Effect of aldehyde lipid oxidation products on myoglobin

Antioxidation Activity Enhancement by Intramolecular Hydrogen Bond and Non-Browning Mechanism of Active Ingredients in Rosemary: Carnosic Acid and Carnosol

Rosemary is one of the most promising, versatile, and studied natural preservatives. Carnosic acid (CA) and carnosol (CARN), as the primary active ingredients of rosemary extracts, have little difference in structure, but their antioxidant activities vary significantly, depending on the system studied. The underlying molecular mechanisms remain unclear. By means of optical spectroscopies, stopped-flow, laser photolysis, and density functional theory (DFT) calculations, we have compared CA and CARN between their reaction dynamics of radical scavenging, metal ion chelation, and oxidation inhibition in lipid emulsion and beef, as well as between their interactions with β-carotene (β-Car). For reference, 3-isopropyl catechol (IC), which is structurally similar to the active groups of CA and CARN, was studied in parallel. It is found for CA that the intramolecular hydrogen bond can boost the acidity of its phenol hydroxyl and that the synergistic effect with β-Car can substantially enhance its antioxidation activity in the model systems of lipid and meat via the CA-to-β-Car electron transfer reaction. The substitution of A and B rings on the catechol group in both CA and CARN limits browning caused by their formation of oxidative products as antioxidants.

The Effect of Enzymatic Hydrolysis and Maillard Reaction on the Flavor of Chicken Osteopontin

To reveal the changes in the flavor quality of chicken osteopontin (CO) before and after enzymatic hydrolysis and a thermal reaction, the present study was carried out to evaluate the volatile compounds and non-volatile compounds in CO. The results show that the chicken boneset enzymatic solution (CBES) presented a notably richer aroma after the enzymatic hydrolysis treatment. At the same time, the concentrations of the total free amino acids (FAAs) and 5'-nucleotides in the CBES increased dramatically. The ERP (enzymatic reaction paste) scores and the ORC (osteopontin reactive cream) scores were exceptionally high in terms of the umami and salty flavor profiles. As precursors, FAAs and 5'-nucleotides also boosted the Maillard reaction, leading to the generation of wide volatile compounds. Compared to CO, CBES, and ORC, the sensory evaluation showed that ERP scored the highest. In summary, the enzymatic hydrolysis treatment coupled with the Maillard reaction significantly enhanced the flavor profile of CO. These findings offer valuable insights into the high-value utilization of bone by-products, making a significant advancement in the field.

Lipid Peroxidation Products Influence Calpain-1 Functionality In Vitro by Covalent Binding

The objective of the current study was to evaluate the effects of lipid peroxidation products, malondialdehyde (MDA), hexenal, and 4-hydroxynonenal (HNE), on calpain-1 function, and liquid chromatography and tandem mass spectrometry (LC-MS/MS) identification of adducts on calpain-1. Calpain-1 activity slightly increased after incubation with 100 μM MDA but not with 500 and 1000 μM MDA. However, calpain-1 activity was lowered by hexenal and HNE at 100, 500, and 1000 μM. No difference in calpain-1 autolysis was observed between the control and 1000 μM MDA. However, 1000 μM hexenal and HNE treatments slowed the calpain-1 autolysis. Adducts of MDA were detected on glutamine, arginine, lysine, histidine, and asparagine residues via Schiff base formation, while HNE adducts were detected on histidine, lysine, glutamine, and asparagine residues via Michael addition. These results are the first to demonstrate that lipid peroxidation products can impact calpain-1 activity in a concentration-dependent manner and may impact the development of meat tenderness postmortem.

Metabolomics and bioinformatic analyses to determine the effects of oxygen exposure within longissimus lumborum steak on beef discoloration

Meat discoloration starts from the interior and spreads to oxymyoglobin layer on the surface. The effects of oxygen exposure within a steak on the metabolome have not been evaluated. Therefore, the objective of this study was to evaluate the impact of oxygen exposure on the metabolome of the longissimus lumborum muscle. Six United States Department of Agriculture (USDA) Low Choice beef strip loins were sliced into steaks (1.91-cm) and packaged in polyvinyl chloride overwrap trays for 3 or 6 d of retail display. The oxygen exposed (OE) surface was the display surface during retail, and the non-oxygen exposed (NOE) surface was the intact interior muscle. The instrumental color was evaluated using a HunterLab MiniScan spectrophotometer. To analyze the NOE surface on days 3 and 6, steaks were sliced parallel to the OE surface to expose the NOE surface. Metmyoglobin reducing ability (MRA) was determined by nitrite-induced metmyoglobin reduction. A gas chromatography-mass spectrometry was used to identify metabolites. The a* values of steaks decreased (P < 0.05) with display time. MRA was greater (P < 0.05) in the NOE surface compared with the OE surface on days 3 and 6. The KEGG pathway analysis indicated the tricarboxylic acid (TCA) cycle, pentose and glucuronate interconversions, phenylalanine, tyrosine, and tryptophan metabolism were influenced by the oxygen exposure. The decrease in abundance of succinate from days 0 to 6 during retail display aligned with a decline in redness during display. Furthermore, citric acid and gluconic acid were indicated as important metabolites affected by oxygen exposure and retail display based on the variable importance in the projection in the PLS-DA plot. Citric acid was lower in the NOE surface than the OE surface on day 6 of retail display, which could relate to the formation of succinate for extended oxidative stability. Greater alpha-tocopherol (P < 0.05) in the NOE surface supported less oxidative changes compared to the OE surface during retail display. These results indicate the presence of oxygen can influence metabolite profile and promote migration of the metmyoglobin layer from interior to surface.

