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Abstract Loins from fifty-six lambs were allocated to 2 ageing times (6 and 12 days post mortem) and a Frozen treatment (6 days of ageing followed by freeze/thaw process). Instrumental colour parameters, chroma, hue angle, 630/580 and myoglobin isoforms were assessed repeatedly every 5 min during the first 40 min and every 10 min from 40 to 120 min after surface cutting. Colour stability was measured instrumentally during 4 consecutive days of simulated retail display. L * values were lower for Frozen treatment compared to meat aged for 6 and 12 days. Redness increased at a lower rate for Frozen treatment compared to samples aged for 6 days up to the breakpoint and took a longer time to stabilize. Meat subjected to the ageing-freezing/thaw process required a longer time to reach a fully bloomed status than meat aged up to 12 days post mortem. The ageing-freezing/thaw process improved the redness of lamb meat displayed for 4 days in cold storage. [ABSTRACT FROM AUTHOR]

Abstract The bolar blade, striploin and topside cuts from dark cutting (DC) and normal (nDC) beef carcasses were compared in terms of their eating quality, oxidation and colour traits. Carcass grades were assigned so that striploins assessed to have pH > 5.7 were classified DC. Cuts were aged (14 and 28 d) before their shear force, sarcomere length, ultimate pH, particle size, TBARS, drip and cooking losses, and colour stability traits were analysed. DC effects on tenderness traits were not uniform across all cuts. Only TBARS was influenced by grade and ageing period interactions. Colorimetric variation due to grade was more evident in the striploin than the other cuts, although this was independent to ageing or display. Cuts themselves differed and were impacted by ageing and display periods. It was concluded that unlike the topside and striploin, the bolar blade from DC carcasses had comparable quality to nDC and could therefore retain its value if priced independent to the entire carcasses. [ABSTRACT FROM AUTHOR]

Abstract We compared the capacity for the Nix Colour Sensor Pro™ (NIX) and HunterLab MiniScan™ (HUNTER) to detect colour variation using aged (0, 3 and 5 weeks) and then displayed (0, 1, 2 and 3 d) beef M. longissimus lumborum samples (n = 8). NIX L* and hue values were found to be respectively higher and lower than for the HUNTER. No significant interactions between instrument and display or ageing periods were identified for a* – unlike for b* and chroma where NIX measures were observed to be lower than those from the HUNTER. Both instruments identified ageing and display period effects on colorimetric traits. Based on these results, the NIX cannot be considered comparable to the HUNTER when measuring beef colour – albeit captured similar colorimetric trends over display and ageing periods which suggest its independent usefulness to beef colour assessment. [ABSTRACT FROM AUTHOR]

Intramuscular fat (IMF) is an important trait for beef eating quality. The mechanism of how IMF is deposited in beef cattle muscle is not clear at the molecular level. The muscle ( M. longissimus lumborum : LL) of a group of Xiangxi yellow × Angus cattle with high fat levels (HF), was compared to the muscle of a low fat group (LF). The meat quality and the expressed protein patterns were compared. It was shown that LL from the HF animals had a greater fat content (P < 0.05) and lower moisture content (P < 0.05) than LL from LF animals. Forty seven sarcoplasmic proteins were differentially expressed and identified between the two groups. These proteins are involved in 6 molecular functions and 16 biological processes, and affect the Mitogen-activated protein kinases pathway, insulin pathway and c-Jun N-terminal kinases leading to greater IMF deposition. Cattle in the HF group had greater oxidative capacity and lower glycolytic levels suggesting a greater energetic efficiency. [ABSTRACT FROM AUTHOR]

Carcase pH and temperature decline rates influence lamb tenderness; therefore pH decline parameters are beneficial when modelling tenderness. These include pH at temperature 18 °C (pH@Temp18), temperature when pH is 6 (Temp@pH6), and pH at 24 h post-mortem (pH24). This study aimed to establish a relationship between shear force (SF) as a proxy for tenderness and carcase pH decline parameters estimated using both linear and spline estimation models for the m. longissimus lumborum (LL). The study also compared abattoirs regarding their achievement of ideal pH decline, indicative of optimal tenderness. Based on SF measurements of LL and m. semimembranosus collected as part of the Information Nucleus slaughter programme (CRC for Sheep Industry Innovation) this study found significant relationships between tenderness and pH24LL, consistent across the meat cuts and ageing periods examined. Achievement of ideal pH decline was shown not to have significantly differed across abattoirs, although rates of pH decline varied significantly across years within abattoirs. [ABSTRACT FROM AUTHOR]

Meat scientists often use objective, laboratory-based methods to understand the sensorial properties of red meat. These approaches are advantageous because of their reproducibility, low cost, rapid generation of data and technical ease – comparative to large scale consumer sensory panels. To enhance the value of these methods, effort has been applied to identify specific limits or thresholds that correspond to a consumer's acceptance or satisfaction with the quality of a meat product. From the literature, we observe there to be inconsistencies in these thresholds. This could stem from disparate laboratory methods, consumer panel procedures and demographics, the approach to statistical analysis, sample type and representativeness, and more. This paper aimed to review consumer thresholds, proposed in the literature, to provide insight into their validity and transferability to other studies. Investigations were limited to red meat (beef and sheep meat) and to non-spectroscopic methods that have been used to predict consumer acceptance of colour, tenderness, juiciness, flavour and overall liking. [ABSTRACT FROM AUTHOR]

