Comparison of the quality characteristics of chicken breast meat from conventional and animal welfare farms under refrigerated storage

Exploration of changes in sensory, physicochemical properties and microbial metabolic activities of grass carp meat with five thermal processing treatments during refrigerated storage

This study aimed to employed the effects of five thermal processing methods, namely steaming (SM), boiling (BO), frying (FY), roasting (RO), and vacuum sealing (SV), on the sensory, physicochemical properties, and microbial composition of grass carp meat during refrigerated storage, alongside unheated raw meat (RW) as control. The results showed that thermal treatment improved the sensory quality and shelf life of refrigerated grass carp meat, and their shelf life was RW < BO Collapse

Key Words

• Correlation analysis
• Grass carp
• Microbial metabolism
• Refrigeration
• Thermal processing

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Affiliation(s)

Lu Zhang National R&D Center for Freshwater Fish Processing, College of Life Sciences, Jiangxi Normal University, Nanchang, Jiangxi 330022, China School of Health, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
Yaqin Yu National R&D Center for Freshwater Fish Processing, College of Life Sciences, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
Chunming Tan School of Health, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
Shi Nie National R&D Center for Freshwater Fish Processing, College of Life Sciences, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
Qinghui Wen School of Health, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
Zongcai Tu National R&D Center for Freshwater Fish Processing, College of Life Sciences, Jiangxi Normal University, Nanchang, Jiangxi 330022, China School of Health, Jiangxi Normal University, Nanchang, Jiangxi 330022, China Nanchang University, Nanchang, Jiangxi 330006, China

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Effects of Broth pH and Chilling Storage on the Changes in Volatile Profiles of Boiled Chicken Flesh

This study investigated the changes in volatile compounds in chicken flesh after boiling at various pHs (6.0-9.0) and after chilling storage (4.0±1.0°C) for 7 d. The volatile compounds were assessed qualitatively and quantitatively by using a headspace gas chromatography-mass spectrometry analysis. Twenty-one volatile compounds were discovered and categorized as amine, aldehyde, alcohol, ketone, acid, and furan. One type of amine, (2-aziridinylethyl) amine, was the most prevalent volatile component, followed by aldehyde, ketone, aldehyde, acid, ester, and furan. The results showed that the quantity and quality of the volatile compounds were influenced by a pH of the boiling medium. Additionally, the types and volatile profiles of the chicken were altered during chilling. In particular, in the chicken that was boiled at a pH of 8.0, the hexanal (an aldehyde) content increased the most after 7 d of chilling. Moreover, various alcohols formed after the 7 d of chilling of the chicken that was boiled at pHs of 8.0 and 9.0. Because of the oxidation and degradation of fat and proteins, the most altering volatile compounds were the reducing amines and the increasing aldehydes.

Systematic evaluation of the meat qualities of free-range chicken (Xuan-Zhou) under different ages explored the optimal slaughter age

Meat qualities of free-range chicken (Xuan-Zhou) (XZ-FRC) are closely associated with slaughter age and directly influence the economic benefits of supplier and consumer's preference. Understanding of the relationship between meat qualities and ages will be of prime important to explore a better slaughter age of XZ-FRC. In this study, the quality traits of breast and thigh muscles from XZ-FRCs at 9 to 14 wk were analyzed to establish a relatively reliable method for selecting a better slaughter age. The results showed that the effects of slaughter ages on color (CIE L*, a* and b* values), shear force, centrifugal loss, and flavor of XZ-FRCs were significant (P < 0.05). There were greater differences in meat qualities, whatever breast or thigh muscles, between same or different ages. Eleven feature indexes used for colligation evaluation of slaughter age were selected by combining the quality characteristics and data analysis. The score of colligation evaluation for XZ-FRCs at 12 wk was higher than that at 9 and 14 wk, suggesting that the 12 wk was an optimal slaughter age. This work would provide a reference method that helps the producers of livestock and poultry to select a better slaughter age.

Unraveling the flavor profiles of chicken meat: Classes, biosynthesis, influencing factors in flavor development, and sensory evaluation

Chicken is renowned as the most affordable meat option, prized by consumers worldwide for its unique flavor, and universally recognized for its essential savory flavor. Current research endeavors are increasingly dedicated to exploring the flavor profile of chicken meat. However, there is a noticeable gap in comprehensive reviews dedicated specifically to the flavor quality of chicken meat, although existing reviews cover meat flavor profiles of various animal species. This review aims to fill this gap by synthesizing knowledge from published literature to describe the compounds, chemistry reaction, influencing factors, and sensory evaluation associated with chicken meat flavor. The flavor compounds in chicken meat mainly included water-soluble low-molecular-weight substances and lipids, as well as volatile compounds such as aldehydes, ketones, alcohols, acids, esters, hydrocarbons, furans, nitrogen, and sulfur-containing compounds. The significant synthesis pathways of flavor components were Maillard reaction, Strecker degradation, lipid oxidation, lipid-Maillard interaction, and thiamine degradation. Preslaughter factors, including age, breed/strain, rearing management, muscle type, and sex of chicken, as well as postmortem conditions such as aging, cooking conditions, and low-temperature storage, were closely linked to flavor development and accounted for the significant differences observed in flavor components. Moreover, the sensory methods used to evaluate the chicken meat flavor were elaborated. This review contributes to a more comprehensive understanding of the flavor profile of chicken meat. It can serve as a guide for enhancing chicken meat flavor quality and provide a foundation for developing customized chicken products.

A comparative review on Ayam Cemani chicken - A comparison with the most common chicken species in terms of nutritional values, LCA, price and consumer acceptance

Chickens are definitely among the most prevalent and broadly distributed domestic species. Among these, Ayam Cemani, also known as black chicken, is a rare Indonesian chicken breed originating from the island of Java. The main characteristic of this breed is that the body, both internally and externally, is entirely black. This is due to a condition named fibro melanosis, in which there is an over accumulation of melanin pigment in body tissues. In addition to this, Ayam Cemani meat results to be also higher in protein content and lower in fat. Moreover, Ayam Cemani meat is also known to have antioxidant and glucose-binding capacities. These properties make it very desirable within the market and consequently very expensive. Their meat is also used traditionally by tribal healers in the treatment of some chronic illnesses. In general, compared to other chicken species, the Ayam Cemani showed an higher genetic resistance to some infectious diseases commonly affecting poultry species. As regard the breeding, Ayam Cemani is a unique breed which may only be raised in specific locations, characterized to be a slowly growing breed with a lower body weight in comparison to the other poultry breeds. Nowadays, due to an improvement in the management, the nutrition and diseases control, it is possible to enhance their productivity. To date, there are not many studies in the literature on the specific breed of Ayam Cemani. For this reason, this review aims to provide a comprehensive overview of all the knowledge of the Ayam Cemani breed, the nutritional composition of the meat and consumer acceptance.