Inhibitory mechanisms of polyphenols on heme protein-mediated lipid oxidation in muscle food: New insights and advances

Lipid oxidation is a major cause of quality deterioration that decreases the shelf-life of muscle-based foods (red meat, poultry, and fish), in which heme proteins, particularly hemoglobin and myoglobin, are the primary pro-oxidants. Due to increasing consumer concerns over synthetic chemicals, extensive research has been carried out on natural antioxidants, especially plant polyphenols. The conventional opinion suggests that polyphenols inhibit lipid oxidation of muscle foods primarily owing to their strong hydrogen-donating and transition metal-chelating activities. Recent developments in analytical techniques (e.g., protein crystallography, nuclear magnetic resonance spectroscopy, fluorescence anisotropy, and molecular docking simulation) allow deeper understanding of the molecular interaction of polyphenols with heme proteins, phospholipid membrane, reactive oxygen species, and reactive carbonyl species; hence, novel hypotheses regarding their antioxidant mechanisms have been formulated. In this review, we summarize five direct and three indirect pathways by which polyphenols inhibit heme protein-mediated lipid oxidation in muscle foods. We also discuss the relation between chemical structures and functions of polyphenols as antioxidants.

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. The complexity of muscle tissue -both composition and structure- poses as a formidable challenge in directly clarifying the mechanisms of lipid oxidation in muscle-based foods. Therefore, different in vitro model systems simulating different aspects of muscle have been used to study the pathways of lipid oxidation. In this review, we discuss the principle, preparation, implementation as well as advantages and disadvantages of seven commonly-studied model systems that mimic either compositional or structural aspects of actual meat: emulsions, fatty acid micelles, liposomes, microsomes, erythrocytes, washed muscle mince, and muscle homogenates. Furthermore, we evaluate the prospects of stem cells, tissue cultures and three-dimensional printing for future model system development. Based on this reviewing of oxidation models, tailoring correct model to different study aims could be facilitated, and readers are becoming acquainted with advantages and shortcomings. In addition, insight into recent technology developments, e.g., stem cell- and tissue-cultures as well as three-dimensional printing could provide new opportunities to overcome the current bottlenecks of lipid oxidation studies in muscle.

Improving the Aromatic Profile of Plant-Based Meat Alternatives: Effect of Myoglobin Addition on Volatiles

Market demand for palatable plant-based meat alternatives is on the rise. One of the challenges is formulating products with sensorial characteristics similar to conventional meat. In this study, the effect of myoglobin on the aromatic profile of plant-based meat alternatives was assessed. Plant-based burgers were made with soy-textured protein, supplemented with three levels of myoglobin (0, 0.5 and 1.0%, the latter two mimicking endogenous myoglobin levels in meat), and grilled for 12 min at 250 °C. To evaluate the aromatic profile of the compounds, raw and grilled samples were subjected to headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). Principal component analysis (PCA) analysis was then performed to visualize the interaction between grilling and myoglobin addition, and the effect exerted on the resulting aromatic profile. Myoglobin significantly affected several classes of volatile compounds, either by itself or in conjunction with grilling. A notable increase in aldehydes and a decrease in hydrocarbons were noted after adding myoglobin. As expected, an increase in pyrazines was observed after grilling. The results suggest myoglobin positively influences the aromatic profile of plant-based meat alternatives, contributing to a profile closer to the one of conventional meat.

