Relationship between meat quality and intramuscular collagen characteristics of muscles from calf-fed, yearling-fed and mature crossbred beef cattle

Consumer eating quality and physicochemical traits of pork Longissimus and Semimembranosus differed between genetic lines

Pork eating quality is affected by various factors. In this study, Longissimus thoracis et lumborum (LTL) and Semimembranosus (SM) muscles from seven genetic lines (PM-LR - Pure maternal, Landrace-type; PM-LW - Pure maternal, Large White-type; PM-D - Pure maternal, Duroc-type; PT-D - Pure terminal, Duroc-type; PT-LW - Pure terminal, Large White-type; PT-LR - Pure Terminal, Landrace-type; Comp-P × LW × D - Composite Terminal - Pietran × Large white × Duroc) were analyzed for pH, intramuscular fat (IMF) content, and collagen content and solubility. A consumer sensory test using check-all-that-apply (CATA) and biometric approaches was also conducted. The results showed that the IMF content of line PM-D was the highest (P = 0.004), while line PT-LW received the highest score in tenderness, liking of flavor, purchase intent, and quality grading (P < 0.05). Line PM-LR and PT-LR showed the lowest IMF content and were least preferred by consumers. Compared to LTL, SM showed higher pH, collagen solubility, and sensory scores in tenderness, juiciness, liking of flavor, and overall liking (P < 0.05). Different muscles and lines were associated with different CATA terms but not with differences in consumer emotional responses. pH positively influenced tenderness, juiciness, and overall liking (P < 0.05), but IMF and collagen had little effect. The flavor was the most important sensory attribute contributing to overall liking, followed by tenderness. Genetic line and muscle affected pork chemical properties and eating quality. The findings are important for the Australian pork industry to improve the eating quality of their products.

Myosin heavy chain isoform expression and meat quality characteristics of different muscles in yak (Bos grunniens)

Myosin heavy chain (MHC) isoforms and meat quality characteristics of different muscles were investigated to explore their potential relationships in yaks. Results showed that semitendinosus (ST), longissimus thoracis (LT), and infraspinatus (IS) have a greater ratio of MHC IIb (47.84%), MHC IIa (73.27%), and MHC I (24.26%), respectively, than the other two muscles. Compared with LT or ST, IS exhibited more intense color, greater water-holding capacity, and initial tenderness with higher intermuscular fat (IMF) and collagen (of lower cross-linking level), presenting overall better quality. Variations in MHC isoforms accounted for the muscle-specific meat quality. Specifically, MHC I was positively associated with redness, myoglobin, IMF, collagen, pH, and thermal stability and negatively associated with myofibril fragmentation index, fiber thickness, collagen cross-linking, and drip loss. These results provide insights into the relationships between MHC isoforms and meat quality in yaks and the MHC I isoform has an extensive influence on meat quality.

Characteristics of intramuscular collagen in calf-fed Nellore bulls and steers throughout the finishing phase

This study evaluated collagen solubility and gene expression of biomarkers for intramuscular collagen (IMCT) deposition and remodeling in the Longissimus muscle of bulls and steers through the finishing phase. Thirty-six Nellore calves were used (18 bulls and 18 steers), and six of each sexual condition were randomly assigned to be harvested at 0, 100, or 200 days on feed (DOF) to evaluate collagen characteristics in different time points throughout the finishing phase. Bulls showed a greater collagen solubility than steers (P = 0.03). The gene expression of fibrogenic markers (TGFβ1, COL1A1, and COL3A1) and IMCT remodeling mediators (MMPII, TIMPII, and LOX) were not affected by sexual condition or DOF (P > 0.05). Our data indicate that young Nellore bulls have a higher percentage of soluble intramuscular collagen, possibly due to higher collagen remodeling associated with a faster growth rate and muscle hypertrophy. Moreover, castration and DOF did not modify mRNA levels of fibrogenic and collagen remodeling markers.

