• Food Science of Animal Resources
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• v.18 no.4
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• pp.358-363
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• 1998

The objectives of this study were to evaluate the effect of previous heating temperature and holding times on the thermal behavior of pork loin muscle by DSC. Pork loin muscles were heated to achieve the following end-point temperatures: 40$^{\circ}C$, 50$^{\circ}C$, 60$^{\circ}C$, 70$^{\circ}C$, 80$^{\circ}C$ at heating rate = 10$^{\circ}C$/min. The first peak was disappeared when samples were initially heated to 50$^{\circ}C$ for 1 minute. As end-point temperature was raised, major peaks were progressively disappeared and peaks were lost completely at 80$^{\circ}C$. Especially, peaks were completely disappeared at 70$^{\circ}C$ for 10 minute. Increasing of exposure time to elevated temperature also increased denaturation, thereby reducing the area of the thermogram.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1259-1259
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• 2001

Meat becomes brown and rancid during storage in the refrigerator and display in the case. Color changes, metmyoglobin formation and lipid oxidation are the important problems in the transportation / distribution of meat and retail display. The freshness of meat is determined by the sense of vision and smell. Since conventional method determining lipid oxidation is time consuming and destructive (it needs to homogenize meat with reagents, filtrate, time for reaction and read optical density using spectroscopy), more rapid and nondestructive technical tools are desired. The objective of this work was to evaluate near-infrared spectroscopy as an analytical tool for determining meat color, metmyoglobin formation and lipid oxidation. in beef, pork and chicken. Semitendinosus and longissimus thoracis muscles from six beef steers, biceps femoris and longissimus thoracis muscles from twelve LWD crossbred pigs, and superficial pectoral muscles from twenty-four broilers were used. About a 5-cm diameter and 1-cm thick sample (20.0g) was cut from the muscle and placed on plastic foam, over-wrapped with PVC film, and displayed under flourescent lights at 4 degrees C. during 10 days for beef and pork or 4 days for chicken. The spectra was measured by NIR systems Model 5500 Spectrophotometer using fiber optic scan at range of 400 - 1100 nm. Data were recorded at 2 nm intervals and 10 scans / 10 sec were averaged for every sample. Data obtained were saved as log 1/Re, where Re is the reflectance energy, and then mathematically transformed to second derivatives to reduce effects of differences in particle size. $L^{*}$, $a^{*}$ and $b^{*}$, and metmyoglobin formation were determined by conventional spectrophotometer using the integrating sphere unit. 2-Thiobarbituric acid reactive substances (TBARS) were measured for lipid oxidation. A multiple linear regression was used to find the equation which would best fit the data. The number of wavelengths used in the equation was selected based on the fewer number compared to the increasing multiple correlation and Decreasing standard error. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.7
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• pp.1127-1134
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• 2007

Gels were made from surimi-like pork (SLP) made from muscles obtained at 1, 24 and 72 h post-mortem. The SLP from pre-rigor muscle had higher pH and moisture percentage compared to in- or post-rigor muscles. Also, SLP from pre-rigor muscle showed higher concentration of water-soluble protein that was washed out during the process. Gel from post-rigor muscle exhibited higher a* and b* value, and also resulted in higher Chroma and lower hue values. The dark color of gel from post-rigor muscle was related to higher concentration of sarcoplasmic protein in SLP and denser structure in the gel matrix. SDS-PAGE showed higher intensity of the phosphorylase in the sarcoplasmic protein fraction from pre-rigor muscle. Gel from post-rigor muscle showed higher hardness and sensory firmness, and the greater firmness was related to higher concentration of protein in SLP, and a compact network with smaller pockets in the gel matrix.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.318-322
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• 2015

