Pale, Soft, Exudative Research Articles

Application of isoelectric solubilization/precipitation processing to improve gelation properties of protein isolated from pale, soft, exudative (PSE)-like chicken breast meat

Isoelectric solubilization/precipitation (ISP) process has been attempted to improve gelation properties of pale, soft, exudative (PSE)-like chicken breast meat protein. The protein was recovered at pH values of 2.5, 3.0, 3.5, 11.0, 11.5 and 12.0. The results showed that ISP treated PSE-like chicken breast meat with pH 11.0 and pH 3.5 significantly increased (P < 0.05) gel hardness and water retention capacity. Whiteness of cooked sample was obviously enhanced while the extraction carried out at pH 3.5, 11.0, 11.5 and 12.0 (P < 0.05). SDS-PAGE indicated ISP process significantly affected salt extracted protein profile rather than that of total protein. ISP treatment altered the dynamic rheological behavior of PSE-like samples. Since enhanced hardness was induced by ISP, the low elastic (G′) modulus revealed ISP-extracted sample form more rigid gel instead of elastic one. Based on our study, the best gel properties were obtained by solubilizing the PSE-like chicken breast muscle at pH 11. In conclusion, this method may have potential to increase the economic value of PSE-like chicken breast meat by improving the protein gelation properties.

Pre-slaughter sound levels and pre-slaughter handling from loading at the farm till slaughter influence pork quality

This study investigates the relationship between sound levels, pre-slaughter handling during loading and pork quality. Pre-slaughter variables were investigated from loading till slaughter. A total of 3213 pigs were measured 30min post-mortem for pH30LT (M. Longissimus thoracis). First, a sound level model for the risk to develop PSE meat was established. The difference in maximum and mean sound level during loading, mean sound level during lairage and mean sound level prior to stunning remained significant within the model. This indicated that sound levels during loading had a significant added value to former sound models. Moreover, this study completed the global classification checklist (Vermeulen et al., 2015a) by developing a linear mixed model for pH30LT and PSE prevalence, with the difference in maximum and mean sound level measured during loading, the feed withdrawal period and the difference in temperature during loading and lairage. Hence, this study provided new insights over previous research where loading procedures were not included.

Antemortem stress regulates protein acetylation and glycolysis in postmortem muscle

Although exhaustive research has established that preslaughter stress is a major factor contributing to pale, soft, exudative (PSE) meat, questions remain regarding the biochemistry of postmortem glycolysis. In this study, the influence of preslaughter stress on protein acetylation in relationship to glycolysis was studied. The data show that antemortem swimming significantly enhanced glycolysis and the total acetylated proteins in postmortem longissimus dorsi (LD) muscle of mice. Inhibition of protein acetylation by histone acetyltransferase (HAT) inhibitors eliminated stress induced increase in glycolysis. Inversely, antemortem injection of histone deacetylase (HDAC) inhibitors, trichostatin A (TSA) and nicotinamide (NAM), further increased protein acetylation early postmortem and the glycolysis. These data provide new insight into the biochemistry of postmortem glycolysis by showing that protein acetylation regulates glycolysis, which may participate in the regulation of preslaughter stress on glycolysis in postmortem muscle.

Phosphorproteome Changes of Myofibrillar Proteins at Early Post-mortem Time in Relation to Pork Quality As Affected by Season.

The effect of season on phosphorylation of myofibrillar proteins and meat quality of pork longissimus muscles was investigated. Muscle samples were obtained from 40 pork carcasses (10 for each season) at 45 min and 3 and 9 h post-mortem. Myofibrillar proteins were extracted, separated by SDS-PAGE, quantified by phosphor-specific staining, and finally identified by LC-MS/MS. Muscle pH, glycogen, and ATP were measured, and pale, soft, and exudative (PSE) meat was identified by pH value at 45 min post-mortem. A total of 23 bands were detected on SDS-PAGE gels. The phosphorylation levels of bands did not differ between PSE and normal meat. However, the phosphorylation levels of 22 bands were significantly changed by season. Nine of them showed different changes from 45 min to 9 h post-mortem, which were identified to be involved in energy metabolism and sarcomere contraction. Correlation analysis indicated the regulatory progress of these proteins during rigor mortis. These observations contribute to a better understanding of the biochemical processes for the conversion of muscle to meat varying with season.

