• Korean Journal of Poultry Science
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• v.14 no.2
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• pp.145-151
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• 1987

In order to select the optimum freezing condition for the minimization of physico -chemical changes such as protein denaturation, lipid oxidation and pH change, the effect of freezing rates on the poultry meat quality changes was studied during frozen storage at -20$^{\circ}C$. Results obtained from the experiments are as fellows. When chicken breast and leg meat were frozen at above -3cm/hr or the freezing rate, pH change during frozen storage was minimal Although TBA value and free ratty acids were increased during frozen storage, the effect of freezing rates was different depending on muscle types. In terms of protein extractability, the extractability of salt soluble protein and water soluble protein were the highest at above -3cm/hr of the freezing rate during frozen storage. This trend was more obvious with breast meat than leg meat. Considering the above - described results, above -3cm/hr of the freezing rate seemed to be the optimum freezing condition for chicken meat because or the least pH change, low TBA value and high protein extractability.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.88-91
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• 1985

For the systematic investigation of biochemical characteristics of Korean ginseng protein, protein fractions were analyzed by the techniques of sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The effect of pH and various salts on extractibility of ginseng protein were determined while the amino acid composition was studied by amino acid autoanalyzer. The protein was consisted of 66.08% of albumin and 20.51% of glutelin. Extractability of ginseng protein was the lowest in pH 3.0 and the highest in $pH\;6.0{\sim}8.0$. Among the neutral salts solution, $0.4M\;Na_2CO_3$ showed maximum extractability while $1.0M\;MgSO_4$ solution showed the least extractability. Resonable precipitation was obtained by 40% of acetone and ammonium sulfate. It has been shown by SDS polyacrylamide gel electrophoresis that the soluble protein had 11 bands. The molecular weight for the main protein of the soluble protein wasestimated to be 43,000. In amino acid composition of water extracted protein, arginine content was the highest 47.17% while on the contray, proline and cystine contents were very low.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.45-51
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• 2005

This study was carried out to get the informations on microbes and protein extractability through comparing the quality attributes of Hanwoo fed in Korea, Hanwoo fed in Japan and Japanese Wagyu. The fresh beefs were stored at 4±l℃ for 13 days. In microbiological test, the total plate counts were higher in rump than in other beef portion as loin, chuck (p<0.000l). The number of psychrotrobes in the rump were maintained high levels (p>0.0001) for storage period, whereas the loin from Hanwoo fed in Korea, Hanwoo fed in Japan and Wagyu were lowest levels. The number of E. coli were no significantly different among the samples. In lactic acid bacteria, the loin form 3 grade Hanwoo (K3) had highest levels (p<0.0001). Comparing to the protein extractability, water soluble proteins were high in chuck (p<0.001). In the case of loin, water soluble proteins of K3 (3 grade Hanwoo) and Wagyu were high as 3.010 mg/g and 2.977 mg/g, respectively (p<0.001). Salt soluble protein of K1 (1 grade Hanwoo) was high as 7.437 mg/g (p<0.0001).

• Journal of the Korean Society of Food Science and Nutrition
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• v.9 no.1
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• pp.15-22
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• 1980

In this study, two species of algae, Ecklonia stolonifera, Sargassum thunbergii and one species of marine plant, Zostera marina(rhizoid and stem) were collected and extamined to determine the extractability of water soluble protein and the influences of various factors including extraction time, temperature, ratio of sample vs solvent and pH upon the extractability were tested. The effects of precipitation treatments for isolation of algal protein from the extracts(TCA treatment, methanol treatment and pH control) were also tested. Amino nitrogen and total nitrogen of purified samples made by obtained optimum conditions were estimated. The effect of the ratio of sample vs solvent on extractability differed from species to species which was enhances at 1:100(w/v) in Sargassum thunbergii and Zostera marina while 1:150(w/v) for Ecklonia stolonifera. The effect of extraction time and temperature was revealed differently in all species which might be considered to be caused by differences in the constitution of algal tissues. But in case of TCA insoluble nitrogen, it was showed the maximum extractability at $40-50^{\circ}C$ for 1 hour extraction. The optimum pH for the ext action of total nitrogen was 9-12 while the optimum pH was 6-7 for TCA insoluble nitrogen. And the pH control appeared to be most effective in the influence of precipitation treatment for isolation of algal protein.

• The Korean Journal of Food And Nutrition
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• v.11 no.5
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• pp.536-541
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• 1998

This study was carried out to investigate the changes of characteristics of myofibrillar protein for the vacuum chilled, the air frozen or the rechilled Holstein beef loin. The vacuum chilled beef was stored at 1$^{\circ}C$ and the air frozen beef was stored at -20$^{\circ}C$ for 60 days. The rechilled beef was restored for 3 days at 1$^{\circ}C$ by using the vacuum chilled or the air frozen beef. Myofibrillar protein extractability, 30,000 dalton component content and Mg-ATP ase activity for the vacuum chilled beef were higher than those of the air frozen beef. Each parameters increased significantly for the vacuum chilled beef after the 20 days storage, but there was no significant difference for the vacuum chilled beef after the 20 days storage, but there was no significant difference for the air frozen beef during the 60 days storage. By the rechilling process, myofibrillar protein extractability of the vacuum chilled and the frozen beef were not significant difference. The 30,000 dalton component of the vacuum chilled beef was showed not significant increment by rechilling, but the frozen beef was showed significant increment by rechilling. The Mg-ATPase activity of myofibrillar protein of the vacuum chilled beef was not changes by rechilling, but the frozen beef after the 20 days storage was significant increment by rechilling.

