Use of plasma induced modification of biomolecules (PLIMB) to evaluate hemin dissociation from fish and bovine methemoglobins.

Hemin dissociation occurs much faster from fish methemoglobin (metHb) compared to mammalian metHb yet the mechanism remains poorly understood. This may involve enhanced solvent access to His(E7) of fish metHbs by a protonation mechanism. Plasma induced modification of biomolecules (PLIMB) produces free radicals that covalently modify solvent accessible residues of proteins, and so can provide insight regarding accessibility of hydronium ions to protonate His(E7).

Divergent Reactivity of Hemoglobin Isoforms αβ and αβ from in Native and Fatty Acid-Modified States.

(turkey) coexpresses distinct hemoglobin (Hb) isoforms, Hb αβ (HbA) and αβ (HbD), at a ratio of ∼3:1 (HbA:HbD). Herein, the reactivities of HbA and HbD were investigated in their native and free fatty acid (FFA)-modified states. Results indicated that HbD displays elevated autoxidation () and an increased propensity to oxidize lipids in its reduced (oxy) and oxidized (met) forms.

Exploring the potential effect of phospholipase A2 antibody to extend beef shelf-life in a beef liposome model system.

The objective of this study was to elucidate the effect of phospholipase A2 (PLA2) and a PLA2 antibody (aPLA2) on phospholipid (PL) hydrolysis in beef and to understand how the altered PL composition may affect lipid oxidation and antioxidant capacity of beef in an in vitro system. Various combinations of PLA2 and aPLA2 were introduced to a beef liposome model system and exposed to a retail display. The PL and free fatty acid (FFA) profiles, antioxidant capacity and lipid oxidation were measured for the liposome system.

Effects of sodium chloride and sodium tripolyphosphate on the prooxidant properties of hemoglobin in washed turkey muscle system.

This study examined the effects of sodium chloride (NaCl) and sodium tripolyphosphate (STPP) on lipid oxidation induced by oxyhemoglobin (oxyHb) in washed turkey muscle (WTM) model. To explore the reasons for observed effects, the pro-oxidant abilities of Hb derivatives (e.g.

Model systems for studying lipid oxidation associated with muscle foods: Methods, challenges, and prospects.

Lipid oxidation is a complex process in muscle-based foods (red meat, poultry and fish) causing severe quality deterioration, e.g., off-odors, discoloration, texture defects and nutritional loss.

Paradoxical effects of lipolysis on the lipid oxidation in meat and meat products.

Lipolysis in meat and meat products is a phenomenon involving hydrolysis of lipids, notably via enzymatic catalysis that takes place even . During refrigerated and frozen storage of meat, in particular fish, endogenous lipolytic enzymes actively degrade triacylglycerols and phospholipids resulting in accumulation of free fatty acids and other hydrolytic products. A classical conjecture suggests that lipolysis enhances lipid oxidation which is involved in quality deterioration of fresh meat and, to some degrees, flavor development of certain meat products.

Quercetin as an inhibitor of hemoglobin-mediated lipid oxidation: Mechanisms of action and use of molecular docking.

The antioxidant effect of quercetin on hemoglobin(Hb)-mediated lipid oxidation and the mechanisms involved were investigated. Quercetin strongly inhibited Hb-mediated lipid oxidation in washed muscle. Quercetin showed effective hydroxyl radical scavenging ability similar to butylated hydroxytoluene (BHT).

Lipid oxidation and antioxidant delivery systems in muscle food.

Lipid oxidation accelerates quality deterioration in muscle-based foods (fish, red meat, and poultry), resulting in off-odors/flavors, color problems, texture defects, and safety concerns. Adding antioxidants is one approach to control lipid oxidation, and several delivery strategies have been applied, such as supplementing antioxidants to the feed, direct mixing into minces, or, for whole muscle pieces; spraying, glazing, and injection. However, some issues linked to these technologies hinder their wide utilization, such as low effectiveness, noncompatibility with clean label, and off-flavor.

Caffeic acid: an antioxidant with novel antisickling properties.

