• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.688-696
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• 1999

Changes in quality during frozen storage of meat with thermal equalized freezing and various freezing methods were investigated. When beef were frozen at freezing rate of $0.39{\sim}0.66\;cm/h$, average diameter of ice crystal were about $30{\sim}50\;{\mu}m$ and showed broken tissues or irregular cracks. At freezing velocity of $1.14{\sim}2.26\;cm/h$, ice crystals of about $10{\sim}30\;{\mu}m$ was formed mainly inside or between fiber and slight destruction of tissues was occurred. The average diameter (D) of the ice crystals were related to the characteristic freezing time $(t_c)$ by the equation: $D({\mu}m)=4.089+26.88logt_c\;(r^2=0.913)$. Beef with still-air freezing showed higher drip loss than methods of immersion and thermal equalized freezing. Also, drip loss of pork was relatively lower than beef and showed highest value to 7.39% during storage on 40 days at air-blast freezing method. No apparent change of pH during storage of frozen beef and pork by freezing methods were detected. However, least changes for sample with thermal equalized freezing was found compare to sample with still-air and air blast freezing in VBN and TBA value. The fluctuation of frozen storage temperature did not cause noticeable changes on pH and water content. However, drip loss, VBN and TBA values were increased slowly as frequency of fluctuation increased.

• Korean Journal of Veterinary Research
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• v.45 no.4
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• pp.527-536
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• 2005

The effects of dietary Gleditschia on fatty acid composition, lipid oxidation, and pork quality were investigated. Pigs (n=40) were fed a diet containing 0, 0.1, 0.2, 0.4, and 1% Gleditschia for 14 weeks and slaughtered at 110 kg average. The longissimus throracis et lumborum muscle was collected at 24 hr postmortem. Pork loin chops (3 cm thick) were packaged aerobically and stored at $4^{\circ}C$ for 7 days. Samples were analyzed for fatty acid composition, ultimate pH, thiobarbituric acid-reactive substance (TBARS), color ($L^*$, $a^*$, $b^*$), drip loss and water-holding capacity. There was no significant difference of moisture and crude fat percent in between treatment and control group, and the color stability of pork loin better in all treat groups was more improved during cold storage. The change of pH was significantly increased (p<0.05) in 0.2, 0.4, 1% treatment groups compare to the control group. Water-holding capacity of pig loins was significantly higher (p<0.05) in all treat groups than in control group; 0.2% treat group was the highest in the water holding capacity followed by 0.4, 1, and 0.1% treat groups. Less drip loss of pig loin was observed with samples from Gleditschia-fed pigs except 1% treat group. Unsaturated fatty acid were tend to be decreased and saturated fatty acid were tend to be increased in Gleditschia-treated group. Thiobarbituric acid-reactive substance value of control was significantly higher than that of the Gleditschia-fed group (p<0.05).

• Food Science of Animal Resources
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• v.38 no.1
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• pp.143-151
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• 2018

The effects of proteolytic enzymes (bromelain and bromelain+papain) and a ginger extract were assessed on collagen content and solubility, thermal shrinkage temperature of connective tissue, pH, cooking loss, drip loss, and Warner-Bratzler shear force (WBSF) of M. pectoralis profundus isolated from the beef brisket cut. Both proteolytic enzymes and ginger extract led to a significant increase in cooking loss and collagen solubility compared with untreated controls. On the other hand, the peak ($T_p$) thermal shrinkage temperature markedly decreased in all treatments compared with those in controls. Samples treated with bromelain, bromelain + papain, and ginger extract showed a significant decrease in WBSF by 36%, 40%, and 37%, respectively, compared with untreated controls. Our findings suggest that ginger extract are useful for post-mortem tenderization of meat containing high levels of collagen, compared to control even though, bromelain and bromelain + papain treatments have higher collagen solubility than ginger extract.