Undesirable discoloration in edible fish muscle: Impact of indigenous pigments, chemical reactions, processing, and its prevention

Fish is rich in proteins and lipids, especially those containing polyunsaturated fatty acids, which made them vulnerable to chemical or microbial changes associated with quality loss. Meat color is one of vital criteria indicating the freshness, quality, and acceptability of the meat. Color of meat is governed by the presence of various pigments such as hemoglobin, myoglobin (Mb), and so on. Mb, particularly oxy-form, is responsible for the bright red color of fish muscle, especially tuna, and dark fleshed fish, while astaxanthin (AXT) directly determines the color of salmonids muscle. Microbial spoilage and chemical changes such as oxidation of lipid/proteins result in the autoxidation of Mb or fading of AXT, leading to undesirable color with lower acceptability. The discoloration has been affected by chemical composition, post-harvesting handling or storage, processing, cooking, and so on . To tackle discoloration of fish meat, vacuum or modified atmospheric packaging, low- or ultralow-temperature storage, uses of artificial and natural additives have been employed. This review article provides information regarding the factors affecting color and other quality aspects of fish muscle. Moreover, promising methodologies used to control discoloration are also focused.

Inhibition of Protein and Lipid Oxidation in Ready-to-Eat Chicken Patties by a Spondias mombin L. Bagasse Phenolic-Rich Extract

This study evaluated the impact of yellow mombin (Spondias mombin L.) bagasse extract (YMBE) on the color degradation, protein and lipid oxidation in ready-to-eat chicken patties during 15 days of refrigerated storage. Two formulations of chicken patties were developed: chicken patties control - PCON (without the antioxidant extract) and chicken patties with yellow mombin extract - PYME (with the antioxidant extract). The extract was effective in maintaining red color and inhibiting myoglobin degradation in the evaluated samples. The generation of lipid oxidation compounds during storage of the treated samples was delayed by 92.37% for peroxide index, 89.89% for conjugated dienes, 74.29% for tiobarbituric acid reactive substances (TBARs) and 92.55% for ρ-anisidine compared to the control samples. Moreover, the addition of YMBE inhibited the formation of carbonyl compounds during cold storage compared to the control samples. Extracts obtained from the yellow mombin bagasse act as a good natural antioxidant for ready-to-eat chicken patties inhibiting protein and lipid oxidative damage during cold storage, being a potential preservative to replace synthetic antioxidants in meat products.

Principal component analysis of lipid and protein oxidation products and their impact on color stability in bison longissimus lumborum and psoas major muscles

The study aims were to compare lipid (malondialdehyde [MDA], 4-hydroxy-2-nonenal [HNE]) and protein (carbonyl content [CAR]) oxidation products between two bison muscles (longissimus lumborum [LL] and psoas major [PM]) at different aging and retail display time and determine their influence on muscle color stability. Regardless of the aging and retail display time, LL showed greater redness (a* value; P = 0.04) and lower surface discoloration (P < 0.01) than PM as well as LL exhibited lower MDA, HNE, and CAR content compared to PM (P < 0.05). In both muscles, MDA showed the highest correlation to a* (r = -0.78; P < 0.01) and discoloration (rs = 0.82; P < 0.01) scores, particularly in PM muscle compared to LL muscle. In conclusion, the principal component analysis revealed 4 distinct color deterioration clusters within steaks displayed at d 4 according to the muscle and aging time, and MDA critically influences color deterioration patterns in bison muscles.

Biomolecular Interactions Governing Fresh Meat Color in Post-mortem Skeletal Muscle: A Review

Appearance is an important sensory property that significantly influences consumers' perceptions of fresh meat quality. Failure to meet consumer expectations can lead to rejection of meat products, concomitant loss in value, and potential production of organic waste. Immediately after animal harvest, skeletal muscle metabolism changes from aerobic to anaerobic. However, anoxic post-mortem muscle is biochemically active, and biomolecular interaction between myoglobin, mitochondria, metabolites, and lipid oxidation determines meat color. This review examines how metabolites and mitochondrial activity can influence myoglobin oxygenation and metmyoglobin reducing activity. Further, the review highlights recent research that has examined myoglobin redox dynamics, sarcoplasmic metabolite changes, and/or post-mortem biochemistry.

A Chemometric Approach to Oxidative Stability and Physicochemical Quality of Raw Ground Chicken Meat Affected by Black Seed and Other Spice Extracts

The effects of black seed (Nigella sativa), allspice, bay leaf, caraway, cardamom, clove, and nutmeg extracts on the quality of raw ground chicken legs stored at 4 °C were investigated. During 12 days of storage, conjugated diene (CD) content, thiobarbituric acid reactive substances (TBARS), oxidation induction time (IP) by DSC (differential scanning calorimetry), hexanal content by GC-SPME-MS, thiol group (SH) content were determined. Moreover, microbial growth, pH and color of the samples were investigated. Sensory analysis was also realized. All extracts increased oxidative stability and safety of meat, significantly changed the color of the samples, stabilized the pH and increased their sensory scores (except color of samples with bay leaf and black seed) when comparing to control. Black seed, allspice and clove extracts showed high antioxidant capacity in lipid (CD = 0.23%, 0.28%, and 0.37%, respectively; TBARS = 0.55, 0.50, and 0.48 mg/kg, respectively) and protein fraction (SH content = 47.9, 52.1 and 52.7 nmol/g, respectively), although the ABTS•+ radical scavenging activity of black seed (33.1 µM/g) was significantly lower than the cloves (2496 µM/g) and allspice (815 µM/g). In the sensory analysis the highest scores were ascribed to the sample with cardamom followed by cloves. Principal component analysis (PCA) indicated complex and inseparable interrelationship among lipid and protein oxidation processes and the relationship of the protein oxidation on the lightness of meat. The results enabled to discriminate the meat samples, showing a great impact of the extracts on the final quality of raw chicken meat with black seed being potent antioxidant active additive.

