Sensory Tenderness Research Articles

Beef Carcasses Aged at Mild Temperature to Improve Sustainability of Meat Production

Beef carcass aging, which enhances tenderness and flavor through proteolysis, is traditionally costly and slow, requiring long-term storage at temperatures near 0 °C. To reduce energy consumption, a new technique using moderate cooling room temperatures was tested. Six carcasses of Holstein bulls were used. From each carcass, two shoulders were processed in different ways: one was refrigerated at 8 °C (W), and after spraying with a solution with calcium chloride and sodium chloride, was coated with sodium alginate. The other shoulder was stored at 2 ± 1 °C as a cold control (C). After five days of aging, the shoulders were dissected, and two muscles (Caput longum triceps brachii and Supraspinatus) were subjected to physico-chemical analysis, microbiological safety assessment, and sensory testing. The remaining samples of both muscles were stored in domestic conditions for an additional 5 days at various temperatures (2, 4, 8 °C), where the same physic-chemical and sensory tests were conducted. The results showed that moderate aging temperature improved meat quality, significantly reducing the shear force (p = 0.001) and increasing sarcomere length, the myofibrillar fragmentation index, and sensory tenderness (p = 0.042, p = 0.039, and p = 0.027, respectively). However, domestic storage post-dissection should not exceed 4 °C to prevent rapid lipid oxidation, as observed at 8 °C for both muscles (p < 0.001). Mild aging temperature maintained legal safety standards, enhanced certain meat qualities, and promoted enzymatic activity similar to traditional dry aging while reducing high energy consumption.

Carcass chilling method and electrical stimulation effects on meat quality and color in lamb

Five treatments: Control (C), Pre-evisceration Electrical Stimulation (CES: 15 Hz, 700 mA, 500 μs pulse width, 45 s pulse duration), vascular Rinse & Chill® (RC), CES + RC (ESRC), and RC with ES after evisceration (RCES:15 Hz, 600 mA, 1000 μs, 45 s), were applied to 21 lambs each. After being excised from the carcass, muscles were vacuum packaged and aged (Longissimus lumborum, LL, 3 and 22 d postmortem; Semimembranosus, SM, 3 d postmortem). Temperature, pH, purge, cooking loss, color, Warner-Bratzler Shear Force (WBSF), and consumer sensory evaluations were determined. CES and ESRC resulted in the fastest drop in pH below 6 and ESRC had the lowest likelihood of cold shortening. Sensory tenderness in the ESRC LL was greater than C. No differences in WBSF were found among treatments. RC generally produced lamb with higher lightness (L*). The rapid drop in pH likely was responsible for the increased purge and cooking loss observed. Color was affected by the order of ES and RC application.

Maceration Frequency Impacts Semitendinosus and Biceps femoris Surface Area, Cooking Loss, and Palatability Outcomes

We examined the effect of maceration frequency on surface area, purge loss, and palatability of eye of round and bottom round steaks. Beef eye of round (n = 12) was cut into 8 steaks each and randomly assigned to 0, 1, 2, or 3 macerations and uncooked or cooked slice shear force (SSF) tenderness determinations. Bottom round muscles (n = 12) were cut into 12 steaks and randomly assigned to 0, 1, 2, or 3 macerations and uncooked or cooked SSF or trained sensory evaluations. Steaks were trimmed to a common size (50 cm2 for eye of round and 80 cm2 for bottom round) prior to maceration with a commercial steak tenderizer. Data were analyzed via mixed ANOVA models using a randomized complete block design. Surface area increased (P < 0.001) by 15.4%, 38.6%, and 62.4% for eye of round steaks and 22.0%, 51.3%, and 70.3% for bottom round steaks after 1, 2, or 3 macerations, respectively. Purge losses did not differ (P ≥ 0.247) for either muscle due to maceration frequency. Uncooked SSF values for eye of round steaks were decreased (P < 0.001) by 6.6%, 19.5%, and 40.0% after 1, 2, and 3 macerations; however, cooked SSF values did not differ (P = 0.077). For bottom round steaks, uncooked SSF values were decreased (P < 0.001) by 32.0%, 45.5%, and 67.2% after 1, 2, and 3 macerations; cooked SSF values for steaks macerated 3 times were 26.6% lower (P = 0.022) than steaks macerated 0, 1, or 2 times. Cooking losses were greater (P < 0.001) for macerated eye of round (5.4% to 7.2%) and bottom round steaks (7.6% to 10.8%). Maceration decreased (P < 0.001) sensory juiciness and connective tissue ratings and increased (P < 0.001) sensory tenderness ratings. Maceration increased surface area and improved tenderness.