Effect of cinnamon powder on quality attributes and off-flavor in fried chicken drumsticks made from long-term thawed Korean native chicken

The effect of cinnamon powder on the quality and mitigation of off-flavor in fried chicken drumsticks made from long-term thawed Korean native chicken (Woorimatdag No. 1, WRMD1) was investigated. The WRMD1 drumsticks were categorized into 5 groups: conventional thawing (16 h, CT), long-term thawing (48 h, LT), cinnamon powder added into 'LT' as marinade (0.03%, CM) or incorporated into the batter (1.35%, CB), and long-term thawing with cinnamon powder incorporated both in the marinade and batter (0.03% + 1.35%, CMB). The crude fat content was significantly higher in the CT and CMB than that of the CB. The CM, CB, and CMB showed significantly lower levels of 2-thiobarbituric acid reactive substance compared with the CT and LT. The predominant fatty acids in all treatments were C18:1n9, C18:2n6, and C16:0. The LT displayed lower total unsaturated fatty acid content than the CT (P < 0.05). The CM effectively decreased lipid oxidative volatiles, such as 1-octanol, 1-octen-3-ol, and 2-octen-1-ol, (E), in the LT (P < 0.05). Both the CM and CB showed an inclination to increase specific pyrazines associated with pleasant notes compared with the LT, and showed higher levels of pyrazines, such as pyrazine, 2-ethyl-6-methyl-, and pyrazine, 3-ethyl-2,5-dimethyl-, than those of the CMB (P < 0.05). The CM contained higher levels of 2,3-butanedione when compared with the other groups (P < 0.05). Multivariate analysis demonstrated that cinnamon had an effect in discriminating the treatment groups with cinnamon addition from both the CT and LT, whereas the CM, CB, and CMB formed distinct clusters. The CM and CMB received significantly higher aroma scores from panelists in comparison to the other groups. These findings suggest that the CM (0.03% cinnamon powder) can be used to enhance the aroma in fried WRMD1 drumsticks by reducing or masking the off-flavor volatiles associated with long-term thawing.

Effects of intermittent cold stimulation on growth performance, meat quality, antioxidant capacity and liver lipid metabolism in broiler chickens

Intermittent cold stimulation (ICS) enhances broilers' resistance to cold stress. Nonetheless, further research is needed to investigate the underlying mechanisms that enhance cold stress resistance. A total of 160 one-day-old male Ross 308 broilers were randomly divided into 2 groups (CC and CS5), with the CC group managing temperature according to the standard for broiler growth stages, while the CS5 group were subjected to cold stimulation at a temperature 3℃ lower than the CC group for 5 h, every 2 d from 15 to 35 d. Sampling was conducted at 36 d (36D), 50 d (50D) and after acute cold stress for 24 h (Y24). First, we examined the effects of ICS on broiler growth performance, meat quality, antioxidant capacity, and lipid metabolism. The results demonstrated that ICS enhanced the performance of broilers to a certain degree. Specifically, the average weight gain in the CS5 group was significantly higher than that of the CC group, and the feed conversion ratio significantly decreased compared to CC at 4 W and 6 W (P ≤ 0.05). Compared with the CC group, cold stimulation significantly reduced drip loss, shearing force, and yellowness (a* value) of chicken meat, while significantly increased redness (b* value) (P ≤ 0.05). At Y24, the levels of T-AOC and GSH-PX in the serum of the CS5 group were significantly higher than those of the CC group, while the level of MDA was significantly lower (P ≤ 0.05). The content of TG, FFA, and VLDL in the serum of the CS5 group was significantly elevated, whereas the level of TC and HDL was significantly lower (P ≤ 0.05). In addition, we further explored whether AMPK-mTOR pathway is involved in the regulation of changes in lipid metabolism and the possible regulatory mechanisms downstream of the signaling pathway. The results showed that ICS significantly upregulated the expression levels of AMPK mRNA and protein in the liver of the CS5 group at 36D and Y24, while significantly down-regulating mTOR (P ≤ 0.05). Compared with the CC group, ICS significantly down-regulated the mRNA expression levels of lipid synthesis and endoplasmic reticulum stress-related genes (SREBP1c, FAS, SCD, ACC, GRP78 and PERK) at 36D and Y24, while significantly up-regulating the mRNA expression levels of lipid decomposition and autophagy-related genes (PPAR and LC3) (P ≤ 0.05). In addition, at Y24, the protein expression levels of endoplasmic reticulum stress-related genes (GRP78) in the CS5 group were significantly lower, while autophagy-related genes (LC3 and ATG7) were significantly higher (P ≤ 0.05). ICS can affect meat quality and lipid metabolism in broilers, and when broilers are subjected to acute cold stress, broilers trained with cold stimulation have stronger lipid metabolism capacity.

Dietary novel alkaline protease from Bacillus licheniformis improves broiler meat nutritional value and modulates intestinal microbiota and metabolites

BACKGROUND

Different types of exogenous protease supplements have a positive impact on animal performance, but their effects on the nutritional value of meat and the gut microbial community of broilers have not been extensively studied. The objective of this investigation was to determine the impact of supplementation with a novel alkaline protease derived from Bacillus licheniformis (at doses of 0, 100, 200, 300, and 400 g/t) on the fatty acid and amino acid profiles, inosine monophosphate (IMP) levels, total volatile basic nitrogen (TVB-N) content found within the breast muscle, as well as the impact on the cecal microbiota and metabolites.

RESULTS

Supplementation with 200-400 g/t of the novel protease resulted in a significant elevation in the concentration of essential amino acids (P < 0.001), flavor amino acids (P < 0.001), and total protein (P = 0.013) within the breast muscle. Results derived from the 16S rRNA sequencing and untargeted metabolomics analysis of the cecal content revealed that the novel protease reshaped the cecal microbial and metabolite profiles. In particular, it led to increased relative abundances of Bacteroides, Lactobacillus, Alistipes, and Eubacterium, while simultaneously causing a reduction in the metabolites of D-lactic acid and malonic acid. Moreover, correlation analyses unveiled significant relationships between distinct microbes and metabolites with the contents of IMP, fatty acids, and amino acids in the broiler's breast muscle.

CONCLUSION

In summary, the novel protease regulated the intestinal microbial community and metabolism, thereby inducing changes in the compositions of fatty acids and amino acids profiles, as well as IMP levels in broiler meat. These alterations significantly contributed to the enhancement of the nutritional value and flavor of the meat.

