Histological contribution of collagen architecture to beef toughness

Metabolomic profiling of postmortem aged muscle in Japanese Brown beef cattle revealed an interbreed difference from Japanese Black beef

OBJECTIVE

Japanese Brown (JBR) cattle, especially the Kochi (Tosa) pedigree (JBRT), is a local breed of moderately marbled beef. Despite the increasing demand, the interbreed differences in muscle metabolites from the highly marbled Japanese Black (JBL) beef remain poorly understood. We aimed to determine flavor-related metabolites and postmortem metabolisms characteristic to JBRT beef in comparison with JBL beef.

METHODS

Lean portions of the longissimus thoracis (loin) muscle from four JBRT cattle were collected at 0, 1, and 14 d postmortem. The muscle metabolomic profiles were analyzed using capillary electrophoresis time-of-flight mass spectrometry. The difference in postmortem metabolisms and aged muscle metabolites were analyzed by statistical and bioinformatic analyses between JBRT (n = 12) and JBL cattle (n = 6).

RESULTS

A total of 240 metabolite annotations were obtained from the detected signals of the JBRT muscle samples. Principal component analysis separated the beef samples into three different aging point groups. According to metabolite set enrichment analysis, postmortem metabolic changes were associated with the metabolism of pyrimidine, nicotinate and nicotinamide, purine, pyruvate, thiamine, amino sugar, and fatty acid; citric acid cycle; and pentose phosphate pathway as well as various amino acids and mitochondrial fatty acid metabolism. The aged JBRT beef showed higher ultimate pH and lower lactate content than aged JBL beef, suggesting the lower glycolytic activity in postmortem JBRT muscle. JBRT beef was distinguished from JBL beef by significantly different compounds, including choline, amino acids, uridine monophosphate, inosine 5'-monophosphate, fructose 1,6-diphosphate, and betaine, suggesting interbreed differences in the accumulation of nucleotide monophosphate, glutathione metabolism, and phospholipid metabolism.

CONCLUSION

Glycolysis, purine metabolism, fatty acid catabolism, and protein degradation were the most common pathways in beef during postmortem aging. The differentially expressed metabolites and the relevant metabolisms in JBRT beef may contribute to the development of a characteristic flavor.

Investigating the Effect of Various Sous-Vide Cooking Conditions on Protein Structure and Texture Characteristics of Tilapia Fillet Using Synchrotron Radiation-Based FTIR

The effects of various sous-vide (SV) cooking conditions (50-60℃, 30-60 min) on physicochemical properties related to the texture characteristics, protein structure/degradation, and sensory acceptability of tilapia fillet (Oreochromis niloticus) were investigated. With an increasing temperature and processing time of SV cooking, protein degradation (of both myofibrils and connective tissue) was more pronounced, as evaluated by the decrease in water- and salt-soluble proteins, total collagen, as well as the changes in the ratio of secondary protein structures (α-helix, β-sheet, β-turn, etc.), which were determined by synchrotron-FTIR (SR-FTIR). These degradations were associated with the improvement of meat tenderness, as estimated by shear force and texture profile analyzer (TPA) results. Among all SV conditions, using 60 ℃ for 45 min seems to be the optimal condition for tilapia meat, since it delivered the best results for texture characteristics and acceptability (p < 0.05). Moreover, principal component analysis (PCA) results clearly demonstrated that the highest texture-liking score of this condition was well associated with the intensity of β-sheets, which seem to be the crucial component that affected the texture of SV-cooked tilapia more so than other parameters. The findings demonstrated the potential of SR-FTIR to decipher the biomolecular structure, particularly the secondary protein structure, of SV-cooked tilapia. This technique provided essential information for a better understanding of the changes in biomolecules related to the textural characteristics of this product.

Effects of Boiling Processing on Texture of Scallop Adductor Muscle and Its Mechanism

The objective of this study was to reveal the effects of boiling processing on the texture of scallop adductor muscle (SAM) and its mechanism. Compared to the fresh sample, all the texture indicators, including the hardness, chewiness, springiness, resilience, cohesiveness, and shear force of 30-s- and 3-min-boiled SAMs increased time-dependently (p < 0.05). As the boiling time increased further to 15 min, the shear force and cohesiveness still increased significantly (p < 0.05), and the resilience and hardness were maintained (p > 0.05), but the springiness and chewiness decreased significantly (p < 0.05). The overall increase in the texture indicators of the boiled SAMs was due to the boiling-induced protein denaturation, aggregation, and increased hydrophobicity, resulting in the longitudinal contraction and lateral expansion of myofibrils, the longitudinal contraction and lateral cross-linked aggregation of muscle fibers, and the loss of free water. However, the decreasing springiness and chewiness of the 15-min-boiled SAMs was due to the significant degradation of proteins (especially collagen), resulting in the destruction of the connective tissue between the muscle fiber clusters. Both from a subjective sensory point of view and from the objective point of view of protein denaturation and degradation, 3-min-boiled SAMs are recommended. The quality improvement of thermally processed products by controlled, moderate cooking is of practical value from the perspective of food consumption.