The aim of the current study was to identify whether changes in pH or temperature during the development of rigor mortis influence spectral quality and thus the prediction of intramuscular fat (IMF) in hot lamb carcases. Semimembranosus muscles (SM) of 75 lamb carcases were measured pre-rigor 3 times (Runs 1–3) using a near infrared (NIR) spectrometer with muscle pH and temperature also recorded. Calibration models for the prediction of IMF showed that spectra measurements taken at Run 2 (R 2 = 0.42, RMSE = 0.75) and Run 3 (R 2 = 0.38, RMSE = 0.78) provided more accurate and precise models compared to Run 1 (R 2 = 0.27, RMSE = 0.84). An association between spectral variance, internal and surface temperature of the SM was observed across runs. These results suggest that, as muscle temperature declined during the early post-mortem period there was an improved ability of NIR spectra to predict IMF. [ABSTRACT FROM AUTHOR]

Verification of beef production systems and authentication of origin is becoming increasingly important as consumers base purchase decisions on a greater number of perceived values including the healthiness and environmental impact of products. Previously Raman spectroscopy has been explored as a tool to classify carcases from grass and grain fed cattle. Thus, the aim of the current study was to validate Partial Least Squares Discriminant Analysis (PLS-DA) models created using independent samples from carcases sampled from northern and southern Australian production systems in 2019, 2020 and 2021. Validation of the robustness of discrimination models was undertaken using spectral measures of fat from 585 carcases which were measured in 2022 using a Raman handheld device with a sample excised for fatty acid analysis. PLS-DA models were constructed and then employed to classify samples as either grass or grain fed in a two-class model. Overall, predictions were high with accuracies of up to 95.7% however, variation in the predictive ability was noted with models created for southern cattle yielding an accuracy of 73.2%. While some variation in fatty acids and therefore models can be attributed to differences in genetics, management and diet, the impact of duration of feeding is currently unknown and thus further work is warranted. • Raman spectroscopy is a robust and reliable tool for the classification of carcases based on production system of origin. • Overall validation models had accuracies as high as 95%. • Models from data of Northern Australia gave the most robust predictive ability with a positive predictive value of 96%. [ABSTRACT FROM AUTHOR]

Australian grain-fed and grass-fed beef products garner premium market prices and many beef processors market branded beef supported by production system claims. Given beef cattle nutrition alters the fatty acid composition of subcutaneous fat and grass and grain-fed cattle can be differentiated using Raman spectra of the fat, this study aimed to evaluate if Raman spectroscopy and chemometric modelling can differentiate grass fed cattle from a variety of production systems. To this end, subcutaneous fat from a total of 520 beef carcases with 130 from long term grain-fed, short term grain-fed, grass-fed and supplemented grass-fed beef cattle were measured. Classification of carcases using Partial Least Squares Discriminant Analysis (PLS-DA) demonstrated spectra were able to correctly classify long term grain-fed (96%), short term grain-fed (85%), grass-fed (83%) and supplemented grass-fed (83%) carcases based on the test dataset. Spectral patterns including peaks that characterise fatty acids have been shown to underpin this classification. Overall, this study demonstrates Raman spectroscopy is a useful tool for the authentication and discrimination of beef carcases from different production systems. • Raman Spectroscopy with chemometrics can discriminate beef production systems. • Key regions identified as saturated fatty acids are useful in developing models. • Spectra from long grain fed carcases are correctly predicted at a rate of 96%. • Subcutaneous fat provides information on the cattle's diets enabling discrimination. [ABSTRACT FROM AUTHOR]

In this study, pH, meat color analysis, microbial counts and Raman spectroscopic data were obtained from beef steaks stored at 4 °C for up to 21 days using two different packaging methods: vacuum (VP) and modified atmosphere packaging (MAP). Models using partial least square regression (PLSR), indicated that Raman spectroscopy was able to predict total viable counts (TVC) and lactic acid bacteria (LAB) measured at 21d post mortem (TVC in VP: R 2 cv = 0.99, RMSEP = 0.61; TVC in MAP: R 2 cv = 0.90, RMSEP = 0.38; LAB in VP: R 2 cv = 0.99, RMSEP = 0.54; LAB in MAP: R 2 cv = 0.75, RMSEP = 0.60). The results of this study demonstrate that Raman spectroscopy may have potential for the rapid determination of meat spoilage. • Raman spectroscopy has potential for the rapid determination of meat spoilage. • Preliminary investigation suggests total viable counts at 21 d can be predicted. • Models indicated the potential to predict lactic acid bacteria. [ABSTRACT FROM AUTHOR]