In the modern pork industry, selection of high intramuscular fat (IMF) in pigs is necessary to improve pork quality. Ultrasound has been used previously to predict subcutaneous fat thickness and IMF in the longissimus muscles of line pigs and Real-time ultrasound has also been reported as a reliable method for estimating IMF in live pigs. So we estimate the correlation between meat quality traits and IMF percentage to investigate the possibility of utilizing real-time ultrasound technology for predicting IMF percentage in line pigs to improve pork quality. The genetic and phenotypic correlations for chemical intramuscular fat (CIMF) and ultrasound intramuscular fat (UIMF) were estimated to be 0.75 and 0.76, respectively. These results suggest that genetic factors strongly influence meat quality. The genetic and phenotypic correlation between UIMF and CIMF were 0.75, 0.76, respectively. The heritability of UIMF and CIMF were 0.48 and 0.50, respectively. So we concluded that CIMF can be replaced with UIMF and Ultrasound machines can be used to test IMF in live swine. In future, UIMF can be utilized to improve pork quality as an alternative to CIMF.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.6
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• pp.914-918
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• 2018

Objective: The relationship between water-holding capacity (WHC) and intermuscular fat (IMF) was studied in Japanese commercial pork. Methods: Longissimus muscles of pigs (n = 62), obtained from two meat packing plants, were analyzed for IMF content, moisture content, drip loss, cooking loss, and pH. Pairwise relationships among these traits were determined using correlation analyses. Results: IMF content was significantly correlated with moisture content (r = -0.88; p<0.01) and pH (r = 0.32; p<0.05), but not with drip loss (r = -0.23; p = 0.07) or cooking loss (r = -0.10; p = 0.42). In contrast, drip loss was significantly (and negatively) correlated with pH (r = -0.57; p<0.01). Conclusion: IMF content was not significantly correlated with WHC in pork, and so ultimately, we consider pH to be one of the most important factors influencing WHC in pork meat.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.844-851
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• 2020

The objective of this study was to compare effects of two different aging methods on physical, chemical, and microbial traits of pork loin: Dry and wet-aged meat was hung in the cooler at 8±1℃ and 85±2.1% humidity for 14 days, while wet-aged meat was immersed in a 3.5% salt solution of brine in vacuum pouches. On day 7, pH and moisture content were higher in dry-aged loins than in wet-aged, while drip loss and total plate counts (p<0.05) were lower on day 14. As aging continued, the pH and drip loss of dry-aged loins decreased, while their total plate counts and water holding capacity (WHC) increased (p<0.05). After 7 and 14 days of aging, redness in dry-aged loins was higher than that in wet -aged muscles (p<0.05). On day 14 of aging, hardness, chewiness, and adhesiveness were lower in dry-aged pork loin as compared to those in wet-aged samples (p<0.05). Consequently, the results suggested that dry and wet aging methods differently affects meat quality traits of pork loin.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.1
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• pp.122-130
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• 2010

Sensory analyses of pork samples from leg muscles of female pigs raised in New Zealand (n = 17) were conducted using trained and untrained Singaporean panelists. The New Zealand pigs included three dietary groups, with one diet including animal products (NZA), and two containing plant products only (NZP & NZP+), with the NZP+ diet containing a supplement (0.614%) containing conjugated linoleic acid (CLA), selenium, and vitamin E. The New Zealand pork was also compared with Indonesian pork as local reference samples (n = 6). Pork samples from the NZA group had the highest score for mutton flavour and aftertaste, and the lowest score for brothy aroma, brothy flavour, meaty flavour, lightness and juiciness by trained sensory panels. Samples from NZP and NZP+ were similar except the NZP+ group had a stronger stale flavour than the NZP group (1.34 vs. 0.57 on a 100-point scale; p<0.05). The first and second functions of a discriminant analysis based on trained-panel scores for 14 attributes accounted for 95.4% of the variance, with function 1 (83.7%) being related mainly to mutton aroma, mutton flavour and aftertaste. Based on a 20-member untrained panel, the NZA pork had the highest mutton aroma and mutton flavour intensities (p<0.01) and aroma and flavour that was less acceptable than that from the NZP group (p<0.05). The acceptability scores of Indonesian pork were not significantly different from those of New Zealand pork, but its scores for mutton aroma and mutton flavour were significantly lower than NZP. Overall acceptability was positively associated with acceptability of aroma (r = 0.906), juiciness (r = 0.888), and tenderness (r = 0.904), but negatively associated with intensities of mutton aroma (r = -0.478) and flavour (r = -0.551).

