27 results on '"Hopkins, David L."'
Search Results
2. Effect of Pulsed Electric Field Treatment on the Eating and Keeping Qualities of Cold-Boned Beef Loins: Impact of Initial pH and Fibre Orientation
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Suwandy, Via, Carne, Alan, van de Ven, Remy, Bekhit, Alaa El-Din A., and Hopkins, David L.
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- 2015
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3. Effect of Repeated Pulsed Electric Field Treatment on the Quality of Cold-Boned Beef Loins and Topsides
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Suwandy, Via, Carne, Alan, van de Ven, Remy, Bekhit, Alaa El-Din A., and Hopkins, David L.
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- 2015
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4. Effect of Pulsed Electric Field Treatment on Cold-Boned Muscles of Different Potential Tenderness
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Bekhit, Alaa El-Din A., van de Ven, Remy, Suwandy, Via, Fahri, Fahri, and Hopkins, David L.
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- 2014
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5. Using shear force, sarcomere length, particle size, collagen content, and protein solubility metrics to predict consumer acceptance of aged beef tenderness.
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Holman, Benjamin W. B., Collins, Damian, Kilgannon, Ashleigh K., and Hopkins, David L.
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SHEARING force ,PARTICLES ,COLLAGEN ,SOLUBILITY ,CONNECTIN ,BEEF - Abstract
In this study, the relationship between sensory evaluation and several objective metrics of beef tenderness was tested. Objective metrics included shear force, sarcomere length, collagen content, myofibrillar, and sarcoplasmic protein solubility and particle size analysis. These results were compared to consumer panel scores of tenderness for the same aged beef striploin (longissimus lumborum muscle) samples. There was found to be a significant relationship between sarcomere length, shear force, and particle size with tenderness scores. Collagen content and protein solubilities were not associated to tenderness scores (p > 0.05). Sarcomere length contributions for explaining tenderness variation were overlapped by the contributions of shear force (collinearity). Independent models demonstrated that the lower 95% confidence interval of the fitted regression line exceeded 50% acceptance of tenderness when shear force values <42.6 N and when particle size values <198 μm. We can recommend these as thresholds for consumer acceptance of beef tenderness, although considerations of sample type, analytical methodology, and consumer demographics should be made prior to their adoption. This provision was based on the variation in tenderness scores evident between individual panelists and experimental striploins. [ABSTRACT FROM AUTHOR]
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- 2020
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6. Effect of Carcass Chilling on the Palatability Traits and Safety of Fresh Red Meat.
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Zhang, Yimin, Mao, Yanwei, Li, Ke, Luo, Xin, and Hopkins, David L.
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LAMB (Meat) ,MEAT industry ,MEAT quality ,SPRAYING & dusting in agriculture ,COLOR of meat ,MEAT - Abstract
Chilling procedures have been widely used in livestock abattoirs since the development of refrigeration systems. The major criteria when applying chilling regimes is not only complying with regulations, but economic concerns, and also meat safety and quality assurance requirements. Given recent developments, an updated review is required to guide the industry to choose the best chilling method and to inspire the development of new approaches to chilling. Thus in this paper, the quality and microbial safety of beef, lamb, pork, venison, and bison resulting from different chilling treatments has been reviewed, as well as the underlying mechanism(s) for the different impacts on meat quality traits as a result of different chilling regimes. The effect of fast chilling on the tenderness of beef and lamb is a focus, as some new findings, have recently been reported, while multistep chilling is highlighted as it incorporates the advantages of fast chilling to reduce carcass weight loss, resulting in similar quality improvements as found with slow chilling. It is, suggested, that if spray chilling can be combined with the second phase of multi‐step chilling, it will benefit the meat industry in terms of both meat quality and safety. Future studies should focus on combinations of chilling methods with new technologies, such as medium voltage electrical stimulation, muscle stretching, or ultrasound and so on, to move meat quality and safety to a new level. [ABSTRACT FROM AUTHOR]
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- 2019
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7. Using microwave cooking to evaluate tenderness and its relationship to sensory analysis.
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Silva, Douglas R. G., Haddad, Gabriela B. S., Fontes, Paulo R., Ramos, Alcinéia L. S., Ramos, Eduardo M., Holman, Benjamin W. B., and Hopkins, David L.