Australian grass and grain-fed beef products attract premium prices at sale and several beef processors market beef underwritten by production system claims. This preliminary investigation assessed the feasibility of using Raman spectroscopy to detect differences in the chemical composition of subcutaneous fat from cattle raised in extensive and intensive production systems. Raman spectra, fatty acid composition, β-carotene composition and objective colour measurements were measured on 150 grass and 150 grain-fed cattle. Spectral differences at peaks including 1069 cm−1, 1127 cm−1, 1301 cm−1 and 1445 cm−1 suggest that Raman spectra is able to detect differences in saturated fatty acids, which were significantly higher in carcases from grain-fed cattle. Differences in spectra at 1658 cm−1 were observed, however further research is required to investigate the cause of this spectral feature. Overall, this study indicated that Raman spectroscopy is a potential tool for the authentication of beef carcases from grass and grain-fed production systems. • Raman Spectroscopy is able to differentiate between grass and grain fed beef production systems using the subcutaneous fat. • Grass and grain-fed beef cattle differ in total SFAs and omega-3 to omega-6 ratio but not in total PUFAs. • Grass-fed cattle exhibit more β-carotene in the fat and has a higher a* value and lower L* value than grain-fed carcases. [ABSTRACT FROM AUTHOR]

The effects of season (summer, autumn, winter and spring) and post-transportation rest on alpaca meat quality were investigated in 160 castrated male alpacas (23 ± 1 month of age) over a 12 month period. Twice per season, animals were randomly allocated to consignment groups of 20, transported 4 h to slaughter and allocated to either of two treatment groups: (1) overnight lairage pre slaughter (Direct) and (2) seven day rest period with access to feed pre slaughter (Rested). At slaughter, blood was collected for the analysis of plasma cortisol and a longissimus core sample obtain pre rigor for glycogen content determination. Alpaca muscle moisture loss increased through summer and spring in the longissimus thoracics. Seasonal differences did not reflect pasture seasonality or muscle glycogen content. Resting alpacas for 7 days pre-slaughter reduced muscle glycogen content and tenderness. Drip loss and purge was greater for rested animals indicating that resting alpacas post transport is not advantageous to alpaca meat quality. [ABSTRACT FROM AUTHOR]

Despite the value of key nutritional components of lamb to human health, a large scale literature review recently highlighted the lack of nutritional information for value added lamb retail cuts which suit modern consumers. Consequently, the nutritional composition including proximate analysis, fatty acid and mineral composition of 5 lamb retail cuts from 25 commercially produced extensively finished lambs was investigated. Overall, this research indicated that there was variation in nutritional components between these cuts, particularly for nutritional traits which are important for human health including zinc, iron, total fat and protein as well as fatty acids including EPA, DHA, total saturated fatty acids and total polyunsaturated fatty acids. However the reasons for these differences are poorly understood. Therefore, further research is required to ensure that nutritional information provided to consumers for these cuts at retail is accurate. • Nutritional composition varied between value added lamb cuts. • Potential to market lamb cuts based on mineral and omega-3 fatty composition. • Based on nutritional guidelines some lamb cuts can be considered good sources of dietary omega-3, iron and zinc. [ABSTRACT FROM AUTHOR]

Many advances have occurred in the field of smart meat packaging, and the potential for these to be used as tools that respond to challenges faced by industry is exciting. Here, we review packaging solutions to several immediate concerns, encompassing dark cutting, purge and yield losses, product traceability and provenance, packaging durability, microbial spoilage and safety, colour stability, environmental impacts, and the preservation of eating quality. Different active and intelligent packaging approaches to each of these were identified and are discussed in terms of their usefulness – to processors, retailers and/or consumers. From this, it became apparent that prior to selecting a packaging solution, industry should first define their criteria for success (e.g. How much purge is too much? What is a reasonable shelf-life to facilitate product turnover? Is the customer willing to pay for this?), and understand that packaging is not the sole solution, but acts as part of a holistic response to these issues. [ABSTRACT FROM AUTHOR]

This study investigated the proteome basis for color stability variations in beef steaks packaged under two modified atmosphere packaging (MAP) methods: HiOx-MAP (80% O 2 /20% CO 2 ) and CO-MAP (0.4% CO/30% CO 2 /69.6% N 2 ) during 15 days of storage. The color stability, pH, and sarcoplasmic proteome analysis of steaks were evaluated on days 0, 5, 10 and 15 of storage. Proteomic results revealed that the differential expression of the sarcoplasmic proteome during storage contributed to the variations in meat color stability between the two MAP methods. Compared with HiOx-MAP steaks, some glycolytic and energy metabolic enzymes important in NADH regeneration and antioxidant processes, antioxidant peroxiredoxins (thioredoxin-dependent peroxide reductase, peroxiredoxin-2, peroxiredoxin-6) and protein DJ-1 were more abundant in CO-MAP steaks. The over-expression of these proteins could induce CO-MAP steaks to maintain high levels of metmyoglobin reducing activity and oxygen consumption rate, resulting in CO-MAP steaks exhibiting better color stability than HiOx-MAP steaks during storage. [ABSTRACT FROM AUTHOR]