Effect of different sous-vide cooking conditions on textural properties, protein physiochemical properties and microstructure of scallop (Argopecten irradians) adductor muscle

Among 26 sous-vide cooking conditions of scallop adductor muscle (SAM), 65 °C-5.5 h, 70 °C-1.5 h and 100 °C-5 min were selected by the differential scanning calorimetry analysis. After sous-vide cooking, the shear force, hardness, springiness, cohesiveness, chewiness and recoverability of SAM increased significantly compared to fresh sample. The cooking also changed the secondary structures of the proteins in SAM with the rising β-sheet and descending α-helix, and the chemical interactions with the rising hydrophobic interactions and disulfide bonds but the descending ionic bonds and hydrogen bonds. These caused the longitudinal shrinkage and transverse aggregation of muscle fibers, and the aggregation and cross-linking between myofibrils which led to the squeeze of immobile water from myofibril network structure. This indicated that the denaturation, oxidation, aggregation and cross-linking of proteins caused by heat treatment changed the microstructure and water distribution, which contributed to the increased textural indicators of sous-vide cooked SAM.

Content and Solubility of Collagen and Their Relation to Proximate Composition and Shear Force of Meat from Different Anatomical Location in Carcass of European Beaver (Castor fiber)

The content and solubility of collagen in the muscle tissue and cooked meat from three anatomical locations (loin, hind leg and shoulder) in carcasses of adult male European beavers and relationships of collagen fractions with proximate composition and shear force were studied. Shoulder muscle tissue contained the highest amount of intramuscular fat, collagen/protein ratio, total and insoluble collagen, and the lowest percentage of soluble collagen. The cooked meat from hind leg contained the lowest amount of total, soluble and insoluble collagen. The percentage of collagen fractions in cooked meat was comparable in all cuts (p > 0.05). The toughest meat was from the shoulder, followed by the hind leg, and the tenderest meat was from the loin (p < 0.01). Shear force of cooked meat was correlated positively with the amount of total collagen, insoluble collagen and its percentage in muscle tissue (0.597, 0.594 and 0.499, p < 0.01), as well as negatively with percentage of soluble collagen (−0.594, p < 0.001). No correlations between the shear force and the content of total collagen and its fractions in cooked meat were found. In conclusion, our results indicate that the amount of total collagen and its fractions in raw muscle tissue of beaver is a better tenderness predictor for cooked meat than their values in heat-treated meat.

Carcass Composition, Meat Quality, Calpain Activity, Fatty Acid Composition and Ribonucleotide Content in Southern Thai Native Goats and Three-Way Crossbred Goats

Carcass composition, meat quality, calpain activity, fatty acid composition, and ribonucleotide content were examined and compared between male Southern Thai native goats (NG, n = 10) and three-way crossbred goats (CG, 50% Boer × 25% Saanen × 25% Southern Thai native, n = 10). All animals were fed 1.5% body weight of concentrate (16% protein and 70% total digestible nutrients) and fresh Napier grass for 4 months. At the end of raising period, the final weight between the two genotypes was not significantly different. The percentage of carcass, bone, and fat of CG were higher than those of NG. NG presented lower shear force values, insoluble and total collagen content but higher collagen solubility and calpain-1 activity at 24 h postmortem. Additionally, NG meat was high in monounsaturated fatty acids but low in saturated fatty acids. However, the amount of ribonucleotide was no significant difference between two genotypes.

Meat of South American camelids - Sensory quality and nutritional composition

Meat contains a range of nutrients in a highly bioavailable form and when meat is excluded from the diet, without being replaced with suitable alternatives, nutrient deficiencies may occur. For this reason, it is very important to extend our knowledge of nutrients in alternative red meats, such as that provided from the South American camelids- llama and alpaca. This review summarises the current information on the nutritional and sensory parameters of llama and alpaca meat and factors affecting quality. South American camelids produce lean carcases, with an uneven fat distribution across the carcase. Llama and alpaca meat quality traits are mostly influenced by animal nutrition, animal age and processing methods. A feeding strategy based on pasture and hay supplement of barley and alfalfa, and processing younger animals (18 months) has improved the fatty acid composition respectively in llama and alpaca meat, whereas meat colour and tenderness are influenced by processing treatments including electrical stimulation, tenderstretching and enzymatic infusion.

