Impact of arabinoxylan on characteristics, stability and lipid oxidation of oil-in-water emulsions: Arabinoxylan from wheat bran, corn bran, rice bran, and rye bran.

To investigate the impact of arabinoxylan (AX) on the physical and oxidative stability of oil-in-water emulsions, AX from wheat bran, corn bran, rice bran, or rye bran was incorporated into the production of whey protein isolate-stabilised emulsions. Decreased interfacial charge and increased mean particle diameters were recorded in all fresh emulsions with 0.1%-0.5% AX, as recorded by the ζ-potential and particle size measurement, indicating the adsorption of AX onto the oil droplets. No phase separation was observed in all emulsions with ≤0.3% AX after 14-day storage in dark. Spectrophotometric analysis demonstrated that all AX lowered the peroxide value and thiobarbituric acid reactive substance concentration in emulsions, with AX from rice bran being slightly more effective. Consequently, AX has the potential to be used as a natural interfacial antioxidant in emulsions, and the antioxidant capacity of AX varies with its source.

Effect of Freeze-Thaw Cycles on the Oxidation of Protein and Fat and Its Relationship with the Formation of Heterocyclic Aromatic Amines and Advanced Glycation End Products in Raw Meat.

The aim of this research was to investigate the effect of the number of freeze-thaw cycles (0, 1, 3, 5, and 7) on porcine longissimus protein and lipid oxidation, as well as changes in heterocyclic aromatic amines (HAAs) and advanced glycation end products (AGEs) and their precursors. We analyzed the relationship among HAAs, AGEs, oxidation, and precursors and found the following results after seven freeze-thaw cycles. The HAAs, Norharman and Harman, were 20.33% and 16.67% higher, respectively. The AGEs, Nε-carboxyethyllysine (CEL) and Nε-carboxymethyllysine (CML), were 11.81% and 14.02% higher, respectively. Glucose, creatine, and creatinine were reduced by 33.92%, 5.93%, and 1.12%, respectively after seven freeze-thaw cycles. Norharman was significantly correlated with thiobarbituric acid reactive substances (TBARS; r2 = 0.910) and glucose (r2 = -0.914). Harman was significantly correlated to TBARS (r2 = 0.951), carbonyl (r2 = 0.990), and glucose (r2 = -0.920). CEL was correlated to TBARS (r2 = 0.992) and carbonyl (r2 = 0.933). These changes suggest that oxidation and the Maillard reaction during freeze-thaw cycles promote HAA and AGE production in raw pork.

Lipid oxidation in oil-in-water emulsions: Iron complexation by buffer ions and transfer on the interface as a possible mechanism.

Lipid oxidation is the main hurdle for omega-3 fatty acid enrichment in food and beverages. Fat oxidation reduces the quality and safety of supplemented products. A tuna oil-in-water emulsion (20%v/v) was exposed to iron-induced oxidation. Emulsions with changing emulsifiers and buffers were analyzed under different storage conditions (argon purging, pH variation) using Conjugated Dienes and Thiobarbituric acid reactive substances assays. The results showed that free iron ions cannot interact with oxygen. However, buffers (Citrate and phosphate) chelate iron ions (Fe (II)). Depending on the pH value and the type of buffer-Fe (II) complex, its prooxidant activity and spatial distribution are influenced. The complex charge defines the interactions with the oil-water interface, i.e., positively charged interfaces repel positively charged complexes which keeps the prooxidant away. The mechanistic understanding of this work will help formulators and product developers to choose the right buffer and emulsifier combination for oxidation sensitive emulsions.

Redox Potential and Antioxidant Capacity of Bovine Bone Collagen Peptides towards Stable Free Radicals, and Bovine Meat Lipids and Proteins. Effect of Animal Age, Bone Anatomy and Proteases-A Step Forward towards Collagen-Rich Tissue Valorisation.