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]

Abstract: SmartShape™ is a novel meat processing technology that uses air pressure to compress and elongate whole cold-boned primals and packages them to retain form. A two stage study was conducted. The first stage established the ability of the SmartShape™ treated beef cube roll (m. longissimus lumborum) to retain shape in a commercial setting. Twelve hours chilling time following treatment was found to be adequate for steaks to retain their shape for up to 24h after slicing. Steak shape and size did not change substantially until after cooking, when the steaks looked less formed. In the second stage a survey was conducted of 421 consumers to clarify the response to the shaping of a subset of raw and cooked scotch fillet steaks. There was no difference in preference for shaped or control steaks. A secondary survey found that informed consumers were more amenable to the SmartShape™ scotch fillet steaks presented here, but would not pay a premium for them. [Copyright &y& Elsevier]

Abstract: Exponential decay models have been used to model pH and temperature decline in lamb carcases post mortem. Such models, once fitted to carcase data, can then be used to predict a carcase's pH at a temperature of 18°C and its temperature when the pH equals 6. Unfortunately, these models frequently fail when fitted to limited pH/temperature data, because of either insufficient data or inappropriateness of the exponential decay model. To overcome these problems an alternative though similar modelling approach is proposed. This alternative approach replaces the exponential decay model with a more flexible spline modelling approach for the average trend and includes in the model, as random effects, individual deviations from average trend. Including the individual deviations from average trend as random effects in the model allows information on individual carcases to be shared across carcases. [Copyright &y& Elsevier]

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]

Despite the importance of intramuscular fat (IMF) to eating quality, as yet no methodology has been widely adopted by the whole of industry in Australia to measure it routinely. Thus, a study was conducted to investigate the potential for a Near Infra-Red (NIR) device to predict the IMF content of the loin from spectra collected on the topside which is externally located on a hanging carcase and therefore easily accessible. To this end, NIR spectra were collected from topsides (m. semimembranosus) of 258 lamb carcases over 5 data collections and a sample of muscle was collected from the loin and the topside for IMF determination using a wet chemistry method. Subsequent Partial Least Square (PLS) models suggested the ability to predict the absolute IMF content of loins was poor (R 2 = 0.28, RMSE = 1.26), yet there was a moderate ability to predict the IMF content of the topside (R 2 = 0.56, RMSE = 0.82). Partial Least Square Discrimination Analysis (PLS-DA) models to classify cuts based on the IMF eating quality threshold of 4.5% yielded better predictive outcomes with accuracies of 66.7% and 76.7% for loin and topside respectively. However, further research to assess the relationship between the IMF of the loin and topside and reduce the impact of differences in overall absorbance between data collections will improve predictive outcomes. • Loins were able to be classified on eating quality thresholds using data from the topside early post-mortem. • NIR spectra collected on lamb topside yielded a poor prediction of the intramuscular fat content of loins. • Prediction of the intramuscular fat content of the topside was more accurate with less error. [ABSTRACT FROM AUTHOR]

This study compared carcasses as well as the quality and mineral concentration of meat from lambs extensively grazing perennial wheat with clover (PW + C), serradella (PW + S), lucerne (PW + L), or a mineral salt supplement (PW + Min). A split-plot design was used, wherein 3 crossbred ewe lambs (n = 72 in total) (sub-plots) grazed each of 4 forage types (plots), that were replicated across 6 locations (blocks). The feeding study concluded after 96 d, when all the lambs were slaughtered. The left longissimus lumborum muscles (LL) were collected and wet aged for either 5 or 56 d post-mortem. Lambs grazing PW + Min were found to produce carcasses with lower dressing percentage values to those grazing the other forage types (P = 0.037). The LL of lambs grazing PW + L had the lowest crude protein values (P = 0.015). Forage type by ageing period interactions did not affect meat quality. The 56 d ageing period resulted in higher purge loss (P < 0.001) and TVB-N values (P < 0.001) and a decline in shear force (P < 0.001) compared to the 5 d ageing period. The other carcass and meat quality parameters were not affected by forage type; including hot carcass weight, pH decline parameters, eye muscle area, cooking loss, intramuscular fat, sarcomere length, colour stability, and concentrations of calcium, iron, magnesium, sodium, and zinc in the LL. These findings confirm that perennial cereal production systems, that include legume forages with contrasting protein, energy, and micronutrient profiles, can deliver comparable lamb carcasses and meat quality. [ABSTRACT FROM AUTHOR]

