Biochemical and Physicochemical Changes in Spaghetti Meat During Refrigerated Storage of Chicken Breast.

This study investigated postmortem muscle protein degradation and myowater properties in broiler breasts afflicted with the Spaghetti Meat (SM) myopathy during 7 days of storage. Severe SM and unaffected (NORM) breast fillets were analyzed at days 0, 3, and 7 postmortem for TD-NMR myowater traits, myofibrillar protein profiles, calpain activity, free calcium, and desmin and troponin-T degradation patterns. Only at day 0, muscle histology, fiber size and sarcomere length were assessed on multiple fillet portions. In SM breasts, the intramyofibrillar water population exhibited longer relaxation times (p = 0.0172) and a lower proportion (p = 0.0118) compared to NORM. SM had a greater proportion of extramyofibrillar water (p = 0.0080) possessing a longer relaxation time (p = 0.0001). Overall, the SM myopathy had only a minor impact on the myofibrillar proteins profiles and did not affect either free calcium concentration, calpain activity, or the degradation of desmin and TnT, while storage time strongly affected all the traits measured. At microscopic level, muscle tissue from SM fillets exhibited the typical indicators of myodegeneration mostly in the superficial-cranial portion of the breast, while fiber size and sarcomere length were similar between the two muscle conditions irrespectively from the portion considered. The lack of overall significant interaction effects between muscle condition and storage period suggested that SM and NORM breast meat experience similar proteolytic and physical changes during the postmortem period.

Water properties and marinade uptake in broiler pectoralis major with the woody breast condition.

To provide insight into the mechanisms by which the woody breast (WB) condition reduces marinade uptake, water properties of normal (NOR) and WB meat were investigated using TD-NMR. Broiler Pectoralis major was marinated with either water, 0.625% sodium tripolyphosphate, 5% NaCl, or 5% NaCl + 0.625% sodium tripolyphosphate (SP). Targeted final concentrations were 4% NaCl and 0.5% SP. WB reduced meat marinade uptake but did not affect relationships between marinade ingredients and water mobility. WB inhibited increases in extra-myofibrillar water mobility induced by marinade ingredients. Marination increased intra-myofibrillar water (Amp21) regardless of marinade ingredients or muscle condition; however, WB resulted in reduced Amp21. Additionally, NaCl- or phosphate-induced extra-myofibrillar water (Amp22) gain in WB was greater than that in NOR. Our data suggest changes in both Amp21 and Amp22 are related to the difference in marinade uptake between NOR and WB meat marinated with NaCl-phosphate marinade.

Research Note: Texture characteristics of wooden breast fillets deboned at different postmortem times.

The study aimed to understand whether deboning time contributes to the altered texture attributes of wooden breast (WB) fillets. To this purpose, 30 unaffected (NORM) and 30 severely affected (WB) carcasses were selected at 15 min postmortem (PM) and allotted into treatments with different deboning times: A (5 NORM + 5 WB; right fillets deboned at 15 min PM), B (5 NORM + 5 WB; right fillets deboned at 3 h PM), and C (5 NORM + 5 WB; right fillets deboned at 6 h PM). Left fillets from each carcass were deboned at 24 h PM. Multiple instrumental texture analyses were performed on the cranial-middle portion of the Pectoralis major muscles. Irrespective of deboning time, all fillets were subjected to a single 30% compression in the raw state at 24 h PM. All fillets were cooked at 24 h PM and subjected to shear force assessments at 48 h PM using blunt Meullenet-Owens razor shear, Meullenet-Owens razor shear, and Warner-Bratzler shear force. Using an ANOVA mixed model, deboning time was evaluated as a fixed effect within muscle condition (sampling session and carcass ID as random effects). Compression force assessment of raw meat at 24 h PM showed that WB fillets exhibited the greatest hardness when they were deboned at 6 h PM (15 min = 35.4 N; 3 h = 30.9 N; 6 h = 48.0 N; 24 h = 30.6 N; P < 0.05). Differently, deboning time had no effect (P > 0.05) on raw compression force values in NORM fillets. In cooked NORM fillets, shear force values were the greatest in fillets deboned at 15 min, and shear force gradually declined with deboning time through 24 h PM. On the contrary, no changes (P > 0.05) in shear values due to different deboning times were observed in cooked WB meat regardless of shear method. These results suggest that early PM changes in breast muscles and their influence on meat texture are different between normal and WB fillets.

Are Meat Quality Traits and Sensory Attributes in Favor of Slow-Growing Chickens?