The Effect of Temperature and Storage Duration on the Quality and Attributes of the Breast Meat of Hens after Their Laying Periods

The purpose of this study was to evaluate the effect of temperature (2 °C and 6 °C) and storage duration on the quality and attributes of hens' breast meat after their laying periods. The study included physicochemical characteristics (pH, drip loss, colour, shear force), microbiological quality (total Enterobacteriaceae family and Pseudomonas count), and sensory quality. Bacterial identification was performed using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. The increased meat pH and drip loss was greater at 6 than 2 °C (p < 0.05). An increase in the tenderness of the meat stored at 6 °C was found as early as day 4, as well as at 2 °C on day 8 of storage (p < 0.05). On day 4 of storage, the meat was characterised by a darker colour than on the first day, but the darkening was greater at 6 °C than at 2 °C (p < 0.05). At 6 °C, on day 4 of storage, there was an increase in yellow saturation (b*) of the meat, which was higher at 6 °C than at 2 °C (p < 0.05). At 2 °C, the total bacterial count and number of Pseudomonas spp. in the meat gradually increased along with increasing storage duration, reaching 4.64 log cfu/g and 4.48 log cfu/g, respectively, on the 8th day of storage. At 6 °C, on the sixth day of storage, the total bacterial count in the meat exceeded 7 log cfu/g, considered the limit of microbiological safety. The meat stored at 2 °C had an acceptable sensory quality until the 8th day of storage. The study shows that storage at 2 °C preserves the sensory characteristics and microbiological safety of the hen meat longer at an acceptable level after the laying period. Extended storage life may be of importance to consumers and the meat industry.

The Effect of Fermented Grains (koji) on Physicochemical and Sensory Characteristics of Chicken Breasts

This study investigated the tenderizing and flavor-enhancing effects of koji, a fermented grain cultured with a single microorganism, on chicken breasts during curing. Chicken breasts were cured with different ingredients, including 4% (w/w) curing agent (GC), 5% (w/w) Aspergillus oryzae with rice (FR), A. oryzae with soybean (FS), and Bacillus subtilis with soybean (BS) for 4 h at 4 °C prior to cooking. After the superheated steam procedure, all samples were cooked in a convection oven, and their physicochemical properties were analyzed. Koji-treated samples exhibited significantly higher expressible moisture due to the degradation of the protein matrix (p < 0.05). Texture profile analysis showed that the tenderness of koji-treated samples was significantly higher than that of GC (p < 0.05). Furthermore, koji-treated samples were regarded as tenderer, and they were preferred over GC (p < 0.05) in the sensory evaluation. Principal attributes analysis revealed that the overall preference for koji-treated samples was highly correlated with umami, juiciness, and tenderness (p < 0.05). Overall, this study provides insights into applying koji as a potential curing treatment to improve the eating quality of chicken breasts. Koji can be used as a novel technology in the food industry to improve taste and tenderness simultaneously.

Evaluation of Carcass Attributes and Physical, Chemical, and Qualitative Characteristics of Breast Meat of Broiler Chickens Fed on Pulicaria jaubertii Powder

Pulicaria jaubertii (PJ) is a medicinal plant used as a synthetic antioxidant and as a traditional medicine due to its bioactive compounds. The objective of this study was to investigate the effects of PJ on carcass traits and breast meat quality parameters of broiler chickens. Two hundred and forty male broilers (1 day old) were divided into four groups (0, 3, 6, and 9 g of PJ/kg of basal diet). Performance indicators were evaluated during the feeding stages, and carcass characteristics and physiochemical and qualitative parameters of breast meat were measured at 36 days old. The results showed that PJ improved performance parameters such as weight gain, feed conversion ratio, and production efficiency index (p < 0.05) in the finishing stage. The diets supplemented with PJ were associated with better carcass characteristics (p < 0.05), but some body parts, such as legs (6 and 9 g PJ) and backs (3-9 g PJ) decreased (p < 0.05). Temperature and initial pH were decreased by PJ (p < 0.05). Meat color was not affected by PJ (p > 0.05), although the yellowness and saturation index were lower at 9 g PJ. Total saturated fatty acid content was higher at 3 g PJ, while total polyunsaturated fatty acids and unsaturated to saturated fatty acid ratio were lower at 3 and 6 g PJ (p < 0.05). Total monounsaturated fatty acid content increased at 6 and 9 g PJ. Omega-6 fatty acids and the ratio of omega-6 to omega-3 were lower at 3 g PJ. PJ resulted in higher weight loss on cooking (6 and 9 g PJ) and shear force (3-9 g PJ). In conclusion, PJ had a positive influence on performance, carcass characteristics, and fatty acid profile, and some meat quality traits were generally improved by PJ, but knowledge of its mode of action is still limited and therefore requires further investigation.

Effects of Gum Arabic (Acacia senegal) Powder on Characteristics of Carcass and Breast Meat Quality Parameters in Male Broiler Chickens

Gum Arabic, one of the soluble fibers, is considered a source of natural prebiotics that can be fermented by the activity of the intestinal microbiota and, therefore, may have a positive effect on the performance, carcass characteristics, and meat quality of broilers. Therefore, the objective of this study was to investigate the effects of gum Arabic on performance, carcass characteristics, physicochemical properties, and quality of broiler breast meat. Six dietary treatments (T1-T5) with a basal diet (CON) containing 0.12%, 0.25%, 0.5%, 0.75%, and 1.0% gum Arabic, respectively. A total of 432 one-day-old male broiler chickens were conducted for 35 days. Performance and carcass characteristics, as well as physical, qualitative, and chemical indicators of breast meat, were evaluated. The results showed that the treatments improved overall performance (p < 0.05), such as body weight, weight gain, feed conversion ratio, and performance index, except for feed intake, which was lower at T1, T2, and T5 than at CON. Carcass characteristics, body components, and breast meat color or initial pH were not affected by dietary treatments (p > 0.05), but ultimate pH (T1 and T2) and color lightness were comparatively lower, and color change (T2-T3) was comparatively higher. Cooking water loss (T2-T4) and shear force (T1-T5) were higher in the treatments. Cohesiveness and resilience were higher in T2, while gumminess and chewiness were lower in T4 and T5. T1 breast meat had higher crude protein content and lower crude fat content, but the other chemical compositions were not affected by the treatments. Some fatty acids in the breast meat were more affected by treatments compared to CON. In conclusion, the present findings showed that gum Arabic (0.12% to 0.75%) has favorable effects on growth performance and some quality indicators of breast meat (such as cooking water loss, shear force, protein, and fat content), especially at the level of 0.12% with no alterations on the carcass characteristics and body components or physical indicators of breast meat.

Effect of dietary Agriophyllum squarrosum on average daily gain, meat quality and muscle fatty acids in growing Tan lambs

The herb A. squarrosum is reputed to possess medicinal properties for humans, and has the potential to be a feed resource for livestock. We hypothesized that this herb would improve the meat quality of lambs. To test this hypothesis, 24 Tan ewe-lambs (27.7 ± 0.45 kg) were offered diets containing 0 (CON), 100 (AS₁₀₀), 200 (AS₂₀₀) and 300 (AS₃₀₀) g A. squarrosum/kg DM, and average daily gain, carcass traits, blood metabolites, meat quality and fatty acid profiles were determined. Drip loss % and cooking loss % decreased with the AS₁₀₀ and AS₂₀₀ diets (P < 0.05). Dietary A. squarrosum reduced muscle fiber area and diameter and increased density of the meat (P < 0.05), which indicated that the meat was more tender. The concentrations of C10:0 and C18:1n-9 t were 1ower and of C17:0 and C18:3n-3 were greater in the AS₂₀₀ and AS₃₀₀ treatments than CON (P < 0.05). Our results suggest that feeding lambs up to 200 g/kg DM of A. squarrosum can increase the water-holding capacity and L* value of meat without compromising growth. Further research is needed to determine the optimal level.

