Meat Science最新文献

This study investigated the synergistic effects of ε-poly- L -lysine (ε-PL) and lysozyme against P. aeruginosa and L. monocytogenes biofilms. Single-culture biofilms of two bacteria were formed on silicone rubber (SR), stainless steel (SS), and beef surfaces and then treated with lysozyme (0.05–5 mg/mL) and ε-PL at minimum inhibitory concentrations (MICs) of 1 to 4 separately or in combination. On the SR surface, P. aeruginosa biofilm was reduced by 1.4 and 1.9 log CFU/cm² within 2 h when treated with lysozyme (5 mg/mL) and ε-PL (4 MIC), respectively, but this reduction increased significantly to 4.1 log CFU/cm² (P < 0.05) with the combined treatment. On beef surface, P. aeruginosa and L. monocytogenes biofilm was reduced by 4.2–5.0, and 3.3–4.2 log CFU/g when lysozyme was combined with 1, 2, and 4 MIC of ε-PL at 25 °C, respectively. Compared to 5 mg/mL lysozyme alone, the combined treatment with 1, 2, and 4 MIC of ε-PL on beef surface achieved additional reduction against P. aeruginosa biofilm of 0.5, 0.8, and 0.7 log CFU/g, respectively, at 25 °C. In addition, 0.25 mg/mL lysozyme and 0.5 MIC of ε-PL significantly (P < 0.05) suppressed the quorum-sensing (agrA) and virulence-associated (hlyA and prfA) genes of L. monocytogenes.

This study aimed to clarify the effect of electrostatic spraying of lactic acid (LE) and ascorbic acid (AE) on vacuum-packaged beef aged at 10 °C. The physicochemical attributes, flavor profiles, and microbial diversities were evaluated. Beef steaks were electrostatically sprayed twice with 4% LE, 0.5% AE, or a mixture of them (LAE). Afterward, the beef was vacuum-packaged and aged. All treated beef exhibited a decrease in quality and sensory scores over time. At the end of the study period, the total viable count (TVC) and the total volatile basic nitrogen values in the control group (7.34 log CFU/g and 15.52 mg/100 g, respectively) were higher than those in the acid-treated groups. The LAE group exhibited the best color stability and the lowest TVC and Enterobacteriaceae counts after aging. High-throughput sequencing analysis revealed that acid types and electrostatic spray could change the microbiota structure. Leuconostoc was the dominant bacteria in the AE and LAE groups, while Enterococcus became the predominant bacteria in the NLE and LE groups with aging. This indicates that electrostatic spray combined with acid treatment can ensure beef quality and microbiological safety at mild temperatures.

Meat consumption is declining in developed countries but increasing in emerging countries. This study, for the first time, compares the socio-behavioural factors influencing individuals' meat consumption level and meat reduction intention between Vietnam, an emerging economy and Switzerland, a developed country. Online consumer surveys were conducted in late 2022, yielding 552 usable replies from Switzerland and 592 from Vietnam for this study. Drawing upon an extended Protection Motivation Theory and using structural equation modelling, we found similarities as well as differences in the determinants of meat consumption behaviour. Perceived health risks of meat overconsumption, self-efficacy of meat reduction, attitude toward ethical and environmental issues, and pressure from family members' reluctance to change diet drove the intention to reduce meat in both countries. Meat attachment emerges as the most important determinant of meat consumption level in not only Switzerland but also Vietnam and thus presents the largest barrier to meat reduction. The association between response cost of eating less meat and intention to reduce meat was negative in Switzerland but positive in Vietnam. Self-efficacy of meat consumption reduction influenced meat consumption level solely in Switzerland. Ethical and environmental attitudes significantly facilitated meat reduction intention of Swiss respondents only, reflecting cultural differences. Policy implications were discussed.