Quality Characteristics of PSE-Like Turkey Pectoralis major Muscles Generated by High Post-Mortem Temperature in a Local Turkish Slaughterhouse.

The objective of this study was to investigate the effects of high post-mortem temperature application on development of pale, soft, exudative (PSE) turkey meat characteristics in terms of local slaughter conditions. Within this scope, it was targeted to obtain PSE-like muscles benefiting from different post-mortem temperature applications. Immediately after slaughter, turkey Pectoralis major (n=15) muscles were kept at various post-mortem temperatures (0, 10, 20, 30, and 40℃) for 5 h. pH values of 40℃ treatment were lower than four other treatments (p<0.05). L* values, drip loss, cook loss, and thawing loss of 40℃ group were higher than the other groups (p< 0.05). Napole yield of 40℃ treatment indicated that high post-mortem temperature decreases brine uptake. Protein solubility of 40℃ group was lower than 0℃ group (p<0.05). Expressible moisture did not differ between 0 and 40℃ treatments. Hardness, gumminess and chewiness of 40℃ treatment were higher than 0℃ treatment. The results of this research showed that high post-mortem temperature treatment induced development of PSE-like turkey meat, with lower pH, paler color, higher technological and storage losses, and reduced protein solubility and texture.

Effect of transportation and pre-slaughter water shower spray with resting on AMP-activated protein kinase, glycolysis and meat quality of broilers during summer.

The aim of this study was to determine the effects of pre-slaughter transport during summer and subsequent water shower spray on stress, postmortem glycolysis, energy metabolism and adenosine monophosphate-activated protein kinase (AMPK) in Pectoralis major (PM) muscle of broilers. Results indicated that transport during high ambient temperature induced the release of plasma corticosterone, which significantly affected stress conditions. Moreover, we found a lower energy status in the early postmortem period compared to the control group. AMPK was activated in this situation, following by the rapid glycolysis and accumulation of lactic acid, leading to a high incidence of pale, soft, exudative (PSE)-like meat. Water shower spray with resting after transport relieved the stress situation, recovered energy homeostasis and lessened the deterioration of meat quality. As a key molecular target for the control of energy status, AMPK has a similar potential in regulating postmortem muscle glycolysis of broilers as in mammals.

Improving transport container design to reduce broiler chicken PSE (pale, soft, exudative) meat in Brazil.

Throughout the chicken production chain, transport from farm to the commercial abattoir is one of the most critical sources of stress, particularly heat stress. The aim of this work was to describe the performance of a new prototype truck container designed to improve the microenvironment and reduce the incidence of pale, soft and exudative (PSE) meat and dead on arrival (DOA) occurrences. Experiments were carried out for four different conditions: regular and prototype truck, both with and without wetting loaded cages at the farm (for bird thermal stress relief) just before transporting. While there was no difference in the DOA index (P ≥ 0.05), the prototype truck caused a reduction (P < 0.05) in the occurrence of PSE meat by 66.3% and 49.6% with and without wetting, respectively. The results of this experiment clearly revealed a low-cost solution for transporting chickens that yields better animal welfare conditions and improves meat quality.

Use of computer vision system (CVS) for detection of PSE pork meat obtained from m. semimembranosus

The aim of this research was to apply color parameters determined with the computer vision systems (CVS) in detection of PSE (pale, soft, exudative) porcine semimembranosus muscles. Based on pH measurements taken 24 h post mortem, meat were classified into two quality groups: RFN (red, firm, normal, non-exudative) and PSE. The color parameters were evaluated using the CVS and in CIEL*a*b* scale. In order to confirm or deny incidence of PSE the selected characteristics of technological quality of meat were also determined. Using CVS and CIEL*a*b* the considerable differences in color lightness for PSE were observed when compared to normal meat. The obtained correlation and determination coefficients between color parameters characterized by lightness reached low values 0.44 and 19.4%, respectively. Considerable dispersion of results and overlapping ranges of color parameters obtained for selected meat quality groups have proven the possibility of CVS application for m. semimembranosus classification to be limited.