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MICROWAVE cooking ,BEEF ,COOKING ,PROTEOLYSIS ,FROZEN meat ,STEAK (Beef) - Abstract
This study evaluated a microwave (Mw) cooking method for determining beef toughness using the Warner–Bratzler slice shear force (WBsSF) protocol. Longissimus thoracis muscles were aged for 1, 10, 19, and 28 days at 4C. They were then either cooked on a clam‐shell grill until reaching an internal temperature of 72C, in a Mw for 100 s at maximum power (Mw100) or for 140 s at 60% of maximum power (Mw60). Cooking loss and shear force (SF) values were higher in Mw samples than in grilled ones. SF assessment by grill and Mw100 were able to discriminate tenderness by aging times in the same way as the sensory panel. The SF measured in a grilled sample had higher repeatability (R = .74) and correlation with sensory scores (r = −.79) than Mw100 (R = .61; r = −.62) and Mw60 (R = .51; r = −.53). Mw100 can be considered as an appropriate alternative for the WBsSF protocol. Practical applications: Tenderness is the most important attribute for consumers. Many studies have evaluated tenderness in meat and different protocols for cooking. This work was intended to optimize and evaluate the use of the microwave as a cooking method for shear force determination, against a standard protocol and establish the correlation to sensory tenderness. [ABSTRACT FROM AUTHOR]
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- 2018
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8. Are shear force methods adequately reported?
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Holman, Benjamin W.B., Fowler, Stephanie M., and Hopkins, David L.
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SHEARING force , *MEAT analysis , *MEAT industry , *MEAT microbiology , *FOOD science periodicals , *FOOD of animal origin - Abstract
This study aimed to determine the detail to which shear force (SF) protocols and methods have been reported in the scientific literature between 2009 and 2015. Articles ( n = 734) published in peer-reviewed animal and food science journals and limited to only those testing the SF of unprocessed and non-fabricated mammal meats were evaluated. It was found that most of these SF articles originated in Europe (35.3%), investigated bovine species (49.0%), measured m. longissimus samples (55.2%), used tenderometers manufactured by Instron (31.2%), and equipped with Warner–Bratzler blades (68.8%). SF samples were also predominantly thawed prior to cooking (37.1%) and cooked sous vide , using a water bath (50.5%). Information pertaining to blade crosshead speed (47.5%), recorded SF resistance (56.7%), muscle fibre orientation when tested (49.2%), sub-section or core dimension (21.8%), end-point temperature (29.3%), and other factors contributing to SF variation were often omitted. This base failure diminishes repeatability and accurate SF interpretation, and must therefore be rectified. [ABSTRACT FROM AUTHOR]
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- 2016
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9. Electrical stimulation and wet ageing effects on the carcass and meat quality of Australian rangeland goats.
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Holman, Benjamin W.B., Toohey, Edwina S., Lamb, Tracy A., and Hopkins, David L.
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Medium voltage electrical stimulation and wet ageing periods effects on the carcasses and meat quality of Australian rangeland goats were investigated. 64 rangeland goats were slaughtered as 2 equal consignments, wherein half were exposed to post-dressing electrical stimulation (300 V, 500 ms pulse width, 45 s) and half were not (control). Carcass and pH decline parameters and glycogen concentration were recorded. At 24 h post-mortem , fresh colour was measured and longissimus lumborum muscles (LL) removed. Within carcass, paired LL were halved and allocated to each of 4 ageing periods (1, 2, 4, or 21 d). There were no significant effects from electric stimulation on LL pH at 18 °C, LL temperature at pH 6, LL pH at 24 h post-mortem , semitendinosus pH at 24 h post-mortem , and LL glycogen concentration. There were no significant interactions between stimulation and ageing period on cooking loss, particle size, purge loss, sarcomere length, shear force, and ultimate pH. Independent to stimulation, shear force, particle size, and cooking values declined as ageing period increased. Purge loss was highest after 21 d of ageing. Colour stability was unaffected by ageing, although all CIE colour coordinates varied across the 74 h total retail display period. There were negative linear relationships found between LL glycogen concentrations and LL temperature at pH 6, ultimate pH, and sarcomere length. These findings suggest there to be little benefit to post-dressing electrical stimulation of rangeland goat carcasses, when applied independent to or in combination with ageing. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Effects and mechanism of sub-freezing storage on water holding capacity and tenderness of beef.
