• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.663-668
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• 2007

This study evaluated the microbial, nutritional, and rheological changes in potatoes, during storage at room, low, and freezing temperatures for 6 months. No significant changes in total aerobic plate counts were observed for any of the samples in the assessment of microbiological quality changes. For the 4 types of frozen potatoes, yeasts and molds were not found until 24 weeks. The sugar contents of the potatoes stored at room and low temperature ($10^{\circ}C$) increased during the first 4 weeks of storage, but then decreased rapidly thereafter; while those in the frozen potatoes did not change significantly throughout the 48 weeks. The vitamin C, B1, and B2 contents of the potatoes stored at room and low temperature had decreased significantly after 4 weeks of storage, however, the levels in the frozen potatoes did not change rapidly. The weight, volume, and hardness of the frozen potatoes changed much less as compared to the potatoes stored at room and low temperature over the 48 weeks of storage. Finally, the cohesiveness of all the samples, except for the frozen mashed potatoes, did not change during storage.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.274-281
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• 2015

BACKGROUND: A lasting release of low levels of persistence chemicals including pesticides and pharmaceuticals into river has a bad influence on aquatic ecosystems and humans. The present study monitored pesticide residues in the Yeongsan and Seomjin river basins and their tributaries as a fundamental study for water quality standard of pesticides.METHODS AND RESULTS: Nine pesticides(aldicarb, carbaryl, carbofuran, chlorpyrifos, 2,4-D, MCPA, methomyl, metolachlor, and molinate) were determined from water samples using SPE-Oasis HLB(pH 2) and LC/MS/MS. Validation of the method was conducted through matrix-matched internal calibration curve, method detection limit(MDL), limit of quantification(LOQ), accuracy, precision, and recovery. MDLs of all pesticides satisfied the GV/10 values. Linearity(r²) was 0.9965- 0.9999, and a percentage of accuracy, precision, and recovery was 89.4-113.6%, 3.1-14.0%, and 90.8-106.2%, respectively. All pesticides exclusive of aldicarb were determined in the river samples, and there was a connection between the positive monitoring results and agricultural use of the pesticides.CONCLUSION: Monitoring outcomes of the present study implied that pesticides were a possible non-point pollutant source in the Yeongsan and Seomjin river basins and tributaries. Therefore, it is required to produce and accumulate more monitoring results on pesticides in river waters to set water quality standards, finally to preserve aquatic ecosystems.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.345-356
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• 2012

We investigated the changes of fruit quality parameters, polysaccharide contents and cell wall components during maturation and ripening of two Korean pear cultivar 'Hanareum' and 'Manpungbae' compared with 'Niitaka' pear (Pyrus pyrifolia Nakai) which showed different physiological maturity based on days after full bloom (DAFB). Flesh firmness decreased continuously with fruit development and maturation, reaching a final level of 29.4, 33.5, and 27.4N at maturity in 'Hanareum' (127 DAFB), 'Manpungbae' (163 DAFB), and 'Niitaka' (170 DAFB), respectively. The level of ethylene production was very low in early season 'Hanareum' pear which showed at most 0.39 ${\mu}L{\cdot}L^{-1}$ at maturity and no ethylene was detected in 'Manpungbae' and 'Niitaka' at maturity. Fructose was the most abundant soluble sugar during fruit maturation in the pears tested and an increase of sucrose was observed during fruit ripening in the Asian pears commonly. Ethanol insoluble solids (EIS) content decreased gradually with different levels among the pear cultivars as fruit ripens consisted of 10.79, 12.72, and 12.75 $mg{\cdot}g^{-1}$ FW. The amount of total soluble polyuronides was higher in early season cultivars 'Hanareum' than those of mid-season cultivar 'Manpungbae' and 'Niitaka'. In 'Niitaka' which harvested most late season, the level of 4% KOH soluble hemicelluloses was lower than 'Hanareum' and 'Manpungbae' and maintained constantly during fruit ripening period. Cellulosic residues were determined high level in 'Niitaka' which showed 612.33 ${\mu}g{\cdot}mg^{-1}$ EIS at maturity when compared with 'Hanareum' (408.0 ${\mu}g{\cdot}mg^{-1}$ EIS) and 'Manpungbae' (538.67 ${\mu}g{\cdot}mg^{-1}$ EIS). The main constituents of cell wall neutral sugars which consisted of arabinose, xylose, galactose, and glucose were decreased gradually with onset of fruit ripening regardless of cultivar. Arabinose which was predominant in 'Hanareum' pear decreased at the last stage of ripening, but the changes of cell wall neutral sugar during ripening were not occurred in 'Niitaka' pear. The change of molecular mass distribution in water soluble pectin observed dominantly at the early stage of fruit development. Depolymerization of 4% KOH-soluble hemicelluloses and degradation of xyloglucan showed in early-season cultivar 'Hanareum' during fruit maturation, and degradation of those fractions were detected only at the early stage fruit development in mid-season cultivar 'Manpungbae' and 'Niitaka'. The molecular mass profile of CDTA soluble pectin, $Na_2CO_3$-SP and 24% KOH soluble hemicelluloses showed no significant change during fruit maturation regardless of cultivar.

