scholarly journals Impact of post mortem aging of pork on changes in the isoelectric point of the proteins and tenderness

2016 ◽  
Vol 72 (7) ◽  
pp. 458-462
Author(s):  
Ewa Iwańska ◽  
Beata Mikołajczak ◽  
Bożena Grześ ◽  
Edward Pospiech
Keyword(s):  
Isoelectric Point ◽  
Ph Value ◽  
Troponin T ◽  
Degradation Products ◽  
Electrophoretic Analysis ◽  
Meat Tenderness ◽  
Post Mortem ◽  
Longissimus Lumborum ◽  
Meat Tenderization ◽  
Ph Range

The aim of the study was to evaluate the post mortem proteolysis of centrifugal drip protein derived from pork. The varied course of the process of meat tenderization in muscles using the isoelectric focusing (IEF) technique was observed. The experimental material was the longissimus lumborum et thoracis muscle excised from 24 pigs of known origin, breeding and rearing conditions. Meat of normal quality (RFN) was examined in this study. On the basis of shear force values, the experimental muscles were divided into 4 groups of different courses of tenderization: A – meat remaining tough during the entire 6-day period of post-slaughter changes; B – meat characterized by a typical tenderization process, i.e. tough 48 h after slaughter and tender after 6 days of storage; C – tender or relatively tender meat on both dates of examination; D – meat which was the toughest 48 hours after slaughter and the most tender 144 hours after slaughter. Proteins for electrophoretic analysis on the agarose gel of the centrifugal drip fraction were submitted after 48 h and 144 h post mortem. The separation of the proteins was performed in a horizontal layout, using an FBE-3000 apparatus and an ECPS power pack (Pharmacia). On every path of the proteins separation, four ranges of pH value were evaluated, namely: 4.0 ÷ 6.0 pI, 6.1 ÷ 7.2 pI, 7.3 ÷ 7.7 pI and > 7.7 pI. Meat tenderness on the second day after slaughter was influenced by proteins, in which their pI was in the range of 6.1÷ 7.2 and 4.0 ÷ 6.0. From the evaluation which was carried out in the immunoblotting analysis of proteins using troponin T (9D) antibodies it was demonstrated that 48 h after slaughtering the most intense reactions were observed in the range of pI of 5.5 ÷ 5.9, which is the pH range corresponding to the isoelectric point of troponin T. However, after 144 h post mortem the most intense reaction was demonstrated in the range of pI of 6.1÷ 7.7. This indicates the breakdown of troponin T and an increase of the number of degradation products of this protein occurring while the meat tenderization process progresses. The degradation products of troponin T identified by IEF can be an indicator of meat tenderization.

Changes in tenderness and cathepsins activity during post mortem ageing of yak meat

2013 ◽  
Vol 93 (3) ◽  
pp. 321-328 ◽  
Author(s):  
Jia-Chun Tian ◽  
Ling Han ◽  
Qun-Li Yu ◽  
Xi-Xiong Shi ◽  
Wen-Ting Wang
Keyword(s):  
Shear Force ◽  
Profile Analysis ◽  
Texture Profile Analysis ◽  
Water Holding Capacity ◽  
Meat Tenderness ◽  
Post Mortem ◽  
Texture Profile ◽  
Longissimus Dorsi Muscle ◽  
Meat Tenderization ◽  
Water Holding

