Probiotic supplementation and fast freezing to improve quality attributes and oxidation stability of frozen chicken breast muscle

Effect of a probiotic supplement (Bacillus subtilis) on struggling behavior, immune response, and meat quality of shackled broiler chickens exposed to preslaughter stress

This study aimed to investigate the impact of a dietary probiotic supplement on struggling behavior, immune response, and meat quality of shackled broiler chickens exposed to preslaughter stress. Two hundred and ten 1-day-old male Ross 708 broiler chicks were divided among 21 floor pens (10 chicks per pen). The pens were randomly distributed to 1 of 3 dietary treatments containing a probiotic, Bacillus subtilis, at 0 (control), 0.25 (0.25×), and 0.5 (0.5×) g/kg (n = 7). At the end of the experiment (d 35), birds were transported for a journey of 80 km to the abattoir, each crate contained 5 pen mates, 2 birds of them (2 bird per crate, total 14 birds per treatment) were randomly selected for testing. Struggling behavior measurements began after the birds had arrived at the abattoir. Serum and muscle samples (right leg and breast) were collected for immune response and meat quality parameters. The results indicated that probiotic supplemented broilers had lower breast muscle protein carbonyls and serum levels of IgM but higher breast muscle total antioxidant capacity (TAC) compared to those of controls. In addition, probiotic supplemented broilers' leg and breast muscle had higher color lightness and greater water holding capacity (WHC%) with lower cooking loss (CL) and lower pH values (P < 0.05). Probiotic supplemented broilers' breast and leg meat was also tastier (P < 0.05) compared to controls. There were no treatment effects on other measured parameters including struggling behavior, serum IgA and IgG concentrations, and breast muscle malondialdehyde (MDA) (P > 0.05). These results suggest that the probiotic supplement could be an alternative management tool for promoting broiler health and welfare by modifying immune response and meat quality.

Heat Stress and an Immune Challenge Influence Turkey Meat Quality, but Conspecific-Directed Pecking Behavior Does Not

Heat stress (HS), immune challenges (IC) and pecking behavior are some of the many stressors poultry can experience in commercial settings that may affect bird welfare and meat quality after harvest. The first objective was to determine if HS or IC turkeys displayed greater negative effects on meat quality, and the second objective was to determine if the frequency of non-aggressive pecking behaviors among the birds was related to meat quality. Ninety-two, commercial male, beak-trimmed turkeys were used with a total of 15 rooms and 4–7 birds per room. Each treatment was applied for 1 week prior to harvest: the Control (CON) group had no stressors added, the HS group ambient temperature was approximately 29 °C for 120 min, and the IC group involved inoculating birds with a live vaccine for hemorrhagic enteritis virus. Birds were recorded and scored to quantify pecking behavior. Once harvested, carcasses were evaluated for feather retention force, pH, color, proximate analysis, fatty acid composition, shear force, and drip loss. Stress treatment resulted in HS breasts having the lowest protein content, and IC breasts having the lowest CIE L* values and the greatest shear force values. Pecking behavior had no impact on any meat quality attributes.

Effects of Toxic Heavy Metal Salts on Oxidative Quality Deterioration in Ground Pork Model during Aerobic Display Storage

The contamination of toxic heavy metals in meat production and processing can cause the oxidative deterioration of processed meat products. Aside from the possible mechanisms of toxic heavy metals on pro-oxidative reaction, little is known about the potential impacts of toxic heavy metal contamination on meat quality attributes within permitted maximum residual levels. Therefore, the objective of this study was to determine the influence of the intentional contamination of toxic heavy metals on the oxidative deterioration in ground pork models during aerobic display storage. Four types of toxic heavy metal salts (As2O3, CdCl2, K2Cr2O7, and Pb(NO3)2) were mixed with ground pork at two different levels (maximum residue limit and its half level), PVC-wrapped, and displayed in a 4 °C showcase equipped with continuous fluorescent natural white light (1400 l×, color temperature = 6500 K). The contamination of toxic heavy metals significantly decreased the redness of ground pork, and rapidly increased the hue angle. The contamination of Cd and Cr equivalent to maximum residue levels (0.05 and 1.0 mg/kg, respectively) could increase the formation of peroxides, 2-thiobarbituric acid reactive substances, and carbonyls, along with an immediate decrease in total reducing activity. However, there was no difference in protein thiol content between treatments (p > 0.05). These results indicate that contamination of certain toxic heavy metals, particularly Cd and Cr, would accelerate discoloration, lipid oxidation, and carbonyl formation of ground pork during aerobic storage.