Effect of slaughter age and postmortem aging time on tenderness and water-holding capacity of yak (Bos grunniens) longissimus thoracis muscle

The present study investigated the effect of slaughter age (2.43 ± 0.20, 4.15 ± 0.19, 6.62 ± 0.18, 10.59 ± 0.74 years) and postmortem aging time (1, 24, and 72 h) on the tenderness and water-holding capacity (WHC) of yak longissimus thoracis muscles to determine the most suitable age for slaughter to ensure product consistency. Under conventional postmortem aging conditions (4 °C), muscles of each age group exhibited the effect of cold shortening. Once the cold shortening occurred, the age effect on thickening muscle fiber and developing cross-links of collagen, considered to intensify the meat toughness, became less important. Owing to greater carcass weight and intramuscular fat, muscles of the older carcass (over 6-year-old) were less influenced by the cold shortening effect during the chilling process and showed lessened sarcomere contraction, delayed formation of drip loss channels, and increased level of myofibril fragmentation index (MFI) and myofiber structural disintegration, resulting in greater tenderness and WHC, especially 6-7 years group. Aging of 72 h structurally disintegrated the collagen cross-linking and integrity of muscle fibers and elevated the MFI, improving the meat tenderness. Therefore, the suitable slaughter age for yak is 6-7 years old and after 72 h aging, improved quality of yak meat can be obtained.

Structural changes in collagen and aggrecan during extended aging may improve beef tenderness

The aim of this study was to characterize structural and property modifications of intramuscular connective tissue (IMCT) during extended aging. Longissimus lumborum (LL), Gluteus medius (GM), and Gastrocnemius (GT) muscles were collected from 10 USDA choice carcasses, fabricated and assigned to one of four aging periods: 3, 21, 42, or 63 days (n = 120). As expected, tenderness improved, and IMCT texture weakened after 21 days of postmortem aging (dpm; P < 0.05). In addition, transition temperature of collagen decreased (P < 0.01) after 42 dpm. It is interesting to note the collagen structure was also altered where relative % of γ chain decreased after 42 dpm (P < 0.05), and the α1 chain % increased at 63 days (P < 0.01). Finally, The LL and GT had a decrease in the 75 kDa aggrecan fragments from 3 to 21 to 42 dpm (P < 0.05). This study provided evidence that IMCT weakens during postmortem aging due to the modifications of IMCT components such as collagen and proteoglycan.

Characterization of Type I and Type III Collagen in the Intramuscular Connective Tissue of Wuzhumuqin Sheep

Intramuscular connective tissue (IMCT) collagen is an important factor in meat quality. This study analyzed the characteristics of type I and III collagen in the IMCT of the semitendinosus (SD) and longissimus dorsi (LD) of Wuzhumuqin sheep at different growth stages (6, 9, 12, and 18 months). Utilizing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared spectroscopy (FTIR), collagen types I and III were successfully isolated and shown to contain an intact triple helix structure. Immunofluorescence revealed that these collagens were located in the endomysium and perimysium. Collagen-related genes were significantly expressed in sheep aged 9 and 12 months. The amino acid content increased with age in type I collagen whereas it decreased in type III collagen. Furthermore, type III collagen contained more hydroxyproline (Hyd) than type I collagen. Differential scanning calorimetry (DSC) revealed that the thermal stability of collagen increased with age, accompanied by a decrease in solubility. Semitendinosus muscle had more collagen cross-linkages than LD muscle due to the high pyridinoline (Pyr) content in the endomysium. Finally, a correlation analysis highlighted the multiple correlations between characteristics in different types of collagen during sheep growth. In summary, the collagen characteristics in the IMCT of sheep were impacted by collagen type, muscle type, and age. Furthermore, the various correlations between these characteristics may play an important role in the development of IMCT.

Preferential deposition of dairy derived fatty acids in muscle tissue is partially due to the upregulation of CD36 in a low-birth-weight swine model