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Li, Jiqiang, Wang, Qiantong, Liang, Rongrong, Mao, Yanwei, Hopkins, David L., Li, Ke, Yang, Xiaoyin, Luo, Xin, Zhu, Lixian, and Zhang, Yimin
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WATER storage , *CYTOSKELETAL proteins , *WATER distribution , *PROTEOLYSIS , *MEAT storage , *BEEF products , *FROZEN foods - Abstract
In order to explore the effect of sub-freezing storage on water holding capacity and tenderness of beef, four treatments were compared in this study: sub-freezing (−7 °C) fast sub-freezing (−38 °C until the core temperature achieved to −7 °C), superchilling (−1 °C) and fast frozen (−38 °C until the core temperature achieved to −18 °C) with the latter two treatments serving as the controls. The differences in muscle fiber structure, water distribution, protein oxidation and cytoskeletal protein degradation were studied. The results demonstrated that compared with other treatments, the fast sub-freezing treatment resulted in less structural damage to the muscle fibers and had better water holding capacity. Both sub-freezing and fast sub-freezing treatments inhibited protein oxidation compared with superchilling, but the former treatment's level of protein oxidation was higher than that in fast sub-freezing treatment during long-term storage (42 weeks). In addition, the structural proteins in the sub-freezing and fast sub-freezing treatments underwent faster degradation during long-term storage and therefore the meat was more tender compared with the fast frozen treatment. The results indicate that the fast sub-freezing treatment can be potentially applied in beef storage. • Factory fast freezing and home refrigerator slow freezing of beef were simulated. • The differences of beef under sub-freezing and other groups were compared. • Beef of the fast sub-freezing group has better water holding capacity. • The reasons for the better tenderness in the fast sub-freezing group were analyzed. • The advantages of fast sub-freezing in beef storage were demonstrated. [ABSTRACT FROM AUTHOR]
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- 2024
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11. LC-MS-based metabolomics reveals metabolite dynamic changes of beef after superchilling early post-mortem.
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Chen, Xue, Mao, Yanwei, Liang, Rongrong, Zhu, Lixian, Yang, Xiaoyin, Hopkins, David L., and Zhang, Yimin
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METABOLOMICS , *BEEF carcasses , *BEEF quality , *PROLINE metabolism , *STATISTICAL correlation , *CASPASES - Abstract
[Display omitted] • Superchilling (SC) caused the earlier activation of μ-calpain and caspase 3. • SC caused an enhancement in the degree of actomyosin dissociation. • Metabolite abundances differed in SC and conventional chilling (CC) samples. • 4-hydroxyproline is a critical metabolite that distinguishes between SC and CC treatments. • The SC affected the arginine and proline metabolism, as well as purine metabolism. To explore the underlying mechanisms by which superchilling (SC, −3 °C within 5 h of slaughter) improves beef tenderness, an untargeted metabolomics strategy was employed. M. Longissimus lumborum (LL) muscles from twelve beef carcasses were assigned to either SC or very fast chilling (VFC, 0 °C within 5 h of slaughter) treatments, with conventional chilling (CC, 0 ∼ 4 °C until 24 h post-mortem) serving as the control (6 per group). Biochemical properties and metabolites were investigated during the early post-mortem period. The results showed that the degradation of μ-calpain and caspase 3 occurred earlier in SC treated sample, which might be attributed to the accelerated accumulation of free Ca2+. The metabolomic profiles of samples from the SC and CC treatments were clearly distinguished based on partial least squares-discriminant analysis (PLS-DA) at each time point. It is noteworthy that more IMP and 4-hydroxyproline were found in the comparison between SC and CC treatments. According to the results of metabolic pathways analysis and the correlation analysis between traits related to tenderness and metabolites with significant differences (SC vs. CC), it can be suggested that the tenderization effect of the SC treatment may be related to the alteration of arginine and proline metabolism, and purine metabolism in the early post-mortem phase. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Investigating the impact of sous vide cooking on the eating quality of spent buffalo (BUBALUS BUBALIS) meat.
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Haq, Ihtesham ul, Asghar, Bilal, Manzoor, Adeel, Ali, Sher, Nauman, Kashif, Ahmad, Sohail, Hopkins, David L., and Nasir, Jamal
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WATER buffalo , *DENATURATION of proteins , *COLOR of meat , *CONNECTIVE tissues , *MYOFIBRILS , *SHEARING force , *HAMSTRING muscle , *ERECTOR spinae muscles - Abstract
This study describes the impact of sous vide cooking at different temperatures and time intervals on the eating quality, specifically tenderness of two muscles, bicep femoris (BF) and semitendinosus (ST) from spent buffalo (Bubalus bubalis). Spent buffalo refers to water buffalo that are no longer considered productive following a sixth lactation cycle. Steaks from each muscle were obtained and cooked at three combinations of time and temperature, namely 55 °C-8H, 65 °C-5H, and 95 °C-45 M, respectively. Warner-Bratzler Shear Force (WBSF), cooking loss, cooking yield, color, water activity (a w), total water content (TWC), total collagen content (TCC), heat soluble collagen (HSC), myofibrillar fragmentation index (MFI), and sensory evaluation were measured. The collagen solubilization results showed that temperature and time interacted (P ≤ 0.05), reducing the toughness of the muscles. The tenderization achieved through sous vide cooking was mainly attributed to the thermal denaturation of proteins at the typically lower temperatures and extended time used, weakening of connective tissue through collagen solubilization, and water retention. More cooking loss (P ≤ 0.05) was observed at high temperature treatment of 95 °C-45 M. Meat color, TWC, MFI, and overall acceptability exhibited differences among treatments (P ≤ 0.05). An extended heat interval at lower temperatures caused initial denaturation of myofibrillar proteins, then solubilization of connective tissue proteins. Cooking treatment 55 °C-8H (P ≤ 0.05) reduced the WBSF in both muscles; however, the ST appeared more tender than BF. [ABSTRACT FROM AUTHOR]
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- 2024
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13. Sous vide cooking improved the physicochemical parameters of hot-boned bovine semimembranosus muscles.
