The high growth rates of modern broiler breeds increased the risk for novel breast muscle myopathies as serious quality issue, relevant for the industry. In affected muscles, a depletion of the dipeptides carnosine and anserine was reported. Therefore, this study was performed to test whether a supplementation of the precursors histidine and β-alanine, alone or in combination can increase the dipeptide content in the breast muscle and improve meat quality. Ross 308 broiler chickens were supplemented with 3 different histidine:lysine ratios (0.44, 0.54, 0.64) of standardized ileal digestible amino acids ( SID ) combined with 0 or 0.5% β-alanine in total. The birds’ performance was recorded at different ages: birds were slaughtered in 2 batches after 33 and 53 d of life. Meat quality was tested at different time points after slaughter on breast fillets stored aerobically. The concentration of the dipeptides and amino acids in blood plasma and muscle tissue was tested postmortem at 35 and 54 d. All performance and meat quality data, as well as peptide and amino acid concentrations, of the 2 × 2 × 3 randomized block design were analyzed separately for the influence of both supplements and for slaughter age. Moreover, the influence of storage time was analyzed separately for meat quality parameters. At both slaughter ages, lesser feed intake ( P ≤ 0.005) and breast yield ( P ≤ 0.05) were observed in the birds receiving β-alanine. A greater SID histidine:lysine ratio increased the carnosine concentrations in blood plasma ( P < 0.001) and in skeletal muscle ( P < 0.001), whereas β-alanine increased carnosine in plasma at 35 d only ( P = 0.004). Anserine was increased in plasma and muscle of older birds ( P = 0.003), whereas carnosine was reduced in muscle tissue ( P < 0.001). The main impact on meat quality parameters was seen for the age of the birds and storage time of the fillets. In conclusion, the supplementation of histidine increased carnosine in breast muscle but both supplements showed only minor effects on meat quality.

Production-speci c factors, such as breeding, diet, and stress, are known to in uence meat quality, but the e ect of di erent husbandry systems on the development of quality parameters and shelf life has hardly been investigated. us, the aim of the study was the investigation of an alternative production system based on a slow-growing, corn-fed, and antibiotics-free chicken line compared with conventional poultry production. Additionally, the e ect on meat quality, microbiology, and spoilage was analyzed. In total, 221 breast lets from a German poultry meat producer were investigated. Nutritional, biochemical, and cooking loss analyses were conducted on a subset of samples 24 h after storage. e rest of the samples were stored aerobically at 4°C, and the spoilage process was characterized by investigating pH, color, lipid oxidation, microbiology, and sensory attributes subsequently every two days during storage. e alternative production line showed a signi cantly healthier nutritional pro le with a higher protein and lower fat content. Additionally, the amount of L-lactic acid and D-glucose was signi cantly higher than in the conventional production line. e color values di ered between both production lines, with the corn-fed line displaying more yellowish lets. e lipid oxidation and microbial spoilage were not a ected by the production line. e shelf life did not di er between the investigation groups and was deemed 7 days in both cases. Despite the highest severity of white striping being observed most in the conventional production line, there was no overall di erence in the incidence among groups. e purchase decision was a ected by the occurrence of white striping and showed a tendency for a higher acceptance for the alternative production line.

No abstract

Modified atmosphere (MA) packaging plays an important role in improving food quality and safety. By using different gas mixtures and packaging materials the shelf life of fresh produce can significantly be increased. A Gram-negative-staining, rod-shaped, orange-pigmented strain DH-B6T, has been isolated from MA packed raw pork sausage (20% CO2, 80% O2). The strain produced biofilms and showed growth at high CO2 levels of up to 40%. Complete 16S rRNA gene and whole-genome sequences revealed that strain DH-B6T belongs to the genus Chryseobacterium , being closely related to strain Chryseobacterium indologenes DSM 16777T (98.4%), followed by Chryseobacterium gleum NCTC11432T (98.3%) and Chryseobacterium lactis KC1864T (98.2%). Average nucleotide identity value between DH-B6T and C. indologenes DSM 16777T was 81.1% and digital DNA–DNA hybridisation was 24.9%, respectively. The DNA G+C content was 35.51 mol%. Chemotaxonomical analysis revealed the presence of the rare glycine lipid cytolipin, the serine-glycine lipid flavolipin and the sulfonolipid sulfobacin A, as well as phosphatidylethanolamine, monohexosyldiacylglycerol and ornithine lipid, including the hydroxylated forms. Major fatty acids were iC15 : 0 (50.7%) and iC17 : 1 cis 9 (28.7%), followed by iC15 : 0 2-OH (7.0%) and iC17 : 0 3-OH (6.2%). The isolated strain contained MK-6 as the only respiratory quinone and flexirubin-like pigments were detected as the major pigments. Based on the phenotypic, chemotaxonomic and phylogenetic characteristics, the strain DH-B6T (=DSM 110542T=LMG 31915T) represents a novel species of the genus Chryseobacterium , for which the name Chryseobacterium capnotolerans sp. nov. is proposed. Emended descriptions of the genus Chryseobacterium and eight species of this genus based on polar lipid characterisation are also proposed.

The high perishability of fresh meat results in short sales and consumption periods, which can lead to high amounts of food waste, especially when a fixed best-before date is stated. Thus, the aim of this study was the development of a real-time dynamic shelf-life criterion (DSLC) for fresh pork filets based on a multi-model approach combining predictive microbiology and sensory modeling. Therefore, 647 samples of ma-packed pork loin were investigated in isothermal and non-isothermal storage trials. For the identification of the most suitable spoilage predictors, typical meat quality parameters (pH-value, color, texture, and sensory characteristics) as well as microbial contamination (total viable count, Pseudomonas spp., lactic acid bacteria, Brochothrix thermosphacta, Enterobacteriaceae) were analyzed at specific investigation points. Dynamic modeling was conducted using a combination of the modified Gompertz model (microbial data) or a linear approach (sensory data) and the Arrhenius model. Based on these models, a four-point scale grading system for the DSLC was developed to predict the product status and shelf-life as a function of temperature data in the supply chain. The applicability of the DSLC was validated in a pilot study under real chain conditions and showed an accurate real-time prediction of the product status.