Effect of freeze-thaw cycles on the quality of quick-frozen pork patty with different fat content by consumer assessment and instrument-based detection

The change in quality of quick-frozen patties containing different amounts of added fat (0%, 5%, 10%, 15%, and 20%) under different freeze-thaw (F-T) cycles (a F-T cycle was performed by freezing at -18 °C and thawing at 4 °C) was evaluated. The results showed that the a*-values of samples were significantly decreased, while L*-values, b*-values, thawing loss, and cooking loss were notably increased after 3 F-T cycles. Low-field nuclear magnetic resonance (LF-NMR) results showed that the water mobility of patties was enhanced. Textural properties (hardness, springiness, cohesiveness, and chewiness) of patties were significantly decreased after 5 F-T cycles (P < 0.05). Lipid and protein oxidation were aggravated with increasing fat content and number of F-T cycles, as confirmed by the increase in lipid peroxides, TBARS, and carbonyl content. Therefore, the results from instrument-based detection and consumer scores indicated that repeated F-T cycles accelerated the quality deterioration of quick-frozen pork patties, and rendered them unacceptable after 3 F-T cycles.

Effect of the exposure to oxidation and malondialdehyde on turkey and rabbit meat protein oxidative stability

The present study aimed at evaluating the effect of the exposure to a strong oxidative environment (100 mM NaClO) and the concurrent incubation with different malondialdehyde (MDA) concentrations (0 to 5 mM) on protein carbonylation, free thiol groups, total heme pigments, and on the relative concentration of the different myoglobin (Mb) derivatives in turkey thigh and rabbit hind leg meat to elucidate their eventual role in inducing oxidative modifications on the protein fraction. With regard to turkey meat, the addition of a strong oxidant resulted in remarkably higher (P < 0.001) carbonyls along with a reduction in free thiol groups (which become undetectable). The relative concentration of MbO₂ and MetMb was significantly affected (P < 0.001) and total heme pigment was reduced by 62% when fresh meat is compared to its oxidized counterpart. The addition of MDA 2.5 mM (or greater) resulted in a 1.4-fold increase in carbonyls and a tendency (P = 0.07) has been observed for free thiol groups whose content decreased as the MDA level increased. Overall, the aforementioned results are in agreement with those obtained on rabbit hind leg meat in which a three-fold increase (P < 0.001) in carbonyls and a remarkably higher (P < 0.001) MetMb content coupled with a 53% reduction in free thiol groups were found. No significant differences ascribable to MDA addition were found. In conclusion, exposing turkey and rabbit meat to the same environment resulted in distinctive oxidative changes that might be related to the compositional traits and a species-specific susceptibility of the meat toward oxidation. PRACTICAL APPLICATION: Protein and lipid oxidation have been investigated in different meat types; nevertheless, the knowledge concerning the interaction between these two phenomena is limited. According to their compositional traits (high Polyunsaturated fatty acids (PUFA) and heme pigment content), turkey and rabbit leg meats are particularly susceptible to oxidation. Providing information concerning the oxidative stability of turkey thigh and rabbit hind leg meat exposed to strong oxidative conditions and to a concurrent increasing content of a secondary product of lipid oxidation, the findings of the present study can be useful when proper processing strategies and storage conditions have to be implemented for manufacturing processed products.

Effect of Chinese Cinnamon Powder on the Quality and Storage Properties of Ground Lamb Meat during Refrigerated Storage

This study was undertaken to evaluate the impact of Chinese cinnamon powder (w/w), at the levels of 0.5%, 1.5%, and 2.5% and control (without additive) on ground lamb meat quality. The samples were stored at 4°C and examined for pH, color, lipid oxidation (thiobarbituric acid reactive substances) and total viable counts (TVC). The results demonstrated that pH values were declined with the increase of Chinese cinnamon levels compared to control group. The L* values throughout the storage were significantly higher (p<0.05) in the control group than in other treatment groups, while a* values were decreased with the increase of Chinese cinnamon levels. The addition of Chinese cinnamon powder strongly inhibited (p<0.05) thiobarbituric acid reactive substances (TBARS) and TVC in all treated samples. It can be concluded that Chinese cinnamon powder in lower concentration 0.5% has the ability to maintain the quality of ground lamb in comparison with other treated samples.