Collagen antioxidant peptides are being widely studied. However, no research has paid attention to biological parameters such as the age and anatomy of collagen-rich tissues, which can determine a change in tissue structure and composition, and then in bioactivity. Moreover, only few research works have studied and assessed peptides antioxidant activity on the food matrix. This work aimed to investigate the effect of bovine's bone age and anatomy, and of six different enzymes, on the antioxidant activity of collagen peptides. Collagen was extracted from young and old bovine femur and tibia; six different enzymes were used for peptides' release. The redox potential, the quenching of stable free radicals, and the antioxidant capacity on bovine meat lipids and proteins was evaluated, under heating from ambient temperature to 80 °C. Age and anatomy showed a significant effect; the influence of anatomy becomes most important with age. Each enzyme's effectiveness toward age and anatomy was not the same. The greatest amount of peptides was released from young bones' collagen hydrolysed with papain. The antioxidant activity was higher at higher temperatures, except for meat proteins. Assessing the effect of age and anatomy of collagen-rich tissues can promote a better application of collagen bioactive peptides.

Metabolomic Profiling of Mango (Mangifera indica Linn) Leaf Extract and Its Intestinal Protective Effect and Antioxidant Activity in Different Biological Models.

Mangifera indica Linn popularly known as mango is used in folk medicine to treat gastrointestinal disorders. The aim of this study was to identify the metabolomic composition of lyophilized extract of mango leaf (MIE), to evaluate the antioxidant activity on several oxidative stress systems (DPPH, FRAP, TBARS, and ABTS), the spasmolytic and antispasmodic activity, and intestinal protective effect on oxidative stress induced by H2O2 in rat ileum. Twenty-nine metabolites were identified and characterized based on their ultra-high-performance liquid chromatography (UHPLC) high-resolution orbitrap mass spectrometry, these include: benzophenone derivatives, xanthones, phenolic acids, fatty acids, flavonoids and procyanidins. Extract demonstrated a high antioxidant activity in in-vitro assays. MIE relaxed (p < 0.001) intestinal segments of rat pre-contracted with acetylcholine (ACh) (10-5 M). Pre-incubation of intestinal segments with 100 µg/mL MIE significantly reduced (p < 0.001) the contraction to H2O2. Similar effects were observed with mangiferin and quercetin (10-5 M; p < 0.05) but not for gallic acid. Chronic treatment of rats with MIE (50 mg/kg) for 28 days significantly reduced (p < 0.001) the H2O2-induced contractions. MIE exhibited a strong antioxidant activity, spasmolytic and antispasmodic activity, which could contribute to its use as an alternative for the management of several intestinal diseases related to oxidative stress.

Serum and milk concentrations of oxidant and anti-oxidant markers in dairy cows affected with bloody milk.

This study was conducted to determine the serum and milk levels of thiobarbturic acid-reac- tive substances (TBARS), nitric oxide (NO), superoxide dismutase (SOD), glutathione peroxi- dase (GSH-Px), vitamin E and selenium, IL-4 and IL-6 in lactating dairy cows affected with bloody milk using commercially available ELISA kits. Milk and whole blood samples were collected from 60 cows affected with bloody milk and 20 apparently healthy cows for control. In the serum, levels of GSH-Px and SOD were significantly (p˂0.05) higher in healthy cows compared to cows affected with bloody milk while the levels of TBARS and NO were significantly (p˂0.05) higher in affected cows. In the milk, levels of SOD, TBARS and NO were significantly (p˂0.05) higher in affected cows. In the serum, levels of vitamin E were significantly (p˂0.05) lower in affected cows compared to healthy cows, while no significant changes were observed in the levels of this vitamin in the milk between healthy and affected cows. In the serum, levels of selenium were significantly (p˂0.05) lower in affected cows while in milk, selenium levels were significantly (p˂0.05) higher in affected cows compared to healthy ones. Levels of IL-4 were significantly (p˂0.05) lower in the serum and milk of affected cows compared to healthy cows while levels of IL-6 were significantly (p˂0.05) higher in both serum and milk of affected cows. Results of this study suggest a possible role of oxidative stress in the pathogenesis of bloody milk in dairy cows.

Influence of formulation parameters on lipid oxidative stability of Pickering emulsion stabilized by hydrophobically modified starch particles.