Tian, J.-C., Han, L., Yu, Q.-L., Shi, X.-X. and Wang, W.-T. 2013. Changes in tenderness and cathepsins activity during post mortem ageing of yak meat. Can. J. Anim. Sci. 93: 321–328. Very little research has been conducted on yak meat tenderization. In this study we investigated the changes in physical characteristics (e.g., pH, water-holding capacity, texture profile analysis, shear force) and cathepsins L, B and H activities in the tenderization process. These traits were quantified in longissimus dorsi muscle from 10 yaks during 192 h post mortem. Samples were aged at 4°C for 0, 12, 24, 36, 48, 72, 120, 168 and 192 h. pH decreased (P<0.05) from 6.84 to 5.54 in the first 72 h and did not change significantly during the next 120 h. Water-holding capacity showed an overall decreasing trend (P<0.05). Shear force decreased? (P<0.05) and myofibrillar fragmentation index increased? (P<0.05), and it was concluded that ageing can improve yak meat tenderness. Our results on texture profile analysis showed a decrease in hardness (P<0.05), springiness (P<0.05) and chewiness (P<0.05), reflected in a progressive softening during ageing (P<0.05). Cathepsins L, B and H activity showed an increased trend (P<0.05). In conclusion, our results show potential roles for cathepsins L, B and H in the tenderization process. This study provides further insights into the tenderization process of yak meat, which may ultimately be used for the advantageous manipulation of the process.

scholarly journals Effects of Farm Management Practices and Transport Time on Post-Mortem Changes of Longissimus lumborum Muscle Proteins in Suckling Goat Kids

Foods ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 934
Author(s):  
Tomás Francisco Martínez ◽  
María Jesús Alcalde ◽  
María Isabel Sáez ◽  
María Dolores Suárez
Keyword(s):  
Management Practices ◽  
Troponin T ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Farm Management ◽  
Post Mortem ◽  
Muscle Proteins ◽  
Transport Time ◽  
Longissimus Lumborum ◽  
On Farm

The combined effect of farm management practices, transport time, and ageing time on the electrophoretic changes of sarcoplasmic (SPP) and myofibrillar (MFP) protein fractions of goat kids was studied. A total of 64 suckling goat kids were withdrawn from two farms with “high” (GW) and “low” (DW) welfare-friendly management practices, and they were transported for 2 or 6 h immediately before slaughtering. Longissimus lumborum samples were obtained at 3, 8, and 21 days post-mortem, and muscle proteins were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis SDS-PAGE. Both protein extracts displayed significant changes attributable to meat maturation. Managing conditions of kids in DW farms increased the post-mortem susceptibility of muscle proteins. Some MFP of Longissimus lumborum muscle, such as troponin T, as well as 26–30 and 35–37 kDa fractions were influenced significantly by deficient on-farm management, and therefore, these protein fragments might be considered as indicators of low-welfare on-farm management in goat kids.

scholarly journals Influence of the isoelectric point of gelatin on its adsorption on nanosilica surface

2021 ◽  
Vol 12 (3) ◽  
pp. 175-183
Author(s):  
E. P. Voronin ◽  
◽  
L. P. Golovkova ◽  
L. V. Nosach ◽  
S. L. Los ◽  
...  
Keyword(s):  
Isoelectric Point ◽  
Ph Value ◽  
Single Point ◽  
Adsorption Activity ◽  
Maximum Value ◽  
Three Samples ◽  
Ph Range ◽  
Combined Drugs ◽  
Adsorption Curve