Impacts of genetic selection in meat quality of pigs

Advances in breeding pigs that have occurred in recent years have led to an increase in weight gain, decreased feed conversion and back fat thickness in swine. But this intense selection has caused some negative impacts on the final quality of the meat. The objective of this work was discussing the impact of genetic selection on the meat quality characteristics of pigs. Halothane gene carrier animals have lower meat quality, since this gene is related to the onset of PSE meat (pale, soft, exudative) presenting pale and low water retention capacity, one type of meat is not well accepted in the market because of their visual and organoleptic characteristics. The gene meat acidic pH promotes reduction in final pH meat around 5.4, which causes decrease in yield during the industrial processing and cooked cured products. The type of muscle fiber also affects the quality of meal; modern pigs have a higher proportion of modern glycolytic fibers, so meat lighter and less ability to retain water. The marbling is one of the main features related to tenderness and juiciness, but notes that breeds with high meat yield, have lower intramuscular fat content. Thus genetic selection for increasing the quantity of meat in the carcass led to a decrease in the rate of marbling. We conclude that it is important to have a breeding program aimed not only for the quality of housing, but also meets the requirements for better meat quality.

ABOUT THE QUALITY OF MEAT WITH PSE AND DFD PROPERTIES

Abstract: The use of modern technologies in meat production often leads to the formation of raw meat with uncharacteristic course of autolysis, one raw meat being characterized by a low pH value (less than 5.2), it is pale, flabby and watery (Pale, Soft, Exudative (PSE) with a loose consistency. Meat juice is allocated and meat has a sour smell. Other meat has a high ultimate pH (more than 6.2), it is dark, tough and dry (Dark, Firm, Dry (DFD) with coarse fiber and sticky. One of the quality indices enabling to identify meat into PSE and DFD groups is color. The pH of meat correlates with the loss of meat juice and color. Pork protein with PSE defect is characterized by a small amount of fractions with a high molecular weight and a large proportion of protein fractions with the molecular weight from 100 to 50 kDa. During meat production the technological solution for the rational use of raw meat with deviations in the autolysis process can be modes of heat treatment and the use of food additives. Stress causes a significant impact on the meat quality of slaughtered animals. The appearance of meat with PSE quality is associated with the animal susceptibility and its response to the stressful situation, and the specificity of biochemical processes in pork is caused by the development of a stress syndrome PSS (Porcine Stress Syndrome), the syndrome of poor adaptation. The meat quality is affected by breed, for example, hybrid pigs are superior to pure bred in technological properties and meat productivity. The meat of pigs of large white x Landrace x Duroc refers to NOR meat, which makes it more valuable. Due to the fact that the susceptibility of pigs to stress is inherited as a single recessive gene, the pigs are divided by genotype into two groups: stress sensitive and stress resistant. It has been shown that the activity of antiperoxide enzymes is higher in stress resistant broiler chickens than in stress sensitive ones.

Comparative quality assessment of nor, pse and dfd beef

Comparative quality assessment of meat with NOR, PSE and DFD attributes was given in the paper. Application of NOR, PSE and DFD beef indicators in the industry was substantiated. The basic causes of attributes with the specific autolysis development were analyzed and it was found that these are age peculiarities, improper preparation of animals for slaughter and violation of their feeding and keeping. As a result, meat with deviated development of autolytic processes, including the emergence of NOR, PSE and DFD attributes may be observed. For this purpose, organoleptic quality assessment of the NOR, PSE and DFD meat in different age periods was conducted. It was found that the pigmentation in beef has directly proportional dependence on the age and sex of slaughtered animals and the meat color. The pigmentation in DFD meat was higher compared to NOR meat from bulls aged 18-24 months - by 85.9% (p<0.001); bulls aged 24-36 months - by 86.8% (p<0.001); cows - by 74.8% (p<0.001). Least pigments are contained in PSE beef: from bulls aged 18-24 months - 1.88 mg/cm 3 , bulls aged 24-36 months - 2.09, cows - 2.71 mg/cm 3 , so pale pink color is typical for such meat.