Sunflower oil-in-water Pickering emulsions were fabricated using octenyl succinic anhydride modified rice starches as particulate stabilizers. The major factors influencing oxidative stability of emulsions were investigated. Results indicated that oxidative stability was enhanced with the increase of starch particle concentration and oil fractions. The emulsions had excellent oxidative stability at pH 6.0-7.0. Low NaCl concentration of 40 mmol/L slightly increased lipid stability, while high NaCl concentration decreased oxidative stability. Sucrose concentrations ranging from 0 to 200 mmol/L had no obvious effect on oxidative stability. Results of confocal laser scanning microscope showed that the hydrophobically modified starch particles built up 3D-network barrier around oil droplets at oil-water interface, which increased the viscosity of continuous phase and prevented oil droplets from contacting with pro-oxidants in water phase, thus decreasing peroxide value and thiobarbituric acid reactive substances. These results implied that starch-based Pickering emulsion may be a promising delivery vehicle for bioactive compounds.

Effect of edible composite film based on chitosan and cumin essential oil-loaded nanoemulsion combined with low-dose gamma irradiation on microbiological safety and quality of beef loins during refrigerated storage.

This research was conducted to assess the combined effect of chitosan (Ch) film containing cumin essential oil nanoemulsion (CNE) and low-dose gamma irradiation (GI) at 2.5 kGy on microbiological safety and quality of beef loins during 21 days of chilled storage. The growth of mesophilic and psychrophilic bacteria, Enterobacteriaceae, and lactic acid bacteria were retarded in all treated groups (Ch, GI, Ch + CNE, Ch + GI, and Ch + CNE + GI groups) compared to control group during storage time. The treatments also slowed down the increasing level of total volatile basic nitrogen and pH during storage, while irradiation increased the levels of thiobarbituric acid reactive substances and protein carbonyls in beef loins. All treatments except Ch were effective to control the growth of inoculated pathogenic bacteria, including Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhimurium, in loin samples. The combination of Ch + CNE + GI was the most effective treatment to control the population of microbial flora and inoculated pathogens, slow down some physicochemical changes, and enhance the storage life of beef loins. As a result, the combination of active chitosan film and low-dose gamma irradiation can ensure microbiological safety and is suggested for long time preservation of beef during chilled storage.

Effect of pomegranate peel extract on the oxidative stability of pomegranate seed oil.

Pomegranate seed oil is valuable source of bioactive compounds with health-beneficial effects, but it is sensitive to oxidation due to high content of PUFA. In order to improve stability of pomegranate seed oil, the influence of natural antioxidant (0.1% pomegranate peel extract) and a combination of synthetic antioxidant (0.01% butylhydroxytoluene) and pomegranate peel extract (0.05%) was investigated. The oxidation process was followed by monitoring fatty acid composition and measuring the quality and stability parameters of oil (acid value, peroxide value, anisidine value and thiobarbituric acid reactive substances value) during storage for 12 days at 65 °C. Furthermore, total phenolic content and DPPH radical scavenging activity was measured. Pomegranate peel extract as well as a combination of pomegranate peel extract and BHT can have a significant positive impact (P < 0.05) on improvement of the quality and stability parameters of pomegranate seed oil. Furthermore, such activity was better than BHT used alone.

Effect of antioxidants on the sensory quality and physicochemical stability of Atlantic mackerel (Scomber scombrus) fillets during frozen storage.

This study aimed to evaluate the shelf-life of mechanically filleted well-fed Atlantic mackerel during frozen storage at -25 °C and effect of treatment with antioxidants (sodium erythorbate and a polyphosphate mixture) and different antioxidant application methods (dipping, spraying and glazing). Both physicochemical measurements and sensory analysis were applied. Antioxidant treatments prolonged shelf-life of mackerel. Sensory analysis indicated that untreated fillets had a shelf-life of less than 2.5 months, while all antioxidant treated fillets exceeded that. The most effective treatment, dipping fillets into a sodium erythorbate solution, yielding a shelf-life of 15 months. Physicochemical methods used to evaluate degradation of lipids in the fillets were free fatty acids (FFA), lipid hydroperoxides (PV) and thiobarbituric acid reactive substances (TBARS). They did not correlate with sensory results and might therefore be a questionable choice for evaluation of oxidation and development of rancid flavour and odour in complex matrixes such as Atlantic mackerel.

