• Food Science of Animal Resources
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• v.39 no.6
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• pp.1008-1014
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• 2019

This study investigated the effects of pressure-mediated protein changes on the ice nucleation temperature of pork loins. To variate chemical state of meat proteins, pork loin was pressurized at varying pressure levels (100-500 MPa) for 3 min, and moisture content, expressible moisture (EM) and differential scanning calorimetry (DSC) were analyzed. Although, all treatments showed similar moisture content, EM and degree of protein unfolding of pork loin showed different features as of 300 MPa. At moderate pressure treatments (100-200 MPa), all protein fractions were detected in DSC experiments, and pork loin had lower EM than control (p<0.05). Meanwhile, myosin and actin of pork loin treated at greater than 300 MPa were completely unfolded, and the treatments showed high EM compared to control (p<0.05). Unfolding of meat proteins was a factor suppressing ice nucleation, and the ice nucleation temperature tended to decrease with increasing applied pressure level. The ice nucleation characteristics of pressurized pork loin exhibited a potential application in freezing storage of pressurized meat with less tissue damage comparing to freeze fresh meat, and further exploration regarding the quality change after freezing of fresh and pressurized meat was warranted.

• Food Science of Animal Resources
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• v.35 no.4
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• pp.524-532
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• 2015

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°C 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.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.817-821
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• 2007

The effect of acetylated rice (AR) starch at different concentrations (0, 4, 6, and 8%) on rheological properties of surimi sols and gels was studied. Dynamic frequency sweeps of surimi-AR starch sols at $10^{\circ}C$ showed that the magnitudes of storage moduli (G') decreased with an increase in starch concentration while those of tan ${\delta}$ increased, indicating that the effect of AR starch on the viscoelastic properties of surimi sols depended on starch concentration. In general, the G' thermograms of surimi sols showed the similar sol-gel transition pattern and they were also influenced by the addition of AR starch. The presence of AR starch in the surimi gel system reduced the gel strength and expressible moisture content (EMC). Surimi-AR starch gels showed better freeze-thaw stability compared to the control (0% starch concentration). The effect of AR starch on the rheological properties of surimi sols and gels appeared to be related to the swelling ability of starch granules in the presence of limited water available for starch.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.36-42
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• 2009

This study was performed to develop low-fat/reduced-salt sausages (LFRSS; <3% fat and <1.5% salt) containing milk protein (whey protein concentrate, WPC, or sodium caseinate, SC) that showed the similar cooking yield and textural characteristics to those of regular-fat/salt sausage control (RFC; 20% fat and 1.5% salt) or low-fat sausage control (LFC; <3% fat and 1.5% salt). Low-fat sausages (LFS) were formulated with a 2.5% fat replacer (konjac flour:carrageenan:soy protein isolate=1:1:3) and various salt levels (0.75, 1.0, 1.25, and 1.5%). LFS had differences in color and expressible moisture (EM, %) values as compared to those of RFC. A minimum salt level of 1% and addition of nonmeat proteins were required to manufacture LFRSS that have similar characteristics to those of RFC. However, LFS with 2% milk proteins reduced the hardness and gumminess as compared to LFC. These results indicated that 1% milk protein in combined with 1% salt was a proper level for manufacturing of LFRSS.

• Food Science of Animal Resources
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• v.36 no.5
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• pp.650-655
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• 2016

This study investigated the effects of artificial supercooling followed by still air freezing (SSF) on the qualities of pork loin. The qualities of pork frozen by SSF were compared with the fresh control (CT, stored at 4℃ for 24 h), slow freezing (SAF, still air freezing) and rapid freezing (EIF, ethanol immersion freezing) treatments. Compared with no supercooling phenomena of SAF and EIF, the extent of supercooling obtained by SSF treatment was 1.4℃. Despite that SSF was conducted with the same method with SAF, application of artificial supercooling accelerated the phase transition (traverse from -0.6℃ to -5℃) from 3.07 h (SAF) to 2.23 h (SSF). The observation of a microstructure indicated that the SSF prevented tissue damage caused by ice crystallization and maintained the structural integrity. The estimated quality parameters reflected that SSF exhibited superior meat quality compared with slow freezing (SAF). SSF showed better water-holding capacity (lower thawing loss, cooking loss and expressible moisture) and tenderness than SAF, and these quality parameters of SSF were not significantly different with ultra-fast freezing treatment (EIF). Consequently, the results demonstrated that the generation of supercooling followed by conventional freezing potentially had the advantage of minimizing the quality deterioration caused by the slow freezing of meat.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.1
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• pp.144-151
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• 2019

Objective: Curdlan has been widely used as a gelling agent in various food systems. This study was performed to evaluate the rheological properties of pork myofibrillar protein (MP) with different levels of curdlan (0.5% to 1.5%) and its application to low-fat model sausages (LFS). Methods: MP mixtures were prepared with 0.5%, 1.0%, and 1.5% of curdlan. Cooking loss (%), gel strength (gf), shear stress (Pa), and scanning electron microscopy were measured. Physicochemical and textural properties of LFS containing different levels of curdlan were measured. Results: The shear stress of MP mixtures increased with increasing levels of curdlan. MP gels with increased levels of curdlan decreased cooking loss and increased gel strength (p<0.05). The MPs with 1.0% and 1.5% of curdlan were observed more compact three-dimensional structure than those with 0.5% curdlan. Increased curdlan level in LFS affected redness ($a^{\star}$) and yellowness ($b^{\star}$) values. Although expressible moisture of LFS did not differ among curdlan levels, LFSs with various levels of curdlan decreased cooking loss as compared to control sausages. Hardness values (2,251 to 2,311 gf) of LFS with 0.5% and 1.0% curdlan was increased and differ from those (1,901 gf) of control sausages. Conclusion: The addition of 1.0% curdlan improved the functional and textural properties of LFS.