Antioxidant activities of mamao luang (Antidesma thwaitesianum Müll. Arg.) fruit: Extraction and application in raw chicken patties

Extraction of mamao luang (hereafter called mamao) with different solvents and varying solid to liquid (S:L) ratio was conducted to verify its antioxidant activities. Total phenolic content (TPC), total flavonoid content, total monomeric anthocyanin content, and antioxidant activities, namely, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and ferric reducing antioxidant power (FRAP) of the unrefined extracts, were analyzed. The extraction with 70% acetone and 70% methanol and the S:L ratio of 1:30 seemed to be more appropriate and gave significantly (P < 0.05) higher values of the previously mentioned properties. Whole ground fruits were then incorporated into the blended chicken patties to compare their antioxidant and antimicrobial properties with butylated hydroxyanisole (BHA). During refrigeration storage of 20 days, the highest level (1,000 mg TPC/kg meat) could retard lipid oxidation relatively comparable to the efficiency of BHA (200 ppm). However, when microbiological aspect was considered together, a limited storage of 12 days was consequently suggested. PRACTICAL APPLICATION: Mamao fruit is a splendid source of phenolic compounds. The antioxidant properties have been demonstrated using DPPH and FRAP assay. The suitable type of solvent and S:L ratio were provided for the extraction. Our findings have shown that addition of mamao, a source of natural antioxidants, especially at the highest level increased oxidative stability of chicken patties. The research outcomes identify the potential bioactive compound and provide beneficial information related to the feasibility of incorporation of mamao phenolics as antioxidant agents in suitable food matrices. However, further investigation is still required for successful application in meat and meat products.

Carbon Chain Length of Lipid Oxidation Products Influence Lactate Dehydrogenase and NADH-Dependent Metmyoglobin Reductase Activity

The biochemical basis of lower metmyoglobin reducing activity (MRA) in high-oxygen modified atmospheric packaged (HiOx-MAP) beef than those in vacuum and polyvinyl chloride (PVC) packaging is not clear. To explore this, the effects of lipid oxidation products with varying carbon chain length on lactate dehydrogenase (LDH) and NADH-dependent metmyoglobin reductase activity were evaluated. Surface color, MRA, and lipid oxidation of beef longissimus lumborum steaks (n = 10) were measured during 6-day display. Further, two enzymes, LDH and NADH-dependent metmyoglobin reductase (n = 5), critical for MRA were incubated with or without (control) lipid oxidation products of varying carbon chain length: malondialdehyde (3-carbon), hexenal (6-carbon), and 4-hydroxynonenal (9-carbon). Steaks in HiOx-MAP had greater (P < 0.05) redness than vacuum and PVC, but had lower (P < 0.05) MRA and greater (P < 0.05) lipid oxidation on day 6. LDH and NADH-dependent metmyoglobin reductase activities were differentially influenced by lipid oxidation products (P < 0.05). The results indicate that the difference in reactivity of various lipid oxidation products on LDH (HNE > MDA = hexenal) and NADH-dependent metmyoglobin reductase (HNE = MDA > hexenal) activity could be responsible for lower MRA in HiOx-MAP.

Performance, beef quality and expression of lipogenic genes in young bulls fed low-fat dried distillers grains

Two studies were carried out, the first with the objective to evaluate performance, beef quality and expression of genes involved in lipid metabolism in the muscle of bulls fed with or without low-fat dried distillers grains with solubles (DDGS, 21% DM) in the diet. In the second, eight rumen-fistulated bulls were assigned in a switch back design to evaluate the fatty acid profile of omasal fluid. We hypothesized that bulls fed DDGS may have an improved fatty acid profile and expression of genes involved in lipid metabolism may be altered, without affecting performance. Bulls fed DDGS had greater (P < .05) concentrations of PUFA n-6 in the omasum and muscle. CLA t10, c12 content was higher and there was lower expression of the LPL gene (P = .05) in the muscle of animals fed DDGS (P = .03). In conclusion, DDGS can be used as a protein feedstuff because it maintains beef quality.