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Xu, Baochen, Zhang, Qingwei, Zhang, Yimin, Yang, Xiaoyin, Mao, Yanwei, Luo, Xin, Hopkins, David L., Niu, Lebao, and Liang, Rongrong
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ERECTOR spinae muscles , *COLOR of meat , *BEEF industry , *BOS , *CONNECTIVE tissues , *COOKING - Abstract
The physicochemical parameters of hot-boned bovine semimembranosus muscles after s ous vide cooking were investigated. Hot-boned or wet-aged steaks were collected, and cooked by different cooking methods, including sous vide (57 °C, 11 h, SV), grilling (at 200 °C to the central temperature of 72 °C, GR) or boiling (100 °C, 2 h, BO). The meat color, tenderness, water-holding capacity, degree of oxidation, myoglobin denaturation and sensory quality traits were determined, as well as the changes in the microstructure. Compared to other cooking methods, SV reduced the degree of oxidation and muscle shortening, and significantly improved the water holding capacity (WHC), tenderness, connective tissue content and overall acceptability for both hot-boned and wet-aged steaks. The oxidation and muscle shortening were reduced in hot-boned SV steaks (P < 0.05), and the water-holding capacity and sensory scores for juiciness, connective tissue content and overall acceptability were increased (P < 0.05) compared to the wet-aged steaks. The combination of hot-boning and SV cooking resulted in an acceptable tenderness, better overall sensory acceptability and higher WHC than other combinations of muscle states and cooking methods. Therefore, it is a good choice to cook hot-boned semimembranosus muscles using SV to improve the eating quality, which can eliminate the need for aging, benefiting the beef industry. [ABSTRACT FROM AUTHOR]
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- 2023
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14. Effects of different protein phosphorylation levels on the tenderness of different ultimate pH beef.
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Li, Jiqiang, Zhao, Yan, Liang, Rongrong, Mao, Yanwei, Zuo, Huixin, Hopkins, David L., Yang, Xiaoyin, Luo, Xin, Zhu, Lixian, and Zhang, Yimin
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STEAK (Beef) , *CALPAIN , *SHEARING force , *PHOSPHORYLATION , *PROTEINS , *TROPONIN - Abstract
[Display omitted] • Beef steaks were divided into three groups according to ultimate pH (pHu): N, I, H. • IpHu and HpHu group showed the highest and lowest shear force. • The earlier activation of caspase 9 contributed on the better tenderness of HpHu beef. • Nine differential phosphorylated peptides were detected to link with pH u and WBSF. • Phosphorylation of glycogen synthase may cause the delay of tenderization of IpHu beef. This study investigated the relationship between tenderness and protein phosphorylation levels of normal ultimate pH (pH u , 5.4–5.8, NpH u), intermediate pH u (5.8–6.2, IpH u) and high pH u (≥6.2, HpH u) Longissimus lumborum from beef. During 21 d of ageing, the HpH u group had the lowest Warner-Bratzler shear force (WBSF) values, while the IpH u group showed the highest and even after 21 days of ageing still had high levels. In the late stage of the 24 h post-mortem period the faster degradation rate of troponin T and earlier activation of caspase 9 in the HpH u group were the key reasons for the lower WBSF compared with the NpH u and IpH u groups. The activity of caspase 3 cannot explain the tenderness differences between IpH u and HpH u groups, since their activities did not show any difference. At 24 h post-mortem , 17 common differential phosphorylated peptides were detected among pH u groups, of which nine were associated with pH u and WBSF. The higher phosphorylation level of glycogen synthase may have caused the delay of meat tenderization in the IpH u group. [ABSTRACT FROM AUTHOR]
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- 2023
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15. The effect of freezing time on the quality of normal and pale, soft and exudative (PSE)-like pork.