Influence of Cooling on the Glycolysis Rate and Development of PSE (Pale, Soft, Exudative) Meat

The aim of this work was to evaluate pH values fall rate in chicken breast meat under commercial refrigeration processing conditions and the development of PSE (pale, soft, exudative) meat. Broiler breast samples from the Cobb breed, both genders, at 47 days of age (n = 100) were taken from refrigerated carcasses (RS) immersed in water and ice in a tank chilled at 0°C (±2). pH and temperature (T) values were recorded at several periods throughout refrigeration in comparison to samples left at room T as control (CS). The ultimate pH (pHu) value of 5.86 for RS carcasses were only reached at 11°C after 8.35 h post mortem (PM) while, for CS samples, pHu value was 5.94 at 22°C after 4.08 h PM. Thus, under commercial refrigeration conditions, the glycolysis rate was retarded by over 4.0 h PM and the breast meat color was affected. At 24.02 h PM, PSE meat incidence was 30% while for CS, meat remained dark and PSE meat was not detected. Results show retardation in the glycolysis rate and PSE meat development was promoted by the refrigeration treatment when compared with samples stored at processing room temperature.

Evaluación de factores de riesgo de carne pálida, suave y exudativa (PSE) debido a las condiciones presacrificio en cerdos

El objetivo del estudio fue determinar el efecto del manejo presacrificio porcino sobre la incidencia de carne pálida, suave y exudativa (PSE) y describir los factores de riesgo. Se recolectaron un total de 20 variables relacionadas con el transporte y las condiciones presacrificio durante un período de tres meses. Se estudiaron 134 lotes (3.156 cerdos) en una planta de beneficio comercial colombiana. Se usó una regresión logística multivariada para identificar los factores de riesgo previos al sacrificio. La calidad de la carne fue descrita como una variable de respuesta binomial (1: carne normal, 2: condición PSE). La incidencia de carne PSE fue 5,8%. Los resultados indican que el peso, el tiempo de estadía en la planta de beneficio y la presencia de contusiones cutáneas incrementan el riesgo de presentación de la condición PSE (p &lt; 0,05). El tiempo de reposo en planta entre 12,1 y 36 h incrementó de 4,3 hasta 9,9 veces la incidencia de la condición PSE comparado con tiempos de estadía en planta entre 4 y 12 h. Además, el peso de los cerdos es un factor de riesgo que incrementó la incidencia de la condición PSE (p &lt; 0,05). Sin embargo, el tiempo de transporte no estuvo relacionado con la presencia de valores de pH bajos.

Genome-wide detection and characterization of positive selection in Korean Native Black Pig from Jeju Island.

BackgroundIn the 1980s, Korean native black pigs from Jeju Island (Jeju black pigs) served as representative sample of Korean native black pigs, and efforts were made to help the species rebound from the brink of extinction, which occurred as a result of the introduction of Western pig breeds. Geographical separation of Jeju Island from the Korean peninsula has allowed Jeju black pigs not only to acquire unique characteristics but also to retain merits of rare Korean native black pigs.ResultsTo further analyze the Jeju black pig genome, we performed whole-genome re-sequencing (average read depth of 14×) of 8 Jeju black pig and 6 Korean pigs (which live on the Korean peninsula) to compare and identify putative signatures of positive selection in Jeju black pig, the true and pure Korean native black pigs. The candidate genes potentially under positive selection in Jeju black pig support previous reports of high marbling score, rare occurrence of pale, soft, exudative (PSE) meat, but low growth rate and carcass weight compared to Western breeds.ConclusionsSeveral candidate genes potentially under positive selection were involved in fatty acid transport and may have contributed to the unique characteristics of meat quality in JBP. Jeju black pigs can offer a unique opportunity to investigate the true genetic resource of once endangered Korean native black pigs. Further genome-wide analyses of Jeju black pigs on a larger population scale are required in order to define a conservation strategy and improvement of native pig resources.Electronic supplementary materialThe online version of this article (doi:10.1186/s12863-014-0160-1) contains supplementary material, which is available to authorized users.

