• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1599-1605
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• 2005

The object of this study is to develop the method for differentiating fresh meat from frozen meat by using the measurement of the mitochondrial malate dehydrogenase in the Korean native cattle. The principle of this experiment is based on the fact that the enzyme proteins associated with mitochondrial membrane could be released by freezing. The methods of differentiating fresh meat from thawed, frozen meat were studied by measurements of mitochondrial malate dehydrogenase activity of meat press juice. Fresh and frozen beef were stored at 4, -4, -18 and -77$^{\circ}C$ for 15-day storage period. A meat press machine using air pressure was manufactured especially for these experiments, and sufficient amount of drip (about 0.15 mL/g) from 1.5 g of beef sample was efficiently obtained under a pressure of 8 kg/$cm^{2}$ generated by the meat pressing machine. The mitochondrial malate dehydrogenase activities of frozen meat drip i년ices stored at -18 and -77$^{\circ}C$ were significantly higher than those of fresh and frozen meat samples at -4$^{\circ}C$ (p < 0.05) during 10-min reaction period. However, the enzyme activities of the frozen meat drip juices (-18 and -77$^{\circ}C$) disappeared after 5 minutes of the reaction, which was not observed from the fresh and -4$^{\circ}C$ frozen meats. The enzyme activity maintained until 12 minutes for the fresh and -4$^{\circ}C$ frozen meats. From these results, the mitochondrial malate dehydrogenase could be considered as an indicator to differentiate fresh beef from frozen one.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.359-364
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• 2003

Frozen doughs for danish pastries were made by straight dough method to study the effect of thawing temperature on the quality of pastries. Danish pastry doughs were immediately frozen at -40 $^{\circ}C$ quickly after make-up and stored for 6 weeks at -20$^{\circ}C$ and baked after thawing and fermentation a week. Thawing temperature and fermentation time were controled to 3 hr at 5$^{\circ}C$, 2 hr at 10$^{\circ}C$, and 1.5 hr at 20$^{\circ}C$, respectively. The number of survival yeast cells in dough and the volume, the moisture content, the texture of danish pastries were investigated. Survival yeast cells showed the highest number at thawing temperature of 5 $^{\circ}C$. The volume of danish pastries decreased significantly according to the increase of frozen storage time and danish pastries thawed at 5$^{\circ}C$ revealed the largest volume. In moisture contents of danish pastry, there was no significantly difference without regard to the thawing temperature but showed the highest moisture content at thawing temperature of 20$^{\circ}C$. Danish pastries thawed at 5$^{\circ}C$ accomplished the best texture in the resulting pastry.

• Culinary science and hospitality research
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• v.7 no.1
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• pp.91-105
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• 2001

Chou-cream bread and Red bean paste bread were made by sponge & dough method with the sweet dough formula. The bread quality was studied by the measurements of the temperature variation, the fermentation level of frozen dough in the special condition(dough conditioner of 5$^{\circ}C$, 10$^{\circ}C$, 15$^{\circ}C$, 20$^{\circ}C$ and 30$^{\circ}C$), the product volume and thesensory evaluation with frozen dough thawed, fermented and baked. When thawing temperature was low, the core temperature of frozen dough increased slowly and the time for thawing and fermentationwas long. In thawing and fermentation, the core temperature of Red bean paste dough increased faster than that of Chou-cream dough. When the thawing conditions of dough conditioner(retarder) were 20$^{\circ}C$ and 30$^{\circ}C$, the level of total time decrease for thawing and fermentation was 55 and 86 min in Chou-cream dough and 62 and 90 min in Red bean paste dough respectively in comparison to dough conditioner of 5$^{\circ}C$. In volume of baked products, they showed no significant difference for three weeks of storage, but slight difference for four weeks of storage. The result was that Chou-cream bread was larger than Red bean paste bread in the decrease of volume. In sensory evaluation, the bread quality became low according to the time. When stored for four weeks in the freezer, significant differences were found in Chou-cream vread, but slight difference appeared in Red bean paste bread. The research identified that Red bean paste dough was more effective in manufacturing time than that of Chou-cream dough, when thawing temperature was high, and if frozen dough was thawed in the retarder of lower than 20$^{\circ}C$, the bread quality in terms of volume and sensory evaluation had no significant difference in comparison to the none-freezing Red bean paste bread.