It is well documented that caffeic acid (3,4-dihydroxycinnamic acid) (CA) interacts with and inhibits the oxidative reactions of myoglobin (Mb) and hemoglobin (Hb), and this interaction underlies its antioxidative action in meat. Sickle cell hemoglobin (HbS) is known for its tendency to oxidize more readily than normal HbA in the presence of hydrogen peroxide (H O ), which leads to a more persistent and highly oxidizing ferryl Hb (HbFe ). We have investigated the effects of CA on HbS oxidation intermediates, specifically on the ferric/ferryl forms.

Hexanal as a Predictor of Development of Oxidation Flavor in Cured and Uncured Deli Meat Products as Affected by Natural Antioxidants.

Effectiveness of commercial natural antioxidants from rosemary and green tea were investigated in deli-style meat products via headspace hexanal by solid-phase microextraction gas chromatography and sensory oxidation flavor by a trained panel at weeks 1, 7, and 13 of refrigerated storage. A water/oil-soluble rosemary extract at 400 mg/kg proved the most effective antioxidant in cured deli turkey (CDT). In chicken fillet (CF), a water-soluble rosemary extract at 400 mg/kg was most efficient, especially in combination with phosphate.

Vascular infusion with concurrent vascular rinsing on color, tenderness, and lipid oxidation of hog meat.

Market hogs were conventionally chilled (CN, n = 12) or Rinse & Chill® processed (RC, n = 13, MPSC Inc.). Muscles (Longissimus lumborum, LL; picnic shoulder, PS) were processed (chops, ground), packaged, and displayed or stored in the dark.

Factors influencing the antioxidant effect of phospholipase A2 against lipid oxidation promoted by trout hemoglobin and hemin in washed muscle.

The antioxidant effect of porcine pancreatic phospholipase A2 (PLA2) was previously demonstrated. Understanding how PLA2 inhibits lipid oxidation promoted by hemoglobin (Hb) is important for its applications in muscle foods. Effects of enzyme dose, pH, and calcium ion on the ability of PLA2 to inhibit trout hemoglobin-mediated lipid oxidation were investigated in washed cod muscle (WCM).

Mechanisms involved in the inhibitory effects of free fatty acids on lipid peroxidation in turkey muscle.

The pro-oxidant and anti-oxidant effects of free fatty acids (FFA) in meat remain ambiguous. To clarify the role of FFA in lipid oxidation of muscle food, the FFA was added into two systems (turkey mince and washed turkey muscle (WTM)) and lipid oxidation was investigated. A mixture of FFA inhibited lipid oxidation in both systems.

Impact of lipid composition and muscle microstructure on myoglobin-mediated lipid oxidation in washed cod and pig muscle.

The roles of lipid oxidation substrates and muscle microstructure in lipid oxidation were investigated in two muscle models (cod and pig). Added myoglobin (Mb) promoted lipid oxidation in washed cod muscle (WCM) but not in washed pig muscle (WPM). The differing microstructure of WCM e.

Presence of lipid oxidation products in swine diet lowers pork quality and stability during storage.

Studies examining the effects of feeding lipid oxidation products (LOPs) to pigs on pork quality and storage stability have mostly focused on refrigerated storage and produced mixed results. We investigated the effects of adding yellow grease, containing commercially relevant levels of LOPs, to swine diets on quality and storage stability of ground salted pork. Twenty-four domestic pigs were divided into three study groups and fed the following diet regimens for five months: (1) Standard Diet (STD), (2) STD + yellow grease (YG, high LOPs), or (3) STD + corn oil (CO, negligible LOPs).

Exogenous phospholipase A2 affects inflammatory gene expression in primary bovine mammary epithelial cells.

This Research Communication addresses the hypothesis that exogenously administered phospholipase A2 (PLA2) affects the inflammatory responses of bovine mammary epithelial cells (bMEC) in vitro with the aim of providing preliminary justification of investigation into the uses of exogenously administered PLA2 to manage or treat bovine mastitis. Primary bMEC lines from 11 lactating Holstein dairy cows were established and the expression of 14 pro-inflammatory genes compared under unchallenged and lipopolysaccharide (LPS)-challenged conditions, with and without concurrent treatment with bovine pancreatic PLA2G1B, a secreted form of PLA2. No differences in the expression of these genes were noted between PLA2-treated and untreated bMEC under unchallenged conditions.