Effects of Aging, Modified Atmospheric Packaging, and Display Time on Metmyoglobin Reducing Activity and Oxygen Consumption of High-pH Beef

The objective of current research was to determine the effects of extended aging, modified atmospheric packaging (MAP), and display time on metmyoglobin reducing activity (MRA) and oxygen consumption (OC) of high-pH beef using pH sensitive methodology for MRA and OC. Ten normal-pH (mean pH = 5.6) and 10 high-pH loins (mean pH = 6.4) were vacuum packaged on d 3 postmortem and aged for 0, 21, 42, and 62 d at 2°C. Following aging, 2.0-cm-thick steaks were cut from each of the normal- and high-pH loin sections and packaged in either PVC film, high-oxygen (HiOx-MAP), or carbon monoxide modified atmospheric (CO-MAP) packaging. Surface color, OC, and MRA were measured on d 0 and 6 of the respective aging periods. Steaks in HiOx-MAP and CO-MAP had similar (P > 0.05) L* values, which were greater (P < 0.05) than high-pH steaks packaged in PVC film. On 21-d of aging, steaks with at both pHs in CO-MAP and HiOx-MAP had greater (P < 0.05) a* values than steaks packaged in PVC. As aging time increased, MRA decreased (P < 0.05) for steaks with normal- and high-pH when packaged in PVC and HiOx-MAP. Steaks with a high-pH in CO-MAP had greater (P < 0.05) MRA than steaks with a normal-pH in CO-MAP at all aging periods. Steaks with a high-pH had greater (P < 0.05) OC on d 0 and 6 than normal-pH steaks. Steaks with a normal-pH aged for 21 d and packaged in PVC and HiOx-MAP had greater (P < 0.05) lipid oxidation than high-pH steaks aged for 21 d and packaged in PVC and HiOx-MAP. After 62 d of aging and 6 d of display, the greatest color stability chemistry (based on MRA and OC for all package types) were: high-pH meat > normal-pH meat; thus the MRA and OC methodology was useful in relative comparison of packaged meat color stability differences due to pH.

Effect of Saccharomyces uvarum on lipid oxidation and carbonyl compounds in silver carp mince during cold storage

Fish lipid is highly susceptible to oxidation, resulting in accumulation of toxic substances reactive carbonyl compounds (RCCs), the reduction of nutritional value, and the production of odorous substances. In this study, the effect of yeast (Saccharomyces uvarum) on RCCs, fat acid composition, volatiles, and sensory traits in silver carp mince stored at 4°C was evaluated. Yeast eliminated malondialdehyde, 4-hydroxyl-2-hexenal, and 4-hydroxyl-2-nonenal by about 80%, 68%, and 60%, which increased by about 170%, 340%, and 300% in the control, respectively. Yeast helped retain about 80% of the polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively; only about 53% and 46% of EPA and DHA, respectively, were maintained in the control. Yeast removed off-odors hexanal, nonanal, and decenal, resulting in enhanced sensory traits. These findings were economically important for improving the quality of fish products. It might present an approach to improve the flavor of fish products.

Changes in the Volatile Composition of Fresh Pork Sausage with Natural Antioxidants During Long-Term Frozen Storage

Pre-rigor meat was formulated into fresh pork sausages with a combination of synthetic antioxidants (butylated hydroxyanisole, butylated hydroxytoluene, and propyl gallate) or the same synthetic antioxidants in combination with rosemary (R, 1500, 2000, 2500 mg/kg) and green tea (G, 100, 200, 300 mg/kg). Sausages were stored frozen (-20°C) for 15, 90, or 180 d followed by refrigerated storage (3 ± 1°C). The volatile compounds from these sausages were identified using solid phase microextraction (SPME), gas chromatography coupled with a mass selective detector (GC-MSD), and OSME-gas chromatography-olfactometry (GCO-OSME). Fifty-five aroma compounds were identified from the headspace of pork sausage where spice-derived volatiles such as terpenes (α-pinene, α-thujene) and terpenoids (isopulegol, 1,8-cineole) were the most abundant compounds in the headspace of the fresh product (0 d). Aldehydes (heptanal, 2-heptenal, (E,E)-2,4-decadienal) and alcohols (1-octen-3-ol, 1-penten-3-ol) characteristic of lipid degradation and microbial metabolites (methanethiol, 3-methylbutanoic acid, acetoin) were associated with more intense odorants as the product neared the end of shelf life at 14 d of refrigerated storage. Incorporation of R resulted in lower levels of hexanal (cut grass) and 1-octen-3-ol (mushroom) across all frozen storage periods. After 180 d of frozen storage, higher levels of G contained lower concentrations of ethanol (alcoholic), 3-methylbutanoic acid (sweaty), and 2-acetyl-1-pyrroline (popcorn). As R and G concentration increased in the sausage, there were greater (P < 0.05) concentrations of terpenes and less (P < 0.05) acetic acid throughout refrigerated storage. Incorporation of R resulted in less (P < 0.05) 2,4-decadienal (oxidized ginger-nutmeg), and methanethiol (sulfur) following 90 d of freezing. After 180 d frozen storage, higher levels of G led to less (P < 0.05) 3-methyl-1-butanol and methyl isovalerate (spoiled fruit). Enhanced protection by natural plant extract combinations was observed, especially beyond 90 d of frozen storage where oxidation associated aroma-impact volatiles were reduced in sausages with higher rosemary and/or green tea extract concentrations.