Metabolic syndrome is a worldwide health issue. Previous research has revealed that low-birth weight (LBW) swine fed a high-fat (HF) diet were susceptible to insulin resistance (IR) and developed a preferential intestinal lipid absorption, hypertriglyceridemia, and muscle steatosis. We hypothesized that fatty acid transporters such as CD36, FATP4, and FABP2 could potentially explain the development of these conditions. In addition, dairy-derived fatty acids have been shown to be valid biomarkers to assess dairy intake, which can be utilized to investigate muscle lipid deposition in LBW swine. The overall aim of this study was to delineate molecular transport candidates responsible for intestinal lipid absorption and muscle lipid deposition in LBW swine; and secondly to determine what dietary fatty acids might accumulate preferentially in pork muscle when consuming dairy products. At 5 weeks of age, normal birth weight (NBW) and LBW piglets were randomly assigned to three experimental diets: 1-chow diet, 2-HF diet, or 3-isocaloric HF diet supplemented with full fat dairy products. At 12 weeks of age, piglets were euthanized, and carcass, fasting plasma, biceps femoris and jejunum mucosal scrapings were collected. Results showed that HF-fed LBW swine exhibited early signs of IR (fasting glucose, P < 0.05; fasting insulin, P = 0.091; HOMA-IR, P = 0.086) compared with NBW-Chow, which were attenuated with increased dairy intake. Muscle samples from HF-fed LBW swine contained significantly more triglyceride compared to Chow-fed NBW swine (P < 0.05). Increased dairy intake significantly increased myristic acid (C14:0) and DPA (C22:5n3) relative to HF feeding alone (P < 0.05). All HF-fed LBW swine (regardless of dairy intake) exhibited an upregulation of CD36 expression (but not FABP2) compared with NBW littermates in both the small intestine and muscle (P < 0.05). Interestingly, increased dairy intake significantly increased the Canadian Lean Yield percentage in LBW swine fed an HF diet (P < 0.05). Findings from this study provide evidence on the mechanistic pathway of intestinal and muscle lipid metabolism in an innovative LBW swine model. We have also revealed that increasing dairy intake can enhance the incorporation of dietary long-chain polyunsaturated fatty acids into pork, as well as increasing the predicted lean yield of the carcass.

Effects of Sheep Sires on Muscle Fiber Characteristics, Fatty Acid Composition and Volatile Flavor Compounds in F1 Crossbred Lambs

Crossbreeding significantly improves meat production performance in sheep; however, whether hybridization changes the meat quality characteristics of lambs is uncertain. We analyzed the effects of three different hybrid sires on muscle fiber characteristics (MFCs), fatty acid composition (FAC), and volatile flavor compounds (VFCs) in lambs under identical feeding conditions. Compared with those of purebred lambs, the muscle fiber diameter and cross-sectional areas of the crossbred lambs were significantly decreased (p < 0.05), and the collagen fiber content was significantly increased (p < 0.05). The numbers and area ratios of the fast and slow muscle fibers did not significantly differ between the purebred and crossbred lambs, but the expressions of four MyHC gene types differed significantly (p < 0.05). Twenty-three fatty acids were identified in both the purebred and crossbred lambs, of which thirteen were differentially expressed (p < 0.05). Saturated fatty acid (SFA) contents in the crossbred lambs were significantly increased (p < 0.05), whereas the monounsaturated fatty acid content was significantly decreased (p < 0.05). Polyunsaturated fatty acid/SFA and n-6/n-3 ratios were significantly lower in the crossbred lambs than in the purebred lambs (p < 0.05). Twenty-five VFCs were identified among the three hybrids, and aldehydes were the main VFCs. Eleven VFCs were differentially expressed in the crossbred lambs (p < 0.05). Hybrid sires affected the MFCs, FAC, and VFCs of the F1 lambs, thus providing a reference for high-quality mutton production.

Effect of heat treatments on the physicochemical and sensory properties of the longissimus thoracis muscle in unweaned Limousin calves

The aim of the study was to assess the effect of methods of heat treatment on selected quality parameters of longissimus thoracis muscle of Limousin calves, subjected to grilling, steaming, and sous vide cooking. The type of heat treatment did not significantly affect shear force or water activity. Cooking loss in the grilled and steamed meat was significantly higher than in the sous vide. While the content of vitamin E was significantly lower in the cooked meat, it was retained to the greatest degree in the grilled meat and least in the steamed meat. The TBARS index significantly increased during all cooking methods with the highest level in steamed meat. The sensory analysis revealed a preference for the sous vide and grilled meat, while the steamed meat received the lowest scores. Although veal is commonly assumed to be highly nutritious and palatable, its quality can be significantly influenced by the type of heat treatment.