Effects of three different grass silage-based total mixed rations on meat quality of finishing Holstein and Nordic Red dairy bulls

The objective of the present experiment was to study the effects of different silage-based diets on beef quality of Holstein (HO) and Nordic Red (NR) bulls. Moderate concentrate diet (MC) included grass silage (GS), barley grain and mineral-vitamin mixture in proportions of 600:385:15 on dry matter basis while the respective proportions on low concentrate diet (LC) were 850:135:15. No concentrate diet (NC) included GS, whole-crop barley silage and mineral-vitamin mixture (685:300:15). Thirty-five HO and 30 NR bulls (21–22 bulls per feeding treatment) were randomly selected for the meat quality research. One day post-slaughter, the muscle longissimus lumborum (LL) from the right side of each carcass was cut at the level of the first lumbar vertebra. The pH value of LL muscle was highest in LC, intermediate in MC and lowest in NC diet but did not differ between the breeds. For meat lightness a significant (P < 0.05) breed × diet interaction was observed. The NR bulls had lighter meat compared to the HO bulls especially with MC, but not with LC. Meat redness and yellowness were higher in MC compared to LC or NC fed bulls (P < 0.001). The breed did not affect meat redness, but yellowness was higher in HO compared to NR bulls (P < 0.05). Drip loss was higher in LL of HO than NR bulls (P < 0.01). The diets had no effects on marbling score but it was higher in NR than HO bulls (P < 0.05). Shear force was lowest in MC but no difference was found between the LC and NC and between the breeds. No differences between the treatments were found in sensory tenderness, juiciness, and flavour. Overall, the observed diet effects on meat eating quality were minor. This demonstrated the ability of finishing dairy bulls to adapt to different feedings without major effects on meat quality.

Meta-Regression Analysis of Relationships between Fibre Type and Meat Quality in Beef and Pork-Focus on Pork.

This meta-regression analysis was conducted to identify the relationship between fibretype cross-sectional area (CSA) and frequency (%) and meat quality traits, especially tenderness (sensory and Warner-Bratzler Shear Force, WBSF). Literature searches were conducted using specific keywords which resulted in 32 peer-reviewed manuscripts that contained averages and correlation coefficients for fibre type (frequency and CSA) and quality traits of longissimus muscle for beef and pork (7 and 25 studies respectively). Correlations were analysed in meta-regression using R-Studio and linear regression was also conducted. For the combined beef and pork analysis, only pH, WBSF, and drip loss were associated with fibre type frequency and CSA (p < 0.05 for all). Limiting the analysis to pork, the key results were frequency of type I fibres were associated with decreased drip loss, increased cook loss, decreased lightness (L*) and increased sensory tenderness whereas frequency of type IIb fibres were associated with increased drip loss (p < 0.05 for all). In addition, the CSA of type I and IIb fibres was associated with colour traits lightness and redness (p < 0.05 for all). Future research should focus on fibre type across breeds and muscles to further understand the impacts of fibre type frequency and CSA on quality.

Bos indicus Carcasses Suspended by the Pelvic Bone Require a Shorter Aging Time to Meet Consumer Expectations Regarding Meat Quality.

