• The Korean Journal of Food And Nutrition
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• v.30 no.5
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• pp.935-942
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• 2017

In the present study, kohlrabi-kimchi was prepared for assessment of changes in sensory qualities and measurement of changes in quality characteristics according to the storage period for the purpose of using kohlrabi as an ingredient of Kimchi. Examination of the physicochemical properties of kohlrabi-kimchi according to the storage period showed that the acidity increased steadily throughout the storage period, while soluble-solids content, pH and hardness decreased as the storage period elapsed. Meanwhile, the L value increased and then it decreased as the storage period elapsed, but, the a value increased and the b value gradually decreased after day 14 of storage. Reducing sugars increased up to day 10 of storage, and then they decreased slowly after day 15 of storage. Measurement of changes in lactic acid bacteria in kohlrabi-kimchi according to the storage period showed bacterial growth showing typical tendencies of Kimchi with a rapid increase on day 5 of storage and a decrease thereafter. Assessment of sensory qualities of kohlrabi-kimchi according to the storage period showed that the highest scores for appearance and sourness, odor, texture, and overall scores were obtained on day 15 of storage. Based on the above results, it was determined that the optimal maturity period of kohlrabi-kimchi is day 15 of storage.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.820-830
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• 2019

Most consumers consider yogurt to be a healthy food because it contains probiotic microorganisms. Although a plethora of commercially produced yogurts exists, nutritional and functional aspects of the commercial yogurts have not been well characterized. In this study, the microbiological and physicochemical properties of popular drinking yogurts in Korea were extensively characterized. The viability of lactic acid bacteria, including lactobacilli and bifidobacteria, varied between yogurt samples. These lactobacilli and bifidobacteria showed effective antimicrobial activities against foodborne pathogenic bacteria. Unlike the titratable acidity and pH, the soluble solids content varied between yogurt samples. All the yogurt samples contained high levels of potassium (average 143.53 mg/100 g) and calcium (average 133.92 mg/100 g), as well as phosphorus and sodium. Lactose, fructose, and glucose were the major sugar components in most yogurt samples, whereas the levels of sucrose and maltose were relatively low. Among several organic acids analyzed in the yogurt samples, lactic acid (average 767.67 mg/100 g) and citric acid (average 170.91 mg/100 g) were the most predominant. Taken together, this study provides preliminary information about the nutritional and functional characteristics of commercially available drinking yogurts.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.521-529
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• 2022

This study evaluated the effects of agricultural reflective film and HANSPEK film on the fruit quality attributes and peel color variables of 'Fuji' apples. The reflective films were applied under the tree canopies at 20 and 30 days before harvest (DBH), and a tree with no films was used as the control. Depending on the measurement locations, the light intensity was 7.4 - 14.6% higher in the reflective film treatments than that of the control. However, no difference in the light intensity was observed between the reflective and HASPEK films. In addition, the light intensity was not also different between the 20 and 30 DBH. At harvest, the flesh firmness, fruit weight, soluble solids content, titratable acidity, and internal ethylene concentration were not different regardless of the type of reflective film and treatment time. In addition, the peel color variables were not affected in the equatorial region. However, in the calyx region, the L* and b* values were decreased, and the a* value was increased by the reflective and HANSPEK films compared with the control. Hence, the hue angle was decreased to near 0^o (red), and the peel color was improved. Therefore, this study suggests that the application of the HANSPEK film under a tree canopy could improve the fruit peel color of 'Fuji' apples.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.387-390
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• 2000

The experiment was conducted to investigate the effects of vine management and yield on fruit quality and bud burst of 'Campbell Early' grapevines in Hwaseong and Suwon area. The extreme value of minimum temperature of Hwaseong area, frequently causing cold damage, was lower than that of Suwon area in winter. Narrow spacing, overbearing, and poor vine management were observed in Hwaseong area, where the harvest time was delayed by 7 days compared with that of Suwon area. Total carbohydrate content of bearing mother branches was lower with 1.2~1.7%, and the percentage of bud burst was extremely lower at $-15^{\circ}C$. In Suwon area, there were no differences in cluster and berry size, but soluble solids content was lower and skin coloration was poorer when yield was high. Total carbohydrate content was lower when yield was high. The percentage of bud burst was lower at cold treatments below $-20^{\circ}C$. The results suggest that appropriate yield based on fruit quality is 2.3~2.6 MT/10a.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.807-817
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• 2016