Bos indicus cattle possess greater basal concentrations of HSP27, alpha B-crystallin, and HSP70 in skeletal muscle in vivo compared with cattle

The objectives of the present study were to evaluate the basal concentrations of heat shock proteins (HSP) between and cattle and to determine if HSP basal concentrations change as an animal matures. A total of 40 cattle were used in a 2 × 2 factorial design to evaluate the effects of genotype and age (heifers and mature cows) on basal concentrations of heat shock protein 27 (HSP27), α B-crystallin (Cryab), and heat shock protein 70 (HSP70). Each experimental group of 10 animals was sampled on a separate day over a period of 4 wk during July 2014. A muscle sample was collected from the longissimus thoracis (LT) and concentrations of HSP were quantified using ELISA. There were no significant differences in HSP concentration for the interaction between age and genotype or for age alone. cattle had greater ( < 0.05) basal concentrations of HSP27, Cryab, and HSP70 in the LT than cattle. The results of this study show that basal in vivo HSP concentrations differ between and cattle. However, further studies are needed to investigate the relationship between HSP concentrations and meat tenderness with respect to genotypes to see if HSP concentrations account for at least some variability in tenderness differences.

Slaughter and carcass characteristics, chemical composition and physical properties of <i>longissimus lumborum</i> muscle of heifers as related to marbling class

Abstract. The experiment involved 68 heifers obtained from Polish Black-and-White Lowland dams (with no more than 50% Holstein Friesian blood) sired by Limousin bulls. The study was arranged to determine the slaughter and carcass traits, chemical composition and physical properties of musculus longissimus lumborum (MLL) as related to the level of marbling, and to examine the correlation between some of the traits mentioned above and the culinary characteristics of meat. The results of the study show that marbling significantly affected the dressing percentage and carcass traits such as subcutaneous fat content, fat of valuable cuts and MLL area. Most of the physico-chemical properties of tested muscles, with the exception of total protein and total collagen content, were related to the level of marbling. Based on the results obtained, it appears that age at slaughter and carcass weight turned out to be poor predictors of colour lightness within all marbling classes. The same conclusion applies to the amount of total collagen in large and strong marbled muscles for shear force value. In turn, soluble collagen content for shear force could be a quite good forecaster of meat tenderness but not in highly marbled muscles. Of all tested slaughter and carcass traits, only MLL fat content seems to be appropriate to assess both: the tenderness and lightness of meat.

Quality of lamb meat from the Information Nucleus Flock

The effects of production and processing factors on tenderness, and colour of lamb meat produced from 7 locations as part of the Australian Sheep Industry CRC’s Information Nucleus flock were investigated, using data from 2052 lambs slaughtered in 2007. At 24 h post-slaughter, samples of m. longissimus lumborum (LL) and m. semimembranosus (SM) were collected for measurement of intramuscular fat (IMF), myoglobin, iron and copper and fresh meat colour (L*, a*, b*) and pH at 24 h measured on the LL. pH and temperature measurements made pre-rigor were used to calculate the pH at 18°C. Tenderness was measured by LL shear force at days 1 (SF1) and 5 (SF5) post-slaughter, the shear force difference (SF-diff) and SM compression and collagen concentration were determined. Retail colour stability was assessed using over-wrapped LL under simulated retail display for 3 days, according to the change in the oxymyoglobin/metmyoglobin ratio. All traits were affected by flock and date of slaughter (P < 0.001). After 4 days of ageing, 70–95% of the LL samples from all flocks, except for one, had acceptable tenderness for consumers based on their shear force. Low IMF, high LL pH at 18°C and high pH at 24 h increased SF1 and SF5 and also had an effect on SF-diff (P < 0.001). The retail colour of 44.8% of the samples on day 3 of retail display were lower than acceptable. Retail colour was influenced by IMF, pH18 and the concentration of iron and copper (P < 0.001). In conclusion, breeding and management practices that increase muscle IMF levels and reduce ultimate pH values and processing practices that result in moderate rates of pH fall post-slaughter, improve the tenderness of lamb. Extension of retail colour stability may be antagonistic to traits associated with tenderness and nutritional traits, particularly IMF and mineral levels.