Omega-3-Rich Fish-Oil-Influenced Mouse Gut Microbiome Shaped by Intermittent Consumption of Beef

Beef consumption can provide various amino acids, lipids, vitamins, and minerals; however, excessive intake causes metabolic disorders and increases the probability of obesity, atherosclerosis, and colorectal cancer. The intake of omega-3 fatty acids can ameliorate metabolic disorders by lowering blood glucose and triglyceride levels. In the present study, we investigated the effect of omega-3-rich fish oil on body performance and the gut microbiome in a beef-rich diet. Four-week-old C57BL/6 mice were distributed into four groups (chow diet [Chow], chow with beef diet [Beef], chow with omega-3 diet [Cw3], and chow with beef and omega-3 diet [Bw3]). We observed that body weight was unaltered between groups, and serum triglyceride levels were reduced in the omega-3 supplemented groups. The beta diversity indices, unweighted UniFrac distance (P = 0.001), and Jaccard distance (P = 0.001) showed statistically significant differences, and the principal coordinates analysis plot showed a clear separation between groups. In addition, the taxonomic comparison revealed that beef consumption increased numerous potentially pathogenic bacteria, including Escherichia-Shigella, Mucispirillum, Helicobacter, and Desulfovibrio, which were decreased following omega-3 supplementation. Metabolic comparison based on 16S rRNA revealed that energy and glucose metabolism were higher in omega-3 supplemented groups. Our findings suggest that the omega-3 supplementation under intermittent beef consumption contributes to changes in the gut microbiome and microbial metabolic pathways.

Study of the effect of treatment with aqueous extracts by oregano and wild basil on raw poultry meat

The effect of treatment with aqueous antioxidant extracts of oregano (Origanum vulgare L.) and wild basil (Clinopodium vulgare L.) in refrigerated storage of raw poultry meat was studied. Physicochemical analyzes of meat samples were performed - total protein, ash, fat, dry matter, cooking loss and pH value in dynamics. The content of malondialdehyde (MDA) and the protein profile were determined. The microorganisms’ growth rate in meat during storage at 4°C for a period of 14 d was monitored. After the 7th d, the total number of mesophilic microorganisms in the meat samples increased to 7.00 log cfu/g, which is indicative of decay. A significant increase in pH value was observed after 14 d of storage, but there were no significant changes in total protein content and protein profile. In all meat samples, the amounts of MDA on days 7 and 14 were significantly below the thresholds indicated in the literature. Experimental groups treated with extracts showed lower values for MDA content compared to the control, which is an indication of certain inhibition of lipid oxidation processes in meat.

Nano Zinc Oxide Improves Performance, IGF-I mRNA Expression, Meat Quality, and Humeral Immune Response and Alleviates Oxidative Stress and NF-κB Immunohistochemistry of Broiler Chickens

A 35-day trial was set to explore the effects of different dietary zinc sources on growth, insulin-like growth factor I (IGF-I) mRNA expression, meat quality, immune response, antioxidant activity, and immunohistochemistry of nuclear factor kappa B (NF-κ7B) of broiler chickens. Ross 308 broiler chicks (n = 156) were randomly assigned into four experimental groups. The G1 received the basal control diet without zinc supplementation; the G2, G3, and G4 were supplemented with zinc oxide, zinc lysine, and nano zinc oxide, respectively, at a level of 40 mg Zn/kg diet. The data revealed that nano zinc oxide linearly improved the overall growth performance parameters. Nano zinc oxide linearly elevated (P < 0.001) mRNA expression of IGF-I followed by G3. The pH value of breast muscle in G4 shows a linearly decreasing value (P < 0.001). Also, the linearly highest expressible release volume percentage and lightness (L*) value with the lowest redness (a*) value (P < 0.05) were recorded in G4 and G3. A numerical increase in the total antibody titer was recorded on the 35^th day in the G3 and G4. A numerical elevation in the superoxide dismutase (SOD) and a numerical reduction in the serum malondialdehyde (MDA) were recorded in the G4. The section of the liver from G4 revealed significantly very low expression of NF-κB staining. It is concluded that nano zinc oxide is considered the more trending zinc source. It had no negative effects on the health status and can be used in broiler diet premix.

Physicochemical Characteristics and Flavor-Related Compounds of Fresh and Frozen-Thawed Thigh Meats from Chickens

The physicochemical characteristics and flavor-related compounds of thigh meat derived from diverse Korean native chickens (KNC), namely Hanhyup No. 3 (HH3), Woorimatdag No 1 (WRMD 1), and Woorimatdag No 2 (WRMD 2), under fresh and frozen-thawed conditions were studied and compared with those of commercial broilers (CB). Regardless of the breed, KNC showed a higher (p < 0.05) percentage of linoleic and arachidonic acid. The highest proportion of docosahexaenoic acid was observed in WRMD 2. Despite having a higher collagen content, thigh meat derived from KNC maintained a similar texture profile in comparison to that of CB. The concentrations of most free amino acids (FAA), except for taurine, tryptophan, and carnosine, were higher in frozen-thawed meat than in fresh meat. Regarding volatile organic compounds (VOC), following freezing, the concentration of favorable VOCs increased in CB, but decreased in WRMD 1, suggesting a loss of pleasant flavor in frozen-thawed meat. This study indicated that changes in VOCs, including hydrocarbons (d-limonene, heptadecane, hexadecane, naphthalene, pentadecane, 3-methyl-, tridecane), esters (arsenous acid, tris(trimethylsilyl) ester, decanoic acid, ethyl ester, hexadecanoic acid, ethyl ester), alcohol (1-hexanol, 2-ethyl-), ketones (5,9-undecadien-2-one, 6,10-dimethyl-), and aldehydes (pentadecanal-, tetradecanal, tridecanal), may be a promising marker for distinguishing between fresh and frozen-thawed chicken thigh meat. These findings are of critical importance as preliminary data for developing high-quality chicken meat products.

Using 2D qNMR analysis to distinguish between frozen and frozen/thawed chicken meat and evaluate freshness

We identified key metabolites reflecting microbial spoilage and differentiated unfrozen meat from frozen/thawed (FT) using 2D qNMR analysis. Unfrozen and FT chicken breasts were prepared, individually aerobically packaged, and stored for 16 days at 2 °C. Only volatile basic nitrogen (VBN) was significantly changed after 6 log CFU/g of total aerobic bacteria (p < 0.05). Extended storage resulted in an increase in organic acids, free amino acids, biogenic amines, and hypoxanthine and a decrease in N,N-dimethylglycine, inosine 5'-monophosphate, and proline. Acetic acid demonstrated the highest correlation with VBN (r = 0.97). Unfrozen and FT breast meat can be differentiated by uniform concentration of carnosine, β-alanine, and histidine levels, consistent changes in nucleotides by storage time, and changes in microbial metabolism patterns that are reflected by some free amino acids. Thus, NMR-based metabolomics can be used to evaluate chicken breast meat freshness and distinguish between unfrozen and FT meat.