This study evaluated the effects of hanging the carcass by the Achilles tendon (AS) versus pelvic suspension (PS) on meat quality traits. Bos indicus carcasses of two distinct biological types/sex categories comprised 10 young Brangus heifers and 10 Nellore bulls which were finished in a feedlot. Half-carcasses of each biological type/sex category were randomly hung using Achilles suspension (n = 20, AS) or pelvic suspension (n = 20, PS) for 48 h. At boning, longissimus samples were collected for evaluation by untrained consumers for tenderness, liking of flavor, juiciness and overall acceptability, after aging for 5 or 15 days. Objective samples were also tested for shear force (SF), Minolta meat colour, ultimate pH, cooking loss (CL) and purge loss (PL). There was a positive effect (p < 0.01) of PS on the sensory tenderness of Nellore bulls and Brangus heifers aged for 5 days compared to the AS method. At 15 days of aging, difference in sensory tenderness was observed (p < 0.05) in either group. Additionally, an interaction occurred between the suspension method and the aging of Nellore beef (p < 0.05) on liking of flavor, juiciness and overall acceptance, while the same effects were not observed for Brangus beef (p > 0.05). Nellore carcasses submitted to PS tended (p = 0.06) to produce more tender meat than those submitted to AS (SF = 44.62 ± 6.96 vs. 50.41 ± 8.04 N), and lower CL (p < 0.05) were found (27.7 vs. 30.9%). Carcass-suspension methods did not influence meat color, pH or PL in either group (p > 0.05). The PS contributes to improve the quality of Bos indicus bulls loins; in addition, this method allows a reduction in the aging time from 15 to 5 days, and it can be used to supply meat consumer markets which accept a certain level of eating quality.

Understanding the effects of chilling on color and quality characteristics of bovine longissimus thoracis

Meat quality in the m. longissimus thoracis (LT) associated with decreased muscle temperature early post-mortem was investigated using ten Angus crossbred steer carcasses. LT chill rate of each carcass right side was increased by removing superficial subcutaneous fat and associated muscles. LT muscles were removed at 24 h post-mortem and divided into halves with the posterior portion analyzed immediately and the anterior portion analyzed after 14 days post-mortem ageing. Denuding the LT decreased its temperature by 2 °C at 3 h post-mortem and decreased intramuscular lactate concentration, sensory panel tenderness score, a*, b* and chroma values, and proportion of oxymyoglobin and increased proportions of metmyoglobin and deoxymyoglobin at day 2 post-mortem without affecting intramuscular pH, or cooked LT shear force. Small shifts in early post-mortem muscle temperature can alter the extent of anaerobic glycolysis, influencing early retail display color and sensory tenderness, emphasizing the importance of proper early post-mortem management of carcasses in controlling beef quality.

Extending the feeding period beyond 8.0 mm of subcutaneous fat reduces feed efficiency without improving meat colour and tenderness of non-implanted feedlot steers

1. Battaglia C., Vilella G.F., Bernardo A.P.S., Gomes C.L., Biase A.G., Albertini T.Z., Pflanzer S.B., 2019. Comparison of methods for measuring shear force and sarcomere length and their relationship with sensorial tenderness of longissimus muscle in beef. J. Texture Stud. 1, 1–11, https://doi.org/10.1111/jtxs.1... CrossRef Google Scholar

Effects of feeding high oleic soybean oil to growing-finishing pigs on loin and belly quality.

Feeding growing-finishing pigs supplemental fat is a common practice in the swine industry and can result in improved feed efficiency and reduced feed intake; however, dietary lipids also play a key role in determining pork quality. Objectives of the study were to evaluate the effects of feeding graded levels of high oleic soybean oil (HOSO) on loin and belly quality. A total of 288 pig raised in two separate blocks (144 pigs each) were assigned to one of four diets containing either 25% dried distiller's grains with solubles (DDGS), 2% high oleic soybean oil (HOSO2), 4% high oleic soybean oil (HOSO4), or 6% high oleic soybean oil (HOSO6). Following the conclusion of the feeding trial, 144 pigs were slaughtered at the University of Illinois Meat Science Laboratory. Following fabrication, loins were collected for the evaluation of fresh quality measurements and color stability. Belly quality and fatty acid composition were evaluated using skin-on natural fall bellies. There were no differences (P ≥ 0.11) in pH, visual color, lightness (L*), drip loss, or WBSF among dietary treatments. However, visual marbling was increased (P ≤ 0.01) in loin chops from pigs fed HOSO4 and HOSO6 treatments compared with chops from pigs fed the DDGS dietary treatment. Additionally, loin chops were more red (a*) (P ≤ 0.01) from pigs fed HOSO diets when compared with pigs fed DDGS. Extractable lipid was decreased (P ≤ 0.01) in fresh loin chops from pigs fed DDGS and HOSO2 diets compared with pigs fed HOSO6. There were no differences (P ≥ 0.75) in trained sensory tenderness, juiciness, or flavor for loin chops from pigs fed different dietary treatments. Pork fatty acid composition was altered by dietary HOSO inclusion, with pigs fed DDGS having (P ≤ 0.01) the greatest concentration of C16:0 and was decreased with increasing levels of HOSO inclusion. Inversely, the percentage of C18:1n-9 was least (P ≤ 0.01) in pigs fed DDGS and increased with increasing levels of HOSO inclusion. Pigs fed DDGS produced wider (P ≤ 0.03) and thinner (P ≤ 0.04) bellies with reduced flop distance compared with pigs fed HOSO diets. Overall, HOSO diets did not negatively affect fresh loin quality or sensory traits of loin chops. Furthermore, feeding HOSO to swine resulted in bellies containing greater percentages of oleic acid and reduced percentages of palmitic and linoleic acid.