• Food Science of Animal Resources
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• v.40 no.3
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• pp.444-460
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• 2020

This study was conducted to investigate the effects of freezing and storage temperature (-18℃, -50℃, and -60℃) on the physicochemical properties of pork neck and chicken leg meat in home-scale deep freezers. Pork neck was cut into a thickness of 3 cm (9×9×3 cm, 150 g), individually packed in air-containing packages, and stored at different temperature (-18℃, -50℃, and -60℃) for 6 months. Chicken leg meats were prepared (10 cm long, weighing 70 g) and packed in the same manner. Frozen samples were thawed at 2℃. Physicochemical properties such as thawing loss, cooking loss, water-holding capacity, color, volatile basic nitrogen (VBN), and thiobarbituric acid reactive substances (TBARS) were evaluated. The samples frozen by deep freezing (-60℃) was favorable with respect to thawing loss, color, and VBN. Samples frozen at -60℃ had lower values of thawing loss and VBN than those frozen at -18℃ for all storage periods (p<0.05). Color parameters were more similar to those of fresh meat than to those of samples frozen at -18℃ for 6 months. The TBARS of all samples were below 0.3 mg malondialdehyde/kg, thereby indicating oxidative stability of lipids. Consequently, deep freezing at -60℃ may be acceptable for maintaining the quality of fresh pork neck and chicken leg meat for 6 months without deterioration.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.92-96
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• 2003

Effects of vitamin C on the properties of bread including number of yeast cells, volume of bread, specific loaf volume, and hardness and sensory characteristics were evaluated. Vitamin C was added at various amounts to frozen doughs made through sponge &dough method using sweet dough formula and quickly frozen at $-40^{\circ}C$. Doughs were stored for 4 weeks at $-20^{\circ}C$. Evaluations were done after frozen dough was thawed, fermented, and baked every week. The bread with 150 ppm vitamin C revealed higher yeast cell survival rate during freezing storage, and higher specific and bread volumes than other doughs. Hardness of bread increased with increasing amount of vitamin C added. Bread with 100 ppm vitamin C revealed the highest sensory score. Consequently, addition of 100 ppm vitamin C to bread dough resulted in the highest overall evaluation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.117-124
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• 1983

Qualify changes of the precooked frozen sardine (Sardinops melanosticta) during frozen storage were investigated by measuring extractable protein, expressible drip, available lysine and lipid oxidation as peroxide value. Fresh sardine was dressed, washed in chilled water, cooked in boiling water to have $55^{\circ}C\;and\;70^{\circ}$ at the center of the body, frozen at $-40^{\circ}C$, and finally stored at $-20^{\circ}C$ for 84 days. The quality factor mentioned above were determined in both ordinary and dark muscle at 14 day intervals through the period of storage. When cooked at $70^{\circ}C$, the changes in expressible drip were less than that of raw and the one cooked at $55^{\circ}C$. In observation of the extractability of muscle protein, no great change in extractable sarcoplasmic protein was observed, the extractable myofibrillar protein, however, showed a tendency to decrease during the period of frozen storage, accompanying the increase of the alkali-soluble protein. That was more excessive in ordinary muscle than dark muscle. Lipid oxidation of dark muscle was faster than that of ordinary muscle. Acid value was not changed, and peroxide value of the samples cooked at $70^{\circ}C\;and\;55^{\circ}$ was higher than that of raw at the early stage of the storage, after 40-50 day storage, it became lower than that of raw muscle.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1621-1629
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• 2019