Effects of Photoperiod on the Performance, Blood Profile, Welfare Parameters, and Carcass Characteristics in Broiler Chickens

We studied the effects of photoperiods on the growth performance, blood profile, welfare parameters, and carcass characteristics of broilers. A total of 336 male broiler chicks (Ross 308) were randomly allocated into 4 treatments (84 birds per treatment with 4 replicates), based on the following lighting regimen: 24 h continuous light (24L), 18 h continuous light (18L:6D), 8 h continuous light (8L:16D), and intermittent light (4L:2D). Body weight and feed intake of 7- and 35-day-old broilers were measured. At 5 weeks of age, 12 birds per treatment were selected for blood collection and carcass analysis. Body weight, body weight gain, and feed intake were the lowest in the 8L:16D treatment (p < 0.05). The heterophil-to-lymphocyte ratio, aspartate aminotransferase, interleukin-6, and corticosterone levels in the 24L treatment increased significantly when compared to that in the 18L:6D treatment (p < 0.05). The footpad dermatitis score was significantly lower in the 18L:6D and 8L:16D treatments than in the 24L and 4L:2D treatments (p < 0.001). There was no significant difference in the carcass and meat characteristics, except for the shear force of breast meat (Pectoralis major), which was the lowest in the 8L:16D treatment (p < 0.05). These results indicate that a photoperiod of 18 h resulted in an improvement in the performance and welfare of birds and a simultaneous decrease in stress level. However, further research is needed to establish a lighting regimen that satisfies both the productivity and welfare requirements of broilers in different feeding phases.

The Comparison between Tanzanian Indigenous (Ufipa Breed) and Commercial Broiler (Ross Chicken) Meat on the Physicochemical Characteristics, Collagen and Nucleic Acid Contents

The objective of this study was to characterize the meat quality traits that affect the texture and savory taste of Ufipa indigenous chickens by comparing the proximate composition, physical characteristics, collagen, and nucleic acid contents with those of commercial broilers. It was found that Ufipa chicken breast and thigh meat had a higher protein content (p<0.05) than broiler chicken meat, whereas the fat content was lower (p<0.01). The moisture content of thigh meat was lower in Ufipa chicken meat than in broiler chicken meat (p<0.05). Regarding meat color, broiler chickens had considerably higher L* and b* than Ufipa chickens in both the breast and the thigh meat, except for a* (p<0.01). Regarding water holding capacity, Ufipa chicken breast exhibited higher drip loss but lower thawing and cooking losses than broiler chicken (p<0.01). In contrast, its thigh meat had a much lower drip and thawing losses but higher cooking losses (p<0.01). The shear force of Ufipa chickens’ breasts and thighs was higher than that of broiler chickens (p<0.05), while the amount of total collagen in the thigh meat was higher than that of broiler chickens (p<0.05). Additionally, the inosine-5’-monophosphate (IMP) of Ufipa chicken breast and thigh meat was higher than that of broiler meat (p<0.05). The principal component analysis of meat quality traits provides a correlation between the proximate and physical-chemical prosperties of both breeds with some contrast. In conclusion, the present study provides information on healthy food with good-tasting Ufipa indigenous chickens, which offer a promising market due to consumers’ preferences.

Approaching to biogenic amines as quality markers in packaged chicken meat

Following the chicken meat quality decay remains a tricky procedure. On one hand, food companies need of fast and affordable methods to keep constant higher sensory and safety standards, on the other hand, food scientists and operators find difficult conjugating these exigencies by means of univocal parameters. Food quality definition itself is, in fact, a multi-layered and composite concept in which many features play a part. Thus, here we propose an index that relies on biogenic amines (BAs) evolution. These compounds may indirectly inform about microbial contamination and wrong management, production, and storage conditions of meat and meat products. In this study, three cuts of chicken meat (breast filets, drumsticks, and legs) packed under modified atmosphere, under vacuum, and in air-packaging, stored at +4°C (until to 15 days), were analyzed. Some BAs were combined in an index (BAI) and their evolution was followed. The Thiobarbituric Acid Reactive Species assay (TBARS) was also used as a common reference method. Generally, BAI may better identify the beginning of quality impairment than lipid oxidation spreading. ANOVA statistical analysis has highlighted that the storage time is anyway the most detrimental factor for chicken decay when it is stored in refrigerated rooms (p > 0.01). Despite TBARS still remains a powerful tool for chicken goods, its exclusive use may not be enough to explain quality loss. On the contrary, BAI implementation in fresh meat can give a more complete information combining food safety exigencies with sensory attributes.

Effects of Thai native chicken breast meat consumption on serum uric acid level, biochemical parameters, and antioxidant activities in rats

This study aimed to evaluate the effect of a high protein diet comprising breast meat from commercial broiler (BR), Thai native (PD), and commercial broiler × Thai native crossbred (KKU-ONE) chicken on serum uric acid, biochemical parameters, and antioxidant activities in rats. Male Sprague–Dawley rats were divided into four groups. The control group received a standard chow diet, and the other three groups were fed a high protein diet (70% standard diet + 30% BR, PD, or KKU-ONE chicken breast) for five weeks. The PD- and KKU-ONE-fed rats had lower plasma total cholesterol and triglyceride levels than the control rats. A decrease in HDL-c was also observed in rats fed a diet containing BR. Liver weight, liver enzyme, plasma ALP, xanthine oxidase activity, serum uric acid, creatinine, superoxide production, and plasma malondialdehyde levels increased in BR-fed rats. The findings of this study might provide evidence to support the use of Thai native and Thai native crossbred chicken breast meat as functional foods.

Effect of Feeding Alfalfa and Concentrate on Meat Quality and Bioactive Compounds in Korean Native Black Goat Loin during Storage at 4°C

The primary aim of this study was to evaluate the effect of feeding alfalfa: Concentrate at different ratios (8:2 or 2:8) to Korean native black goats (KNBG) for 90 days on meat quality and bioactive compound content. Feeding KNBG alfalfa and concentrate at different ratios did not impact meat pH, color, microorganism composition, volatile basic nitrogen levels, or lipid oxidation. The low alfalfa (KLA) group exhibited increased oleic acid and monosaturated fatty acid levels, both of which impact the palatability traits of meat. The abundance of bioactive compounds increased in the loin meat of the KLA group, leading to an increase in antioxidant activities. Our results suggest that feeding alfalfa and concentrate at a 2:8 ratio to KNBG can increase taste-related fatty acids and bioactive compounds in loin meat, relative to that achieved by feeding at an 8:2 ratio. Further investigation is required to evaluate the quality and the metabolites of bioactive compounds in KNBG meat and the effect of the different dietary ratios of forage and concentrate.