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Zequan, Xu, Zirong, Wang, Jiankun, Li, Xin, Ma, Hopkins, David L., Holman, Benjamin W.B., and Bekhit, Alaa El-Din A.
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ERECTOR spinae muscles , *PORK , *BICEPS femoris , *SHEARING force , *MEAT quality , *QUALITY - Abstract
Abstract This study investigated the effects of frozen storage time on the quality and muscle structure in normal and pale, soft and exudative (PSE)-like pork. The meat quality of M. longissimus et lumborum (LL) was studied at 0, 3, 6, 9, 12, 15 and 18 weeks of storage at −18 °C, and M. Biceps femoris (BF) was studied at 0, 3 and 18 weeks of storage at −18 °C. Storage time affected all the measured parameters (pH, thaw loss, TVB-N, shear force and muscle structure). There were no differences between normal and PSE-like meat for thaw loss (%) or TVB-N (mg/100 g) values at all storage times. An initial tenderizing effect in PSE-like samples was observed at weeks 3 and 6 in LL samples, but thereafter samples became tougher during frozen storage and after 3 weeks in the BF. Storage for 6 weeks for PSE-like and 9 weeks for normal pork at −18 °C does not reduce quality. Highlights • The effects of freezing storage time on the quality of normal and PSE pork was studied over 18 weeks. • Freezing time affected the thawing loss, pH value, TVB-N, and shear force of LL and BF muscles. • An initial tenderizing effect in PSE samples as a result of freezing was observed at weeks 3 and 6 in LL samples. • No differences in thawing loss (%) and TVB-N (mg/ 100 g) values between normal and PSE pork at all storage times. • The results suggest a storage time of 6 weeks for PSE and 9 weeks for normal pork at -18°C before major changes in the quality occur. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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16. Effects of chilled-then-frozen storage (up to 52 weeks) on lamb M. longissimus lumborum quality and safety parameters.
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Coombs, Cassius E.O., Holman, Benjamin W.B., Collins, Damian, Friend, Michael A., and Hopkins, David L.
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ERECTOR spinae muscles , *MEAT quality , *FROZEN meat , *COLOR of meat , *MEAT microbiology - Abstract
This study evaluated the effect of chilled followed by frozen storage on lamb quality and safety parameters. Experimental ( n = 360) M. longissimus lumborum (LL) were randomly sampled from the boning room of a commercial Australian abattoir, at 24 h post-mortem, and assigned to five chilled storage periods (0, 2, 4, 6 and 8 weeks) and six subsequent frozen storage periods (0, 4, 8, 12, 24 and 52 weeks). Upon completion of each storage treatment combination, corresponding LL were sub-sectioned and analysed for colour stability (0, 1, 2 and 3 days), shear force, fluid losses (purge, thaw and cooking losses), intramuscular fat content, sarcomere length, water activity and microbial load (lactic acid bacteria, Enterobacteriaceae sp. , Brochothrix thermosphacta , Clostridium perfringens and Escherichia coli ). LL stored chilled for 2–4 weeks prior to freezing presented superior results for shear force, display colour and low levels of spoilage microbes, correlating with good eating quality and safety following more than one year of frozen storage. [ABSTRACT FROM AUTHOR]
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- 2017
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17. Effect of long term chilled (up to 5 weeks) then frozen (up to 12 months) storage at two different sub-zero holding temperatures on beef: 1. Meat quality and microbial loads.
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Holman, Benjamin W.B., Coombs, Cassius E.O., Morris, Stephen, Kerr, Matthew J., and Hopkins, David L.
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BEEF storage , *BEEF microbiology , *BEEF quality , *FROZEN meat , *MEAT industry - Abstract
Beef loins (LL) stored under different chilled-then-frozen storage combinations (up to 5 and 52 weeks, respectively) and two frozen holding temperatures were evaluated for microbial load and meat quality parameters. We found holding temperature effects to be negligible, which suggest − 12 °C could deliver comparable quality LL to − 18 °C across these same storage periods. Meat quality parameters varied significantly, but when compared to existing consumer thresholds these may not be perceptible, colour being the exception which proved unacceptable, earlier into retail display when either chilled and subsequent frozen storage periods were increased. There was insufficient detection of key spoilage microbes to allow for statistical analysis, potentially due to the hygienic and commercially representative LL source, although variation in water activity, glycogen content, pH and other moisture parameters conducive to microbial proliferation were influenced by chilled-then-frozen storage. These outcomes could be applied to defining storage thresholds that assure beef quality within export networks, leveraging market access, and improving product management. [ABSTRACT FROM AUTHOR]
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- 2017
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18. The relationship between shear force, compression, collagen characteristics, desmin degradation and sarcomere length in lamb biceps femoris.