Crystallization Behavior and Quality of Frozen Meat

Preservation of meat through freezing entails the use of low temperatures to extend a product’s shelf-life, mainly by reducing the rate of microbial spoilage and deterioration reactions. Characteristics of meat that are important to be preserve include tenderness, water holding capacity, color, and flavor. In general, freezing improves meat tenderness, but negatively impacts other quality attributes. The extent to which these attributes are affected depends on the ice crystalline size and distribution, which itself is governed by freezing rate and storage temperature and duration. Although novel technology has made it possible to mitigate the negative effects of freezing, the complex nature of muscle tissue makes it difficult to accurately and consistently predict outcome of meat quality following freezing. This review provides an overview of the current understanding of energy and heat transfer during freezing and its effect on meat quality. Furthermore, the review provides an overview of the current novel technologies utilized to improve the freezing process.

Production and stability of a multi-strain Bacillus based probiotic product for commercial use in poultry

Probiotics can be effective alternatives to the prophylactic use of antibiotic growth promoters (AGPs) in response to industry and consumer concerns around their use in poultry. Studies on the suitability of Bacillus probiotics are emerging and showing benefits, but information on the production technology is limited. We developed the production process for a novel probiotic product previously shown to be effective in field trials. All strains were cultivated to a spore concentration exceeding 1 × 10¹⁰ CFU. mL^-1. The spores of each strain were harvested, processed into a powder intermediate and formulated into an end product with 100 % recoveries and a shelf life stability >1 year. The probiotic was shown to be incorporated into broiler feed exceeding the desired concentration of 1 × 10⁶ CFU. g^-1. Using efficient process technology and lower cost materials, this study presents a commercially relevant case for the potential adoption of probiotic products by the poultry industry.

A comprehensive insight into the effects of microbial spoilage, myoglobin autoxidation, lipid oxidation, and protein oxidation on the discoloration of rabbit meat during retail display

The effects of the retail display temperature (8 °C, 3 °C and - 1 °C) on the discoloration of the Longissimus thoracis et lumborum of rabbits and the associations among such effects with microbial spoilage, myoglobin autoxidation, lipid oxidation, and protein oxidation were investigated. The total aerobic count, total volatile basic nitrogen content, metmyoglobin content, protein carbonyl content, and contents of thiobarbituric acid-reactive substances steadily increased during retail display. Moreover, the lightness and redness of the rabbit meat significantly (P < 0.05) declined over time, whereas the yellowness increased considerably (P < 0.05) with prolonged retail time. Canonical correlation analysis suggested that microbial spoilage, myoglobin autoxidation, lipid oxidation, and protein oxidation jointly affected rabbit meat color. Linear mixed models further revealed that microbial spoilage, myoglobin autoxidation, lipid oxidation and protein oxidation positively affected yellowness, and they inversely impacted lightness and redness.