An investigation on the influence of various biochemical tenderness factors on eight different bovine muscles

This study's objective was to understand the relationships between biochemical tenderness components and subject/objective tenderness of eight muscles from beef carcasses. Longissimus thoracis (LT), pectoralis profundus (PP), supraspinatus (SS), triceps brachii (TB), gluteus medius (GM), rectus abdominus (RA), rectus femoris (RF), and semitendinosus (ST) were collected from 10 USDA upper 2/3 Choice beef carcasses and assigned to a two- or 21-day aging period (n=160). Troponin-T (TNT) degradation, desmin degradation, sarcomere length, collagen content, mature collagen crosslink density, intramuscular lipid content, pH, Warner-Bratzler Shear Force (WBSF) and trained sensory panel analyses were measured. A Pearson correlation analysis was conducted to determine the relationship between each tenderness contributor measured in this study with WBSF or the overall tenderness evaluated by the trained panelist for each of the eight muscles. In addition, multivariate regression models were constructed to confirm this relationship. The results showed that muscle anatomical locations and physiological functions driven by muscle fiber types may explain some of the biochemical/tenderness differences found in this study. The correlation analysis showed that each muscle had a specific tenderness factor(s) that contributed to the overall tenderness. For instance, tenderness for LT, TB, GM, RA, and ST may be influenced more by proteolytic degradation, while the collagen characteristics may primarily influence tenderness for PP. Also, lipid content has a significant influence on GM tenderness. Finally, the multivariate regression model showed that almost all of the biochemical measurements conducted in this study played a minor but important role as an overall tenderness predictor on a whole carcass basis. Increasing the knowledge base on the various tenderness components' level of contribution will allow end-users to develop specific tenderness management strategies to ensure consistent tenderness in beef products.

Tumbling and subsequent aging improves tenderness of beef longissimus lumborum and semitendinosus steaks by disrupting myofibrillar structure and enhancing proteolysis

Tenderness is an important sensory attribute to the overall eating experience of beef. Identifying novel methods to ensure consistent tenderness, especially in inherently tough cuts, is critical for the industry. This study investigated if tumbling without brine inclusion could be an effective method to improve the quality and palatability attributes of beef longissimus lumborum (LL) and semitendinosus (ST) steaks. Furthermore, interactions with postmortem aging were evaluated to determine how tumbling might affect protein degradation and muscle ultrastructure. At 5 d postmortem, pairs of LL and ST muscles from beef carcasses (n = 16) were bisected, vacuum packaged, and tumbled for 0, 40, 80, or 120 min. Sections were divided and subsequently aged an additional 0 or 10 d at 2 °C. Tumbling for any duration improved instrumental tenderness of LL (P < 0.001) but not ST (P > 0.05) steaks, regardless of aging time. Tumbling exacerbated moisture loss in both muscles shown by greater purge and cooking losses (P < 0.05). Myofibrillar fragmentation was induced through tumbling in both muscles (P < 0.001), which was supported by transmission electron microscopy images. Tumbling for 120 min followed by 10 d of aging resulted in less abundant intact troponin-T in both LL and ST (P < 0.05), as well as less intact desmin in ST (P < 0.05); however, calpain-1 autolysis was not affected by tumbling (P > 0.05). No effects of tumbling, aging, nor the interaction were found for the content and solubility of collagen (P > 0.05). Consumer panelists (n = 120/muscle) rated LL steaks tumbled for any duration higher for tenderness and overall liking compared to control steaks (P < 0.05). For ST, significant interactions were found for consumer liking of tenderness and juiciness. In general, tumbling without subsequent aging resulted in poorer juiciness than non-tumbled (P < 0.05), while at 10 d no differences in juiciness were found between treatments (P > 0.05). For ST steaks that were aged 10 d, 120 min of tumbling resulted in greater tenderness liking than non-tumbled steaks (P < 0.05). These results suggest that tumbling would result in myofibrillar fragmentation and may benefit the degradation of myofibrillar proteins; however, there would be negligible impacts on collagen. Accordingly, tumbling without brine inclusion alone may be sufficient to improve tenderness and overall liking of LL steaks, while combined tumbling with subsequent postmortem aging would be necessary to improve tenderness liking of ST.