Non-destructive determination of chemical and microbial spoilage indicators of beef for freshness evaluation using front-face synchronous fluorescence spectroscopy.

We investigated the potential of front-face synchronous fluorescence spectroscopy (△λ = 75 nm) to non-destructively evaluate beef freshness and quality decline during chilled storage. The total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS) and total viable count (TVC) values were used as standard freshness indicators. The fluorescent substances, including amino acids, collagen and conjugated Schiff bases, were highly correlated with the chemical and microbial deterioration of the beef. Quantitative models for simultaneously predicting the three freshness indicators were built combined with partial least squares (PLS) algorithm and showed good reliability. For TVB-N and TBARS values, Rc2 and Rp2 were both above 0.900, and for TVC values Rc2 and Rp2 were 0.912 and 0.871, respectively. The qualitative model established by partial least squares discriminant analysis (PLS-DA) algorithm could accurately classify beef samples as fresh, acceptable or spoiled. The accuracy of the calibration and validation sets were 92.54% and 86.96%, respectively.

Improving the oxidative stability and lengthening the shelf life of DHA algae oil with composite antioxidants.

Based on various antioxidant mechanisms, four kinds of antioxidants including ascorbyl palmitate (AP), vitamin E (VE), phytic acid (PA) and one of the polyphenols (antioxidant of bamboo leaves, tea polyphenol palmitate or tea polyphenols (TP)) were used in combination to improve oxidative stability of docosahexaenoic acid (DHA) algae oil. To achieve the best effect, the formulations and mixture ratios of the antioxidant combinations were optimized. The effects were monitored by peroxide value, thiobarbituric acid-reactive substances, acid value, free radicals, Rancimat induction time and fatty acid composition of DHA algae oil undergoing accelerated storage. Finally, the DHA algae oil containing 80 mg/kg AP, 80 mg/kg VE, 40 mg/kg PA and 80 mg/kg TP had the highest oxidative stability. Furthermore, the shelf life of DHA algae oil containing the optimum composite antioxidant was predicted by using accelerated shelf life testing coupled with Arrhenius model, which was 3.80-fold longer than the control sample.

Preparation of chitosan based magnetic nanocomposite for tetracycline adsorption: Kinetic and thermodynamic studies.

In the present study, the magnetic nanocomposite is fabricated using chitosan, thiobarbituric acid, malondialdehyde and Fe3O4 nanoparticles (CTM@Fe3O4). The fabricated nanocomposite (CTM@Fe3O4) is characterized using FTIR, TGA, BET, XRD, Raman, XPS, FESEM, and HRTEM techniques. The results of BET analysis confirmed that the nanocomposite has a mesoporous structure with high surface area of 376 m2 g-1 and high pore volume 0.3828 cm3 g-1. The adsorption of tetracycline (TC) onto CTM@Fe3O4 adsorbent is carried out using batch technique by changing several factors such as pH, concentration, contact time, and temperature. Langmuir and pseudo-second-order nonlinear models were found to be the best-fit models to predict isotherms and kinetics of adsorption, respectively. The highest adsorption capacity of 215.31mg/g was achieved at the optimum conditions of 0.05g adsorbent dosage, 60mg/L TC concentration. Overall, results demonstrated that CTM@Fe3O4 nanocomposite was an excellent adsorbent material with superparamagnetic properties, which allowed the separation as well as recovery of the adsorbent from aqueous solution using external magnet for effective industrial applications.

Effects of freezing and thawing on microbiological and physical-chemical properties of dry-aged beef.