Comparison of meat quality characteristics of dry aged lamb loins and optimization of dry aging process.

The purpose of the present study was to investigate the physicochemical characteristics, meat quality, oxidative stability and sensory properties of lamb meat during 0, 7 and 14 day of the dry aging process. The M. longissimus lumborum (LL) and M. longissimus thoracis (LT) muscles from male Akkaraman lambs were used. The pH values of the LT and LL cuts were not changed during the aging periods. The LT cuts had significantly higher weight loss, a* and b* values, and lower shear force compared to the LL cuts. However, dry aging led to greater decreases in shear force in the LL cuts on 7th day of aging. The total mesophilic aerobic counts, total psychrophilic counts, Enterobacteriaceae counts, lactic acid bacteria, and yeast-mold counts were increased during the aging process. The sensory panel scoring showed a significant difference in the LL cuts and no significant difference in the LT cuts compared to the control group. There were significant changes in sensory panel scores for the LL cuts, whereas there were no significant changes for the LT cuts according to the non-aged samples. In conclusion, dry aging improved the quality of both cuts, however, the LL muscle of lamb was more suitable for dry aging. Moreover, 7 days were sufficient to produce the desired sensory properties in the lamb loins. Increasing the aging time from 7 to 14 days did not appreciably affect the sensory attributes or tenderness.

Morphological Parameters And Assessment Of The Technological, Organoleptic And Nutritional Quality Of Giant African Snails Flesh Meat Harvested In South Benin

The snail meat is very appreciated by the Beninese population, however, its quality is not under control. This study aims to evaluate the morphological characteristics, technological, organoleptic and nutritional quality of snail meat marketed for consumption. For this purpose, 120 giant African snails ( Archachatina marginata , Archachatina ventricosa and Achatina fulica ) per species were purchased in the markets of Southern Benin and their morphology and the flesh quality were assessed. SAS software was used for statistical analyses. he results that there was a significant difference in the flesh’s yield (p<0.001) with the highest value obtained for Archachatina marginata . Achatina fulica and Archachatina ventricose had the highest shell proportions (p <0.01). Regarding technological quality, a difference (p <0.001) in pH values was observed at one hour and 24 hours after slaughter in the flesh. As for the organoleptic quality, the sensory tenderness was better in the flesh of Achatina fulica. The flesh of Archachatina ventricosa had better juiciness. The flesh of Achatina fulica lost more water during cooking than the flesh of other species. The physicochemical and nutritional quality had little variation between species. From these results, we can conclude that, on the one hand, Archachatina marginata had a good yield and, on the other hand, the flesh of Archachatina ventricosa and Archachatina marginata were more tender than that of Achatina fulica and also Archachatina ventricosa was juicier so the conservation of its flesh would be easy.

Meta-analysis of the relationship between collagen characteristics and meat tenderness

Meta-analysis methods were used to investigate the effects of collagen content, solubility and pyridinoline cross-link content on Warner-Bratzler shear force (WBSF) and sensory tenderness in major meat species. Data was collected from the literature on pork, beef and lamb and analyzed independently for each species. The beef data was categorized into subgroups according to muscle (loin and other muscle) and age (young, <18 months and old, ≥18 months). The results showed that in beef, collagen content and pyridinoline cross-link content were positively correlated with WBSF and negatively with sensory tenderness, while collagen solubility was negatively correlated with WBSF. The correlation coefficients were greater in other beef muscles than loin. Significant correlations between collagen content and tenderness attributes were observed in old beef animals. However, non-significant relationships and large variations were found in pork and lamb. More studies with various muscles and ages are required for an in-depth understanding of the relationship between collagen characteristics and meat tenderness.