Effect of postmortem tenderization strategies (pretumbling, blade tenderization, moisture enhancement) on processing yield parameters and eating quality of selected hip and loin muscles from youthful and mature beef carcasses

Several muscles from mature beef carcasses have been identified as failing to provide adequate tenderness required for a satisfactory consumer eating experience. Postmortem processing strategies can help improve the tenderness and subsequent eating quality of mature beef muscles. The current study was undertaken to investigate the impact of processing strategies (blade tenderization [BT], pretumbling [PT], and moisture enhancement [ME]), alone and in combination, on processing yield and eating quality-related parameters of selected loin and hip muscles (gluteus medius [GM], longissimus lumborum [LL], semimembranosus [SM], and biceps femoris [BF]) from youthful and mature beef cattle. Results indicate that muscles from mature beef were inherently less tender (P < 0.05), but some tenderization procedures produced meat that was similar in tenderness to that of youthful cattle. Of the different tenderization strategies evaluated, BT followed by ME (injection of a salt/phosphate solution) was the most effective strategy for improving (P < 0.05) tenderness of tougher muscle cuts such as BF and SM. Moisture enhancement alone improved tenderness (P < 0.05) and juiciness (P < 0.01) of SM, GM and LL, but with the exception of samples tenderized prior to injection, was not effective (P > 0.05) in BF muscles. No additional tenderization of GM and LL samples was observed (P > 0.05) by combining PT or BT with ME. Combining PT or BT with ME; however, was effective (P < 0.05) to control the increased purge loss observed following ME treatment in SM and LL muscles. Pretumbling as a single treatment was ineffective (P > 0.05) in all of the muscles, and only treatments that included BT were sufficient to effect an increase (P < 0.05) in tenderness of BF.

Effects of Age and Rice Straw Inclusion Levels in the Diet of Yiling Cull Cows on Growth Performance, Meat Quality, and Antioxidant Status of Tissues

Simple Summary

Several negative attributes are associated with carcass and meat from cull cows, including lower carcass weights, inferior tenderness, etc. These undesirable characteristics are normally more distinct with increasing age. In addition, there are no recommended standards for forage levels in the diet of Chinese local cattle to produce high marbled beef. In the current study, we evaluated the effects of age and forage levels on the finishing performance of Yiling cull cows under high-energy ration conditions, and also investigated their antioxidant status related to age and diet. We found that younger age and adequate forage had better growth performance and carcass traits. Our findings highlight the importance of selecting according to age and providing adequate forage feed for Yiling cull cows. Moreover, our study also demonstrated the excellent capability of producing high marbled beef for Yiling cattle.

Abstract

The objectives of this study were to investigate the effects of age and dietary straw levels on growth performance, carcass and meat traits, as well as tissue antioxidant status of Yiling cull cows. Twenty-four Yiling cull cows were arranged in a 2 × 2 factorial design: two age classes consisting of younger cull cows (YCC; appearing with three or four pairs of permanent teeth) and older cull cows (OCC; worn out teeth); two dietary treatments consisting of lower and higher rice straw levels (LRS and HRS; providing 0.7 kg/d and 1.2 kg/d rice straw per head based on air-dry basis, respectively). Cows were fed twice a day. Straw was offered at half of the predetermined weight each meal; concentrate was separately supplied ad libitum. After 300 d of feeding, final body weight (BW), total BW gain, average daily gain and gain:feed intake were higher (p < 0.01) in the YCC group than in the OCC group. Total dry matter intake was higher (p = 0.03) in the HRS group than in the LRS group, but neutral detergent fiber apparent digestibility was negatively affected (p = 0.01) by increased straw levels. Decreased C15:0, C17:0, C20:5n3c, and saturated fatty acids (SFAs) proportion as well as increased C18:1n9c and monounsaturated fatty acids (MUFAs) proportion in meat from YCC with HRS diet were observed as compared to that in meat from YCC with LRS diet (p < 0.05). Meat from HRS group had higher (p = 0.04) C18:3n3c proportion than meat from LRS group. No significant differences (p > 0.05) were found for meat quality attributes except for cooking loss, which was higher (p = 0.02) in the HRS group than in the LRS group. Both YCC group and HRS group had higher (p < 0.05) cold carcass weight compared to OCC group and LRS group. Moreover, catalase activity of liver tissue was higher (p = 0.045) in YCC than in OCC, while superoxide dismutase activity of muscle tissue was higher (p = 0.01) in LRS than in HRS. Based on results, we concluded that younger age and feeding high-level straw can improve the finishing performance of Yiling cull cows.