stability of fish oil‐enriched mayonnaise‐based salads

“…However, tuna salad with oregano had a significantly higher PV than the standard. The pro-oxidative effect of oregano on hydroperoxide formation was also observed by Jimenez-Alvarez et al [9], who explained it by the ability of oregano to reduce Fe 3þ to Fe 2þ , which would then promote peroxide formation. The sample T_FO þ O had lower concentrations of volatiles and, taken together, these findings thus indicate that the decomposition rate from PV to volatiles is slower in the salad with oregano than in the other tuna salads.…”

“…Several studies have proved that spices, or extracts based on spices, possess anti-oxidative activity [9,10,13,14,30]; however, the studies have not been performed in complex food matrices such as tuna salads. In the present experiment, addition of 1% of one of the three spices to fish oil-enriched tuna salads reduced the volatile concentration compared to the standard (T_STD_FO).…”

“…However, their activity and mechanism of action depend on the structure of the phenols: the location and number of hydroxyl (-OH) groups and the nature of substitutions on the aromatic rings [8]. Several experiments have indicated that different vegetables and spices, such as sweet pepper (bell pepper), asparagus, snow peas, oregano, thyme, and rosemary, possess anti-oxidative activity [9][10][11][12][13][14][15][16][17]. Moreover, Zheng and Wang [13] observed a positive linear correlation between the phenolic content and the antioxidative capacity of the above-mentioned spices.…”

Feed additives for swine: Fact sheets – prebiotics and probiotics, and phytogenics (2010)

“…Anti-oxidative properties of some phytogenic substances have been attributed to the phenolic terpenes in the essential oils. 17,18 Essential oils of plants belonging to the Labiatae family have been widely used as antioxidants in human and pet foods with high fat content. 10 Plants high in terpenes include rosemary, oregano, and thyme.…”