The joint efforts of chemists, physicians and technologists conducting researches to create new medical sorbents and combined drugs based on nanosilica, which have not only a detoxifying effect, but also antibacterial, wound healing, hemostatic and other important properties. One of the stages of such a research is developing regulatory documentation. To control the quality of the sorbent, the method of point measurements is most often used, according to it, the amount of adsorption of the marker substance at the single point of the adsorption curve is determined. The suitability of sorbents based on nanosilicа for using is determined by the value of the adsorption capacity concerning to medical gelatin. No other requirements for the process of test adsorption of gelatin by the sorbent are given. although it is known that the adsorption of proteins depends on the pH of the solution. Its maximum value is reached at a pH value corresponding to the isoelectric point (pI) of the protein. Each protein can be characterized by its own isoelectric point. Domestic and foreign standards give only the value of “pH of aqueous solutions” of gelatin and do not contain the indicator “isoelectric point”. The aim of the work is to study the influence of the isoelectric point of gelatin on its adsorption on nanosilica surface at different pH to appreciate the suitability of conditions for determining the adsorption activity of medical sorbents based on nanosilica. The adsorption of three samples of gelatin was examined in the work: A – edible gelatin (pI = 4.3–4.8); B – that from the catalog “Merck” (pI = 4.3–4.8) and C – that from the catalog “Fluka” (pI = 7.5–7.7) on nanosilica surface in the pH range from 3 to 8. It has been shown that for samples A and B the dependence has a maximum at pH ~ 4.5–5; and for sample C, the adsorption increases monotonically with increasing pH. It was noted that at pH ~ 5 the adsorption values for all gelatin samples were approximately equal. The adsorption activity of nanosilica concerning to proteins determined from the isotherms and the method of point measurements is compared. It has been found that the adsorption value of gelatin A onto the nanosilica at Cinitial = 700 mg/100 ml is equal to the Aave value determined by the Langmuir isotherms. This fact verifies the applicability of the method of point measurements for nanosilica/gelatin system to characterize the pharmacological activity of nanosilica based sorbents.

scholarly journals PSIII-1 A preliminary study to investigate the contribution of different tenderness factors to beef loin, tri-tip and heel tenderness

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 233-234
Author(s):  
Colin Chun ◽  
Wanjun Wu ◽  
Amelia Welter ◽  
Travis O'Quinn ◽  
Geraldine Magnin ◽  
...  
Keyword(s):  
Muscle Tissue ◽  
Lipid Content ◽  
Crosslink Density ◽  
Troponin T ◽  
Collagen Content ◽  
Aging Period ◽  
Relative Contribution ◽  
Beef Carcasses ◽  
Trained Panel ◽  
Longissimus Lumborum

Abstract The objective of this study was to identify the relative contribution of tenderness factors for 3 beef muscles with similar tenderness ratings. Longissimus lumborum (loin), tensor fascia latae (tri-tip) and gastrocnemius (heel) were collected from 10 USDA choice beef carcasses, fabricated into steaks and assigned to a 5 or 21 d aging period (n=60). Heel had the greatest relative troponin-T degradation %, followed by tri-tip and loin (68.10, 53.42 and 35.01 % respectively; P&lt; 0.01). Tri-tip had the longest sarcomere, followed by heel and loin (3.01, 2.59 and 1.71 µm, respectively; P &lt; 0.01), and heel increased in sarcomere length from 5 to 21 d of postmortem storage (2.49 vs 2.70 µm; P&lt; 0.05). As expected, heel had the greatest collagen content, followed by tri-tip and loin (6.06, 3.98 and 2.76 mg/g of muscle tissue, respectively; P&lt; 0.01), and collagen content decreased for all cuts from 5 to 21 d of postmortem storage (4.64 vs 3.90 mg/g muscle tissue; P&lt; 0.05). Out of the 3 cuts, heel had the highest collagen crosslink density (0.20 mol/mol collagen; P&lt; 0.05), while loin and tri-tip did not differ (0.13 and 0.15 mol/mol collagen, respectively; P &gt;0.05). Collagen crosslink density increased for all cuts from 5 to 21 d of postmortem storage (0.14 vs 0.20; P&lt; 0.01). Heel had lower lipid content than the others (2.68 %; P&lt; 0.01), while tri-tip and loin did not differ in lipid content (8.24 vs. 6.99 %; P &gt;0.05). Loin was ranked by the trained panel to have the highest overall tenderness, while tri-tip and heel did not differ in overall tenderness (P &gt;0.05). The overall tenderness value for heel was positively correlated with troponin-T degradation (P&lt; 0.01). On the other hand, overall tenderness value for loin was negatively correlated with lipid content (P&lt; 0.05), and overall tenderness value for tri-tip was negatively correlated with collagen content (P&lt; 0.05). These results indicated that each beef cut had a unique profile of tenderness contributors.