Meat Quality of Nellore Young Bulls-Effects of Different Days on Feed and Zilpaterol Hydrochloride Supplementation.

Simple Summaryβ-adrenergic agonists have been widely used to improve meat production efficiency and can be a valuable tool for increasing world meat supply. They act as nutrient repartitioning agents, increasing lean tissue deposition but negatively affecting meat quality, notably reducing palatability. While this metabolic modifier improves the growth performance of Zebu breeds, they can impair even more meat quality in feedlot-finished cattle. This study was developed to evaluate the impact of zilpaterol hydrochloride (ZH) feeding duration and time on feed (90 or 117 days), on meat quality, and on composition properties of meat from young Zebu bulls. Supplementing ZH resulted in a leaner and less tender and juicy meat compared to non-supplemented animals, with few differences in fatty acid composition. Feeding animals for 90 or 117 days had a small impact on meat quality attributes. Feeding ZH to Zebu bulls would require additional tenderization practices to reduce the negative effects of ZH on meat quality.Ninety-six Nellore young bulls were fed (90 or 117 day) diets containing ZH (8.33 mg/kg) for 0, 20, 30, or 40 days to evaluate the effects of days on feed (DOF) and length of zilpaterol hydrochloride (ZH) supplementation on meat quality. At the end of feeding period, animals were slaughtered, and samples of the Longissimus muscle were collected to evaluate the chemical composition, fatty acid profile, color stability, shear force, and sensory profile. DOF did not affect chemical composition, shear force, sensory tenderness, and most of fatty acids; however, animals fed for 90 d had lower redness (p < 0.01), sustained juiciness (p < 0.01), and more flavor (p = 0.03) than those fed for 117 d. The ZH supplementation decreased lipid content and redness (p < 0.01), initial and sustained tenderness (p < 0.01), initial and sustained juiciness (p < 0.01), but increased protein (p < 0.01) and shear force (p < 0.01) as compared to non-supplemented animals. The ZH supplementation increased total PUFA, c9,c12-18:2, and 20:4-n6, and decreased c9-20:1 (p < 0.05). Feeding ZH impairs meat quality attributes of Nellore young bulls, regardless of duration of supplementation, while DOF has a small effect on meat quality properties.

Shotgun proteomics for the preliminary identification of biomarkers of beef sensory tenderness, juiciness and chewiness from plasma and muscle of young Limousin-sired bulls

Label free shotgun proteomics was used to analyse plasma and Longissimus muscle biopsies of Limousin-sired bulls, classified as 5 high-quality and 5 low-quality meat based on sensory texture traits (tenderness, juiciness and chewiness). A total of 31 putative protein biomarkers (16 in plasma and 15 in muscle) differed significantly in abundance between the two quality groups. The proteins were associated with muscle structure, energy metabolism, heat shock proteins, oxidative stress and proteolysis related pathways. Among them, B2M, AHSG, APOA4 and HP-20 (plasma), PFKM, MYH2, PTER, GSTM1 and MYPN (muscle) were good predictors of the three texture quality traits. Further, significant correlations were identified for FETUB, SERPINA7, ASL, TREH, HP, HP-25, AZGP1, APCS and SYT15, which are novel biomarkers from plasma that warrant further evaluation. This study is a significant step forward in elucidating proteomic profiles in bovine bio-fluids and muscle tissue, which may ultimately provide opportunities to processors for early assessment of beef sensory quality.

Dried tomato pomace in rabbit nutrition: effects on carcass characteristics and meat quality

This study was conducted to assess the effect of dried tomato pomace (DTP) feeding on the carcass characteristics and the quality of the meat of growing rabbits. For this purpose, 54 weaned rabbits (40 days old) were divided into three equal groups and fed isoproteic and isoenergetic diets. The first group was the control group (CON), while the other two groups were fed 10 (DTP-10), and 20 (DTP-20) percent DTP for 6 weeks. Eighty-three-day-old rabbits were slaughtered then, the carcass characteristics, mechanical and sensorial tenderness of the meat were determined. Rabbits fed with DTP-10 had the highest final weight at slaughter (2100 g) and the highest hot and cold carcass yields. Whereas, the highest weight of full gastrointestinal tracts and liver were observed within the DTP- 20. Besides, optical property showed that rabbits, which were fed DTP-10, provided the reddest meat. Interestingly, DTP ameliorated textural quality. Indeed, rabbit meat became more tender and appreciated by consumers. In conclusion, the incorporation of the DTP into the rabbit's ration has improved remarkably the rabbit meat quality. Thus, DTP can be fed to rabbits at levels of up to 20% of the diet.