• Korean Journal of Agricultural Science
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• v.21 no.2
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• pp.133-141
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• 1994

Optimal thawing conditions of frozen model foods containing protein and starch were nvestigated at various thawing conditions such as room temperature, hot air, and microwave heating. Hardness of the frozen model foods was getting higher as the water content increased. Thawing rates at room temperature, hot-air heating at $50^{\circ}C$, and microwave heating were 0.02 Kg/min, 0.08 Kg/min, 0.01 Kg/min, respectively. Final thawing time was as follows; control 60min, 5% sucrose: 50 min, 10% sucrose: 30 min, 5% NaCl: 30 min. Total drip loss was as follows; room temperature thawing: 22.5%, 200W microwave thawing 1.3%, and $50^{\circ}C$ hot air thawing nearly negligible.

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.88-92
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• 1994

The influence of the storage temperature between $0^{\circ}C$ and $30^{\circ}C$ on the biochemical, physical changes and meat qualities in the red muscle(M. sternomandibularis and M. mastoideus) of Korean native cattle postmortem were studied. The results obtained were summarized as follows; The pH-value during the first hours post mortem was dropped faster in storage temperature $0^{\circ}C$ than in $10^{\circ}C$, but the final pH-value reached after about 30 hrs. post mortem. The muscle which was stored in $30^{\circ}C$ reached the final pH within 10 hrs. The muscle which was stored in $0^{\circ}C$ showed the increased R-value at fast speed from the beginning. It reached maximum R-value after 20 hrs as it gradually increase showing low R-value by 10 hrs. in $10^{\circ}C$. The muscle which was stored in $0^{\circ}C$ shortened to about 46% after 10 hrs. It was contracted about 17% after 15 hrs in $10{\sim}20^{\circ}C$. The sarcomere length of Korean native cattle had the least contraction in $10^{\circ}C$ and it was contracted $18{\sim}20%\;(1.60{\sim}1.63\;{\mu}m)$ after 5 hrs., $45{\sim}46%$after 24 hrs in $0^{\circ}C$ and $30^{\circ}C$ which was generated cold shortening and rigor shortening. The meat that was stored in $0^{\circ}C$ and $30^{\circ}C$ showed about 2-fold higher shear force than it that was stored in $10^{\circ}C$ at postmortem 24 hrs. The meat that was stored in $10^{\circ}C$ at postmortem 24 hrs. showed drip loss less than 3% during the 9 days ripening period. The meat with cold shortening and rigor shortening showed the high drip loss.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.700-705
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• 2009

This study was conducted to evaluate the effects of Ligustrum lucidum (LL) on growth performance, antioxidation, and meat quality in broilers. 270 birds (1 d old) were allotted to 3 treatments with 6 replicates per treatment. The feeding program included a starter diet from d 1 to 21 of age and a grower diet from d 22 to 42 of age. The birds were given a basal corn-soybean meal diet supplemented with 0 (the control), 5 or 10 g of LL/kg, respectively. The results showed that in the starter, grower and overall phase, broilers fed with 5 or 10 g of LL/kg had better (p<0.01) average daily gain, but there were no differences in feed: gain between treatments. In the starter and overall phase, average daily feed intake of LL groups was greater (p<0.05) than that of the control, but this difference was not observed in the grower phase. Supplementation of LL significantly increased (p<0.05) superoxide dismutase activity and total antioxidant capability in serum of chickens. In breast muscle, birds fed 5 g of LL/kg had an increase (p<0.05) in superoxide dismutase activity. The LL supplementation significantly decreased (p<0.05) malondialdehyde contents. Adding 5 or 10 g of LL/kg to the diet significantly increased pH value and reduced drip loss of meat (p<0.05). The results of this study indicated that dietary LL could improve growth performance, increase pH value and reduce drip loss of meat by decreasing lipid peroxidation and by improving antioxidative status in broilers.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.435-441
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• 2015