The rate of pH decline, early post-mortem, has been identified as a key factor that impacts the tenderness of meat, and manipulating this rate of pH decline is highly relevant to ensure consistent high quality meat. Ultrasound is a potential intervention in early post – mortem muscle that may have an impact on the rate of glycolysis through its ability to alter enzyme activity. Following a variety of different ultrasound treatments frequencies (25 and 45 kHz) and durations (15, 30 and 45 min), it was found, when analysed in muscle, that ultrasound treatment duration, specifically the 30 min treatment, and interaction between treatment duration and frequency, had a significant impact on the rate of pH decline, post – treatment. Frequency did not have a significant effect on the rate of pH decline, post – treatment, in muscle. Ultrasound did not have a significant permanent effect on the activity of glycolytic enzymes present in bovine Longissimus lumborum et thoracis muscle, where no significant differences were observed on the rate of pH decline and rate of change of reducing sugars, glycogen and lactic acid, when analysed in an in vitro glycolytic buffer. It seems that the impact observed in intact muscle is not as a consequence of a permanent change in enzymatic activity, instead indicating an impact on conditions in the muscle which enhanced enzyme activity.

Salt content standardization in dry-cured ham production is complex as there are many factors that influence salt uptake. The aim of this work was to study and model salt uptake as a function of salting time and the characteristics of green ham in two different ham types using a large amount of data obtained from an inline non-invasive characterization technology. The usefulness of these models to standardize the salt content of the industrial production was also evaluated. Magnetic induction technology was used to characterize lean and fatty hams in order to further model the salt uptake using different statistical methods. Salt content increased with the salting time showing an asymptotic behaviour which was lower in fatty hams. The best models were those that considered the salting time, weight, and fat content of hams as model independent variables. These models are helpful for salt content standardization within the industry and can be used to simulate process modifications and avoid the time-consuming and costly trial and error tests.

Verification of beef production systems and authentication of origin is becoming increasingly important as consumers base purchase decisions on a greater number of perceived values including the healthiness and environmental impact of products. Previously Raman spectroscopy has been explored as a tool to classify carcases from grass and grain fed cattle. Thus, the aim of the current study was to validate Partial Least Squares Discriminant Analysis (PLS-DA) models created using independent samples from carcases sampled from northern and southern Australian production systems in 2019, 2020 and 2021. Validation of the robustness of discrimination models was undertaken using spectral measures of fat from 585 carcases which were measured in 2022 using a Raman handheld device with a sample excised for fatty acid analysis. PLS-DA models were constructed and then employed to classify samples as either grass or grain fed in a two-class model. Overall, predictions were high with accuracies of up to 95.7% however, variation in the predictive ability was noted with models created for southern cattle yielding an accuracy of 73.2%. While some variation in fatty acids and therefore models can be attributed to differences in genetics, management and diet, the impact of duration of feeding is currently unknown and thus further work is warranted.

Classifying kid carcasses according to their fatness and conformation scores guides producers toward higher quality and income-generating production methods and determines the ideal slaughter time. This study aimed to determine the effects of Colomer–Rocher fatness and conformation classes on carcass and meat quality characteristics in goat kids. A total of 102 male kid carcasses were used in the study. Carcasses were divided into fatness (1-, 1, 1+, 2-) and conformation (P-, P, P+; O-) classes according to the Colomer–Rocher classification, and these groups were accepted as the experimental group. Hierarchical clustering analysis divided the kid carcasses into 5 clusters using certain carcass characteristics. Differences between clusters in most of the carcass characteristics were significant. The difference between the cluster groups in terms of meat colour and sensory characteristics was also significant. Fatness and conformation classes significantly affected most characteristics except kidney knob and channel fat (KKCF) percentages and carcass joints percentages. The Colomer-Rocher conformation classification was found to be more discriminatory in terms of meat quality than the fatness classification.

Microbiological safety and quality of beef is crucial as beef can serve as a reservoir for a variety of bacteria, including spoilage-related and foodborne pathogens. Controlling microbial contamination is a critical aspect of food quality and safety, but it is difficult to prevent as there are several potential sources of contamination from production to distribution. In this study, the microbiological ecology of cattle/beef and associated environmental samples (n = 69) were trace-investigated to reveal microbiome shifts in cattle/beef and possible cross-contaminants throughout the entire supply chain using 16S rRNA gene sequencing. Pseudomonas, Psychrobacter, and Acinetobacter, known as spoilage bacteria, opportunistic pathogens, or antibiotic-resistant bacteria, were the main microorganisms present in cattle/beef, and Staphylococcus became abundant in the final products. The dominance of Acinetobacter and Pseudomonas was noticeable in the slaughtered carcasses and slaughterhouse environment, indicating that the slaughterhouse is a critical site where hygienic practices are required to prevent further contamination. Taxonomic similarities between cattle/beef and several environmental samples, as well as diversity analysis, presented a high potential for microbial transmission. Source tracking identified environmental samples that primarily contributed to the microbiota of cattle/beef. Farm floor (48%), workers' gloves (73%), and carcass splitters (20%) in the slaughterhouse were found to be major sources influencing the microbiome of cattle/beef at the farm, slaughterhouse, and processing plant, respectively. These findings demonstrated the dynamics of bacterial communities in cattle/beef according to stage and detected potential contamination sources, which may aid in a better understanding and control of microbial transmission in beef production.