• Journal of Life Science
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• v.30 no.7
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• pp.606-613
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• 2020

This study investigated the effect of olive oil substitution ratio on physicochemical quality of pork patty. Five treatments were performed as follows: control (T0, 20% pork fat), T1 (pork fat 15% and olive oil gel 5%), T2 (pork fat 10% and olive oil gel 10%), T3 (pork fat 5% and olive oil gel 15%), and T4 (olive oil gel 20%). The moisture increased and fat amount was decreased in proportion to olive oil substitution ratio. The L^* and a^* values were highest levels in raw and cooked pork patty of T0, and the b^* value was highly enhanced in of cooked pork patty of T4. The water holding capacity, moisture and fat retention were significantly increased, and the cooking loss, diameter reduction and shrinkage ratio were decreased by olive oil substitution ratio. The hardness, springiness and chewiness showed the highest level in T4, and the cohesiveness and gumminess were highest in T0. The reduction ratio of cholesterol in T1, T2, T3 and T4 were 13.8%, 21.6%, 34.5% and 49.0%, respectively, indicating that the content was lowest level in T4. The palmitic acid was the most abundant saturated fatty acid, and the oleic acid was the most abundant unsaturated fatty acid. The unsaturated fatty acid of pork patty was increased in proportion to olive oil substitution ratio. Therefore, the olive oil gel substitution of low-fat pork patty results in a positive effect on the physicochemical qualities due to reduced cholesterol and saturated fatty acids.

• Food Science and Preservation
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• v.21 no.5
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• pp.676-687
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• 2014

This study investigated the quality changes in cabbage brined with deep sea water salt and in a commercial brined cabbage product. The subject cabbages were separated into two groups: those manufactured in the Lab (ML) and the commercial brined cabbage product (CP). Each group had three brining treatments: with sun-dried salt (S, CS), refined salt (R, CR), and deep sea water salt (D, CD). The salinity level of the ML group was 2.1~2.3%, higher than that of the CP group (1.1~1.5%). The total plate count (TPC) was detected as 5.0 log CFU/g with the S, R, and D treatments at Day 7, but the growth rate of the TPC with the CS, CR, and CD treatments was faster than that with the S, R, and D treatments (6.9~7.7 log CFU/g). A lactic acid bacteria (LAB) level of 5.0~6.6 log CFU/g was also detected in the S, R, and D samples, but only 7.0~7.6 log CFU/g was detected in the CP groups at Day 14. The instrumental hardness levels of the cabbage brined with the deep sea water salts (D and CD) were 3,971 g and 3,932.4 g, respectively, which were significantly higher than those of the samples that were salted with sun-dried salt and refined salt (p<0.05). As for the sensory attributes, S, D, and CD maintained their marketability scores until the end of the storage period for all the properties. CD presented the highest total free amino acid (478.9 mg%), glutamic acid (107.0 mg%), citric acid (428 mg%), and sodium (189 ppm) contents.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.200-204
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• 2001