Arginine supplementation may improve color and redox stability of beef loins through delayed onset of mitochondrial-mediated apoptotic processes

The objective of this study was to evaluate the effects of arginine (ARG) and/or lysine (LYS) supplementation on meat quality and oxidative stability of beef loins. Steers (n = 40) were split among four dietary treatments (control, ARG, LYS or ARGLYS). The loins (longissimus lumborum) were obtained at 1 day postmortem and aged either 14 or 28 days prior to cutting of steaks for 7 days of display. No impacts of diet treatments on instrumental tenderness, water-holding capacity and fatty acid profiles were found (P > 0.05). Extended aging significantly decreased lipid oxidative stability, color stability and reducing ability of loins. However, steaks from ARG and ARGLYS maintained superior color stability coupled with lower mitochondrial membrane permeability and higher cytochrome c redox stability compared to control (P < 0.05). These results indicate that ARG supplementation can improve color stability of beef loins possibly through delayed onset of mitochondrial-mediated apoptotic processes.

Effects of probiotic supplementation and postmortem storage condition on the oxidative stability of M. Pectoralis major of laying hens

Dietary probiotic supplementation is a promising alternative to antibiotics in the poultry industry, and some studies have found its positive impacts on meat quality attributes. The objective of this study was to evaluate the effects of dietary treatments on oxidative stability of postmortem chicken fillet (M. Pectoralis major) muscles during 7 d of storage under either high oxygen (HIOX) or vacuum (VAC) conditions. A total of 264 Hy-Line Brown laying hens (11 birds per cage) were assigned to 2 different dietary treatments (regular diet or 300 ppm probiotic, Sporulin enhanced diet) before being sacrificed. At 17 wk, one bird per cage from 6 cages per treatment was randomly selected and slaughtered (n = 12). Chicken fillets from both sides were collected and randomly assigned to HIOX or VAC conditions. Within each fillet side, the muscle was divided into 3 portions, assigned to 1 or 7 d storage period, while the caudal portion was allocated as the 0 d samples for proximate composition and fatty acid profiling. Results revealed that the muscle crude compositions were not altered in laying hens that were fed probiotic supplementary diet compared to controls (P > 0.05). However, the muscle samples from probiotic fed laying hens had higher proportions of unsaturated fatty acid (74.76 vs. 71.65%, P < 0.05) and 2-thiobarbituric acid reactive substances (0.79 vs. 0.67 mg malondialdehyde/kg meat, P < 0.05) than the samples from the control. In addition, the probiotic fed laying hens, but not controls, had higher levels of conjugated dienes (3.32 vs. 2.63 μg/g meat) and peroxides (0.40 vs. 0.30 milliequivalent O₂/kg fat) in the muscle samples after 7 d of storage (P < 0.05). The results from the present study indicated that postmortem fillet muscles obtained from the laying hens fed with probiotic supplementation would be more prone to be oxidized, especially under more oxidizing conditions (HIOX and extended storage time).

Effects of probiotic (Bacillus subtilis) supplementation on meat quality characteristics of breast muscle from broilers exposed to chronic heat stress

The aim of this study was to determine the impact of probiotic feeding and chronic heat stress on meat quality, total lipid and phospholipid contents, lipid oxidation, antioxidant capacity, and heat shock protein abundance of broiler breast muscle. A total of 240 male broilers (5 birds per pen) were subjected to 4 treatments consisting of a 2 × 2 factorial design. Broilers were kept at 21-32-21°C for 10 h daily (heat stress, HS) or 21°C (thermoneutral condition) and fed a regular diet or the diet mixed with probiotic (250 ppm of Sporulin containing 3 strains of Bacillus subtilis). A total of 48 broilers (12 birds/treatment) were harvested at 46 d. Neither HS nor probiotic had substantial impacts on water-holding capacity, shear force, and color characteristics. HS induced lipid oxidation as increased 2-thiobarbituric acid reactive substances (TBARS), in which probiotic feeding decreased TBARS value (P = 0.002) and phospholipid contents (P = 0.0033) in breast muscle of HS broilers. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was increased with HS (P < 0.0001), but no significant impact of probiotic supplementation was found. Neither probiotic nor HS affected catalase activity, but superoxide dismutase and glutathione peroxidase activities were lower in HS broilers compared to thermoneutral controls (P < 0.0001) and in probiotics-fed broilers (P < 0.0001) compared to their counterparts. In addition, a significant interaction between probiotic and HS was found at glutathione peroxidase activities, in which breast muscle of broilers fed probiotic at thermoneutral condition showed the highest activity (P < 0.05). Regarding heat shock protein (HSP) determination, HS slightly increased the levels of both HSP70 (P = 0.08) and HSP27 (P = 0.05), but no significant impacts of probiotic supplementation were found. Our results indicate that probiotic feeding could improve breast muscle weight without adverse impacts on meat quality attributes, as well as alleviate oxidative deterioration of breast muscle of broilers undergoing heat stress.

