• Food Science of Animal Resources
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• v.28 no.2
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• pp.154-159
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• 2008

To investigate the rheological properties of protein mixed gels mediated by microbial transglutaminase (MTGase), pork myofibrillar protein (MFP), sodium caseinate (SC) and their mixture (MS), the various gels were incubated at different temperatures for various times. Extracted MFP, SC and their mixture (MS, 1:1) were incubated at different temperatures ($4^{\circ}C$ vs $37^{\circ}C$) for various times (0, 0.5, 2, 4 hr), and assessed for viscosity, gel strength and other characteristics using differential scanning calorimeter (DSC) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). DSC measurements showed that incubation at $37^{\circ}C$ rather than $4^{\circ}C$ caused marked changes in thermal transition, and MS displayed similar thermal curves (three endothermic transitions) to MFP and SC alone. After incubation at $37^{\circ}C$ for 2 hrs, the viscosity (cP) of MS increased (p<0.05) due to induction by MTGase, whereas no differences were observed at $4^{\circ}C$. However, gel strength values were no different, regardless of incubation temperatures and times. Future research will address how longer incubation times affect the functionality of protein mixed gels mediated by MTGase.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.728-734
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• 2007

In this study, we prepared surimi from pork leg and chicken breast by pH adjustments of 3.0 and 11.0. The content of crude protein, yield, water-holding capacity, redness, yellowness, myoglobin(Mb) and metmyoglobin(metMb) were significantly higher in the surimi manufactured from pork leg at adjustment pH 3.0 compared to the other surimi samples; whereas whiteness, myofibrillar protein, breaking force, deformation and gel strength were lower than other samples(P<0.05). The textural attributes were significantly higher in the surimi manufactured from pork leg at adjustment pH 11.0 compared to the other surimi samples; whereas Mb, metMb, cooking loss, breaking force, deformation and gel strength were lower than other samples(P<0.05). Again, the content of crude protein, yield, pH, breaking force, deformation, gel strength and lightness were significantly higher in the surimi manufactured from chicken breast at adjustment pH 3.0 compared to the other surimi samples; whereas myofibrillar protein, redness and metMb were higher than other samples(P<0.05). The content of myofibrillar protein, deformation, lightness and cohesiveness were significantly higher in the suriml manufactured from chicken breast at adjustment pH 11.0 compared to the other surimi samples; whereas Mb, cooking loss, yield and breaking force were higher than other samples(P<0.05). The chicken breast surimi had superior color and gel characteristics than manufactured from pork leg, and adjustment pH 11.0 had superior whiteness and cohesiveness than the pH 3.0 adjusted sample, however, there were no significant differences in sensory attributes among the surimi samples.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1676-1684
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• 2004

Gel properties of recovered protein from mackerel, frozen blackspotted croaker, chicken breast and pork leg using acidic and alkaline processing were evaluated. Myofibrillar protein from mackerel by acidic processing did not form a heat-induced gel. However, the recovered protein including sarcoplasmic protein formed heatinduced gel. Breaking force of gel from mackerel processed at pH 10.5 was the lowest. A deformation value of frozen blackspotted croaker was the highest, followed by chicken breast, pork leg and mackerel. Whiteness of frozen blackspotted croaker was the highest among heat-induced gel. Breaking force, deformation and whiteness were decreased by addition of recovered protein from mackerel, but price was increased. A breaking force and whiteness of heat-induced gel added recovered protein from chicken breast were increased, and the price was greatly decreased. When the constraint of breaking force, deformation and price of raw material were set up above 110 g, 4.5 mm and below 2,000 won/kg. A optimum formulation for blending protein was 36∼50% for frozen blackspotted croaker, 34∼40% for chicken breast, 14∼25% for pork leg. The heat-induced gel of recovered protein from frozen blackspotted croaker showed compact structure compared to that of recovered protein from mackerel. A formulation of chicken breast and pork leg based on blackspotted croaker can be used in surimi based seafood products having various texture.

• Food Science of Animal Resources
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• v.31 no.5
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• pp.782-790
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• 2011

The effects of soy protein isolate (SPI) and red bean protein isolate (RBPI) on gelling properties of pork myofibrillar protein (MP) in the presence of microbial transglutaminase (MTG) were studied at 0.45 M NaCl. MP paste was incubated with MTG (0.1%) at various levels (0.1, 0.3, 0.5, and 1%) of SPI and RBPI before incubating at $4^{\circ}C$ for 4 h. The rheological property results showed that MP gel shear stress increased with increasing RBPI concentration. Cooking yield (CY) of the MP gel increased with increasing RBPI and SPI, whereas gel strength (GS) was not affected by adding RBPI or SPI. Thus, effects of incubation time (0, 4, 8, 10, and 12 h) were measured at 0.1% SPI and RBPI. GS values of the MP gel at 10 and 12 h were similar and were higher than those of the others. CY values were highest when RBPI (0.1%) was added, regardless of incubation time. The protein patterns indicated that incubating the MP with MTG for 10 h resulted in protein crosslinking between MP and RBPI or SPI. Based on these results, RBPI and SPI could be used as an ingredient to increase textural properties and cooking yield of meat protein gel.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.6
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• pp.846-852
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• 2007