This study evaluated the effects of freezing, prior to and after dry aging, on the microbiological and physical-chemical quality of beef. Strip loins (n = 24) from 12 carcasses were assigned to four treatments: non-frozen dry aging (Dry); dry aging, steak fabrication, freezing and slow thawing (Dry + ST); freezing, fast thawing (FT; 20 °C/15 h) and dry aging (FT + Dry); freezing, slow thawing (ST; 4 °C/48 h) and dry aging (ST + Dry). Freezing conditions were - 20 °C/28 days and dry aging conditions were 2 °C/70% relative humidity, for 28 days. Freezing prior to dry aging did not affect the microbial counts compared to Dry. However, FT + Dry and ST + Dry increased (16%) total process loss (P < .05) compared to Dry and Dry+ST. Moreover, freezing changed volatile compounds profile. Thus, freezing prior to dry aging was not a feasible process due to increased process loss, while freezing after dry aging was considered a viable alternative to preserve the steaks without compromising beef physical-chemical traits.

The impact of polar fraction of the fine particulate matter on redox responses in different rat tissues.

Particulate matter (PM) contains different chemical substances that have been associated with health effects and an increased risk of mortality due to their toxicity. In this study, fine particulate matter (PM2.5) samples were collected in a region with rural characteristics (Seropédica (Se)) and another with some industries (Duque de Caxias (DC)) (Brazil, RJ). Rats were exposed to PM2.5 extracts daily for 25 days at different dilutions: 10×, 5×, and a concentrated solution (CS). Biochemical analyses were investigated for total antioxidant capacity (ACAP), lipid peroxidation (LPO) levels, reduced glutathione (GSH) concentration, activity of glutamate cysteine ligase (GCL), and activity of glutathione S-transferase (GST). The liver showed a significant increase in GCL (DC-5×, DC-CS and Se-CS) and GST activities (DC-CS and Se-CS) in both regions when compared to the control group. In the renal cortex, GCL activity decreased in most of the tested groups while GST activity increased only in the 5× groups of both regions (DC and Se). In the renal medulla, GCL activity decreased for Se-10× and DC-CS but increased for Se-5×, and GST activity increased in the Se-10×, DC-5×, and DC-CS groups. Lung GCL increased in all groups for both regions. Moreover, this organ also showed an increase in GST activity when higher metal concentrations were present (5× and CS). TBARS levels were increased for all tissues in most tested concentrations. These data indicate that soluble compounds (e.g., metals) from PM2.5 sampled in areas with different pollution indexes can change the redox status and cause damage to different tissues.

Formation of gallic acid layer on γ-AlOOH nanoparticles surface and their antioxidant and membrane-protective activity.

In the reported study we prepared gallic acid modified γ-AlOOH nanoparticles. We proposed mechanism of phenolic compounds binding on the alumina, suggesting covalent and electrostatic interactions. Most of the properties of alumina nanoparticles (NPs) are unchanged, but there is partial reduction of surface charge. Prepared samples are colloidally stable hydrosols. It allowed us to perform biological studies on cellular and non-cellular models, which showed nontoxicity of both pure and hybrid γ-AlOOH nanoparticles. Furthermore, pure alumina NPs exhibit antioxidant properties, which are enhanced after gallic acid immobilization on their surface. Also, hybrid alumina-gallic acid NPs showed membrane-protective activity.

Effects of Chelating Agents and Salts on Interfacial Properties and Lipid Oxidation in Oil-in-Water Emulsions.

The effects of chelating agents and salts on the interfacial characteristics and oxidative stability of oil-in-water emulsions containing an endogenous concentration of metal ions were investigated. Emulsions were fabricated by high-pressure homogenization of 10% oil phase (sacha inchi oil) and 90% aqueous phase (1% Tween 60 in phosphate buffer solution, pH 7, 50 mM). The oxidative stability of the emulsions was characterized by measuring peroxide values and thiobarbituric acid reactive substances throughout storage. Endogenous iron and copper ion levels in the emulsions were detected by atom absorption spectroscopy as 1.99 and 0.86 ppm, respectively. Incorporation of chelating agents, either ethylenediaminetetraacetic acid or sodium citrate, into the emulsions effectively inhibited lipid oxidation, showing that even these low levels of endogenous metal ions ( parts per million) were sufficient to promote oxidation. Conversely, the addition of monovalent salts, NaCl or KCl, slightly increased the rate of lipid oxidation in the emulsions, which was attributed to their impact on the physical properties of the surfactant layer at the oil droplet surfaces. The impact of chelating agents and salts on the electrical characteristics (ξ potential) and relaxation time (TR) of the surfactant-coated lipid droplets were characterized by particle electrophoresis and nuclear magnetic resonance spectroscopy, respectively. The chelating agents and salts altered the surface potential of the droplets, indicative of a change in the adsorption of metal ions to the droplet surfaces. Moreover, they altered the arrangement of surface-active molecules at the droplet surfaces, thereby impacting the contact of pro-/antioxidants with the oil phase. These results have important implications for the formulation of emulsion-based materials that are more stable to lipid oxidation.