Effect of dietary chromium supplementation on meat nutritional quality and antioxidant status from broilers fed with Camelina-meal-supplemented diets

Poultry meat is a valuable source of nutrients and the enrichment with health-promoting substances such as polyunsaturated fatty acids (n-3 PUFA) is an important factor for consumers' choice. Camelina meal (Camelina sativa) is an animal feedstuff used to achieve this goal, but the administration of n-3 PUFA-enriched diets in broiler nutrition can accelerate the oxidative processes in meat leading to a decreased quality of final product. The aim of this study was to investigate the effect of the organic Cr as chromium picolinate (CrPic) on meat quality, fatty acid profile of fat and oxidative stability of meat from broilers fed supplemented dietary Camelina meal. An experiment was conducted on 240 Ross 308 broiler chicken aged 14 days which were assigned to 6 dietary treatments in a randomized complete block design with a 2 × 3 factorial arrangement. Within the treatment arrangement two concentrations of Camelina meal (0% and 3%) and three concentrations of Cr3+ (0, 200 and 400 μg/kg) were used. Dietary treatments were: (1) Control diet (C) containing a corn-soybean diet with no added Camelina meal or Cr3+; (2) a C diet containing an additional 200 μg/kg of Cr3+ as CrPic; (3) a C diet containing an additional 400 μg/kg of Cr3+ as CrPic; (4) a C diet containing an additional 3% Camelina meal; (5) diet 2 containing an additional 3% Camelina meal; (6) diet 3 containing an additional 3% Camelina meal. Chromium supplementation significantly (P<0.05) increased the CP concentrations and significantly (P<0.05) decreased the crude fat concentrations in breast samples. The Camelina meal groups presented higher values of unsaturated fatty acids, particularly n-3 fatty acids (P<0.05). In CrPic groups, increased retention of Zn and Fe (P < 0.05) was observed in breast samples, compared to control group, and thiobarbituric acid reactive substances values were significantly (P<0.05) smaller. Myoglobin fraction (metmyoglobin and oximyoglobin) concentrations differ significantly (P<0.05) from the control group, under the influence of Cr3+ supplements. This study found that broilers fed with CrPic supplements showed improved mineral composition and oxidative stability of breast meat, proving an effective protection of lipid molecules from oxidation in PUFA-enriched meat.

Kimchi extracts as inhibitors of colour deterioration and lipid oxidation in raw ground pork meat during refrigerated storage

BACKGROUND

Kimchi is a Korean, traditional fermented food made from Korean cabbage, radish, fermented jeotgal, ginger, garlic, and red pepper powder. It is a good source of natural antioxidants such as phenolic compounds, flavonoids, vitamins, and carotenoids. In this study, the antioxidant effects of various kimchi extracts on raw ground pork during refrigerated storage were investigated. Raw ground pork samples were treated with ascorbic acid, butylated hydroxyl toluene, baechu kimchi extract (BKE), gat kimchi extract (GKE), puchu kimchi extract (PKE), and white kimchi extract (WKE) and compared with raw ground pork without antioxidant treatment (NC).

RESULTS

Increased metmyoglobin (MetMb), thiobarbituric acid reacting substance (TBARS), and total bacterial counts (TBC) were observed in all meat samples after storage, whereas pH, lightness, and redness values tended to decrease with increased storage time. All treated samples had lower TBARS and MetMb values and TBC compared to the control samples. Various kimchi ethanol extracts protected raw ground pork from lipid oxidation. The most potent antioxidant was GKE, whereas WKE was the weakest.

CONCLUSIONS

This study suggests that the tested extracts, especially kimchi, have potential as natural preservatives to reduce colour degradation, lipid oxidation, and bacterial count in raw ground pork meat. © 2018 Society of Chemical Industry.

Effect of long term chilled (up to 5 weeks) then frozen (up to 12 months) storage at two different sub-zero holding temperatures on beef: 3. Protein structure degradation and a marker of protein oxidation

Different chilled (~0.1 °C for up to 5 weeks) then frozen storage (up to 12 months) combinations and two frozen storage holding temperatures (-12 °C and -18 °C) effects on beef M. longissimus lumborum (LL) protein structure degradation and a marker of protein oxidation were tested. Particle size (PS) analysis and protein solubility results found storage combination effects on protein degradation to be significant (P < 0.05), although the influence of frozen holding temperatures was negligible. LL carbonyl, and nitrate and nitrite content responses were variable and yet broadly reflected an increased incidence of protein oxidation across increasing chilled storage and ensuing frozen storage periods - this aspect meriting future exploration. Total myoglobin content and the estimated myoglobin redox fractions (metmyoglobin, deoxymyoglobin, and oxymyoglobin) were also subject to storage treatment. These findings demonstrate the capacity for beef storage selection (chilled-then-frozen) to manage compositional protein changes and its implications on sensory quality traits across comparative 'long term' durations.