Formulation and Stability Test of Lip Cream Preparation of Kenop Flower Ethanol Extract (Gomphrena globosa L.)

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Mevi Irianti Tonapa ◽  
Rani Dewi Pratiwi ◽  
Elsye Gunawan
Keyword(s):  
Ph Value ◽  
Ethanol Extract ◽  
Stability Test ◽  
Gomphrena Globosa ◽  
Homogeneous Composition ◽  
Semi Solid ◽  
The Stability ◽  
Ph Range ◽  
Average Dispersion ◽  
Brown Color

Kenop Flower (Gomphrena globosa L.) is used in the manufacture of lip cream because contains betacyanin pigments that function as color pigments. This study aims to determine the physical quality and stability of the lip cream preparation of the ethanol extract of kenop flower (Gomphrena globosa L.). This research was conducted experimentally, including the manufacture of lip cream formulations with ethanol extract of kenop flower (Gomphrena globosa L.) with a concentration of 10%. The results of the physical examination test for lip cream preparations for all preparations have a distinctive vanilla aroma with a semi-solid texture, F0 has ivory white color and F1-F3 has a brown color. The preparations had a homogeneous composition, average pH 6-7, had good greasing power, 5.0-5.8 average dispersion and 60.33-66.67 seconds average adhesion. The stability test carried out on day 28 found that all preparations were stable, had a distinctive vanilla aroma with a semi-solid texture, F0 had ivory white color and F1-F3 had a brown color. The preparation has a homogeneous composition; the average pH is 6-7. Where the lip cream formulas F1 and F3 decreased the pH value on the 28th day from 7 to 6 but tended to be stable and in the pH range that matched the lip pH. And there is no phase separation in all formulas.

SIGNIFICANT EFFECT OF PH ON PHOTOCATALYTIC DEGRADATION OF ORGANIC POLLUTANTS USING SEMICONDUCTOR CATALYSTS

2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Nur Farhana Jaafar ◽  
Aishah Abdul Jalil ◽  
Sugeng Triwahyono ◽  
Adnan Ripin ◽  
Mohamad Wijayanuddin Ali
Keyword(s):  
Carbon Dioxide ◽  
Methyl Orange ◽  
Physicochemical Properties ◽  
Photocatalytic Degradation ◽  
Organic Pollutants ◽  
Ph Value ◽  
Effect Of Ph ◽  
Electrolysis Method ◽  
Ph Range ◽  
Positively Charged

Photocatalytic is one of the inexpensive and non-toxic techniques for degradation of organic pollutants into harmless substances such as water and carbon dioxide. In this study, simple electrolysis method was used in preparation of Ag/TiO2 and α-Fe2O3/HY catalysts. The physicochemical properties of the catalysts were studied using XRD, FTIR, FESEM-EDX and surface area analysis. The pH of solution plays an important role in the photocatalytic degradation of organic pollutants which influences the surface-charge properties of the catalysts. Ag/TiO2 and α-Fe2O3/HY were used as catalyst on degradation of 2-chlorophenol (2-CP) and methyl orange (MO), respectively. The effect of pH on degradation of 2-CP and MO were investigated over a pH range from 2 to 9. Higher degradation of 2-CP and MO were obtained at pH 5 (74%) and pH 2 (80%), respectively. This finding might be explained by the amphoteric performance of the catalyst using point zero charge (pHZPC). The pHZPC for Ag/TiO2 and α-Fe2O3/HY was found to be at pH 6.3 and pH 7.2, respectively. Hence, the activities of the catalysts may have been affected by the existence of a strong electrostatic field between the positively charged catalysts surface and negatively charged 2-CP and MO caused a pH value lower than their pHZPC give greater degradation.

scholarly journals New Insights on the Impact of Cattle Handling on Post-Mortem Myofibrillar Muscle Proteome and Meat Tenderization