A comparative study of chemical composition, color, and thermal gelling properties of normal and PSE-like chicken breast meat

The objective of this study was to evaluate the differences between normal and pale, soft, exudative (PSE)-like chicken breast meat in the chemical composition, pH, color, water binding capacity, textural properties, salt-soluble protein (SSP) extraction as well as dynamic rheological properties. Compared with normal meat, PSE-like chicken meat showed similar moisture, fat, and ash content (P > 0.05), but significantly lower protein content (P < 0.05). It had a significantly higher L* and lower pH and SSP extraction (P < 0.05). Heated PSE-like meat batter had lower water-binding capacity, textural characteristics (P < 0.05) and reduced gel elasticity (G′) and viscosity. However, the color variation of PSE-like meat gels was decreased. No significant changes were observed in the SSP electrophoretic patterns by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In conclusion, PSE-like poultry meat changed the chemical composition and impaired protein functionality; however, the difference in color was small when used in further products.

The Quality Evaluation of RFN and PSE Pork Longissimus Lumborum Muscle Considering Its Microstructure

Abstract The aim of this study was to evaluate selected quality attributes of pork longissimus lumborum (LL) muscle characterized by Rfn and PSe occurrence considering its microstructure. The material used in the research was 100 pork meat samples of normal quality (RFN – red, firm, normal, non-exudative) and 100 pork meat samples with PSe defect. The digital images of microstructure of selected meat samples were captured and some quality attributes, including ph level, drip loss, electrical conductivity (ec), water holding capacity (Whc) and ciel*a*b* parameters, were determined. Based on the findings obtained it was concluded that PSE meat (pH24h≤5.5) was characterized by higher degradation of muscle fibre structure when compared with the normal meat (RFN). The differences in the microstructure of PSE and RFN meat influenced the colour, electrical conductivity, drip loss and WHC of the meat. The PSE meat was characterized by a signifi- cantly lighter color and significantly higher electrical conductivity, along with more intense drip loss and worsened water holding capacity in comparison with Rfn meat.

The incidence of pale, soft, and exudative (PSE) turkey meat at a Brazilian commercial plant and the functional properties in its meat product

The objective of this study was to report the incidence of pale, soft, and exudative (PSE) turkey breast meat at a commercial plant in southern Brazil and the consequences on the quality of meat processing. This study was subdivided into 2 experiments: I) incidence of PSE meat and II) effects on meat processing. Experiment I: A total of 2610 breast filets were collected, and pH and color were tested. A value of 53.0 was determined using a Minolta lightness test (L*) as the cutoff value for PSE meat characterization. The incidence of PSE meat was 41.7%. Experiment II: A total of 16 filets in natura, 8 PSE and 8 normal samples, were analyzed for pH, color, and water holding capacity (WHC); they were processed into smoked products and yield, color, pH, texture, and moisture were evaluated. Functional properties were compared between PSE and normal meat samples; a 5.5% lower WHC was identified as the consequence of color abnormality. Finally, these PSE meat samples were processed into smoked meat, and the product was 31.3% harder than processed normal meat. The results showed approximately 5%–10% weight loss in PSE meat, with a risk of serious some economic losses for the poultry industry.

Comparison of protein degradation, protein oxidation, and μ-calpain activation between pale, soft, and exudative and red, firm, and nonexudative pork during postmortem aging.

