• Animal Bioscience
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• v.34 no.8
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• pp.1375-1381
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• 2021

Objective: This study was conducted to determine the effect of freeze-thawed cycles (Fresh meat, F-T 1 cycle and F-T 2 cycles) on the quality characteristics of porcine longissimus dorsi muscle. Methods: A total of 20 three-crossbred pigs (Duroc×[Large White×Landrace]) were randomly obtained from a commercial slaughterhouse in Thailand. Muscle samples were immediately taken from 10 to 11th of the longissimus dorsi for histochemical analysis. The muscles were cut into 2.54 cm-thick chops. A minimum of 20 chops were used for each treatment (fresh meat, freeze-thawed 1 and 2 cycles). Individually chops were packaged in polyethylene bags and frozen at -20℃ for 6 months followed by thawing in refrigerator at 4℃ for 24 h (the 1st freeze-thawed cycle). The freeze-thawed procedure was repeated for two cycles (the 2nd freeze-thawed cycle). Thawing loss, shear force value, citrate synthase activity and muscle fiber characteristics were determined on the muscles. Results: Results showed that increasing of freeze-thawed cycle increased the thawing loss (p<0.01) and citrate synthase activity (p<0.001). Shear force value of fresh meat was higher than freeze-thawed 1 and 2 cycles (F-T 1 cycle and F-T 2 cycles). Freeze-thawed cycles affected muscle characteristics. Muscle fiber area and muscle fiber diameter decreased with an increasing number of freeze-thawed cycles (p<0.001), while the thickness of endomysium and perimysium were increased (p<0.001). Conclusion: Repeated freeze-thawed cycles degraded muscle fiber structure and deteriorated pork quality.

• Animal Bioscience
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• v.36 no.9
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• pp.1414-1425
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• 2023

Objective: Long chain n-3 polyunsaturated fatty acids (PUFA) exert positive effects on human health. The long chain n-3 PUFA of pork can be increased by adding fish oil to the diet. Due to the cost and availability of fish oil an alternative source must be found. Methods: This study evaluated the effect of five dietary oils on meat quality, fatty acid composition and lipid stability. The five diets contained 1% palm oil (Control), 1% soya oil, 1% linseed oil, 1% fish oil, and 1% Echium oil, respectively. The trial consisted of 60 gilts, randomly allocated to five groups. Results: All color parameters, extractable fat content, fat free dry matter, and moisture content of the m. longissimus muscle were unaffected by dietary treatment. Consumers and a trained sensory panel could not detect a difference between the control samples and the Echium oil sample during sensory analysis. Samples containing higher levels of PUFA (soya, linseed, fish, and Echium oil) had higher levels of primary and secondary lipid oxidation products after refrigerated and frozen storage. However, these values were still well below the threshold value where off flavors can be detected. The Echium oil treatment had significantly higher levels of long chain PUFA than the linseed oil treatment, but it was still significantly lower than that of the fish oil treatment. Conclusion: Echium oil supplementation did not increase the levels of n-3 to the same extent as fish oil did. The result did however suggest that Echium oil can be used in pig diets to improve muscle long chain n-3 fatty acid content without any adverse effects on meat quality when compared to linseed, soya, and palm oil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1600-1607
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• 2013

The aim of this study was to investigate effect of nutrition education methodology on consumption of processed food and personality of middle school students aged 14 to 16 years who live in Busan. We categorized questionnaire based on students' consumption of processed food and personality characteristics. Based on the above, we determined serum mineral level to validate the correlation between personal characteristics and quantifiable serum mineral level. Following adoption of a proper nutrient education methodology, we found that consumption of processed foods such as meat and meat products, frozen food, noodles, bread and snacks, and drink was significantly reduced. In addition, there were distinct changes in personality characteristics such as stability, governmentality, sociality, and responsibility that became markedly increased, whereas impulsiveness decreased. We found that these distinct nutrition- education-based changes were statistically significant, when compared before and after providing proper nutrition education. We interpret these results as group with low stability showed a high consumption of meat and meat products, noodles, bread and snacks, and drink, whereas group with high stability showed a high consumption of milk and dairy products. Similarly, we also found that group with low impulsiveness showed a high consumption of canned foods, whereas group with high impulsiveness showed a high consumption of meat and meat products, frozen food, noodles, bread and snacks. Our results indicated that serum Na after nutrition education decreased, whereas other minerals including Ca, Fe, Zn, Mg and K increased, when compared with before nutrition education procedure. This study suggests that nutrition education methodology and establishment of proper dietary educational programs keeping in view balanced dietary habits for middle school students would not only appear to make them get along with healthy dietary habits, but also change their personality characteristics.