This study aimed to develop an appropriate modified atmosphere packaging (MAP) system for displayed beef steaks following long-term superchilled (−1 °C) storage. After superchilled storage for 0, 2, 8, or 16 weeks, beef loins were fabricated into steaks and displayed with 20%, 50%, or 80% O 2 -MAP under chilled conditions. At each storage point, after display for 0, 3, 7, or 10 days, instrumental color, myoglobin redox forms percentage, lipid oxidation, total viable count (TVC), and total volatile basic nitrogen (TVB-N) were evaluated. Meat color stability decreased, with prolonged storage period and display time. When the storage period was within 8 weeks, under all the above MAP conditions, the display time for the beef steaks was up to 10 days. Considering 80% O 2 -MAP promoted lipid oxidation, 50% and 80% O 2 -MAP were not recommended for displaying steaks for more than 10 and 7 days respectively after 16 weeks of storage. However, 20%, 50%, or 80% O 2 -MAP could maintain 3 days of microbial shelf-life according to TVC and TVB-N results. Additionally, after long-term superchilled storage for 16 weeks, the various O 2 concentrations had minimal impact on microbiota succession during the MAP display period. Furthermore, beef steaks packaged under various MAP systems exhibited similar microbial compositions, with the dominant bacteria alternating between Lactobacillus and Carnobacterium. This study provided practical guidance for improving beef color stability after long-term superchilled storage. [ABSTRACT FROM AUTHOR]

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]

[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]

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]

Abstract: A prototype handheld Raman system was used as a rapid non-invasive optical device to measure raw sheep meat to estimate cooked meat tenderness and cooking loss. Raman measurements were conducted on m. longissimus thoracis et lumborum samples from two sheep flocks from two different origins which had been aged for five days at 3–4°C before deep freezing and further analysis. The Raman data of 140 samples were correlated with shear force and cooking loss data using PLS regression. Both sample origins could be discriminated and separate correlation models yielded better correlations than the joint correlation model. For shear force, R 2 =0.79 and R 2 =0.86 were obtained for the two sites. Results for cooking loss were comparable: separate models yielded R 2 =0.79 and R 2 =0.83 for the two sites. The results show the potential usefulness of Raman spectra which can be recorded during meat processing for the prediction of quality traits such as tenderness and cooking loss. [Copyright &y& Elsevier]

Abstract: Assuming an exponential decay model (EDM) for pH decline as a function of temperature, ideal shortening (i.e. neither hot nor cold shortening) for an individual carcase occurs if and only if that carcase''s model parameters fall within a specific sub-region of three dimensional space. This paper demonstrates that simply fitting EDMs to a sample of carcases and using the proportion of sampled carcases with estimated parameters within the specific sub-region can lead to seriously biassed estimates for the proportion of carcases ideally shortened. This is particularly so if the EDMs are fitted separately to each sampled carcase but also remains the case, to a lesser extent, if the models are fitted jointly using random effects modelling. A preferred estimate is based on the probability that an independently selected carcase has model parameters within the specific region, based on the distribution of the EMD parameters. The distribution of EMD parameters is obtained via the fitted random effects exponential decay model. [Copyright &y& Elsevier]

This study investigated the effect of feeding unsaleable carrots to lambs within a total-mixed ration (TMR) on performance, carcass characteristics, meat quality and sensory parameters. Thirty-six Australian Merino wether lambs were fed a control (barley-based) or carrot-based TMR for 11-weeks. Carrot-fed lambs had 2.7% higher cold dressing percentage (P = 0.03) while consuming less than control lambs. Subcutaneous fat of carrot-fed lambs contained less branch-chained, and more cis- and trans-monounsaturated fatty acids (FA; P ≤ 0.01) compared to control-fed lambs, which tended (P = 0.08) to have higher concentrations of polyunsaturated FA, despite the Longissimus lumborum (LL) muscle being unchanged by diet. Under retail display conditions, L* and hue values were lower (P ≤ 0.04) for 5 d aged LL samples from carrot-fed lambs. No differences were observed in other meat quality and sensory parameters between diets. Therefore, feeding unsaleable carrots at 45% DM in a TMR can improve lamb performance and carcass characteristics, while maintaining meat quality and FA composition. • Unsaleable carrots are a viable alternative feedstuff for lambs. • Carrot-based diets can improve lamb carcass yields. • Carrot-based diets are not detrimental to meat quality. [ABSTRACT FROM AUTHOR]