Hemolysis, tocopherol, and lipid oxidation in erythrocytes and muscle tissue in chickens, ducks, and turkeys.

Muscle from turkeys is more sensitive to lipid oxidation during post mortem storage compared with that of chicken and duck which may involve increased lysis of turkey erythrocytes that releases hemoglobin oxidant. Three separate experiments were conducted to study characteristics of chicken, duck, and turkey erythrocytes in which dietary tocopherols were standardized. In Experiment I, tocopherol, fatty acid composition, and lipid oxidation capacity were measured in erythrocytes from chickens, ducks, and turkeys.

Mechanisms involved in hemoglobin-mediated oxidation of lipids in washed fish muscle and inhibitory effects of phospholipase A2.

Background: Hemoglobin (Hb) is a lipid oxidation promoter in fish muscle. Phospholipase A2 (PLA2; EC 3.1.

Factors Affecting Lipid Oxidation Due to Pig and Turkey Hemolysate.

Turkey hemolysate promoted lipid oxidation in washed muscle more effectively than pig hemolysate, which was partly attributed to the greater ability of HO that formed during auto-oxidation to oxidize the avian hemoglobin (Hb). Turkey and pig hemolysate (2.5 μM Hb) exposed to 10 μM HO oxidized to 48% and 4% metHb, respectively.

Attributes of lipid oxidation due to bovine myoglobin, hemoglobin and hemolysate.

Bovine hemolysate was purified by size exclusion chromatography, and one high molecular weight protein was detected relative to the hemoglobin (Hb) fraction. Purified Hb promoted lipid oxidation in washed muscle slightly but significantly better than hemolysate, which may have been due to the absence of catalase and peroxiredoxin in the purified Hb. Purified Hb auto-oxidized to metHb more rapidly than Hb in the hemolysate (P<0.

Effect of 4-hydroxy-2-nonenal on myoglobin-mediated lipid oxidation when varying histidine content and hemin affinity.

The compound 4-hydroxy-2-nonenal (HNE) dissolved in water was examined to remove potential effects of using ethanol to solubilize the aldehyde such as altering protein structure or redox properties of myoglobin (Mb). HNE became covalently bound to sperm whale Mb at up to five sites based on ESI-MS analysis. Adducted Mb promoted lipid oxidation in washed muscle more effectively than non-adducted Mb.

Role of Cytochrome P450 Hydroxylase in the Decreased Accumulation of Vitamin E in Muscle from Turkeys Compared to that from Chickens.

Turkeys and chickens reared to 5 weeks of age and fed diets with feedstuffs low in endogenous tocopherols were examined. Treatments included feed supplemented with RRR (natural source vitamin E) alpha tocopheryl acetate (AcT, 35 mg/kg feed) and all-racemic (synthetic vitamin E) AcT (10 and 58 mg/kg feed). Alpha tocopherol hydroxylase activity was greater in liver microsomes prepared from turkeys compared to that from chickens (p < 0.

Assessing Low Redox Stability of Myoglobin Relative to Rapid Hemin Loss from Hemoglobin.

Bovine myoglobin (Mb) auto-oxidized 11-fold faster at pH 5.7 compared to bovine hemoglobin (Hb). Replacement of Ser(F7) in bovine Mb with positively charged or large apolar residues decreased auto-oxidation rates (2- to 4-fold) in comparison with wild-type Mb (P < 0.

Myoglobin and haemoglobin-mediated lipid oxidation in washed muscle: observations on crosslinking, ferryl formation, porphyrin degradation, and haemin loss rate.

Reduced trout haemoglobin (Hb) is a mixture of oxy- and deoxy-Hb at pH 6.3. Addition of oxy/deoxyHb to washed muscle resulted in detectable ferryl Hb while adding bovine oxyHb, trout metHb, or bovine metHb did not.

Factors affecting the binding of trout HbI and HbIV to washed cod mince model system and their influence on lipid oxidation.

Electrostatic interactions between haemoglobin (Hb) and muscle components of fish may be an initial step of Hb-mediated lipid oxidation. This mechanism was investigated by examining the interaction of anionic HbIV and cationic HbI with insoluble components of washed cod mince under different pH and salt conditions. Lipid oxidation was monitored in parallel using the thiobarbituric acid reactive substances (TBARS) test.