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Starkey, Colin P., Geesink, Geert H., van de Ven, Remy, and Hopkins, David L.
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LAMB (Meat) , *BICEPS femoris , *SHEARING force , *COMPRESSION loads , *COLLAGEN , *SARCOMERES - Abstract
This study aimed to identity the relationships between known variants of tenderness (collagen content (total and soluble), desmin degradation and sarcomere length) and shear force and compression in the biceps femoris aged for 14 days from 112 mixed sex lambs. Desmin degradation was related to compression (P < 0.05) such that as desmin degradation increased compression decreased. Sarcomere length (SL) was related to shear force (P < 0.05), such that as SL increased shear force declined. Shear force was also related to compression (P < 0.05), and soluble collagen (P < 0.05), with male lambs producing higher shear force values than females (4.4 ± 1.72 N: P < 0.05) when adjusted for compression, sarcomere length and soluble collagen. The findings from this experiment indicate that the known variants (soluble collagen, sarcomere length and desmin degradation) are related to shear force and compression in ovine biceps femoris . [ABSTRACT FROM AUTHOR]
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- 2017
- Full Text
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19. The underlying mechanisms of the effect of superchilling on the tenderness of beef Longissimus lumborum.
- Author
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Chen, Xue, Luo, Xin, Zhu, Lixian, Liang, Rongrong, Dong, Pengcheng, Yang, Xiaoyin, Niu, Lebao, Hopkins, David L., Gao, Shujuan, Mao, Yanwei, and Zhang, Yimin
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ERECTOR spinae muscles , *CALPAIN , *SHEARING force , *GLYCOLYSIS , *MONOCARBOXYLATE transporters , *ENERGY metabolism - Abstract
This study investigated the effect of superchilling (−30 °C until the core temperature achieved −3 °C, then stored at −1 °C until 24 h, SC) on the tenderness of hot boned beef M. longissimus lumborum (LL), with very fast chilling (−30 °C until the core temperature achieved 0 °C, then stored at −1 °C until 24 h, VFC) and conventional chilling (0– 4 °C for 24 h, CC) as the controls. The lowest initial shear force values were obtained in SC samples compared to those from the VFC and CC treatments (P < 0.05). Clear freezing damage of muscle fibers and more myofibril fragmentation were found in SC samples compared with the other samples early post-mortem. Moreover, SC samples showed the highest level of inosine 5-monophosphate at 3 h post-mortem (P < 0.05). A reduced glycolysis rate (as evidenced by lactate content) was also found in SC treated samples suggesting little contribution of glycolysis on the tenderization of SC. • Superchilling (SC) can improve beef tenderness. • SC caused greater desmin and troponin-T degradation at 7 and 14 days of ageing. • SC caused obvious freezing damage of muscle fibers and more myofibril fragmentation. • The higher level of IMP in SC treatment may weaken the actin-myosin bridge. • SC did not affect the levels of glycolysis enzymes but reduced the glycolysis rate. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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20. Do sarcomere length, collagen content, pH, intramuscular fat and desmin degradation explain variation in the tenderness of three ovine muscles?
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Starkey, Colin.P., Geesink, Geert.H., Collins, Damian, Hutton Oddy, V., and Hopkins, David L.
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SARCOMERES , *HYDROGEN-ion concentration , *TASTE testing of food , *FAT content of meat , *COLLAGEN - Abstract
The longissimus (n = 118) (LL), semimembranosus (n = 104) (SM) and biceps femoris (n = 134) (BF) muscles were collected from lamb and sheep carcases and aged for 5 days (LL and SM) and 14 days (BF) to study the impact of muscle characteristics on tenderness as assessed by shear force (SF) and sensory evaluation. The impact of gender, animal age, collagen content, sarcomere length (SL), desmin degradation, ultimate pH and intramuscular fat (IMF) on tenderness was examined. The main factors which influenced SF of the LL were IMF, SL and desmin degradation, but for sensory tenderness, IMF, ultimate pH and gender were the main factors. The SF and sensory tenderness of the SM was best predicted by the degree of desmin degradation. For the BF soluble collagen and animal age both influenced SF. Different factors affect tenderness across muscles and not one prediction model applied across all muscles equally well. [ABSTRACT FROM AUTHOR]
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- 2016
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21. Effect of repeated pulsed electric field treatment on the quality of hot-boned beef loins and topsides.
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Bekhit, Alaa El-Din A., Suwandy, Via, Carne, Alan, van de Ven, Remy, and Hopkins, David L.