Meat is a perishable product and during storage, the actions of microorganisms and endogenous enzymes result in chemical compositional changes. Total volatile basic nitrogen (TVB-N) is often used as a biomarker of protein and amine degradation. The broad adoption of TVB-N to interpret meat freshness is somewhat restricted. This is the result of limited or inconsistent knowledge pertaining to the association between TVB-N and other freshness parameters, for beef, sheep/goat meat, pork, chicken and other types of meat, especially when compared to fish. Current meat studies have failed to address the mechanisms between TVB-N generation and production, processing and preservation strategies. Etiology of spoilage and freshness indicators in fresh meat are discussed and various mechanisms contributing to meat spoilage are highlighted. Further, the use and application of TVB-N for understanding the freshness of different meat types has been comprehensively reviewed with the aim of establishing its usefulness as a freshness marker. TVB-N increases with meat storage and is aligned with other biomarkers of spoilage (i.e. function of duration, temperature, packaging, etc.). But these increases are not always consistent. There are different recommendations of TVB-N limits for meat freshness. These are primarily for fish and seafood products and therefore inappropriate for other meat types, are species specific, arbitrary, or have an element of ambiguity (e.g. an intermediary 'stale' classification between fresh and spoilt states). The selection of TVB-N limits can therefore introduce inaccuracy and subjectivity into the appraisal of meat freshness. Several destructive and non-destructive methods have been used to determine TVB-N, however, their capacity is limited to the differential between spoilt and non-spoilt samples through chemometric classification systems based on predefined TVB-N guidelines. Further reference populations and investigations of red meat types are required. • Total volatile basic nitrogen (TVB-N) in fresh meat is reviewed for the first time. • The etiology of meat spoilage is described. • Inconsistent knowledge pertaining to the association between TVB-N and meat freshness. • Standards for TVB-N levels in meat from different species need to be specie-specific. • Comprehensive guidelines to standardise the interpretation of research to extend the shelf-life of meat products is needed. [ABSTRACT FROM AUTHOR]

The current study examined the growth rates, carcase characteristics, meat quality, and consumer sensory evaluation of the longissimus lumborum muscle (striploin) from steers that were supplemented with either canola meal or grain-based pellets. Forty Angus and Hereford × Angus steers received one of these two supplements with ad libitum lucerne hay for 60 d prior to slaughter. Average daily weight gain was not affected by dietary treatment; however, hot standard carcase weight was significantly lower for steers offered canola meal compared with steers on the grain-based pellets. Dietary treatment did not affect the carcase characteristics, meat quality traits, and consumer sensory evaluation, irrespective of ageing periods. Therefore, canola meal can be used as an approved Pasturefed Cattle Assurance System (PCAS) supplement on moderate dry quality forages without negatively affecting carcase and meat quality traits. [ABSTRACT FROM AUTHOR]

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]

[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]

Intramuscular fat (IMF) content is critical in the determination of eating quality. At present the Australian lamb industry has no ability to measure IMF as carcases are not split and processing speeds of up to 15 animals per minute prohibit the use of traditional methods. Consequently, the potential for a hand-held Near- Infrared (NIR) device to predict the IMF content of lamb topside in-situ was investigated. Models demonstrated that there is an ability to predict the IMF content of topside (R 2 = 0.58, RMSEP = 0.85) using NIR spectra collected at 24 h post-mortem and loin (R 2 = 0.50, RMSEP = 0.91). However, the models were limited by the range and distribution of the lamb population measured. Thus, further research is required to determine whether these models can be improved by increasing the range of data in the calibration models and considering alternate methods of analysis which are suitable for skewed populations. • A hand held device was able to predict the intramuscular fat content of lamb topside. • The fat content of the loin was able to be predicted using spectra collected on the topside. • NIR hand held device shows potential for commercial use of grading lamb carcases. [ABSTRACT FROM AUTHOR]

The effect of muscle fibre orientation and measurement interval on lamb meat drip losses was tested using the EZ-DripLoss (EZ) method. Sample cores were removed from 100 semimembranosus (SM) and longissimus lumborum (LL) muscles, sourced from different Merino lamb carcasses. Two cores with either horizontal or vertical fibre orientation, relative to the core diameter, were removed from each SM. One core with vertical fibre orientation was removed from each LL. The drip loss (%) of these cores was then monitored across four 24 h measurement intervals. It was found that fibre orientation did not impact on SM drip losses. Both SM and LL drip losses increased, linear to measurement interval. SM drip loss increased more than LL over the four measurement intervals and consequently, SM drip losses were higher than LL. Longer measurement intervals which are defined in the methods section are recommended when testing lamb meat drip losses using the EZ method. [ABSTRACT FROM AUTHOR]

Despite the research to ensure Australian prime lamb carcases remain a premium meat, there are no objective carcase assessment tools which enable economic incentives to be translated to producers of high meat yielding lambs. Consequently, a probe developed in Iceland, the Icemeat probe, was investigated as a tool for measuring the tissue depth at the Greville (GR) site. To this end, 1087 lambs were measured at two abattoirs over a period of 4 months using the device and a GR knife on every lamb. Agreement was assessed by linear regression and by graphical analysis for systematic patterns of disagreement. Overall, these results highlighted increasing variability of the Icemeat probe measurements with increasing GR tissue depth. Therefore, further developments are required prior to industry adoption. • An Icemeat probe was assessed for its potential to measure tissue depth of lambs over the 12th rib. • For leaner carcases GR tissue depth measures were routinely underestimated using the Icemeat probe. • The variability of the probe measurement increased with increasing GR knife measures. [ABSTRACT FROM AUTHOR]