Comparison of chicken breast quality characteristics and metabolites due to different rearing environments and refrigerated storage

The objective of the present study was to compare the breast meat quality and metabolomic characteristics from broilers that were raised in conventional (conventional farm reared-broilers; CB, n = 20) and legally approved animal welfare farms (welfare farm reared-broilers; WB, n = 20) in aerobic cold storage (1, 3, 5, and 7 d). Compared to CB chickens, the WB chickens had a larger floor size as well as lower stocking density, atmospheric ammonia, and nipple-shared chicken counts. The results demonstrated significantly higher pH, L^⁎- and b^⁎-value, and lower shear force in CB compared to WB during cold storage. Using ¹H NMR analysis, 25 compounds were identified in the chicken breast meat. Partial least square-discriminant analysis (PLS-DA) was performed based on the identified metabolites. The content of 15 metabolites (1 di-peptide, 9 free amino acids, 2 glycolytic potential-related products, 2 nucleotide-related products, and 1 organic acid) was significantly different due to the rearing environment (CB vs. WB). Among them, all free amino acids were higher in CB than in WB. Six free amino acids (glycine, isoleucine, leucine, phenylalanine, valine, and β-alanine) had variable importance in projection (VIP) score >1, regardless of the number of cold storage days. Therefore, these compounds in the breast meat may be used as potential markers to determine the rearing environment of broilers. Also, this result might be an indication of stress-related meat quality changes in broilers.

Effects of Stocking Density on Growth Performance, Antioxidant Status, and Meat Quality of Finisher Broiler Chickens under High Temperature

Environmental factors such as stocking density and high temperature can cause oxidative stress and negatively affect the physiological status and meat quality of broiler chickens. Here, we evaluated the effects of heat stress on the growth performance, antioxidant levels, and meat quality of broilers under different stocking densities. A total of 885 28-day-old male broilers (Ross 308) were subjected to five treatments (16, 18, 21, 23, and 26 birds/m2) and exposed to high temperatures (33 °C for 24 h) for 7 days. High stocking density (23 and 26 birds/m2) resulted in significantly decreased body weight (p < 0.01) and superoxide dismutase activity in the blood (p < 0.05) and increased (p < 0.05) rectal temperature and corticosterone. Additionally, the concentrations of heat shock protein 70 and malondialdehyde in the liver were higher in the 26 birds/m2 group (p < 0.05). Similarly, the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of breast meat increased linearly as the stocking density increased (p < 0.05). There was increased shear force in breast meat at low stocking density (p < 0.01). Thus, lower stocking density can relieve oxidative stress induced by high temperatures in broilers and improve the antioxidant capacity and quality of breast meat during hot seasons.

Effects of In Ovo Injection of Zinc or Diet Supplementation of Zinc on Performance, Serum Biochemical Profiles, and Meat Quality in Broilers

Simple Summary

Zinc (Zn) is known as an essential trace mineral that plays a key role in metabolic processes such as synthesis, stability, and catalytic activity of many proteins in broilers. In ovo technology provides an alternative for delivering nutrient compounds to the embryo prior to hatching by injecting small amounts of material into a broiler egg during hatching. In this study, the in ovo injection of Zn and dietary supplementation of Zn were evaluated on their effects on growth performance, serum biochemical profiles, and meat quality in broilers. In ovo injection and Zn supplementation (i.e., 200 mg/kg) increased (p < 0.05) body weight and immunoglobulin G (IgG) compared to broilers fed with the control diet. In ovo injection group decreased (p < 0.05) feed conversion ratios compared to broilers fed with the no injection group. Our results indicated that broilers fed with a diet supplemented with 200 mg/kg of Zn could ameliorate growth performance, immune responses, and increase the unsaturated fatty acids of breast meat. The findings of this result highlighted that the diet supplemented with Zn has the effect to improve performance, blood immune response, and fatty acid profile of breast meat.

Abstract

This study investigated the main effects of the in ovo injection of inorganic zinc (Zn) or diet supplementation of Zn on performance, serum biochemical profiles, and breast meat quality in broilers. A total of 480 one-day-old broilers (Ross 308) were randomly divided into four groups: the control (Con, noninjected and basal diet), in ovo (injected 60 mg Zn/egg at 18 embryonic days of incubation and basal diet), Zn100 (noninjected and basal diet with Zn (100 mg/kg) for 35 days), and Zn200 (noninjected and basal diet with Zn (200 mg/kg) for 35 days) groups. The dietary supplementation of Zn increased feed intake (2860.42–2861.08 g), weight (1975.06–1985.25 g), and weight gain (1936.36–1946.53 g) compared to Con (2785.74, 1891.38, and 1852.62 g, respectively) after five weeks of age. No significant difference was found in biochemical parameters and leukocyte and erythrocyte levels in the blood among the four different groups. In ovo injected or supplemental Zn (100 and 200 mg/kg) increased IgG in the blood of broilers. Zn200 increased polyunsaturated fatty acids, and saturated fatty acid contents were reduced in breast meat compared with Con. In conclusion, Zn supplementation at 200 mg/kg could improve the weight, feed intake, blood immune response, and fatty acid profile of breast meat.

Effect of Breed and Diet on Carcass Parameters and Meat Quality of Spent Hens

Two spent hen breeds (Mos and Isa Brown) fed with three different diets [commercial feeding (CF); corn, pea, and triticale (CPT); and corn and wheat (CW)] were studied to assess their laying performance, carcass characteristics, and meat quality parameters (breast and drumstick). A total of 48 hens reared in a traditional free-range system were used. Birds were slaughtered at 72 weeks of age after the moulting in an accredited abattoir, and measurements (for each bird) of carcass and meat started at 24 h post-mortem. The results demonstrated a breed and diet effect (P<0.05) on laying performance, carcass, and meat quality. The Mos breed showed lower laying performance, higher live weight (P<0.001), carcass weight (P<0.001), dressing percentage (P<0.001), and carcass fat (P<0.001) than Isa Brown. The breed also affected physicochemical parameters of drumstick and breast (P<0.05). Concerning the diet effect, spent hens fed with commercial feeding showed heavier live weight (P<0.01) and carcass weight (P<0.01). Diet significantly affected most of meat quality parameters, CPT being the formulation that most affected (P<0.05) drumstick composition, while in the breast was CF (P<0.001). Significant (P≤0.005) effects on breast colour, cooking loss and hardness were observed in animals fed with alternative diets to CF. Regarding nutritional quality, no breed or diet effect (P<0.05) was observed in MUFA s, PUFA s and n-6 contents of meat. Overall, both breeds showed a high protein and low-fat content in the breast, showing these hens as an opportunity for the development of meat products as well as an economic purpose for spent hens that reach the end of their productive lives.

