scholarly journals Quantifying production, processing and post-slaughter effects on pork eating quality using random effects meta-regression1

2017 ◽  
Vol 1 (4) ◽  
pp. 412-425 ◽  
Author(s):  
H. A. Channon ◽  
D. N. D'Souza ◽  
F. R. Dunshea

Abstract Random effects meta-regression techniques, analyzed using a restricted maximum likelihood (REML) approach, was used to determine the influence of various factors that may be experienced or imposed on pigs, carcases and pork on pork eating quality attributes and shear force of the M. longissimus dorsi (loin). This was done to inform the development of a pathway based eating quality system for pork. Estimated means of explanatory variables were obtained for those pathway factors where sufficient published studies met the criteria for inclusion in the analysis. Due to a lack of data for interactions between factors investigated, only single factors were included as fixed terms in the REML models. This analysis identified that moisture infusion (P < 0.001), ageing for more than 2 d post-slaughter (P = 0.006) and tenderstretching (P = 0.006) each resulted in significant improvements in tenderness. Cooking loins to an endpoint temperature of ≥ 80°C negatively impacted both tenderness (P = 0.022) and juiciness (P < 0.001) scores compared with 70 to 74°C. It was not possible to develop algorithms to reliably estimate the effects of multiple factors on pork eating quality attributes to a cuts-based level due to limited studies reporting data for treatment interactions.

2009 ◽  
Vol 2009 ◽  
pp. 138-138
Author(s):  
F O Lively ◽  
B W Moss ◽  
T W J Keady ◽  
L Farmer ◽  
N F S Gault ◽  
...  

Mixing of cattle prior to slaughter which results in aggressive activity (Mohan Raj et al 1992) leads to glycogen depletion pre-slaughter and subsequently meat with a higher ultimate pH (pHu). Purchas et al (1990) reported a quadratic relationship between pHu and tenderness with highest shear force values recorded between pHu 5.8 to 6.2. The aim of this study was to determine the effect of fasting and mixing of steers prior to slaughter on the meat eating quality of longissimus dorsi (LD) muscle.


2009 ◽  
Vol 2009 ◽  
pp. 115-115
Author(s):  
B W Moss ◽  
A Gordon

Prediction of eating quality of beef at an early stage post mortem would enable selection of carcases for specific markets. Shackelford (2004) reported the design of near infra red (NIR) equipment suitable for measurement of larger areas of the muscle and also the prediction of 14 day slice shear force values from NIR measurements made at 2 days post slaughter (Shackelford 2005). The aim of the present study was to evaluate the use of equipment of a similar design and manufacture to that used by Shackelford et al (2005), to evaluate repeatability and time of measurement of NIR spectra on the prediction of Warner-Bratzler Shear force values.


2018 ◽  
Vol 98 (2) ◽  
pp. 230-240 ◽  
Author(s):  
Jordan C. Roberts ◽  
Argenis Rodas-González ◽  
Manuel Juárez ◽  
Óscar López-Campos ◽  
Ivy L. Larsen ◽  
...  

The eating quality and shear force of meat from mature beef carcasses graded within the Canadian grading system were compared with youthful carcasses. Eleven muscles were obtained from mature-graded carcasses with >50% ossification (D1, D2, D3, and D4; n = 84) and youthful carcasses with <50% ossification [over 30 mo (OTM); n = 18, and under 30 mo (UTM) of age; n = 18, based on dentition]; muscles were aged 14 d prior to sensory and shear force analysis. Many muscles from mature-graded carcasses were juicier than UTM, however, most were less tender (P < 0.05). Psoas major was tender, particularly in D1 and OTM carcasses where tenderness measures were not significantly different from UTM (P > 0.05). Shear force values from the infraspinatus of D1 and OTM carcasses were not different from UTM. Flavour intensity was higher in several muscles from D1, D2, and D4 carcasses (P < 0.05), whereas flavour intensity was lower in several muscles from D3 (P < 0.05). Changes to eating quality attributes differed among mature grades; therefore, processors could potentially use the information presented here as a guide for utilizing cuts which retain high eating quality and separating those requiring tenderness intervention to reach consumer acceptability.


