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.

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.

Dietary Protected Sodium Butyrate and/or Olive Leaf and Grape-Based By-Product Supplementation Modifies Productive Performance, Antioxidant Status and Meat Quality in Broilers.

To meet the demand for chicken meat production, new additives that promote growth and health without adverse effects on meat quality are being investigated. This study was conducted to investigate the effect of protected sodium butyrate (PSB) (0 vs. 2 g/kg), an olive leaf and grape-based by-product (OLG-mix), or a combined supplementation of PSB and OLG-mix on productive performance, antioxidant status, carcass, and meat quality in broilers. PSB improved performance parameters with greater effect in the initial phase. Both, PSB and OLG-mix increased the plasma superoxide dismutase (SOD); however, PSB supplementation was more effective to delay the lipid oxidation of meat from the initial day of storage. OLG-mix produced meat with greater color intensity, b* value and lesser drip losses than PSB. The combination of PSB + OLG-mix did not produce more marked effects that the individual administration; except to control the oxidation of meat. Linear and positive correlations between antioxidant enzymes and weight gain were observed. Significant linear and negative relationships were quantified between plasma SOD and meat lipid oxidation according to dietary treatment. Therefore, the present study would be a first approximation to the possibilities for predicting growth range and meat quality through the evaluation of the blood oxidative status.

Short-Term Spirulina (Spirulina platensis) Supplementation and Laying Hen Strain Effects on Eggs' Lipid Profile and Stability.

The aim of the study was to investigate the effect of short-term dietary spirulina supplementation (1% and 3%) and the strain of laying hens (White Leghorn: WL and Rhode Island Red: RIR) on color, nutritional value, and stability of yolk. Egg weight was not affected by any of the studied effects. Yolks from 3%-spirulina supplemented hens had higher retinol and lower α-tocopherol content (p = 0.0001) when compared to control. The supplementation with 1%-spirulina markedly decreased luminosity and increased redness (p = 0.0001) and yellowness (p = 0.0103). Short-term spirulina supplementation slightly modified the fatty acid composition of yolk. The C16-desaturase index increased with the algae, whereas other egg quality indices (hypocholesterolemic, thrombombogenic, n-6/n-3) were not modified. Hen strain mainly affected to the lipid profile. The RIR hens accumulated greater yolk retinol with supplementation doses of 3% (p < 0.05), while the WL hardly suffered changes in the accumulation. Also, yolks from RIR hens had lower C16:0 (p = 0.0001), C18:0 (p = 0.0001), saturated (SAT) (p = 0.0001), and thrombogenic index (p = 0.0001), C20:3n-6 (p = 0.0001), n-6/n-3 ratio (p = 0.003), Δ-6+5-desaturase (p = 0.0005), total elongase indices (p = 0.0001) when compared to WL. Moreover, RIR had higher monounsaturated (MUFA), Δ-9-desaturase and hypocholesterolemic indices (p < 0.05) than WL. A different response to spirulina supplementation was observed for C18:1n-9, MUFA, Δ-9-desaturase and thiesterase indices (p < 0.05) according to hen strain. Yolks from RIR had higher MUFA and Δ-9-desaturase indices than WL at 1%-spirulina supplementation, whereas these parameters were less affected in RIR supplemented with 3%. SAT and Δ-9-desaturase were significantly correlated (r = -0.38 and 0.47, respectively) with retinol content according to a linear adjustment (p < 0.05). Lipid oxidation of yolk was slightly modified by the dietary treatment or hen strain. It was detected a relationship between TBARS and α-tocopherol, C22:5n-3 or C22:6n-3 (p < 0.05). L* and a* were also inversely or positively related with yolk retinol content according to a linear response (p < 0.05). The administration of 1% of spirulina in diets of red hens would be an interesting alternative to get healthier eggs from the nutritional point of view, obtaining an adequate color and without modifications in other yolk quality traits.

Changes in Plasma Fatty Acids, Free Amino Acids, Antioxidant Defense, and Physiological Stress by Oleuropein Supplementation in Pigs Prior to Slaughter.

Olive tree leaves are characterized for having not only a potent antioxidant power but also effects on glucose and lipid metabolism. The impact of the individual oleuropein (OLE), vitamin E + Se (VE), or a combined supplementation of oleuropein, vitamin E, and selenium (VEOLE) was evaluated on pig plasma metabolites under fasting prior to slaughter. VEOLE and OLE had lesser n-3 plasma polyunsaturated fatty acids and greater monounsaturated free fatty acids compared to control. The n-3-fatty acid mobilization was directly correlated with greater cysteine and inversely with oxidized glutathione/reduced glutathione (GSSH/GSH) levels. This faster use of n-3 fatty acids might act as an indicator of glutathione synthesis mediated by an increase of cysteine in plasma. Different correlations and linear adjustments were observed between plasma antioxidant power and free cysteine, free glycine, free glutamine, monounsaturated free fatty acids, and total n-3. The best response to stress was found in VEOLE. Cortisol reached the greatest positive correlation with plasma total n-3 fatty acids, which suggests a faster uptake of n-3 for biological functions such as stress control or energy supply in the brain. From a practical point of view, an enhanced oxidative status as well as control of physiological stress prior to slaughter by the combined antioxidants supplementation might have positive effects on pork quality.