The objective of this study was to investigate the differences in protein modifications between pale, soft, and exudative (PSE) and red, firm, and nonexudative (RFN) pork during postmortem (PM) aging. Longissimus dorsi (LD) including 8 PSE and 8 RFN muscles were individually removed from 16 carcasses. These 16 LD muscles were vacuum packaged at 24 h after slaughter and stored at 4°C for 1, 3, and 5 d. The centrifugation loss, drip loss, color, protein solubility, protein oxidation, protein degradation including desmin, troponin T, and integrin, and μ-calpain activation were determined. The pH of PSE samples was significantly lower than that of RFN samples at both 1 and 24 h PM (P < 0.05). The L* values of PSE pork were significantly greater than that of RFN pork at different time point during PM storage (P < 0.01). The centrifugation loss of PSE samples at d 1 was extremely greater than samples from RFN pork (P < 0.01). The cumulative drip loss for d 0 to 1, d 0 to 3, and d 0 to 5 in PSE pork were significantly greater than that from RFN pork (P < 0.05). The carbonyl content of myofibrillar proteins was not significantly different between PSE and RFN pork samples (P > 0.05). In addition, PSE pork presented a lower solubility of sarcoplasmic protein, myofibrillar protein, and total protein than RFN pork except the solubility of myofibrillar protein at d 1 (P < 0.05). The intensity of intact desmin and troponin T 2 in PSE pork at d 3 and 5 were significantly greater than that in RFN pork (P < 0.05), whereas no significant difference was detected at d 1. The intensity of intact troponin T 1 in PSE pork at d 5 was greater than that in RFN pork (P < 0.05). However, more degradation products of integrin were detected in PSE pork compared to that of RFN pork at d 1 (P < 0.05). Red, firm, and nonexudative pork presented lower intensity of intact 80 kDa calpain and greater intensity of autolyzed 76 kDa product compared to PSE pork (P < 0.01). The results indicate that the degree of μ-calpain activation, the extent of protein degradation including desmin and integrin, and the level of protein solubility in PSE pork could contribute to its low water holding capacity during PM storage.

Use of High-Intensity Ultrasound to Improve Functional Properties of Batter Suspensions Prepared from PSE-like Chicken Breast Meat

In order to explore novel processing for modifying the functional properties of pale, soft, exudative (PSE)-like chicken breast meat, we investigated the effects of high-intensity ultrasound on the functional and rheological properties, particle size distribution, microstructure, and protein secondary structures of PSE-like meat batter suspension. Normal and PSE-like chicken breast meat batter suspensions (7.5 % meat proteins, w/w) were prepared and treated by ultrasound for either 0, 3, or 6 min (frequency 20 kHz and amplitude 60 %). Ultrasound treatment significantly increased pH, gel strength, and water holding capacity of normal and PSE-like meat gels (P < 0.05). Ultrasound treatment altered the rheological behavior of normal and PSE-like batter samples, which was accompanied with the increase of the elastic (G′) and viscous (G″) modulus. After ultrasound treatment, the microstructure of heated normal and PSE-like batter samples enabled the formation of a compact and more dense gel network. Ultrasound treatment reduced the salt solubility of myosin as indicated by its intensity in SDS-PAGE. However, the particle size of ultrasound-treated normal and PSE-like batter samples was reduced and became more uniform. Moreover, ultrasound decreased the α-helical content and increased the formation β-sheet, β-turns, and unordered contents of normal and PSE-like meat proteins. These results suggest that high-intensity ultrasound may be used to modify the functionality of PSE-like meat with the potential to increase economical benefits for the poultry industry.

Microbiological growth in normal and PSE pork stored under refrigeration

The study was conducted to evaluate the microbiological development in PSE pork compared with normal meat and the effect of season of the year on the rate of proliferation of the same. Longissimus dorsi muscle samples from carcasses classified as PSE slaughter (pH45 &lt;5.8) and normal (pH45 &gt; 5.8) were collected after 24 hours of refrigeration, at the time of deboning, in a commercial slaughterhouse, with service federal inspection, located in the Grande Dourados region (MS). The samples (12 normal and 12 PSE) were collected at two different times of the year (fall and winter) for analysis of total and 45ºC coliforms, mesophylls, psychotropic, pseudomonas, yeasts and molds at 0, 5, 10 and 15 days of storage under refrigeration. Microbial growth behaved similarly between the two types of meat throughout the storage period, except for the count of mesophilic aerobic microorganisms, whose development was superior in PSE meat until the 5th day storage, matching between both types of meat later. Was no effect of season on the count of total coliforms and 45ºC, and their proliferation rate higher in meat from the slaughtered animals the warmer season (autumn).