2017 ◽  
Vol 57 (5) ◽  
pp. 981 ◽  
Author(s):  
Hoa Van Ba ◽  
Cynthia M. Oliveros ◽  
KyoungMi Park ◽  
Dashmaa Dashdorj ◽  
Inho Hwang

Effects of marbling and chilled ageing on technological quality traits, volatile compounds and sensory characteristics of Hanwoo beef were investigated. Three marbling groups of longissimus dorsi muscles (n = 10 each), namely, high marbling (HM), moderate marbling (MM) and slight marbling (SM), classified according to the Korean carcass-grading system, were used. Each longissimus dorsi muscle from each marbling group was divided into two equal portions, vaccum-packaged and then assigned to 1- and 7-day ageing groups. The ageing was conducted in a chilling room at 4°C. Marbling level was significantly correlated with intramuscular fat content, shear force, cooking loss, tenderness and flavour. Particularly, the HM group had a lower shear force value, and higher fat content, lightness, tenderness, flavour and overall-liking scores than did MM and SM groups. Ageing significantly reduced the shear force value and increased tenderness, flavour and overall-liking scores for the HM group. Twenty-four volatile compounds were significantly influenced by marbling and/or ageing. The SM group had the highest concentration of benzaldehyde, while HM group had the highest concentrations of octanal, nonanal and dimethyl sulfide. In conclusion, our results demonstrated that a high marbling positively affected some technological quality traits and eating quality of beef, and ageing for 7 days reduced the shear force and improved eating quality of samples in the HM group, suggesting that the highly marbled beef responds to the ageing at a faster rate.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Umer Seid Geletu ◽  
Munera Ahmednur Usmael ◽  
Yesihak Yusuf Mummed ◽  
Abdulmuen Mohammed Ibrahim

Meat is the most valuable livestock product since it is one of the main sources of protein for human consumption. Meat quality can be evaluated according to the following parameters: pH, amount of lactic acid, volatile fatty acids, bounded water, solubility of proteins, color, and tenderness. The meat composition and physical properties of muscles have been characterized for ensuring improved eating quality. Thus, the purpose of this paper was to review the major chemical compositional and physicochemical properties of meat and, at the same time, its quality attributes and factors that affect quality of meat. A number of structural features of meat as connective tissue, muscle fibers, and tendon that attaches the muscle to the bone are visible in joint meat examined through naked eyes. Water is quantitatively the most important component of meat comprising up to 75% of weight. Meat is also composed of amino acids, fatty acids, vitamins, minerals, and other important ingredients. Quality factors perceived by consumers are related to sensory attributes (e.g., color, tenderness, and flavor), nutritional properties (e.g., calories, vitamins’ content, and fatty acids’ profile), and appearance (e.g., exudation, marbling, and visible amount of fat). However, fresh meat quality can be defined instrumentally including composition, nutrients, color, water-holding capacity, tenderness, functionality, flavors, spoilage, and contamination. Visual inspection based on sensory quality attributes and different chemical methods are used to analyze meat quality. Other methods such as computer vision and imaging spectroscopy, gas chromatographic analysis, near-infrared technology, dual-energy X-ray absorptiometry, and computerized tomography scanning are also used in the meat industry. So, the aim of the present review is to review quality characteristics of cattle meat and its composition constituents.


2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Derico Setyabrata ◽  
Jacob R. Tuell ◽  
Brad Kim

The objective of this study was to determine the effect of different aging/freezing sequences combined with different freezing rates on quality attributes of beef loins (M. longissimus lumborum). Loins from 1 side of 8 beef carcasses (USDA Low Choice grade) were obtained at 2 d postmortem, cut into 10 steaks (2.54 cm), and randomly assigned into 5 treatments, where factorial combinations of 2 aging/freezing sequences (aging first then freezing/thawing [AFT] and freezing first then thawing/aging [FTA]) and 2 freezing rates (fast freezing [FF] and slow freezing [SF]) were used and compared to an aged only (AO) treatment as a control. Samples frozen using the FF condition were found to have a critical freezing time (Tc) of 21.5 min while the SF counterpart had a Tc of 175 min. Histological observation showed more visually enlarged gaps between muscle fibers in the SF samples, regardless of aging/freezing sequence. The SF-FTA samples had a significantly higher purge/ thaw loss followed by FF-FTA, while the loss from FF-AFT, SF-AFT, and AO were not different from each other (P > 0.05), suggesting that freezing rate effect might be more profound when applied in FTA. Cook loss was higher in AO compared to both FTA treatments (P < 0.05); however, it was not different when compared to AFT (P > 0.05). A lower shear force value and higher troponin-T protein degradation were found in both AFT and FTA compared to AO (P < 0.05), which would be attributed to the ice-crystal damage due to freezing. These results suggest that aging/freezing sequence could be an overriding factor in determining major meat quality attributes of frozen/thawed meat over freezing rate. However, fast freezing could negate some quality defects associated with the FTA process.