Persimmon (Diospyros kaki. cv. Fuyu) fruits were packaged under different conditions, and then stored at $0^{\circ}C$ for 21 weeks. The tried packages were heat-sealed bag of one fruit, heat-sealed bag of five fruits, and tie-sealed bag of five fruits, which used films of three different thickness (0.03 ㎜, 0.05 ㎜ and 0.06 ㎜). Throughout the storage, package free volume, package atmosphere and quality were measured. Package free volume decreased with time with higher rate for heat-sealed bags, in which close contact between fruit and the film was eventually reached in longer storage. However, tie-sealed bags maintained the levels of stabilized free volume. The rate of free volume decrease was faster with thinner film and larger bag size for the packs sealed by the same method. Package atmosphere covered $O_2$ concentration of $1.1{\sim}17.1%$ and $CO_2$ concentration of $1.1{\sim}8.3%$, $O_2$ concentration decreased during storage, whereas $CO_2$ increased. Thinner film package created the internal atmosphere of higher $O_2$ and lower $CO_2$ concentrations. Tie-sealed bags of 5 fruits in the films of 0.05 mm and 0.06 mm thickness maintained the equilibrated package atmosphere of $1.1{\sim}3.0%\;O_2$ and $4.0{\sim}5.5%\;CO_2$, which preserved the fruits best in terms of firmness and less physiological changes of flesh browning and peel browning. At five fruit heat-sealed bag in the films of 0.06 mm thickness with $CO_2\;8.3%$, flesh browning occurred at a high rate, whereas all treatments in the film of 0.03 mm thickness with high $O_2$ and relatively low $CO_2$ contents, flesh and peel browning rates were high.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.8
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• pp.1048-1054
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• 2007

The quality characteristics of cookies, prepared with the freeze dried fresh garlic (FGP) and steamed ($100^{\circ}C$, 20 min) garlic (SGP) powders, were investigated. The cookie samples in the present study were made by adding the garlic powders at different levels (0, 0.5, 1, 2, 4, and 6%). The highest spread ratio, $8.48{\pm}0.31$ and $8.62{\pm}0.21$, were obtained by mixing 6% FGP and 0.5% SGP with the cookies. Among the surface color of the cookies, the L-value decreased with increasing garlic powder contents compared to that of the control group, but the difference in the surface color among the kinds of garlic powders was insignificant. Although increases in the garlic powder content resulted in no noticeable difference among the a-value of the test group, the b-value was decreased significantly, particularly with increasing SGP contents. Hardness was also increased along with the garlic powder contents and was highest at its 2% content. When viewed from the sensor properties, the measured color tended to become brown at the garlic powder contents greater than 2%. The surface crack of the cookies also increased as the SGP content increased. Its garlic taste and flavor were slightly low at SGP added with 6% garlic powder content than FGP. The overall acceptability was higher in $0.5{\sim}4%$ added test samples than those in control group sample; it was highest for 1%, 2% and 0.5%, in decreasing order. In the sensor evaluation, the overall acceptability of the cookies was considerably different in the comparison of FGP added cookies with SGP added ones. Therefore, the optimal ratio investigated for making the garlic added cookies was shown to be 1 %, and its acceptability was relatively high for SGP added cookies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1217-1227
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• 2014