The effect of repeated freeze-thaw cycles on the meat quality of rabbit

<p>We investigated the effect of repeated freeze-thaw cycles on the quality of rabbit meat. Twenty-five Hyla rabbits were slaughtered using standard commercial procedures. A freeze-thaw procedure—i.e., seven days frozen at –18°C followed by thawing at 4°C for 12h— was repeated 5 times, and 9 <em>Longissimus thoracis et lumborum</em> muscles were randomly selected at pre-set cycles (0, 1, 2, 3, and 5). The <em>Longissimus lumborum</em> muscles were used to determine meat quality parameters, while the <em>Longissimus thoracis</em> muscles were used for chemical analysis. During the repeated freeze-thaw process, muscle pH, redness, hardness, and water holding capacity gradually decreased, whereas meat lightness and yellowness gradually increased. The amount of total volatile basic nitrogen significantly increased (<em>P</em>&lt;0.05) and exceeded the threshold value for frozen meat after 5 repeated freeze-thaw cycles. The metmyoglobin proportion, thiobarbituric acid-reactive substances (TBARS) and protein carbonyl content in rabbit meat samples increased with a higher number of freeze-thaw cycles (<em>P</em>&lt;0.05), and the proportions of these compounds were positively correlated. During the repeated freeze-thaw process, extractable haeme iron levels significantly decreased (<em>P</em>&lt;0.05), and non-haeme iron levels markedly increased (<em>P</em>&lt;0.05). An sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis indicated that the degradation of both water- and salt-soluble proteins was more prevalent in samples subjected to higher numbers of freeze-thaw cycles. Additionally, a principal component analysis identified good correlations between physicochemical properties (TBARS, protein carbonyl levels and metmyoglobin content) and quality parameters (thawing loss, redness, lightness and hardness). Taken together, we conclude that the repeated freeze-thaw process can strongly affect rabbit meat quality as well as its physicochemical properties.</p>

Effects of heat stress and probiotic supplementation on protein functionality and oxidative stability of ground chicken leg meat during display storage

BACKGROUND

The present study aimed to evaluate the effects of heat stress and probiotic supplementation on protein functionality and oxidative stability of ground chicken leg during display storage. Two hundred and forty, 1-day-old male chicks (5 birds per pen) were subjected to four treatments in a 2 (thermoneutral condition at 21 °C and cyclic heat stress at 32-21-32 °C for 10 h day^-1 ) × 2 (regular diet with 0 or 0.25 g kg^-1 Bacillus subtilis) factorial design. Chickens were harvested at day 46, and pairs of whole legs were collected at 1 day postmortem. The chicken legs were deboned, ground, tray-packaged with oxygen-permeable film, and displayed for 3 days.

RESULTS

Heat stress and probiotic supplementation had no impact on pH, water-holding capacity, color, protein functionality, lipid lipolysis and lipid/protein oxidation stability (P > 0.05). Display storage increased the pH and lipid oxidation of ground chicken legs (P < 0.05). In addition, protein oxidation occurred during display storage, as determined via an increased carbonyl group (P = 0.0109) and reduced thiol group (P < 0.0001).

CONCLUSION

The results of the present study indicate that chronic heat stress and probiotic supplementation had no practical adverse impact on protein functionality and oxidative stability of ground chicken leg meat. © 2017 Society of Chemical Industry.