Effects of Animal Welfare-Certified Rearing Systems on the Blood Parameters and Meat Quality Characteristics of Broilers at the Farm Level in Korea

Compared to the conventional farms (CF) rearing of broilers, the rearing management of animal welfare-certified farms (AF) must provide low stocking density, perch, air regulation, and feeding plant-based protein. This study aimed to compare the effects of rearing management in CF and AF on blood parameters, meat quality, and bioactive compound content in Ross 308 broiler chickens at the farm level before transportation to slaughterhouses. Blood and meat samples were obtained at 28-35-day-old chickens from three CF and three AF. In blood samples, low-density lipoprotein cholesterol (p<0.05), triglyceride (p<0.001), glucose (p<0.01), total protein (p<0.001), albumin (p<0.01), and white blood cell (p<0.001) levels as well as the heterophil/ lymphocyte ratio [stress index (SI), p<0.001] were lower in broilers from AF than in CF. In meat samples, shear force (p<0.001, p<0.05), and carnosine contents (p<0.001, p<0.05) in both breast and thigh meat from AF were higher than those in meat from CF. The contents of linoleic acid (p<0.001), α-linolenic acid (p<0.001), and eicosapentaenoic acid (p<0.05) were higher in the samples from AF than those from CF. This study reveals that such differences are influenced by the different rearing factors in nutrition, housing, and management practices between CF and AF. Supplementation of plant-based protein and enough space to move due to lower stocking density accounts for the large differences between them. These results can be used as preliminary data showing that the AF system reduces the SI and enhances carnosine and polyunsaturated fatty acids levels in chicken meat at the farm level before transportation.

Effect of cutting time and cooking temperature on physicochemical properties of chicken breast meat emulsion sausage with olive oil

This study aimed to optimize the emulsification of olive oil in chicken sausage production at varying cutting times (30, 45, and 60 s) and cooking temperatures (63, 73, and 83°C). Pork backfat sausages were prepared as controls, using the same variables. The quality attributes of the sausages were analyzed, and the distribution of lipid droplets was identified using confocal laser scanning microscopy. The combinations of cutting time and cooking temperature in olive oil sausages showed different emulsifying characteristics. Meat emulsion with olive oil at a cutting time of 60 s and cooking temperature of 73°C showed the highest emulsion stability with lowest water and lipid loss (2.49%, P < 0.05). The pH values were lower for olive oil samples than for the controls (5.9 vs. 6.2, P < 0.05). Cutting time of 60 s and cooking temperature of 73°C generated higher hardness, gumminess, and chewiness in olive oil sausages (P < 0.05). The replacement of pork backfat with olive oil resulted in a higher b*, C*, and h values, as well as lower lipid oxidation (P < 0.05). In addition, microstructural images exhibited a finer distribution of lipid droplets in olive oil sausages with a cutting time of 60 s. In conclusion, chicken sausage at a cooking temperature of 73°C and cutting time of 60 s was optimal for producing sausages with olive oil. Given the condition, the sausages produced from olive oil had better emulsion and oxidative stability than sausages produced from pork backfat.

The effect of essential oils on cholesterol content in chicken meat

The study aimed to investigate cholesterol content in chicken breast and thigh muscles by the influence of feed supplements of various content of essential oils. The experiment was carried out under practical conditions in a poultry farm with broiler chickens of the Cobb 500 hybrid combination according to the feed supplement used thyme essential oil, cinnamon essential oil, commercial citrus fruit essential oil, and their combination. The control group was without the use of experimental feed supplements and commercial coccidiostats were used in their feed mixtures. The experiment lasted 40 days in welfare conditions. Broiler chickens were used for sample preparation of breast and thigh muscles with the skin and their analysis for dry matter, fat and cholesterol contents. Samples were analyzed using a Nicolet 6700 FT-IR Fourier transform infrared spectrometer. The results were processed by the SAS system program, version 8.2. The results, which were evaluated, indicated a tendency to reduce the cholesterol content in chicken breast muscle due to cinnamon essential oil and the combination of cinnamon essential oil with citrus fruit essential oil as well as thyme essential oil with citrus fruit essential. In the achieved results of dry matter, fat, and cholesterol content in breast and thigh muscles, the difference between the effects of the used feed supplements based on essential oils and concerning the control group were not statistically significant p >0.05. The correlation was a statistically significant strong linear relation only between dry matter content and fat content due to thyme and cinnamon essential oils. In conclusion, it was stated that the investigation of the feed supplement effect based on essential oils is an open question concerning the production of safe food of animal origin.

Effect of Marination with Black Currant Juice on the Formation of Biogenic Amines in Pork Belly during Refrigerated Storage

The effect of marination with black currant juice (BCJ) was investigated for their effects on meat quality and content of biogenic amines (BAs) [putrescine (PUT), cadaverine (CAD), histamine (HIM), tyramine (TYM), and spermidine (SPD)] in pork belly during storage at 9°C. BCJ was shown to have antibacterial activities against Escherichia coli and Pseudomonas aeruginosa. Additionally, the pH of pork belly marinated with BCJ (PBB) was significantly lower than that of raw pork belly (RPB) during storage. No significant difference in microorganisms between RPB and PBB was observed at day 0 of storage. However, at days 5 and 10 of storage, volatile basic nitrogen (VBN) was significantly decreased in PBB compared to RPB, and PBB also demonstrated significantly lower numbers of bacteria associated with spoilage (Enterobacteriaceae and Pseudomonas spp.) at these time-points. PBB was also associated with significantly reduced formation of BAs (PUT, CAD, TYM, and total BAs) compared to RPB at days 5 and 10 of storage. These results indicated that BCJ can be regarded as a natural additive for improving meat quality by preventing increased pH, VBN, bacterial spoilage, and inhibiting BAs formation during refrigerated storage.

Effect of UVC Light-Emitting Diodes on Pathogenic Bacteria and Quality Attributes of Chicken Breast

ABSTRACT

This study was conducted to investigate the inactivation of foodborne pathogens and the quality characteristics of fresh chicken breasts after UVC light-emitting diode (UVC-LED) treatment. Fresh chicken breasts were separately inoculated with Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes at initial populations of 6.01, 5.80, and 6.22 log CFU/cm2, respectively, and then treated with UVC-LED irradiation at 1,000 to 4,000 mJ/cm2. UVC-LED irradiation inactivated the test bacteria in a dose-dependent manner. After UVC-LED treatment at 4,000 mJ/cm2, the populations of Salmonella Typhimurium, E. coli O157:H7, and L. monocytogenes on chicken breasts were decreased by 1.90, 2.25, and 2.18 log CFU/cm2, respectively. No significant changes (P > 0.05) were found in color, pH, texture, and thiobarbituric acid-reactive substances of chicken breasts following UVC-LED irradiation at doses ≤4,000 mJ/cm2. These results indicate that UVC-LED radiation is a promising technology for reducing the level of microorganisms while maintaining the physicochemical characteristics of poultry meat.