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ELECTRIC field therapy , *BEEF quality , *ERECTOR spinae muscles , *PROTEOLYSIS , *MYOFIBRILS , *COOKING , *BEEF - Abstract
The effects of repeated (1 ×, 2 ×, 3 ×) pulsed electric field (PEF) treatment (10 kV, 90 Hz, 20 μs) on the quality of beef loins and topsides were evaluated, including the tenderness, purge loss, cooking loss, myofibrillar protein profile and post-mortem proteolysis. Both muscle types were obtained from each of 12 steers and were processed within 6 h. After PEF treatment samples of both muscle types were subjected to 3, 7, 14 and 21 days ageing. The 1 × and 2 × PEF treatments had no effect on the tenderisation of hot-boned beef Musculus longissimus lumborum muscle for all ageing treatment times, while the 3 × treatment reduced the tenderness. The opposite effect was observed in hot-boned beef Musculus semimembranosus muscles where the 3 × treatment produced meat with lowest shear force at 3 days post-treatment time, but this beneficial effect disappeared with longer ageing times. An increase in proteolysis of troponin T was seen to the largest extent with 1 × PEF treatment and decreased with every extra application of treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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22. Effect of energy metabolism and proteolysis on the toughness of intermediate ultimate pH beef.
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Zhao, Yan, Kong, Xiao, Yang, Xiaoyin, Zhu, Lixian, Liang, Rongrong, Luo, Xin, Zhang, Liang, Hopkins, David L., Mao, Yanwei, and Zhang, Yimin
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ENERGY metabolism , *HEAT shock proteins , *GUANOSINE triphosphate , *ADENOSINE triphosphate , *ENTHALPY , *PROTEOLYSIS - Abstract
The objective of this study was to identify the tenderness and energy metabolism attributes in normal ultimate pH (pH u , 5.4–5.8, NpH u), intermediate pH u (5.8–6.2, IpH u) and high pH u (> 6.2, HpH u) Longissimus lumborum from beef. During 21 days of aging, the IpH u group exhibited a higher Warner-Bratzler shear force, lower activity of μ-calpain, and a higher content of heat shock protein 27 and greater protein oxidation. Metabolomics analysis revealed that 24 differential metabolites were detected during the first 24 h postmortem between pH groups, and these were mainly the products of glycolysis, the tricarboxylic acid (TCA) cycle and oxidative phosphorylation. The relatively higher adenosine triphosphate content in the IpH u group could delay tenderization by being used as key substrate for protein phosphorylation. In addition, the relationship between guanosine triphosphate, diphosphate and monophosphate, and beef tenderness was worthy to be verified in the future study. [ABSTRACT FROM AUTHOR]
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- 2022
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23. Explaining the variation in lamb longissimus shear force across and within ageing periods using protein degradation, sarcomere length and collagen characteristics.
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Starkey, Colin P., Geesink, Geert H., Oddy, V. Hutton, and Hopkins, David L.
- Subjects
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LAMB (Meat) quality , *ERECTOR spinae muscles , *AGE , *ANIMALS , *PROTEINS , *COLLAGEN , *PROTEOLYSIS - Abstract
Meat tenderness is known to be affected by sarcomere length (SL), proteolysis and collagen content (CC). Sixty lambs were slaughtered and the Longissimus muscle was sampled. Samples for shear force (SF), SL, proteolysis indicators (desmin degradation, particle size: PS) and CC were taken after the allotted ageing periods (1, 7, and 14 days). PS explained a large part of the variation in shear force (approximately 34%) when modelled across ageing periods. Other factors (CC, SL) combined with proteolysis indicators (PS, desmin degradation) explained just under 40% of the variation in shear force. Within ageing periods SL explained a small, but significant, part of the variation in shear force after 14 days of ageing (8%) and at day 1 of ageing desmin degradation explained 17% of the variation in shear force. Methods to improve the tenderness of lamb longissimus muscle should focus on increasing the extent of post-mortem proteolysis, when processing conditions are sufficient to prevent muscle fibre shortening. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
24. SmartStretch™ technology VI. The impact of SmartStretch™ technology on the meat quality of hot-boned beef striploin (m. longissimus lumborum)
- Author
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Taylor, Johanne, Toohey, Edwina S., van de Ven, Remy, and Hopkins, David L.