Eating Quality of Beef from Arsi, Borana, and Harar Cattle Breed, Oromia National Regional State, Ethiopia

The objective of this study was to evaluate the eating qualities of Arsi, Borana, and Harar Cattle breeds in Ethiopia. A total of 39 bulls with age categories of - 6, and 7 - 9 years were used for the study. The bulls were purchased from mixed crop-livestock systems (Arsi and Harar) and Ranch (Borana) and slaughtered to evaluate the eating quality. WBSF device was used to evaluate instrumental tenderness while sensory panel testing was used to evaluate sensory tenderness, juiciness and flavor. The color of the meat was evaluated using Hunter Lab Mini Scan EZ while water holding capacity was evaluated using filter papers. A complete randomized design was used for the study. Breed significantly affected (P 0.0001) instrumental tenderness with beef from Harar and Boran bulls were very tender (18.55 ± 5.34, 20.34 ± 4.06N, respectively) while beef from Arsi bulls intermediate in tenderness (40.60 ± 0.51N). Beef from all age group of Harar and Boran breeds were very tender while beef from the Arsi breed was very tender for age 3 years, intermediate for 4 - 6 and tough for age group > 7 years of age. Flavor and juiciness was significantly (P 0.05) affected by breed. Flavor from Harar and Boran breeds were moderately liked while flavor from Arsi was liked slightly. Beef from Boran breed was ranked juicier than beef from Harar and Arsi breed. Borana ( 0.05) in lightness (L*) than Arsi and Harar indicating more quality beef from Borana breed. From the study it was concluded that Arsi bulls older than four years of age produced tougher beef suggesting the use of this breed for beef at early age while beef from Borana and Harar breed can be used to 9 years of age as they produce very tender meat.

Quantitative changes in peptides derived from proteins in beef tenderloin (psoas major muscle) and striploin (longissimus lumborum muscle) during cold storage

Peptides derived from whole proteins in beef tenderloin (M. psoas major, PM) and striploin (M. longissimus lumborum, LL) associated with meat quality and muscle fiber composition were identified and quantified during 21 days of aging. Peptide quantification revealed 40–43 proteins to be significantly degraded during all aging time, and these were mostly sarcoplasmic proteins. Cooking loss of both muscles was not changed by aging (P > 0.05), whereas Warner-Bratzler shear force and meat color were affected by aging. Sensory tenderness increased in PM after 14 days of aging (P < 0.05). PM had a higher type I fiber content, whereas LL had a higher type IIX fiber content (P < 0.05), resulting in differences in proteolysis during all aging periods tested. These findings improve our understanding of different biochemical and physicochemical changes in aged meat according to the muscle type.

Contribution of connective tissue components, muscle fibres and marbling to beef tenderness variability in longissimus thoracis, rectus abdominis, semimembranosus and semitendinosus muscles.

The present study aimed to identify relationships between components of intramuscular connective tissue, proportions of the different fiber types, intramuscular fat and sensory tenderness of beef cooked at 55 °C. Accordingly, four muscles differing in their metabolic and contractile properties, as well as in their collagen content and butcher value, were obtained from dairy and beef cattle of several ages and sexes and were then used to create variability. Correlation analyses and/or stepwise regressions were applied on Z-scores to identify the existing and robust associations. Tenderness scores were further categorized into tender, medium and tough classes using unsupervised learning methods. The findings revealed a muscle-dependant role with respect to tenderness of total and insoluble collagen, cross-links, and type IIB + X and IIA muscle fibers. The longissimus thoracis and semitendinosus muscles that, in the present study, were found to be extreme in their tenderness potential were also very different from each other and from the rectus abdominis (RA) and semimembranosus (SM). RA and SM muscles were very similar regarding their relationship for muscle components and tenderness. A relationship between marbling and tenderness was only present when the results were analysed irrespective of all factors of variation of the experimental model relating to muscle and animal type. The statistical approaches applied in the present study using Z-scores allowed identification of the robust associations between muscle components and sensory beef tenderness and also identified discriminatory variables of beef tenderness classes. © 2020 Society of Chemical Industry.