• Food Science of Animal Resources
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• v.27 no.2
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• pp.190-196
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• 2007

This study was carried out to investigate the effects of pressure assisted freezing(PAF) on physicochemical properties of pork meat. Pork meat was frozen under pressure up to 200 MPa at $-60^{\circ}C$, and compared with fresh control. Phase transition temperature decreased with increasing pressure level, while pressure level had no effect on supercooling extent. Increasing pressure level increased pH of meat significantly(p<0.05). Thawing losses of all treatments were significantly higher(p<0.05) than control with the exception of PAF at 200 MPa. Water holding capacity(WHC) was increased significantly(p<0.05) with increasing pressure level up to 100 MPa. Cooking loss tended to decrease with increasing pressure level. In color, CIE $L^*-\;and\;b^*-value$ increased with increasing pressure level, while CIE $a^*-value$ decreased significantly(p<0.05). Increasing pressure level up to 150 MPa increased shear force significantly(p<0.05), however, no significant difference between 150 and 200 MPa in shear force was found(p>0.05). Therefore, the results indicated that excessive pressure level in PAF caused several losses in meat qualities, while PAF at mild pressure level improved meat qualities compared to atmosphere freezing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.219-227
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• 1989

A new devised conductivity meter was used in the rapid and convinient determination of freshness of fish meats. Electric conductivity of frozen fishes like cod, tuna, flounder, Alaksa pollock were demonstrated about $6,100\pm200{\mu}u$ at the beginning of spoilage showed VBN content of $30\~35mg\%$ while that of fresh meat of yellow tail, rock trout, and mackerel were in the range of $5,100\~5,400{\mu}u$. The relationship between electric conductivity and freshness as measured by VBN content was direct proportion during the deterioration of fish meat. It was presumed that electric conductivity change of red muscled fish was more temperature dependence than that of white muscled fishes. $Q_{10}$ value of mackerel meat was about 2.34 at the temperature ranged from 15 to $30^{\circ}C(\pm1^{\circ}C)$). The electric conductivity obtained with conductivity meter could be a valuable criteria for the freshness test of fish meat determining in 10 seconds by handy compact portable meter.

• Journal of the Korean Home Economics Association
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• v.25 no.4
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• pp.73-83
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• 1987

This study was conducted to evaluted the industry foodservice management practices, and to suggest guidelines for the effective foodservice management. The results of the study can be summarized as follows: 1) Feeding numbers among the types of industry were varied widely, and foodservice personnels were insufficient when comparing with the feeding numbers. 2) Effective recording as well as management system were not fully established in menu planning, food production, assembly and service. Thermal retention equipments were not provided to control food quality. 3) Convenience food items such as frozen beef cutlet, hambergar patty, retail cuts of meat, and canned fish were seldom used. 4) Sanitary conditions of kitchen and dining areas were evaluated as unsatisfactory comdition. 5) Equiped rate of facilities in surveyed foodservice operations were 52.7 percentage of the required standards.

• Journal of Animal Science and Technology
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• v.44 no.3
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• pp.361-368
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• 2002

The Korean frozen pork loins in vacuum packaged were obtained from three different Korean export companies and investigated for pH, proximate composition, cooking loss, physico-chemical and sensory characteristics. The frozen pork loins were stored at -20$^{\circ}C$ for 40 days. The results were as follows: The protein contents were relatively higher in the samples from the company II and the ash contents were relatively higher in the samples from the company I than those from the other companies. The samples from the company Ⅱ had highest pH and water-holding capacity, and cooking loss and shear force were lowest in the company II. The total plate counts and coliform bacteria for loins from 3 companies were in the range of 3.04${\sim}$3.75 log cfu/$cm^2$ or g and 0.37${\sim}$1.32 log cfu/$cm^2$ or g in average, respectively. The TBARS values were 0.35${\sim}$0.38 mg malonaldehyde/kg sample. There were no significant differences in sensory characteristics for raw and cooked loins from all companies.