- Subjects
- *
BEEF quality , *STRETCH (Physiology) , *STEAK (Beef) , *MEAT analysis , *COOKING , *BEEF , *MEAT science - Abstract
Abstract: The impact of SmartStretch™ technology and ageing (0 or 14days ageing) on the meat quality traits of m. longissimus lumborum hot-boned from adult cull cattle was assessed. Tenderness, as reflected in reduced shear force measurement, was significantly (P <0.05) improved in 0day aged stretched samples over the non stretched samples. After 14days ageing there was no longer any difference in the tenderness between stretched and non stretched samples and the aged meat was significantly tenderer than either the SmartStretch™ treated or non stretched meat aged for 0days. Sarcomere length was unchanged by stretching. Presentation traits such as purge loss and fresh colour were unaffected by the stretch treatment, whilst cooking loss was significantly (P <0.05) increased by stretching and ageing for 14days. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
25. SmartStretch™ technology. IV. The impact on the meat quality of hot-boned beef rostbiff (m. gluteus medius)
- Author
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Taylor, Johanne, Toohey, Edwina S., van de Ven, Remy, and Hopkins, David L.
- Subjects
- *
MEAT quality , *GLUTEUS medius , *BEEF , *FOOD chemistry , *AGE of cattle , *MEAT , *COOKING - Abstract
Abstract: The impacts on traits of the m. gluteus medius hot-boned from young cattle were assessed after stretching (SmartStretch™) and ageing (0 or 8days ageing). Tenderness, as reflected in reduced shear force measurement, was significantly (P <0.05) improved in 0day aged stretched samples over the un-stretched control. After 8days ageing there was no longer a difference in the tenderness between stretch treatments. Meat aged for 8days was significantly more tender than 0day aged meat irrespective of treatment. Sarcomere length was significantly (P <0.05) increased by stretching. There was a significant (P <0.05) negative relationship between sarcomere length and shear force. Presentation traits, such as purge loss and fresh colour, were unaffected by the stretch treatment, while cooking loss was significantly (P <0.05) reduced by stretching in the 0day aged samples. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
26. Water distribution and mobility in meat during the conversion of muscle to meat and ageing and the impacts on fresh meat quality attributes — A review
- Author
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Pearce, Kelly L., Rosenvold, Katja, Andersen, Henrik J., and Hopkins, David L.
- Subjects
- *
MEAT quality , *MUSCLES , *WATER , *NUCLEAR magnetic resonance , *PROTEINS , *MEAT preservation - Abstract
Abstract: This paper reviews current knowledge on the distribution and mobility of water in muscle (myowater) ante- and post mortem and factors affecting these in relation to fresh meat quality parameters; water-holding capacity (WHC), tenderness and juiciness. NMR transverse relaxometry (T2) using bench-top Low-Field Nuclear Magnetic Resonance (LF-NMR) has characterised myowater distribution and mobility as well as structural features in meat which directly affect WHC. The current literature demonstrates that WHC is correlated to the water located outside the myofibrillar network (extra-myofibrillar). This review identifies the critical stages which affect the translocation of water into the extra-myofibrillar space and thus the potential for decreased WHC during proteolysis (the conversion of muscle to meat). This review discusses how the intrinsic properties of the water held within the meat could contribute to juiciness and tenderness. Tenderness has been shown to correlate to T2, however breed and species differences made it difficult to draw firm conclusions. Further understanding of the inherent water properties of fresh meat and the factors affecting water distribution and mobility using NMR technologies will increase the understanding of WHC and tenderisation of fresh meat. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
- View/download PDF
27. Is meat from cull cows tougher?
- Author
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Alvarenga, Tharcilla I.R.C., Palendeng, Mario, Thennadil, Suresh, McGilchrist, Peter, Cafe, Linda M., Almeida, Amelia K., and Hopkins, David L.
- Subjects
- *
ERECTOR spinae muscles , *COWS , *ABERDEEN-Angus cattle , *SHEARING force , *AGE , *CONNECTIVE tissues , *MEAT quality , *CATTLE carcasses - Abstract
Meat from cull cows is traditionally sold in Australia for mincemeat, but this study examined whether there is potential to add value by identifying meat of higher quality from older cattle. Dentition and ossification score were recorded for 173 Angus cattle of known age, ranging from 26 months to 12.6 years. Longissimus and semitendinosus muscles were sampled to assess the effect of chronological age on shear force and connective tissue. Age explained variation in shear force of the semitendinosus better than in the longissimus muscle, but had little effect on shear force values per se. At 2 days postmortem, 18% of the longissimus muscles were classified as tender reaching 65% as ageing extended to 14 days. Soluble collagen was a better predictor of age than total collagen. This study shows that the current practice of routinely selling meat from culled cows as mincemeat overlooks a valuable opportunity to grade and sell a significant proportion at higher price as prime cuts. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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