Hydrolysis and oxidation of lipids in mussel Mytilus edulis during cold storage.

Change in quality of mussels (Mytilus edulis) meat when stored at 4 °C was evaluated by determining volatile basic nitrogen (TVB-N), peroxide value (POV), thiobarbituric acid reactive substance (TBARS), total oxidation (TOTOX), lipid class, fatty acid (FA), phosphatidylcholine (PC) and phosphatidylcholine (PE) content, and glycerophospholipid (GP) molecular species. After 4 days of storage, the percentages of triacylglycerol and polar lipid as well as the contents of PC, PE and major GP molecular species significantly decreased (P < 0.05), while the percentages of free FA and monoacylglycerol significantly increased (P < 0.05), indicating the hydrolysis of lipids. The increase in activities of phospholipase and lipase during storage suggests that they may contribute to the hydrolysis of lipids. The cold storage also resulted in significantly increased POV, TBARS and TOTOX as well as lipoxygenase activity (P < 0.05) but slightly decreased percentage of polyunsaturated FA (PUFA), indicating the occurrence of lipid oxidation.

Evaluation of antioxidant potencial of novel CaAl and NiAl layered double hydroxides loaded with olanzapine.

Olanzapine (OLZ), is used in the treatment of bipolar disorder and schizophrenia, diseases that present oxidative stress in their physiopathology. It has low aqueous solubility, which may lead to low oral bioavailability. The search of new drug delivery systems (DDSs) that may increase dissolution rate of OLZ, associated with the investigation of the antioxidant potential of the loaded-systems become of major importance to understand improvement in bipolar disorder and schizophrenia therapy. Thus, this study aimed to evaluate the in vitro antioxidant potential of two different Layered Double Hydroxides (LDH) loaded with 5% of OLZ (CaAl and NiAl), by radical scavenging activity (2,2-Diphenyl-1-picrylhydrazyl and nitric oxid); radical cation scavenging activity (2,2'-azino-bis3-ethylbenzthiazoline-6-sulfonic acid ABTS) and evaluation of inhibition capacity of lipid peroxidation by thiobarbituric acid (TBARS). The results showed that both obtained LDH systems presented in vitro antioxidant capacity when associated with OLZ in all methods performed, and this activity is more pronounced with the systems containing OLZ compared to pure drug. The systems with CaAl was shown to have increased antioxidant potential, compared to NiAl, increasing the antioxidant activity up to 40,83%, 15,84% and 16,73%, as showed by the DPPH, nitric oxide and TBARS tests, respectively. The results revealed that the use of LDHs as a functional excipient may be promising in the pharmaceutical industry for bipolar disorder and schizophrenia therapy.

Chitosan active films containing agro-industrial residue extracts for shelf life extension of chicken restructured product.

This study aimed to develop chitosan films incorporating natural antioxidants from peanut skin (EPS) and pink pepper residue (EPP) extracts, as well as to evaluate their effects on lipid oxidation, pH, color, and microbial counts of a restructured chicken product. EPS had higher phenolic content and antioxidant activity compared to EPP. When both extracts were applied to chicken meat and the chitosan films, there were no differences for color, pH and total mesophilic counts compared to control at the end of the storage period. For lipid oxidation (peroxide value and thiobarbituric acid reactive substances), both extracts proved to be as effective as butylated hydroxytoluene to maintain the oxidative stability of the chicken product. The microbial counts of psychrotrophic microorganisms were significantly lower for treatments with active films. Chitosan active films with residue extracts may maintain the quality of chicken products due to their antioxidant and antimicrobial potential.