The present study compared certain quality features and sensory attributes of the meat obtained from three different chicken genotypes: two endangered slow-growing indigenous breeds (Padovana: PAD, Polverara: POL) and a commercial broiler (Hybrid). Chickens (n = 42/genotype) were slaughtered at their commercial slaughter age: 183 days for PAD and POL chickens, and 35 days for the Hybrid. Breast and leg meat were dissected and used for qualitative evaluations. Results highlighted that genotype significantly affected final breast weight, with Hybrid showing higher values than both indigenous chickens. Conversely, PAD and POL meat was instrumentally tougher and richer in haem iron compared to the Hybrid. The sensory analysis conducted by a trained panel showed that the textural aspects and metallic flavor perception of PAD and POL meat differed from that of the Hybrid. These aspects were probably responsible for the lower overall acceptability of the PAD and POL meat compared to the Hybrid, as expressed by the consumer panel. A key step in making PAD and POL meat acceptable to consumers and stimulating its market seems thus the development of appropriate marketing strategies to transform product peculiarities in strength points.

Effect of spaghetti meat abnormality on broiler chicken breast meat composition and technological quality.

The effects of spaghetti meat (SM) myopathy and sampling location on chicken breast meat physical traits, composition, and protein functionality were investigated using 30 normal (N) and 30 SM boneless fillets. Weight, drip loss, pH, and color traits were determined on intact fillets. Proximate composition, water holding capacity, mineral profile, SDS-PAGE, myofibrillar, and sarcoplasmic protein solubility, and emulsifying properties were assessed on both the superficial (S) and deep (D) layers of the breasts. SM fillets were heavier (P < 0.0001) and exhibited greater drip loss (P = 0.0131) and higher b* index on the skin side of the muscle (P < 0.0001). Muscle condition by layer interaction effect revealed that the superficial portion of SM fillets (SM-S) exhibited the highest moisture (P = 0.0003) and fat contents (P = 0.0011) coupled with the lowest protein (P < 0.0001) and ash contents (P = 0.0458). Total and soluble collagen amounts were higher in N-S and SM-S groups compared with N-D and SM-D (P < 0.0001). SM-S group exhibited the highest calcium (P = 0.0035) and sodium (P < 0.0001) levels. Overall, the myopathy had only minor impacts on protein profiles, while the muscle layer exerted a more remarkable effect. SM fillets exhibited higher pH but a lower myofibrillar protein solubility (P < 0.0001). Salt-induced water uptake, cooking loss, and final yield values suggested a potential impairment of water-holding capacity in SM-affected meat. Sarcoplasmic and myofibrillar emulsion activity indexes were similar between the 2 muscle conditions, but the stability of the emulsions was lower in SM meat. Overall, significant layer and muscle condition by layer effects were not observed in the functional properties of the breast meat. SM exerted a profound and negative impact on breast meat composition that led to detrimental consequences on functionality traits. Given the fundamental role of protein quality for meat processing, these data suggest that a further step toward the understanding of this myopathy should be the investigation of intrinsic protein characteristics.

Supplementing growing rabbit diets with chestnut hydrolyzable tannins: Effect on meat quality and oxidative status, nutrient digestibilities, and content of tannin metabolites.

The study investigated the effect of dietary inclusion of chestnut hydrolyzable tannin (CHT) in growing rabbit diets on nutrients digestibility, quality and oxidative status of meat, and content of tannin metabolites. At weaning, rabbits were assigned to 5 dietary groups (n = 72 rabbits/diet): control medication-free (Co), control with coccidiostat (Cc), and T200, T400 and T600 (diets supplemented with 200, 400 and 600 g/100 kg CHT extract). Sixteen carcasses/treatment were considered and hindleg meat and Longissimus thoracis et lumborum (LTL) muscle were used for analyses. L*a*b* color values, water holding capacity, Warner Bratzler shear force, haem iron content, oxidative status and nutritional quality were unaffected by dietary treatments. Saturated fatty acids (SFA) and monounsaturated FA (MUFA) in LTL meat were higher in T600 than Cc rabbits (P < .05), even though no differences were found for SFA and MUFA digestibility. Contrarily, polyunsaturated FA digestibility was lower in T400 and T600 than Co rabbits. No tannin metabolites traces were found in rabbit meat. Results of the present study showed that feeding CHT did not improve rabbit meat quality.

Effect of diet and packaging system on the microbial status, pH, color and sensory traits of rabbit meat evaluated during chilled storage.

The combined effect of two dietary lipid sources (sunflower vs linseed oil) and three packaging methods (PVC film - BAG, modified atmosphere CO2 20% + 80% O2 - MAP, and vacuum - VAC) on the shelf-life (pH, color, microbial count, sensory traits) of rabbit loins was tested at days 1, 4 and 10 of refrigerated storage. Linseed oil did not adversely affect neither the physical or sensory traits, nor the microbiological quality of rabbit meat throughout the shelf-life trial. The three packaging methods were all similarly effective in maintaining the physical and sensory quality of the meat, irrespective of the different dietary lipid sources and thus different susceptibility to oxidation. MAP and VAC were more effective than BAG in preserving rabbit meat hygienic quality, as highlighted by the microbial count analyzed at day 4 of shelf-life (P < 0.001). At day 10, the microbiological quality didn't differ between MAP and VAC rabbit meat samples.