Lipid oxidation is the principal driver of meat and meat product deterioration during shelf life, causing the loss of fresh meat color, flavor, and aroma. Currently, synthetic antioxidants are used to prevent oxidation, but increasing consumer demand for natural ones leaves the industry with few alternatives. In this study, protocatechuic acid (PCA), known to have high antioxidant activity, was evaluated as a potential inhibitor of meat lipid oxidation. For this purpose, the antioxidant capacity and lipoxygenase (LOX) inhibitory activity of PCA were evaluated in vitro, and a set of four experiments was conducted, treating minced meat with water (control), lactic acid (LA), rosmarinic acid (RA) and PCA, at different concentrations (1–12 mg mL⁻¹), depending on the experiment. The potential antioxidant effect of PCA when applied to meat cubes was also evaluated, as well as the potential of carboxymethyl cellulose (CMC) as a delivery system for PCA. The in vitro results showed that PCA is a potent antioxidant and an effective LOX inhibitor at 1 mg mL⁻¹. PCA effect on meat lipid oxidation prevention was dose-dependent, and at 2 mg mL⁻¹, it inhibited color change by 50% and lipid peroxidation by up to 70% when compared to water-treated samples, performing better than RA at 0.25 mg mL⁻¹. These results suggest that PCA is a promising molecule to the meat industry as a natural preservative for meat and meat products directly or in a formulation.

This is the first UK genome wide association study investigating potential links between Video Image Analysis (VIA) carcass traits and molecular polymorphisms in crossbred sheep. Phenotypic and genotypic data were collected from two crossbred lamb populations: Texel x Scotch Mule (TxSM, n = 2330) and Texel x Lleyn (TxL, n = 3816). Traits measured included live weights at birth, eight weeks and weaning (∼15 weeks). VIA-predicted traits included total weights and weights of fat, muscle and bone in the whole carcass and primal (hind leg, saddle, shoulder) regions. Within-breed heritabilities estimated for the VIA traits ranged from 0.01 to 0.70, indicating potential for inclusion of some traits in breeding programmes. The two crossbred populations differed in SNPs associated with different traits. Two SNPs on chromosomes two (s74618.1) and eight (s68536.1), respectively, reached genome-wise significance for TxSM, explaining <1% of trait variance, for whole carcass fat and muscle weights, hind leg and saddle fat weights and shoulder bone weights. For TxL, four SNPs reached genome-wise significance, on chromosome two for hind leg muscle weight (OAR2_117,959,202 and OAR2_11804335), on chromosome 10 for whole carcass bone weight (OAR19_8,995,957.1), and on chromosome 19 for weaning weight (s40847.1), each explaining <1% of trait genetic variation. Differences in apparent genetic control of carcass traits may be influenced by the lambs' cross-breed, but also by management decisions affecting environmental variance and trait definitions, which should be understood in order to define protocols for incorporation of carcass traits into (cross)breeding programmes.

Implications

Combining VIA-measured carcass traits with conventional production traits in a breeding programme could potentially improve the production and product quality of meat sheep. Phenotypes for VIA traits could be collected relatively easily if VIA machines were present at all abattoir sites. The current study and future Genome Wide Association Studies may help to identify potentially informative molecular markers, that explain large proportions of the genetic variance observed in VIA-measured carcass traits. Including this information in the estimation of breeding values could increase the accuracy of prediction, increasing the potential rate of genetic improvement for product quality. This study confirms the polygenic architecture of the investigated carcass traits, with a small number of molecular markers that each explain a small amount of genetic variation. Further studies across breed types are recommended to further test and validate molecular markers for traits related to lamb carcass quality, as measured by video image analysis.