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3115
Author(s):  
Verónica Sierra ◽  
Laura González-Blanco ◽  
Yolanda Diñeiro ◽  
Fernando Díaz ◽  
María Josefa García-Espina ◽  
...  
Keyword(s):  
Management Strategies ◽  
Small Heat Shock Protein ◽  
Structural Proteins ◽  
Metabolic Enzyme ◽  
Quality Traits ◽  
Post Mortem ◽  
Beef Quality ◽  
Cattle Management ◽  
Meat Tenderization ◽  
The Impact

This study investigated the effect of different cattle management strategies at farm (Intensive vs. Extensive) and during transport and lairage (mixing vs. non-mixing with unfamiliar animals) on the myofibrillar subproteome of Longissimus thoracis et lumborum (LTL) muscle of “Asturiana de los Valles” yearling bulls. It further aimed to study the relationships with beef quality traits including pH, color, and tenderness evaluated by Warner–Bratzler shear force (WBSF). Thus, comparative proteomics of the myofibrillar fraction along meat maturation (from 2 h to 14 days post-mortem) and different quality traits were analyzed. A total of 23 protein fragments corresponding to 21 unique proteins showed significant differences among the treatments (p < 0.05) due to any of the factors considered (Farm, Transport and Lairage, and post-mortem time ageing). The proteins belong to several biological pathways including three structural proteins (MYBPC2, TNNT3, and MYL1) and one metabolic enzyme (ALDOA) that were affected by both Farm and Transport/Lairage factors. ACTA1, LDB3, and FHL2 were affected by Farm factors, while TNNI2 and MYLPF (structural proteins), PKM (metabolic enzyme), and HSPB1 (small Heat shock protein) were affected by Transport/Lairage factors. Several correlations were found between the changing proteins (PKM, ALDOA, TNNI2, TNNT3, ACTA1, MYL1, and CRYAB) and color and tenderness beef quality traits, indicating their importance in the determination of meat quality and their possible use as putative biomarkers.

scholarly journals The Effect of Aging/Freezing Sequence and Freezing Rate on Quality Attributes of Beef Loins (M. longissimus lumborum)

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Derico Setyabrata ◽  
Jacob R. Tuell ◽  
Brad Kim
Keyword(s):  
Shear Force ◽  
Troponin T ◽  
Quality Attributes ◽  
Freezing Rate ◽  
Histological Observation ◽  
Ice Crystal ◽  
Lower Shear ◽  
Beef Carcasses ◽  
Longissimus Lumborum ◽  
Fast Freezing

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.

scholarly journals Effect of Pre-Slaughter Practises and Early Post-Mortem Interventions on Sheep Meat Tenderness and Its Impact on Microbial Status

Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 181
Author(s):  
Carlos Álvarez ◽  
Leonard Koolman ◽  
Michael Whelan ◽  
Aidan Moloney
Keyword(s):  
Quality Trait ◽  
Meat Tenderness ◽  
Post Mortem ◽  
Subsequent Aging ◽  
Factors Affecting ◽  
Aging Period ◽  
Sheep Meat ◽  
The Impact ◽  
Microbial Status

Tenderness, together with flavour, is the main quality trait that defines consumer acceptance of sheep meat. The factors affecting tenderness can be grouped as those influenced before slaughter, in the early post-mortem intervention and, finally, during the aging period. These factors have been extensively studied with respect to tenderness, but the impact of early post-mortem interventions and subsequent aging on the microbial quality of the final products has not been broadly reviewed to date. In this review, the authors summarize the most recent knowledge on lamb meat tenderness management and how such practices may impact the final meat quality, especially its microbial status. The impacts of pre-slaughter factors (age, sex, diet, genotype and transport) and post-mortem interventions (chilling regime, electrical stimulation, or hanging method), are described and comprehensively discussed.

Sign in / Sign up

Export Citation Format

Share Document