• Food Science of Animal Resources
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• v.39 no.1
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• pp.65-72
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• 2019

This study investigated the effects of temperature ($50^{\circ}C$, $55^{\circ}C$, and $60^{\circ}C$) and time (12 and 24 h) on the cookery properties of sous-vide (SV) processed pork loin. As an indicator of cookery properties, cooking loss, expressible moisture (EM), pH, differential scanning calorimetry (DSC), shear force, total plate count (TPC) and CIE color were measured and compared with fresh (FC) and cooked control (CC, $75^{\circ}C$ for 30 min). SV treatments at $50^{\circ}C$ showed higher tenderness and lower cooking loss comparing to CC. DSC result indicated that thermal transition of collagen was a key factor affecting the cooking loss and shear force of meat. In comparison of CC, risks of insufficient pasteurization and uncooked color generation were not shown in SV processed meat. Therefore, the results indicated that SV had a potential advantage to produce tender and moist meat, and the best SV condition of pork loin was estimated at $50^{\circ}C$ for 24 h.

• Journal of Animal Science and Technology
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• v.63 no.2
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• pp.394-404
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• 2021

The objective of this study was to evaluate quality characteristics of low-nitrite emulsified-sausages (ESs, < 75 ppm) containing paprika oleoresin solution (POS) for replacing sodium nitrite (NaNO2). Pork ESs were prepared with four treatments (reference (REF), 150 ppm NaNO2; TRT1, 0 ppm NaNO2 + 0.1% POS; TRT2, 37.5 ppm NaNO2 + 0.1% POS; and TRT3, 75 ppm NaNO2 + 0.1% POS). The physicochemical and texture properties, microbial counts, residual nitrite and thiobarbituric acid reactant substances (TBARS) were measured during refrigerated storage of 35 days. Although TRT2 and TRT3 had lower levels of NaNO2, they had higher redness and yellowness than REF (p < 0.05). Microbial counts of total bacterial counts and Enterobacteriaceae of TRT2 and TRT3 were similar to those of REF (p > 0.05). Expressible moisture percentages (EM, %) of TRT2 and TRT3 were lower than those of REF (p < 0.05). TBARS values of TRT2 and TRT3 were not different from those of REF (p > 0.05). Among treatments, TRT1 had the highest TBARS values (p < 0.05). In conclusion, 0.1% POS in combination with 37.5 ppm NaNO2 would have quality characteristics similar to those of REF. Therefore, approximately 3/4 of the initial nitrite level could be replaced with 0.1% POS, and eventually developed healthier pork products.

• Animal Bioscience
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• v.35 no.3
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• pp.494-502
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• 2022

Objective: The objective of this study was to evaluate functional properties of reduced-salt pork meat products made of pre-rigor pork loin treated by different freezing temperatures (-30℃ and -70℃) during storage. Methods: Pre-rigor cured pork loin with 1.0% added salt was compared to post-rigor muscle added with 1.5% salt for pH, color (L^*, a^*, b^*), cooking loss (CL), expressible moisture, warner-Bratzler shear value, thiobarbituric acid reactive substances (TBARS), and volatile basic nitrogen (VBN). Results: Pre-rigor cured pork loins had higher pH and temperature than post-rigor ones as raw meat (p<0.05). pH values were higher for pre-rigor pork loins than those of post-rigor pork loins (p<0.05). Color values did not different among treatments (p>0.05). No color differences were observed during storage period after cooking (p>0.05). The CL (%) of pre-rigor cured pork loins was the lowest when frozen at -70℃. The TBARS and VBN increased from 8 weeks of storage (p<0.05), but no further changed thereafter (p>0.05). Pre-rigor cured pork loins added with 1.0% salt showed similar characteristics to post-rigor pork loins added with 1.5% salt. Conclusion: Cured pork loins could be produced using pre-rigor muscle added with 1/3 of the original salt level (1.5%) and could be stored for up to 4 wks of frozen storage, regardless of a frozen temperature of -30℃ or -70℃ without detrimental effects.

• Food Science of Animal Resources
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• v.38 no.1
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• pp.162-171
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• 2018

The purpose of this study was to investigate the quality of duck ham formulated with duck skin through the pre-emulsification process. The experiments to investigate the quality characteristics of duck ham were carried out to measure proximate composition, cooking loss, emulsion stability, pH, color, texture profile analysis, apparent viscosity, and sensory characteristics. Duck ham was prepared with various ratios of duck skin in pre-emulsion as follows: Control (duct skin 30%), T1 (duck skin 20% + pre-emulsified duck skin 10%), T2 (duck skin 15% + pre-emulsified duck skin 15%), T3 (duck skin 10% + pre-emulsified duck skin 20%), and T4 (pre-emulsified duck skin 30%). As the ratio of duck skin to pre-emulsified skin changed, the quality of duck ham in terms of moisture content, fat content, cooking loss, emulsion stability, lightness, textural analysis, apparent viscosity, and overall acceptability changed. The moisture content of T2 was the highest (p<0.05) and that of the control and T4 was the lowest (p<0.05). The fat content of control was higher than all treatments (p<0.05). T2 had the lowest values in cooking loss, total expressible fluid, fat separation, hardness, springiness, and gumminess (p<0.05). The score of overall acceptability of all treatments with pre-emulsified skin was higher than control (p<0.05). Therefore, the pre-emulsification process can improve the quality characteristics of duck ham and 1:1 ratio of duck skin and pre-emulsified skin was the proper ratio to improve the quality characteristics of duck ham.