2011 ◽  
Vol 54 (6) ◽  
pp. 661-675
Author(s):  
N. Mielenz ◽  
K. Thamm ◽  
M. Bulang ◽  
J. Spilke

Abstract. In this paper count data with excess zeros and repeated observations per subject are evaluated. If the number of values observed for the zero event in the trial substantially exceeds the expected number (derived from the Poisson or from the negative binomial distribution), then there is an excess of zeros. Hurdle and zero-inflated models with random effects are available in order to evaluate this type of data. In this paper both model approaches are presented and are used for the evaluation of the number of visits to the feeder per cow per hour. Finally, for the analysis of the target trait a hurdle model with random effects based on a negative binomial distribution was used. This analysis was derived from a detailed comparison of models and was needed because of a simpler computer implementation. For improved interpretation of the results, the levels of the explanatory factors (for example, the classes of lactation) were not averaged in the link scale, but rather in the response scale. The deciding explanatory variables for the pattern of visiting activities in the 24-hour cycle are the milking and cleaning times at hours 4, 7, 12 and 20. The highly significant differences in the visiting frequencies of cows of the first lactation and those of higher lactations were explained by competition for access to the feeder and thus to the feed.


2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 27-28 ◽  
Author(s):  
Robin G Coombs ◽  
C R Richardon

Abstract The focus of this study involved measuring two variables of meat quality: tenderness and cooking loss. Experiments were conducted on a premium cut of meat – the loin. The loin contains the Longissimus muscle, with pieces of the Iliocostalis and Spinalis dorsi muscles. The Longissimus muscle was cored for tenderness. Two sources of loins were evaluated: Akaushi breed, and from a commercial grocery store. Meat used consisted of Akaushi loins from 6 different animals (prime grade) and one select grade loin (control). The protocol involved dividing each loin into 6 (907-1134g) roasts, cooking at 104.40 C (to internal temperature of 73.90 C), measuring by weight the cooking loss of the roasts after a 30-minute resting period, and determining tenderness by Warner-Bratzler Shear Force (WBSF) (after overnight storage in a cooler). Cores were taken at 6 different locations of the roast, over the same regional area for WBSF determinations. The WBSF coring instrument used was provided. Tenderness of each loin was measured in 36 cores (n = 36). In overall tenderness, the control loin ranked third out of the seven loins and had the least amount of cooking loss. No differences were found in tenderness (P > 0.05). However, a difference was found in average cooking loss 181.44g ± 0.03 (control); 254.01g ± 0.03 (Akaushi) (P < 0.05). When observing tenderness consistency, the control loin had a somewhat larger standard deviation (1.38 vs 0.756) than the Akaushi loins.Loins used in this study showed variation in cooking loss, tenderness, and consistency between a commercial grocery store source and the Akaushi beef source. These data indicates that quality attributes of beef loins used in this study may be different in ways not related to grade.


2014 ◽  
Vol 13s4 ◽  
pp. CIN.S13971 ◽  
Author(s):  
Cheng Jia ◽  
Yu Hu ◽  
Yichuan Liu ◽  
Mingyao Li

Background One of the major mechanisms of generating mRNA diversity is alternative splicing, a regulated process that allows for the flexibility of producing functionally different proteins from the same genomic sequences. This process is often altered in cancer cells to produce aberrant proteins that drive the progression of cancer. A better understanding of the misregulation of alternative splicing will shed light on the development of novel targets for pharmacological interventions of cancer. Methods In this study, we evaluated three statistical methods, random effects meta-regression, beta regression, and generalized linear mixed effects model, for the analysis of splicing quantitative trait loci (sQTL) using RNA-Seq data. All the three methods use exon-inclusion levels estimated by the PennSeq algorithm, a statistical method that utilizes paired-end reads and accounts for non-uniform sequencing coverage. Results Using both simulated and real RNA-Seq datasets, we compared these three methods with GLiMMPS, a recently developed method for sQTL analysis. Our results indicate that the most reliable and powerful method was the random effects meta-regression approach, which identified sQTLs at low false discovery rates but higher power when compared to GLiMMPS. Conclusions We have evaluated three statistical methods for the analysis of sQTLs in RNA-Seq. Results from our study will be instructive for researchers in selecting the appropriate statistical methods for sQTL analysis.


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