This study investigated the physicochemical properties and antioxidant activity of vinegar added with different levels (0%, 1%, 3%, 5%, and 7%) of Akebia quinata fruit during two-step fermentation. The physicochemical properties of vinegar evaluated were pH, total acidity, alcohol, and total sugar and amino acid contents. The antioxidant activities were based on ABTS radical scavenging activity, SOD-like activity, and reducing power. During alcohol fermentation, total acidity and alcohol contents of vinegar increased, but total sugar contents decreased. During acid fermentation, total acidities of vinegar increased. Vinegar added with 7% A. quinata fruit showed the highest total sensory score. Total polyphenol contents of vinegar added with 0% and 1% A. quinata fruit were not significantly different. However, vinegar added with 3, 5, and 7% A. quinata fruit showed significantly higher total polyphenol contents of 136.6, 381.59, and 415.35 mg/100 g, respectively, after 13 days of fermentation. Further, total flavonoid contents of vinegar added with 0~7% A. quinata fruit significantly increased to 21.73, 15.79, 15.15, 26.19, and 26.87 mg/100 g, respectively, after 13 days of fermentation. In addition, tannin contents of vinegar added with 0~7% A. quinata fruit significantly increased to 0.2042, 0.2004, 0.1255, 0.1384, and 0.1255 mg/100 g, respectively, after 13 days of fermentation. Moreover, ABTS radical scavenging activities of vinegar added with 0~7% A. quinata fruit significantly increased to 5.87, 12.59, 25.63, 34.02, and 35.25, respectively, after 13 days of fermentation at a concentration of 5 mg/mL. Additionally, SOD-like activities of vinegar added with 0~7% A. quinata fruit significantly increased to 8.22, 17.49, 16.86, 16.89, and 15.68%, respectively, after 13 days of fermentation. Reducing power of 7% A. quinata fruit was 0.527 after 1 day and 1.539 at the end of fermentation. Our results demonstrate that antioxidant activity significantly increased during fermentation according to the content of A. quinata. Further, the total polyphenol, flavonoid, and tannin contents were shown to be closely related with antioxidant activities. Thus, A. quinata could be effectively used as a vinegar and functional food material based on its antioxidant activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.593-598
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• 2011

This research was performed to determine the quality characteristics of steamed bread by the number of times through the fermentation process. The number of fermentations varied from 1 to 5 while the steamed bread was prepared by measuring the duration of fermentation, and samples were analyzed in terms of general ingredients, physical properties, in vitro starch hydrolysis, protein digestibility, and sensory characteristics. Five times of fermentation resulted in significantly higher water content (p<0.01), and single fermentation led to the highest protein content (p<0.01). Protein levels decreased as fermentation was repeated. Single fermentation gave the lowest specific bread volume (p<0.05) and it increased with the number of fermentation times. Physical properties also varied with the number of times of fermentation. With more fermentation, hardness, gumminess, and chewiness decreased (p<0.01), whereas resilience (p<0.01) and cohesiveness (p<0.05) increased. In vitro starch hydrolysis was higher with 5 times of fermentation than with single to 3 times of fermentation (p<0.05). Protein digestibility was also higher with 5 times of fermentation (p<0.05). In sensory evaluations, whiteness scores were higher with 4 to 5 times of fermentation (p<0.01) whereas scores for crumb uniformity were lower with 4 and 5 times of fermentation. Moistness (p<0.01), cohesiveness (p<0.01), and chewiness (p<0.05) showed their highest scores with 4 times of fermentation.

• Korean Journal of Agricultural Science
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• v.10 no.1
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• pp.9-21
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• 1983

The structures of oak stands were studied in relation to their productivity. Three plots classified by the site quality following to altitude, were selected on the oak stand located at Naryongri Eunsanmyun Buyeogun. The site qualities of the stand studied were generally estimated to be moderate in respect to some soil physical and chemical properties. Quercus variabilis was dominant species in the vegetation composition of the stand studied. The crown densities of the stand were varied from 65.4% in plot I to 78.2% in plot III and the parts, occupied with oak trees, ranged from 44.4% in plot I to 65.9% in plot III in the density. In the contrast to crown density, the growing stocks of oak trees ranged from $3.937m^3$ in plot I (73.4% of plot total) to $2.075m^3$ in plot III (84.3% of plot total). The occupied ratios, measured by crown class, exhibited dissimilarity between crown projection area and volume, and also the ratios brought into different patterns by plot. Highly significant correlations were proved between crown projection areas and volumes of individual oak trees by plot, but not proved in the relations by crown class. The cumulative growth, current annual increment and mean annual increment displayed various patterns by plot and by crown class in the heights, D. B. H. s and volumes of oak trees. The maximum values of current annual increment of height were generally recorded in 10 to 20 years, earlier than those of D. B. H. The mean annual increment of height, D. B. H. and volume maintained similar levels after about 10 years and fluctuated irregularly. The crown projection area and volume following to thinning decreased in the order of the thinning methods of grade A < grade B < crown thinning$90m^3/ha$ in about 40 years in the productivity of volume of the oak stand studied.