Comparing Heat Shock Proteins in Angus and Brahman Cattle and their Effect On Tenderness

ObjectivesHeat shock proteins (HSP) are biomarkers of stress and perform chaperoning functions to fold, unfold, and refold proteins after heat stress. Brahman are more heat tolerant than Angus, while Angus beef has been associated with greater palatability than Brahman. The objectives were to determine if HSP content in the longissimus lumborum differs between Angus and Brahman and examine how HSP content relates to the eating quality of beef.Materials and MethodsAngus and Brahman steers (n = 12 per breed) were finished during summer in Florida and harvested at approximately 17 mo of age. Samples of longissimus lumborum were collected at 1 h after exsanguination and were immediately immersed in liquid nitrogen. Samples were then pulverized, diluted in extraction buffer, and homogenized. The protein samples were assayed to assess protein concentration and subsequently diluted to equal concentrations for loading into acrylamide gels. Proteins were separated by gel electrophoresis, and western blotting was used to evaluate content of aβ-crystallin, HSP27, HSP60, HSP70, and HSP90. Target bands were detected and quantified using LI-COR Odyssey and target signal was normalized to total protein stain. Tenderness was evaluated in 14d-aged steaks using Warner-Bratzler shear force (WBSF) and a trained sensory panel. Data were analyzed using one-way ANOVA and Pearson correlations were conducted for content of HSPs and objective and subjective tenderness.ResultsHSP27, HSP60, and HSP70 did not differ between breeds (P &gt; 0.05); however, HSP90 and aβ-crystallin were greater (P = 0.005) in the longissimus lumborum of Angus compared to Brahman. Even though WBSF did not differ (P = 0.29) between breeds, breed affected (P &lt; 0.0001) sensory tenderness. Content of aβ-crystallin was associated with sensory tenderness (r2 = 0.52, P = 0.0098).ConclusionLongissimus dorsi from the Angus were contained more aβ-crystallin and HSP90 than Brahman. Elevated concentrations of both aβ-crystallin and HSP90 could be breed related or may have been influenced by the season they were harvested. While WBSF was not affected by breed, panelists rated Angus steaks as more tender after aging for 14d. Content of aβ-crystallin is associated with tenderness; however further work is necessary to determine if this small HSP affects proteolysis.

Correlation between referred pain distribution and acupoint sensitization in patients with intestinal diseases

To observe the correlation between referred pain distribution and acupoint sensitization in patients with intestinal diseases. In clinical research, 443 patients from 8 hospitals were recruited, including the outpatients and inpatients of Crohn's disease (n=143), ulcerative colitis (n=108), chronic appendicitis (n=87) and other intestinal diseases (n=105). The site with tenderness on the body surface and the morphological changes of local skin were observed and recorded in the patients. Using a sensory tenderness instrument, the pain threshold at the sensitization point was measured in 60 patients with ulcerative colitis. In animal experiment, SD rats were used and divided into a enteritis group (n=8), in which the enteritis model were established, and a control group (n=3), in which no any intervention was given. After the injection of Evans blue (EB) at caudal vein, the blue exudation points on the body surface were observed and the distribution rule was analyzed statistically. The referred pain on the body surface in the patients with intestinal diseases was mainly located in the lower abdomen (93.9%, 416/443), the lumbar region (70.9%, 314/443) and the lower legs (33.0%, 146/443). The diameter of tenderness region was 1.5 to 2.5 cm. Compared with the region without sensitization, the pain threshold of the sensitization point in the patients with ulcerative colitis was reduced significantly (P<0.001). The referred pain on the body surface in the patients with appendicitis was located in the right lower abdomen (97.7%, 85/87), the waist and back (54.0%, 47/87) and the right lower limbs on the medial side (71.3%, 62/87). The tenderness region was 1 to 2 cm in diameter and was irregular in form. After modeling of enteritis in the rats, the EB exudation points were visible from T12 to L2. Intestinal diseases induce referred pain on the body surface where is the same as or adjacent to the location of the spinal segment corresponding to the affected intestinal section. These sensitization regions are related to the locations of acupoints.