Objective: The objective of this study was to evaluate the physicochemical, sensory and taste characteristics of commercial, frozen, dry, and wet aged Hanwoo sirloin. Methods: Grade 2 sirloin from 6 Hanwoo steers (about 30 months old) were obtained after 5 days postmortem. Samples were assigned to four groups which were commercial beef (CON, control group), frozen beef (Hanwoo frozen, HF; 40 days in $-18^{\circ}C$ freezer), wet-aged beef (Hanwoo wet-aging, HW; 21 days), and dry-aged beef (Hanwoo dry-aging, HD; 40 days). HW and HD were stored in a $80%{\pm}5%$ relative humidity cooler at $1^{\circ}C$. Results: The HF group showed a significantly higher cooking loss and expressible drip with significantly higher pH compared to other groups. In addition, protein and fat contents in the HD group were higher than those in other groups (p<0.05). The shear forces in the HW and HD groups were significantly lower than those in the CON group. The HD group had significantly higher omega-3 and polyunsaturated fatty acids compared with other groups. Glutamic acid levels in the HD group were significantly higher compared with those in other groups. Electronic tongue analysis revealed that sourness of the HD group was lower than that of other groups, whereas the HD group showed significantly higher umami, richness, and saltiness compared to other groups (p<0.05). Sensory test results revealed that the HW group had significantly higher tenderness, while the HD group had significantly higher chewiness, juiciness, and overall acceptability scores. Conclusion: These results suggest that both wet- and dry-aging treatments can effectively improve sensory characteristics, and dry-aging was much more useful to enhance umami tastes and meat quality of 2 grade Hanwoo sirloins.

• Animal Bioscience
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• v.35 no.8
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• pp.1270-1278
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• 2022

Objective: The objective of this study was to evaluate quality characteristics of reduced-salt pork sausage (PS) using pre-rigor muscle compared to those of regular-salt PS. In addition, effects of freezing on sausage batter with different temperatures (-30℃ vs -70℃) on quality characteristics of both sausage batter and cooked sausages during frozen storage were observed. Methods: Pre-rigor and post-rigor pork hams were used to manufacture low-fat sausages. Sausages using post-rigor (Post) muscle were manufactured at a salt level of 1.5%, whereas those with pre-rigor (Pre) muscle were processed at salt level of 1.0%. After these muscles were made at two salt levels (1.5% salt, Post-rigor; 1.0% salt, Pre-rigor), Sausage batters were stored at two frozen temperatures (-30℃ vs -70℃). During storage for 12 wks, they were measured for physicochemical and textural properties every 4 wks up to 12 wks. Results: pH values and temperatures of sausage batter of pre-rigor muscle were higher than those of post-rigor muscle regardless of the frozen temperature. The lightness and yellowness values of batter at the initial storage were the highest during storage. For PS, there were no differences in most parameters measured among all treatments. However, expressible moisture values (%) of Pre-30 and Pre-70 were lower than those of Post-30 (p<0.05). Conclusion: Regardless of frozen temperature during storage, quality characteristics of pre-rigor PS with salt level of 1.0% salt were similar to those of post-rigor PS with salt level of 1.5%. By using the pre-rigor muscle, salt content could be reduced by one third of the regular-salt level (1.5%) of post-rigor muscle.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.4
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• pp.321-329
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• 1990

The present study was carried out to investigate the antioxidant effects of onion and ginger on the lipid peroxidation of mackerel during frozen storage. mackerels were reated with onion juice ginger juice tocopherol and BHA and stored at -18$^{\circ}C$ for 6 weeks. lipid peroxidation in samples was estimated by the periodical measurements of acid value iodine value peroxide value carbonyl value 2-thiobarbituric acid value and fatty acid composition. The treatments with ginger and onion were effective on the suppression of acid value and carbonyl value of makerel oil during 4 to 6 weeks of frozen storage. The iodine value was not affected by the treatments with various antioxidants, The production of peroxides was delayed by ginger or onion treatment, the TBA value of the sample muscles was not lowered by the treatments, The treatment with onion resulted in less changes in the contents of $\omega$-3 polyunsaturated fatty acids and in the P/S ration of fish oil than the control did. Results indicate that the applica-tion of ginger or onion juice on the surface of fishes may be useful to lower the degree of rancidity of fish during the froxaen storage.

• 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.