Biopreservative Efficacy of Bacteriocin BacFL31 in Raw Ground Turkey Meat in terms of Microbiological, Physicochemical, and Sensory Qualities

　The effect of the semi purified bacteriocin BacFL31 at 200 and 400 AU/g on the shelf life of refrigerated raw ground turkey meat was investigated. The microbiological, physicochemical, and sensory properties of the meat samples were examined during refrigerated storage. The findings indicated that BacFL31 treatments were effective (p<0.05) against the proliferation of various spoilage microorganisms and suppressed the growth of Listeria monocytogenes and Salmonella Typhimurium. The pH, % Met-MB, and TBA-RS values of the treated samples were lower (p<0.05) than those of their control samples. The addition of BacFL31 extended the shelf life and enhanced the sensory attributes of the turkey meat samples during refrigerated storage. These results suggest that BacFL31 could be considered a promising candidate for future application as an additive to preserve the raw turkey meat during storage at 4℃.

Development of novel fortified beef patties with added functional protein ingredients for the elderly

The effects of clean label functional protein ingredients; pea protein isolate (PPI), rice protein (RP) and lentil flour (LF), at 3% and 7% inclusion levels on technological and shelf life parameters of beef patties were evaluated over 12days. Protein content in the RP7 treatment was higher (P<0.05) than controls, but did not differ significantly from PPI7 and RP3. No effects on moisture, fat or ash content were detected. LF addition reduced product hardness, cohesiveness, gumminess and chewiness compared with controls. RP-enriched and control patties were associated with lower lipid oxidation over storage than PPI- and LF-enriched patties. RP had a differential effect on (L*), (a*) and (b*) when compared with controls. Microbiological characteristics for all treatments were acceptable after 12days. Protein fortified beef patties with a softer texture and acceptable technological properties targeted for ease of consumption by older adults were produced in an attempt to reach dietary targeted protein requirements for this segment.

Proteomic based approach for characterizing 4-hydroxy-2-nonenal induced oxidation of buffalo (Bubalus bubalis) and goat (Capra hircus) meat myoglobins

BACKGROUND

Myoglobin (Mb) is a sarcoplasmic heme protein primarily responsible for meat color and its chemistry is species specific. 4-hydroxy-2-nonenal (HNE) is a cytotoxic lipid derived aldehyde detected in meat and was reported to covalently adduct with nucleophilic histidine residues of Mb and predispose it to greater oxidation. However, no literature is available on characterization of lipid oxidation induced oxidation of Indian water buffalo (Bubalus bubalis) and goat (Capra hircus) myoglobins.

METHODS

Present study characterize the Mb extracted from water buffalo and goat cardiac muscles using two-dimensional gel electrophoresis (2DE), OFFGEL electrophoresis and mass spectrometry (MS). Purified buffalo and goat bright red oxymyoglobin were reacted with HNE in-vitro at physiological pH (7.4) and temperature (37 °C) conditions and the formation of oxidised brown metmyoglobin was measured. The Mb-HNE adducts were detected using MALDI-TOF MS, whereas specific sites of adduction was determined using ESI-QTOF MS/MS.

RESULTS

Purified buffalo and goat Mb samples revealed a molecular mass of 17,043.6 and 16,899.9 Daltons, respectively. The 2DE analysis exhibited 65 (sarcoplasmic protein extract) and 6 (pure Mb) differentially expressed (P < 0.05) protein spots between buffalo and goat samples. OFFGEL electrophoresis revealed an isoelectric point of 6.77 and 7.35 respectively, for buffalo and goat Mb's. In-vitro incubation of HNE with bright red buffalo and goat oxymyoglobin's at pH 7.4 and 37 °C resulted in pronounced (P < 0.05) oxidation and formation of brown metmyoglobin. MALDI-TOF MS analysis of Mb-HNE reaction mix revealed covalent binding (via Michael addition) of 3 and 5 molecules of HNE with buffalo and goat Oxy-Mb's, respectively. ESI-QTOF MS/MS identified seven and nine histidine (HIS) residues of Mb that were readily adducted by HNE in buffalo and goat, respectively.

CONCLUSION

The study demonstrated better redox stability of buffalo Mb than goat Mb. Our findings confirm the hypothesis that relative effect of HNE was greater for Mb's with 12 ± 1 HIS residues than Mb's with 9 HIS residues and helps meat processors in developing species-specific processing strategies to reduce the color variability.