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.364-369
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• 1989

Experiments were carried out to investigate on the effect of cryoprotectants to the quality changes of pork and beef muscles during frozen storage . Beef and pork muscles were mixed with various cryoprotectants and stored at $-20^{\circ}C$ in a chest freezer for 12 weeks. Samples were analyzed for pH changes, TBA value, free atty acid contents, water and salt soluble protein extractability. The results obtained are summerized as follows. The pH value in all of cryoprotectants added samples were increased up to 0.25-0.5 as in non-treated samples . The TBA value, free fatty acid contents were increased with storage time as compared with the non-treated sample. Cryoprotectant effect on water soluble protein extractability was greater in pork than in beef muscle during frozen storage, especially in pork muscle treated CP-B, mixture of sorbitol, sucrose and sodium tripolyphosphate, as compared with non-treated sample. Cryoprotectant effect on salt soluble protein extractability during frozen storage was more pronounced in the beef muscle treated with CP-A which was mixture of sorbitol, mono sodium glutamate and sodium tripolyphosphate, and in the pork muscle treated with CP-B, mixture of sorbitol, sucrose and sodium tripolyphosphate than in the non-treated sample.

• Food Science of Animal Resources
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• v.38 no.4
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• pp.823-828
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• 2018

The purpose of this study was to evaluate the suitability of the released water (RW) method for measuring water-holding capacity (WHC) by pressure and filter-paper absorption within two thin plastic films. One hundred fifty pork loins with considerable variations in WHC (three pork qualities: PSE, pale, soft, and exudative; RFN, reddish-pink, firm, and nonexudative; and DFD, dark, firm, and dry; 50 pork loins in each pork quality group) were used to measure drip loss (DL)% and RW % after applying different loads (1.5, 2.0, 2.5, 3.0 and 3.5 kg). Percentages of DL and RW were significantly (p<0.05) different among pork quality groups. The RW % of 2.5 kg load sample was significantly (p<0.05) higher than that of 2.0 kg or 1.5 kg load sample. However, there were no significant (p>0.05) differences in RW % among 2.5 kg, 3.0 kg, and 3.5 kg load samples for all three pork quality groups. The RW % was highly and positively correlated (r>0.95; p<0.001) with DL %. The highest correlation was observed between DL % and RW % of 2.5 kg load sample (r=0.97; p<0.001). Among all RW loads within each quality groups, the highest correlation between DL % and RW % was observed for 2.5 kg load sample (r=0.43, 0.66, and 0.46 for PSE, RFN and DFD quality groups, respectively, p<0.001). These results imply that applying 2.5 kg load is the best for determination of RW %. It is recommended as a reference method to assess DL % of pork muscles.

• Korean Journal of Veterinary Service
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• v.29 no.3
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• pp.317-330
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• 2006

This study was conducted to develop the analytical method about simultaneous determination for synthetic antimicrobials in muscle by high performance liquid chromatography - mass selective detector (HPLC- MSD). Solid phase extraction (SPE), matrix solid phase dispersion (MSPD) and liquid-liquid extraction (LLE) have been adapted as pretreatment procedures for HPLC- MSD. Among various solvent tested, methanol was chosen for extraction of synthetic antimicrobials in muscles. For the optimized response, the values of various MS parameters including fragment voltage, drying gas flow, nebulizer pressure, drying gas temperature were verified. The average recovery rates using MSPD and SPE for muscles of bovine and pork were 78.9-127.1% and 78.3-121.7%, respectively. This method was verified the satisfactory performance for fourteen synthetic antimicrobials excepting carbadox in muscle of pork as detection limit of $0.05{\mu}g/g$ on API/ES SIM mode.