The effects of tenderstretching (TS; carcase suspension by the pelvic bone) combined with medium voltage electrical stimulation (ES) on alpaca colour and oxidative traits was investigated. Castrated huacya alpacas were processed and treatments applied to the 36 split carcases, in a 2 × 2 factorial arrangement (Achilles hung; AH/TS and ES/non-ES). After 24 h chilling, colour stability analysis and thiobarbituric acid reactive substances evaluation (TBARS) was conducted on samples of longissimus and adductor femoris. An additional 30 cm of longissimus was prepared for TBARS evaluation and sensory assessment using an untrained consumer panel. Electrical stimulation increased lipid oxidation within the longissimus. However, overall oxidation levels were extremely low and as a result ES effects on oxidation were not detected at the consumer level. Therefore, the combined processing treatments did not dramatically impact alpaca meat eating quality or colour stability. Results also indicate that alpaca displays advantageous colour and oxidation traits when compared to other red meats. [ABSTRACT FROM AUTHOR]

This study investigated the effectiveness of visible-near-infrared (VISNIR) spectroscopy at classifying Australian lamb for: a) ultimate pH (pH 24), b) meat tenderness (i.e. shear force at day 5 of ageing, SF5) and c) intramuscular fat (IMF) content at 24 h post-slaughter using a custom-made handheld probe coupled with the ASD Labspec Pro instrument. VISNIR predictive regression models were developed. In the loin muscle (M. longissimus thoracis et lumborum), the models classified the predicted pH 24, SF5 and IMF content at above or below a threshold value with 94%, 98% and 88% accuracy, respectively. The observed difference between the actual and predicted value (i.e. the standard error of cross validation, SECV) for ultimate pH and IMF content are approaching accuracies required to attain highly reliable Meat Standards Australia grading standards. However, further development is required to improve the SECV for SF5. [ABSTRACT FROM AUTHOR]

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]

The aim of this study was to investigate the shelf-life and microbial community dynamics of super-chilled vacuum-packaged beef striploins imported from Australia to China after approximately five weeks of shipping time and an additional 15 weeks of storage at −1 °C ± 0.5 °C. Data analysis using a mixed model (REML) with time as the fixed effect and portion as a random effect, showed that the only beef quality trait that changed during storage was total volatile basic nitrogen (TVBN; P <.05), which reached the threshold of 15 mg/100 g between 15 and 20 weeks (including 5 weeks of transport). The total viable count (TVC) accounted for 78% of the variance in TVBN, when storage time was included in the model. Sensory scores decreased as storage time extended (P <.05), but were still acceptable at 20 weeks. After 9 weeks, Carnobacterium spp. and Lactobacillus spp. dominated alternately and then Lactobacillus became the most prevalent bacteria. An operational taxominc unit based hierarchical cluster analysis using the unweighted pair-group method with arithmetic means was performed and it was shown that the bacterial communities tended to be consistent as storage time extended. Overall indications are that beef which is safe can be imported into China from Australia and aged for extended periods. Unlabelled Image • Shelf-life of beef cuts imported from Australia to China was evaluated based on TVBN. • TVC accounted for 78% of the variance in TVBN during the storage of beef up to 20 weeks. • The sensory scores decreased as time extended, but were still acceptable at 20 weeks. • Carnobacterium spp. and Lactobacillus spp. dominated alternately after 9 weeks. • Lactobacillus became the most prevalent bacteria in the end of the storage. [ABSTRACT FROM AUTHOR]

Abstract The longissimus thoracis et lumborum (LL), and adductor femoris (AF) muscles from 39 castrated, 23 (±1) month old huacaya alpacas were used to determine vitamin E content and the impact on lipid oxidation levels. At 24 h post death the LL and AF muscles were removed and sampled for meat quality analysis and subjected to simulated retail display. Vitamin E content of either muscle had no significant impact on colour stability or oxidation traits during retail display. This is thought to be due to the high levels of vitamin E (>5.4 mg/kg) in both muscles. Lipid oxidation levels were 0.2 mg MDA/kg higher in both muscles post retail display. However, overall differences in TBARS levels detected pre and post display were very low (<1.19 mg MDA/kg) and well below sheep threshold values of >3 mg MDA/kg. The mechanism behind why alpaca meat has such high vitamin E levels compared to other species requires further investigation. [ABSTRACT FROM AUTHOR]

Abstract The ageing of beef is essential to provide a tender product which is deemed acceptable by consumers, with beef processors routinely ageing beef for ~ 14 d at 0–2 °C. The rate of tenderisation is directly affected by temperature, and as such the possibility of decreasing the required ageing time by increasing storage temperature could provide an opportunity to decrease associated costs. To test this, 320 beef M. longissimus lumborum portions were subjected to one of 72temperature-time combinations (TTC) incorporating temperatures of 3, 5 or 7 °C and ageing times of 6, 8, 10 or 12 d, with some temperature changes occurring during ageing. Controls (n = 32) were held at ~ 1 °C for 14 d. The application of TTCs did not affect beef quality, however longer storage at higher temperatures resulted in higher microbial loadings. Therefore, it can be concluded that shorter, cooler TTCs could be implemented to decrease ageing time requirements and maintain beef safety. Highlights • Different temperature-time combinations on eating quality and safety were tested. • Higher temperatures and longer ageing time influenced microbial safety. • Temperature-time combinations did not influence colour or quality. • Temperature-time combinations did not influence consumer satisfaction. [ABSTRACT FROM AUTHOR]