• Food Science of Animal Resources
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• v.21 no.4
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• pp.292-299
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• 2001

Chicken surimi from mechanically deboned chicken meat was prepared with 0.2% oleoresin spices such as rosemary, thyme, sage, mace, marjoram, and bay. Samples were stored at -18$\^{C}$ for 14 weeks to observe quality change including lipid oxidation, color and textural properties. The pH of surimi decreased from pH 7.44∼7.58 stored at 1 day to pH 7.03∼7.13 stored at 14 weeks. The control surimi showed higher level of pH during storage periods. Color stabiilty of surimi decreased during frozen storage both in control and oleoresin added surimi. Control surimi comparatively maintained higher color stability during frozen storage because of higher L* and a* values, and lower b*. On the contrary, the marjoram addition significantly decreased L* and a* value, and increased b* value compared with other oleoresins. Therefore, the color of surimi seems to be affected original color of oleoresin spice itself. Gel strength showed loser level in oleoresin added surimi than control surimi. Oleoresin spices inhibited lipid oxidation significantly because less thiobarbituric acid-reactive substance(TBARS) were accumulated in oleoresin added surimi than control surimi. Sage was the most effective in minimizing lipid oxidation in frozen surimi as TBARS of sage added surimi stored for 14 weeks maintained only 42% compared with that of control. In conclusion, the 6 kinds of oleoresin in this experiment retarded oxidative rancidity in chicken surimi but there was no beneficial effect on the surface color and gel strength.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.682-687
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• 1999

The destruction of tissues by volume increase at food freezing is accepted as one of the factor responsible for quality damage. For this reason, the internal pressure developed in meats were investigated with a pressure transducer during freezing, frozen storage and thawing. Increasement of 6.33% for volume and $942.17\;kg/cm^2$ for density at $-20^{\circ}C$ for beef were shown. In quick and slow freezing of beef, internal pressure reached to highest point after reached to the lowest point at initial of the zone of ice crystal formation. The internal pressure was approximately $8{\sim}10\;psig$ and pressure difference was about 1 psig, which was bigger in immersion freezing than that of still-air freezing. During frozen storage of pork, internal pressure of $1.84{\sim}2.32\;psig$ occurred repeatedly as a function of sample weight at material temperature difference of ${\pm}1^{\circ}C$. The internal pressure during thawing of pork was decreased slowly after rapid increase to the maximum for less than 5min at the beginning of thawing. Internal pressure value at thawing was higher than that at freezing in most cases. Internal pressure of beef with thermal equalized freezing was about $1{\sim}4\;psig$, which was lower than that of non-thermal equalized freezing. Also, freezing time was shortened to $10{\sim}20%$.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.771-775
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• 1997

Treatment with electron beam irradiation was investigated for the elimination of Escherichia coli O157:H7 which has been linked to outbreaks of foodborne illness on undercooked and raw meat. Before treatment, the maximum populations were observed at 16 hr when E. coli O157:H7 was incubated in TSB at $37^{\circ}C$. Incubation at $4^{\circ}C$ did not influence survival and growth of the strain. The numbers of E. coli O157:H7 were present about $10^{7}\;CFU/mL$ in the log $(6\;hr\;at\;37^{\circ}C)$ and stationary phase $(16\;hr\;at\;37^{\circ}C)$ of cells, respectively. Freezing $(24\;hr\;at\;-18^{\circ})$ had a more marked lethal effect. The $D_{10}$ value at $-18^{\circ}C$ of E. coli O157:H7 contaminated in frozen beef was 0.45 kGy, and inactivation factor were $6.67{\sim}11.11$ at the radiation doses of $3{\sim}5\;kGy$. Therefore, electron beam irradiation was an effective method to eleminate of E. coli O157:H7.