• Food Science of Animal Resources
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• v.21 no.2
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• pp.126-132
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• 2001

This study was carried out to investigate the effect of ultrasonic treatment on physicochemical and sensory properties of cooked chicken meat. Moisture content of ultrasonic treated breast meat was higher than that of control, fat content of control of breast and leg meat were higher than that of ultrasonic treatment, and protein of control of breast meat was higher than that of ultrasonic treatment. Hunters L(lightness)-and a(redness)-value were not different between cooking methods, L-value of breast meat and a-value of leg meat were higher without regard to cooking method. Hunterb (yellowness)-value was not different among cooking chicken meats. Cooking yield was not different between cooking methods, pH of ultrasonic treated chicken meats were higher than that of control. Water holding capacity and salt soluble protein extractability of ultrasonic treated breast meat were greater than that of control. Water soluble protein extractability of ultrasonic treated leg meat was higher than that of control, and shear force value was not different between cooking methods. Hardness, cohesiveness and gumminess were not different between cooking methods and parts of muscle. Springiness of ultrasonic treated leg meat was greater than that of control and chewiness of breast meat was higher than that of leg meat. Aroma, texture, juiciness and overall acceptability were not different between cooking methods, taste of ultrasonic treated leg meat was higher than that of control. In addition, the sensory scores of parts of muscle were affected greater than that of cooking methods.

• Korean Journal of Poultry Science
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• v.25 no.2
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• pp.55-64
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• 1998

This study was carried out to investigate the postmortem changes in physico-chemical characteristics of chicken meat with different breeds. Thigh and breast meats from Korean Native Chicken(KNC, 15-wk old), Wangchoo(15-wk old), and broiler(7-wk old) were stored at 5 ˚C. Differences in postmortem pH changes were not recognized among breeds, and pH showed by the lowest value at the 1st day of postmortem in all breeds. Breast meat had tendency to drop pH faster than thigh meat. Heme pigment contents showed no differences among breeds. KNC showed the lowest cholesterol contents in all breeds, total collagen contents showed the lowest value at the 1st day of postmortem, and thereafter it was gradually increased. Heat soluble collagen contents was lowest in Wangchoo. Water soluble and salt soluble protein showed the lowest extractability at the 1st day of storage. Broiler showed the highest extractability of these proteins and Wangchoo showed the lowest. Water holding capacity(WHC) had increasing tendency whilst cooking loss had decreasing tendency by the ageing. WHC of breast and thigh meat showed the highest values in KNC and broiler, respectively. Myofibrillar fragmentation index (MFI) was significantly increased in all breeds by the ageing. Breast and thigh meat showed almost same MFI in KNC and broiler, and in KNC and Wangchoo, respectively. Hardness of breast meat showed decreasing tendency by the ageing.

• Journal of Life Science
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• v.10 no.4
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• pp.326-332
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• 2000

In order to investigate the possibility of functional property improvement of meat products, four kinds of pork patties were prepared with water 10% as control, mugwort extract 10%, pine needle extract 10% and fatsia leaf extract 10%, respectively. In case of control moisture content was higher, but crude fat was lower, compared to patties treated with plant extracts. Crude ash content of pine needle extract treatment showed higher level than that of other patties. pH range of patties revealed to 5.92∼5.978. In raw patties Hunter's L-and a-value of control were higher than those of plant extract treatment, and a-value of raw patties showed higher level than that of cooked. Yield, water holding capacity, salt soluble protein extractability and gel strength among patties did not show significant differences. In control patty, fat retention was lower compared to other plant extract treatments, but water soluble protein extractability was higher compared to pine needle. Values such as hardness, springiness, cohesiveness, gumminess and chewiness were not significantly different among the patties. In sensory scores such as aroma, juiciness and palatability, significant differences were not observed among cooked patties, but texture score was higher in the order pine needle, mugwort, fatsia leaf and control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.758-762
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• 1993

The effect of sodium hexametaphosphate(SHMP) on the extraction of defatted sesame meal protein and the color and amino acid composition of protein concentrate have been studied. The highest amount of protein could be extracted with 1.5% SHMP and the extraction was effective at pH 12.0. The extraction rate tended to increase with increasing the flour to solvent ratio and about 60% of protein was obtained when adjusted the ratio to 1 : 40. Color of sesame protein concentrate was slightly improved by SHMP treatment. Lysine and methionine content were decreased in SHMP-treated protein concentrate but valine and leucine content were increased.

• Korean Journal of Poultry Science
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• v.21 no.4
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• pp.277-284
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• 1994

The functional properties of mechanically deboned chicken meat(MDCM) from whole carcass, whole carcass without exsanguination, neck without skin, leg hone, and upper back and rib were studied. Also, the effects of adding different levels of gelatin and MDCM to the comminuted meats were investigated. Proximate composition values of MDCM ranged from 54.2 to 68.6% moisture, 14.5 to 19.7% protein, 12.3 to 30.1% fat, and 1.1 to 1.3% ash. The MDCM from leg hone had a higher content of fat, and a lower contents of moisture and protein. The MDCM from neck without skin tended to be opposite to the MDCM from leg hone. The total pigment and myoglobin levels were highest in MDCM from whole carcass without exsanguination such as 3.83 and 0.29 rng /g, and those from the other parts were 1.58~2.93 mg /g and 0. 17~0.31 mg /g, respectively. The emulsifying capacity and water holding capacity were highest in MDCM from neck without skin which contained lower levels of fat, collagen and hydroxyproline, but a higher level of salt soluble protein. The emulsifying capacity of comminuted meat decreased as gelatin content increased. The extractability of hydroxyproline from gelatin showed a higher solubility in acidic solution. The MDCM could he added up to 20% level without detrimentally affecting functional properties of comminuted meats although they had less water holding capacity and cooking loss as the proportion of MDCM increased.