The objective of this study was to compare the physical and sensory characteristics of pork from Korean native black pigs ($78{\pm}7kg$, female) to the pork of crossbred black pigs ($115{\pm}5kg$, female), both of which were reared for the same period on Jeju Island. The Korean native black pig showed a lower $L^*$ value (lightness) and higher $a^*$-(redness) and $b^*$-values (yellowness) than the crossbred black pig. There were no statistically meaningful differences between the two pigs' loins, hams and bellies of the two breeds of pig in terms of water holding capacity, thawing loss, cooking loss, myofibrillar protein extract, and fragmentation index. The crossbred black pigs showed greater significant differences among the physical characteristics of each part, as compared to the Korean native black pigs. The cooked meat of the Korean native black pig had superior hardness to that of the crossbred black pig, whereas the raw meat had a lower hardness, chewiness, and shear force value. Finally, there was no significant difference between the two pigs in terms of palatability.

• Food Science of Animal Resources
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• v.39 no.6
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• pp.888-902
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• 2019

Our aim was to investigate the effects of bromelain embedded in double emulsion (DE) on physicochemical properties of pork loin. We evaluated DE characteristics such as size, zeta potential, and microscopy after fabrication. We marinated meat with distilled water (DW), 1% (w/v) bromelain solution, blank DE, and 1% (w/v) bromelain loaded in double emulsion (DE E) for 0, 24, 48, and 72 h at 4℃, and prepared raw meat for control. The marinated samples were assessed for color, water holding capacity, cooking loss, moisture content, pH, protein solubility, Warner-Bratzler shear force (WBSF) and gel electrophoresis. The droplet size of 1% (w/v) bromelain embedded in DE was increased compared with blank DE (p<0.05) and values of zeta potential decreased. The increase in lightness and color difference range of the DE-treated group was lower than that of the DW-treated group (p<0.05). Moreover, treatment by immersion in 1% (w/v) DE E resulted in the highest water holding capacity values (p<0.05) and lower cooking loss values than water base treatment (p<0.05). Results for myofibrillar protein solubility and WBSF showed a similar trend. 1% (w/v) DE E showed degradation of myosin heavy chain after 48 h in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Thus, bromelain-loaded DE is useful for controlling and handling enzyme activity in food industry.

• Food Science of Animal Resources
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• v.24 no.1
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• pp.73-79
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• 2004

Functional properties of farm-grown pheasant meat with different sex, age and cutting portion were investigated, and the textural and sensory characteristics of processed products were also evaluated. Chemical composition of pheasant meat was characterized to be high in protein and low in fat, and breast muscle showed more protein and less moisture than thigh muscle. Moisture/protein ratio of the pheasant meat was relatively low in a range of 2.82∼3.40, indicating the pheasant meat would be a good source of processed meat, and it had high water holding capacity and myofibrillar protein extractability with some variations depending on age and portion cut(p<0.05). Thigh muscle showed higher value of L＊ and b＊ and lower value of a＊ than breast muscle. However, no difference was observed in color of meat with different age and sex. The meat from the 6 months and the breast cut had lower shear force than those of respective 17 months and the thigh regardless of sex. The pressed ham and sausage manufactured with the pheasant meat had better score than the commercial products manufactured with pork or chicken in sensory and textural parameters.

• Food Science of Animal Resources
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• v.44 no.2
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• pp.464-482
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• 2024

This study aimed to determine the effects of humectants on moisture content, water activity, tenderness, color, microbiological analysis, protein denaturation, and oxidation of jerky. A thorough search for papers published in scientific journals that examined the impacts of humectants on jerky was carried out using Web of Science, Google Scholar, PubMed, and Science Direct. Only 14 studies matched inclusion requirements. They were used in the meta-analysis to synthesise quantitative findings. In the current investigation, jerky produced with beef, poultry, goat, or pork was used. The standardised mean difference (SMD) between treatments with humectants and controls was examined to investigate the effects of humectants using random-effects models. Heterogeneity was investigated using meta-regression. A subgroup analysis was carried out for significant factors. Results revealed that the addition of humectants had no significant impact on water activity, pH, fat, ash, CIE L^*, or CIE a^* (p>0.05). However, humectant addition significantly increased moisture (SMD=1.28, p<0.05), CIE b^* (SMD=1.67, p<0.05), and overall acceptability (SMD=1.73, p<0.05). It significantly decreased metmyoglobin (SMD=-0.96, p<0.05), shear force (SMD=-0.84, p<0.05), and protein (SMD=-1.61, p<0.05). However, it was difficult to get a firm conclusion about how humectants affected the myofibrillar fragmentation index, total plate count, and 2-thiobarbituric acid-reactive substances because there were fewer than ten studies. To sum up, the proper use of humectants in jerky demands careful attention to both type and quantity, needing a delicate balancing act with other contributing factors.