HIGHLIGHTS

Effects of Dietary Supplementation of gEGF on the Growth Performance and Immunity of Broilers

EGF has been shown to stimulate the growth of animals. In this study, the content of EGF in chicken embryos (gallus EGF, gEGF) aged from 1 to 20 days of incubation were determined by ELISA kit, and the 5-day-old chicken embryos with the highest content of 5593 pg/g were selected to make gEGF crude extracts. A total of 1500 1-day-old Xianju chickens were randomly divided into five groups with six replicates of 50 chickens each. The control group was fed a basal diet, and other treatment diets were supplemented with 4, 8, 16 and 32 ng/kg gEGF crude extract, respectively. The experiment lasted for 30 days. Chicks were harvested at the end of the experiment, and liver, spleen, thymus, bursa and serum samples were collected. Results showed that average daily gain (ADG) and average daily feed intake (ADFI) of 16 ng/kg group were higher than those in the control group (p < 0.05). The serum uric acid (UA) of the 16 ng/kg group was reduced (p < 0.01), and the serum alkaline phosphatase (AKP) of the 16 ng/kg group increased (p < 0.01). The gEGF extract also increased chick's antioxidant capacity, decreased malondialdehyde (MDA) and increased catalase (CAT) in the liver and serum of 16 ng/kg groups in compared to the control group (p < 0.01). Furthermore, immunity was improved by the addition of gEGF to broiler diets. The serum immunoglobin A (IgA) content of 8 and 16 ng/kg groups and the serum immunoglobin M (IgM) content of 4 and 8 ng/kg groups were increased (p < 0.05) compared to the control group. The bursa index of each experimental group was higher than the control group (p < 0.01). These findings demonstrate that the crude extract of gEGF prepared in this experiment could improve the growth performance, antioxidant capacity and immunity of broilers.

The Effect of Grazing Level and Ageing Time on the Physicochemical and Sensory Characteristics of Beef Meat in Organic and Conventional Production

This study investigated the influence of the production system (conventional vs. organic), the grass consumption level and the ageing period (7 and 14 days) on beef quality. Three groups of samples from Limousin × Avileña calves were analysed: F100, formed by animals fed 100% on forage; F74, formed by animals fed on an average amount of forage of 74%; and F35, formed by animals fed on straw fodder (35%) and concentrate (65%). The results showed that the higher the grass content, the lower the fat oxidation and the higher the n-3 content, but also the higher the SFA level, the initial Warner-Bratzler shear force (WBSF), and the more residue it leaves on chewing. As for the effect of production system, organic samples showed higher intramuscular fat content and lower moisture and MUFA content. These samples were darker and showed lower values for flavour quality. Among the organic samples, F100 had higher n-3 and CLA content and higher values for colour, hardness, odour and flavour quality. Increased ageing time may improve the sensory characteristics of the meat, especially in the case of the F100 samples. The results pointed out that F100 samples aged at least 14 days showed the best physico-chemical, nutritional and sensory characteristics.

Effects of dietary hatchery by-products on growth performance, relative organ weight, plasma measurements, immune organ index, meat quality, and tibia characteristics of broiler chickens

Objective

The objective of the current study was to investigate the effects of dietary hatchery by-products (HBPs) as a replacement of fish meal (FM) on growth performance, relative organ weight, plasma measurements, immune organ index, meat quality, and tibia characteristics of broiler chickens.

Methods

A total of 720 broiler chickens (3 d of age) were randomly allotted to 1 of 9 treatments with 8 replicates. Each replicate consisted of 5 male and 5 female birds. The basal diet was formulated to contain 5.0% commercial FM, whereas eight treatment diets were prepared by replacing 25%, 50%, 75%, or 100% of FM in the basal diet with infertile eggs (IFE) or a mixture of various HBPs (MIX); therefore, the inclusion levels of IFE or MIX in the experimental diets were 1.25%, 2.50%, 3.75%, or 5.00%. The diets and water were provided on an ad libitum basis for 32 d.

Results

Increasing inclusion levels of IFE as a replacement of FM in diets had no effects on growth performance, plasma measurements, immune organ index, and tibia characteristics of broiler chickens. Increasing inclusion levels of IFE in diets increased (linear, p<0.05) meat lightness (L*) but decreased (linear, p<0.05) meat redness (a*). The breast meat pH at 1-h postmortem was increased (linear, p<0.05) by increasing inclusion levels of IFE in diets. Likewise, increasing inclusion levels of MIX in diets had no effects on growth performance, relative organ weight, plasma measurements, immune organ index, and tibia characteristics. However, increasing inclusion levels of MIX in diets increased (linear, p<0.05) 1-h postmortem pH but decreased (linear, p<0.05) 24-h postmortem pH of breast meat. Increasing inclusion levels of MIX in diets decreased (linear, p<0.05) thiobarbituric acid reactive substances values of breast meat.

Conclusion

Both IFE and MIX are suitable alternatives to FM as protein ingredients in broiler diets.

Utilization of Electrical Impedance Spectroscopy and Image Classification for Non-Invasive Early Assessment of Meat Freshness

This study presents a system for assessing the freshness of meat with electrical impedance spectroscopy (EIS) in the frequency range of 125 Hz to 128 kHz combined with an image classifier for non-destructive and low-cost applications. The freshness standard is established by measuring the aerobic plate count (APC), 2-thiobarbituric acid reactive substances (TBARS), and composition analysis (crude fat, crude protein, and moisture) values of the microbiological detection to represent the correlation between EIS and meat freshness. The EIS and images of meat are combined to predict the freshness with the Adaboost classification and gradient boosting regression algorithms. As a result, when the elapsed time of beef storage for 48 h is classified into three classes, the time prediction accuracy is up to 85% compared to prediction accuracy of 56.7% when only images are used without EIS information. Significantly, the relative standard deviation (RSD) of APC and TBARS value predictions with EIS and images datum achieves 0.890 and 0.678, respectively.

Effect of Searing Process on Quality Characteristics and Storage Stability of Sous-Vide Cooked Pork Patties

This study investigated the effects of searing process before sous-vide (SV) treatment on quality traits, visual attributes, palatability, and storage stability of SV cooked pork patties. Patties were seared on each side by pan-frying for 0 (control), 30 (S30), 60 (S60), 90 (S90), or 120 (S120) s in a stainless-steel pan, and all patties were then vacuum-packed and cooked under thermally controlled conditions at 75 °C for 2 h. Marked differences were observed in quality properties between the control and searing groups, and the S120 group exhibited greater brown surface color and cooking loss compared to the other groups (p < 0.001) due to the additional heating process. Patties from the S60 group showed greater appearance and tenderness acceptability scores compared to patties from the S30 and S120 groups (p < 0.001). On another note, the effects of searing on storage stability were somewhat limited, as they were measured by 2-thiobarbituric acid reactive substance, volatile basic nitrogen, total aerobic bacterial count, and coliforms during 49 d of cold storage. Therefore, searing process before SV treatment can improve the visual attributes and palatability of cooked pork patties, and the optimum searing condition was for 60 s, without impairing the storage stability.