Abstract The effect of superchilled storage (SC, −4 °C) on shelf life and quality characteristics of M. longissimus lumborum from Chinese Yellow cattle compared with traditional chilling (TC, 2 °C) and frozen storage (−18 °C) was studied. The shelf life of beef steaks held at −4 °C extended to 12 weeks based on the total volatile basic nitrogen (TVB-N) value, which was 2.4 times longer than steaks stored at 2 °C. As the storage time increased, SC samples showed a lower increase of the total aerobic count (TAC), pH and thiobarbituric acid reactive substances (TBARS) values compared to TC samples. Further, L ⁎ and a⁎ values of SC samples changed more slowly than that of TC samples. Beef steaks held frozen had a longer shelf life than SC steaks, however, the shear force of frozen steaks remained above 55 N throughout the storage time indicative of toughness. Consequently, SC offers an effective approach for maintaining better shelf life and quality of beef steaks. [ABSTRACT FROM AUTHOR]

Abstract Two extraction methods were applied to measure the thiobarbituric acid reactive substances (TBARS) values of vacuum packaged grass-fed beef steaks that were aged under four temperatures and five different time interval combinations to capture a range in lipid oxidation. The relationships between TBARS values and consumer assessment of flavour liking, flavour intensity and overall liking, were examined. M1 values had a normal distribution (0.02 to 2.55 mg MDA/kg), whereas M2 had a skewed distribution with the majority of the values <1.0 mg MDA/kg and the maximum value being 10.72 mg MDA/kg. No relationship was found between these methods. Interestingly, there were no significant effects of TBARS value on the sensory results, irrespective of the method used. This suggests that untrained consumers cannot detect abnormal flavour development due to high levels of lipid oxidation (TBARS) as indicated by the TBARS test, and are therefore undiscouraged when tasting these beef samples. [ABSTRACT FROM AUTHOR]

Abstract In this study, a medium voltage electrical stimulation (ES) system with three parameter combinations (A: 1A, 1.55 ms pulse width, 27 s; B: 0.55A, 1 ms pulse width, 34 s; C: 0.55A, 2 ms pulse width, 20s) were applied to beef carcases (n = 24; 319 ± 26.4 kg), in the context of a very slow pH decline rate in the abattoir. All the ES combinations significantly accelerated the rate of pH decline (reflected by temp@pH 6.0, i.e. temperature when pH drops to 6.0), resulting in a tenderness improvement even after 14 days ageing compared to the controls. Sarcomere length was not different between treatments and controls, and it was not a contributor to the tenderness improvement, instead, physical disruption revealed by transmission electron microscopic images may have led to the improvement. Retail colour was significantly improved by either combination B or C after 7 days of ageing. Combination B shows the most promise for commercial application, however, verification on more animals is required before commercial adoption. [ABSTRACT FROM AUTHOR]

Abstract Within 24 h post-mortem , loin surfaces of Australian beef carcasses (n = 436) were evaluated using the Nix Pro Color Sensor™ (NIX). The potential for colorimetrics (L*, a*, b*, hue and chroma) to discriminate between dark cutting (DC) and non-dark cutting (nDC) carcasses was compared. For this purpose, a chroma threshold of 30.5 delivered maximum total sensitivity and specificity. The bolar blade, striploin and topside from a selection of DC and nDC carcasses were also removed, aged for 14 d and tested for shear force, drip loss, cooking loss, ultimate pH, colour change over 3 d display (ΔE), and sarcomere length. Association between chroma values and these quality traits were investigated by linear models. The hypothesis of zero slope was rejected (P < 0.05) for pH on striploin and topside, but the models had poor predictive ability (R 2 = 0.23). The NIX was found to be a viable grading tool, with limited capacity to provide additional insights into beef quality. [ABSTRACT FROM AUTHOR]

The effect of combining tenderstretching (TS; carcase suspension by the pelvic bone) with medium voltage electrical stimulation (ES) during processing on the tenderness of alpaca muscles was investigated. Thirty-six split alpaca carcases were randomly allocated to treatments in a 2 × 2 factorial arrangement (Achilles hung/TS and ES/non-ES). Samples were collected from the m. longissimus thoracis (LT), m. adductor femoris (AF), m. semimembranosus (SM), m. semitendinosus (ST) and m. psoas major (TL) at 24 h post slaughter for shear force, sarcomere length, collagen and myofibre (particle size) measurement. Additional samples were taken from the m. longissimus lumborum (LL) for sensory assessment using an untrained consumer panel. Tenderstretching reduced shear force and variability within the alpaca AF, without negatively affecting the TL, while ES significantly improved TL and LT tenderness. Consumers were able to detect ES treated LL, rating ES samples higher for all sensory traits. Combining ES and TS maximizes alpaca carcase tenderness when considered on a multiple muscle basis. [ABSTRACT FROM AUTHOR]