Dietary oleuropein extract supplementation and its combination with α‐tocopheryl acetate and selenium modifies the free fatty acid profile of pork and improves its stability

Abstract

BACKGROUND Olive‐derived antioxidants have been shown to affect the oxidative status of meat and have also been associated with greater consumption of glucose, which might affect glycogen stores and muscle characteristics. This study evaluated the effect of oleuropein extract supplementation (OLE) versus vitamin E + Se (VE), and their combination (VEOLE), in pig diets, on pH, drip loss, the proportion of free fatty acids, and meat stability, and their prediction by blood oxidative status markers. RESULTS The drip loss of muscle was lower in antioxidant‐supplemented groups when compared with controls. α‐Tocopherol concentration and total fatty acids profile were not affected by dietary oleuropein supplementation. However, OLE and VEOLE had lower free n‐3 polyunsaturated fatty acid (PUFA) levels when compared with VE and tended to have higher free monounsaturated fatty acid (MUFA) levels. Furthermore, the VEOLE group had lower free n‐6 PUFA levels when compared with controls or VE, whereas the OLE group had intermediated values. Muscle samples from pigs subjected to the antioxidant‐mixed supplementation (VEOLE) had lower malondialdehyde concentration when compared with the others. The VE and OLE groups showed intermediate malondialdehyde values. Chilled meat stability was highly correlated with antioxidant status in vivo. CONCLUSION The administration of 96 mg oleuropein kg−1 feed produced similar meat quality characteristics as the use of 100 mg kg−1 α‐tocopheryl acetate +0.26 mg kg−1 sodium selenite and it would be an interesting alternative in Mediterranean countries. The VEOLE group was the most effective for reducing lipid oxidation and for the production of polyunsaturated free fatty acids in meat, which would result in lower rancidity formation and better aroma development in products. © 2020 Society of Chemical Industry

Supplementation Effect of Oleuropein Extract Combined with Betaine, Magnesium, and Vitamin E on Pigs’ Performance and Meat Quality Characteristics

“…In the present study, no differences in ADWG, ADFI, or FCR were observed in pigs supplemented with the experimental diets and a lack of effects on lean or fat thickness of carcass yield was observed. Similar results have been reported through the single administration of vitamin E and/or oleuropein extract [6,30]. Other feed additives, such as magnesium, have been reported to improve the performance at 0.3% (3000 mg/kg) of MgO on the diets of swine over 7 days [31].…”

“…Vitamin E is one of the most potent antioxidants in the organism that can be accumulated in muscle membranes, so a higher presence of this vitamin has been associated with lower TBARS production and higher lipid stability [9]. In addition, the use of oleuropein extract has been reported to delay lipid oxidation in meat from birds [30] and pork [6], and similar results have been found in pork through the use of olive leaves that may contain not only oleuropein but also other antioxidant components [45]. Lower TBARS values have also been observed in meat from pigs given a short-term feeding of magnesium supplements [46], although supplementation doses were much higher (1500 mg/kg) than those used in the present research.…”

“…NL were eluted with chloroform (5 mL), FFA were eluted with diethylether:acetic acid (98:2) and PL were eluted with 2.5 mL methanol:chloroform (6:1) and sodium acetate in methanol:chloroform (6:1). Lipid fractions were subjected to esterification [5,6]. The fatty acids methyl esters (FAMEs) were directly injected and separated in a gas chromatograph (HP 6890 Series GC System; Hewlett Packard, Avondale, PA, USA) equipped with flame ionization detector held at 250 • C and a capillary column (HP-Innowax Polyethylene Glycol, 30 m × 0.316 mm × 0.25 µm).…”

“…Oleuropein is one of the most abundant polyphenol compounds present in the olive leaves (Olea europaea) but it has also isolated from other plant species and fruits [4]. Recent studies show the positive effects of olive by-products, not only thanks to their antioxidant properties [4], but also due to their capacity to modify nutrient metabolism, with changes in glucose uptake, lipid, and amino acid profiles [5] that may affect meat quality [6,7]. Thus, oleuropein has shown capacity to catch free radicals and metal ions and it has been related with an increase in the glutathione route, cystine and monounsaturated blood levels, as well as reduced cortisol under stressful conditions [5] and other interesting pharmacological and anti-inflammatory effects [4].…”

“…Thus, oleuropein has shown capacity to catch free radicals and metal ions and it has been related with an increase in the glutathione route, cystine and monounsaturated blood levels, as well as reduced cortisol under stressful conditions [5] and other interesting pharmacological and anti-inflammatory effects [4]. In addition, the combination of olive extracts such as oleuropein has been reported to have synergistic effects in vivo with other antioxidants such as vitamin E [5,6]. Vitamin E is one of the most studied compounds in the literature because of its effects in vivo [5,8] and post-mortem [9], explained by its incorporation into biological membranes and consequent accumulation in different tissues.…”