Relationships among different stress parameters (lairage time and blood level of lactate and cortisol), meat quality parameters (initial and ultimate pH value, temperature, drip loss, sensory and instrumental colour, marbling) and carcass quality parameters (degree of rigor mortis and skin damages, hot carcass weight, carcass fat thickness, meatiness) were determined in pigs (n = 100) using Pearson correlations. After longer lairage, blood lactate (p<0.05) and degree of injuries (p<0.001) increased, meat became darker (p<0.001), while drip loss decreased (p<0.05). Higher lactate was associated with lower initial pH value (p<0.01), higher temperature (p<0.001) and skin blemishes score (p<0.05) and more developed rigor mortis (p<0.05), suggesting that lactate could be a predictor of both meat quality and the level of preslaughter stress. Cortisol affected carcass quality, so higher levels of cortisol were associated with increased hot carcass weight, carcass fat thickness on the back and at the sacrum and marbling, but also with decreased meatiness. The most important meat quality parameters (pH and temperature after 60 minutes) deteriorated when blood lactate concentration was above 12 mmol/L.

• Journal of Animal Science and Technology
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• v.53 no.3
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• pp.211-222
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• 2011

The present review was aimed to assess the feasibility of increasing the slaughter weight (SW) of finishing pigs. Growth performance, including ADG, ADFI and gain:feed, does not change significantly with increasing SW between 110 and $135{\pm}5kg$ in lean-genotype pigs, whereas in non-lean pigs, ADG and gain:feed decrease with increasing SW within the similar range of BW. Backfat thickness (BFT) and marbling of the carcass, which are greater in barrows than in gilts, increase with the increase of SW. The SW could be increased by using a low-energy diet and thereby reducing the rate of fat deposition per weight gain. The yield of the belly increases with the increase of SW, which may be economically significant in Korea. However, yields of some other primal cuts do not change so much as to affect the carcass value. The redness and fat content of the muscle increase slightly with the increase of SW whereas moisture content is minimally influenced by SW. Muscular protein content rarely changes, but sometimes increases slightly, with increasing SW. Other physicochemical characteristics, including lightness, pH, drip loss, and cooking loss of the muscle, are barely influenced by SW. Marbling of fresh loin and ham increases with increasing SW. Sensory characteristics of fresh loin, ham, and belly, including color, aroma, off-flavor, drip, and acceptability, are not influenced significantly by SW. The eating quality of cooked pork also has almost no relation to SW. In conclusion, it is thought that the current SW for moderately lean barrows and gilts can be raised up to 125 and 135 kg, respectively, with BFT at these weights predicted to be approximately 24 mm near the last rib, without compromising the meat quality.

• Food Science of Animal Resources
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• v.34 no.1
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• pp.73-79
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• 2014

This study was performed to evaluate the quality characteristics of three deboned categories of chicken thigh meat: one which was slaughtered and deboned in the same plant (fresh); one which was slaughtered, deboned, frozen, and thawed in the same plant (frozen-thawed); and the last which was slaughtered in a plant, deboned in a different plant, but then transferred to the original plant (fresh-outside). Surface color, drip loss, 2-thiobarbituric acid reactive substances (TBARS) value, sensory evaluation, and total aerobic bacterial counts of the chicken samples were determined. Moreover, the torrymeter was used to measure the differences in freshness of the chicken meat. The surface color and the TBARS values did not show significant differences among the three categories. However, the total aerobic bacterial counts of fresh-outside and frozen-thawed chicken meat were significantly higher than the fresh chicken meat on the first storage day, and the drip loss of frozen-thawed chicken meat was significantly higher than the fresh-outside and fresh chicken meat. In addition, the sensory evaluation of frozen-thawed chicken meat was significantly lower than the fresh-outside and fresh chicken meat. Torrymeter values were higher in fresh chicken meat than fresh-outside and frozen-thawed chicken meat during the storage period. These results indicate that the quality of frozen-thawed chicken meat is comparatively lower than the fresh chicken meat, and the torrymeter values can accurately differentiate the fresh-outside and frozen-thawed chicken meat from the fresh ones.