Many onion growers and researchers assert that differences in soil type, agricultural practices, weather, and duration of prolonged onion cultivation in a particular field could affect onion bulb quality. This study evaluates the bulb quality of onions grown in different regions and determines the correlations between bulb characteristics and postharvest loss during cold and ambient storage. Soil and onion bulbs were collected from fields in six onion growing regions in Korea, during the growing season of 2011-2012. The fresh weight, dry matter content, and carbon (C), sulfur and magnesium contents of the onion bulbs were significantly affected by the location in which they were grown. Bulbs grown in Muan had the greatest number of scales, thinnest scale thickness, and the highest total soluble solids (TSS) and total flavonoids (TF). Bulbs originating from Jecheon had the lowest pyruvic acid (PA), total phenolics and TF. Storage loss of bulbs from the different regions was similar in refrigerated storage, but differed in ambient temperature storage. Bulb fresh weight was positively correlated with scale thickness (r = 0.617) and cold storage loss (CSL; r = 0.398). Dry matter content was positively correlated with C (r = 0.958) and TF (r = 0.256) contents, while it was negatively correlated with CSL (r = -0.424). CSL was primarily affected by the fresh weight, as well as the dry matter, C, and PA contents of the bulbs, while ambient storage loss was primarily influenced by the amount of TSS.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.541-545
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• 1995

Physicochemical properties and chemical compositions of Citrus fruits produced in Cheju were investigated. Soluble solids, total sugar and acid content of Citrus unshiu were $10.4{\sim}11.0^{\circ},\;8.24{\sim}8.79%\;and\;1.04{\sim}1.20%$, respectively. Vitamin C ranging from $41.19{\sim}46.55\;mg/100\;g$ was higher on medium type than on early type of Citrus unshiu. In case of inorganic elements in Citrus unshiu, potassium content was the highest, in the range of $108.66{\sim}132.65\;mg/100\;g$, and it was higher on C. platymamma than on Citrus unshiu. however, the kinds and contents of carbohydrate in citrus juice were somewhat different among citrus varieties. Sucrose was $46.8{\sim}64.6%$ and others were glucose and fructose, $18.4{\sim}26.9%\;and\;15.2{\sim}30.2%$, respectively. Citric acid content was $75.7{\sim}96.2%$, and others were malic acid, oxalic acid, and fumaric acid in the decreasing order.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.1
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• pp.29-33
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• 2013

This study investigated the effect of films treated with anti-fogging (LA) agent on the freshness extension of 'Fuji' Apples. Preference, weight loss, total ascorbic acid, sugar content, acidity, change of gas composition in package were evaluated during storage at $15^{\circ}C$. After 150 days of storage, the weight loss of apples in control (L), LA was 1.0 to 1.1%. Total ascorbic acid content of apples in control after 150 days was 2.09 mg/100g F.W, that of apple in LA was 2.47 mg/100g F.W. The titratable acidity of apple in LA was lower than that in control, while soluble solids content of LA was higher than that in control after 150 days. Ethylene gas adsorbability in control package was 192.2 ppm and that in LA was 195.7 ppm. It was verified that LA treated with anti-fogging agent are few different compare to control, but commerdity on the display in market was considered higher than that of non-treated anti-fogging agent.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.239-256
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• 2019

The quality of tomatoes drastically changes according to storage conditions, such as temperature, humidity, and air composition. High storage temperatures result in the degradation of the firmness and color of tomatoes and in decay by bacteria, whereas chilling injury and softening can be caused by storage at low temperatures. The gas composition in the storage and packaging are other parameters that influence the quality and shelf life of tomatoes by preventing excessive transpiration and respiration. In addition, tomato quality is dependent on the degree of maturity and harvest season. Because there are many quality parameters, it is necessary to systemically establish an optimal standard, and this approach requires collecting and reviewing various data on storage conditions. The aim of this review was to provide basic information by comparing and analyzing studies on the changes in tomato quality (firmness, color, lycopene content, and acidity of tomatoes) during storage and to describe a few models that can assess the quality parameters. Many studies have provided results from experiments on the effects of postharvest control (e.g., storage temperature, packaging film, and gas treatment, as reviewed above) on tomato quality including firmness, soluble solids content, and lycopene content. However, it is still necessary to conduct an overall analysis of the published conditions and to determine the best method for preserving the quality of tomatoes as well as other fruits.

• Journal of the Korean Society of Food Culture
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• v.36 no.1
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• pp.84-91
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• 2021

The oriental plum (Prunus salicina) is one of the most popular fruits in Korea due to its sweet taste and pleasant aroma. The objective of this study was to analyze the quality characteristics and antioxidant activities of a puree made using plums stored at low-temperatures. The quality characteristics were determined by estimating total soluble solids (TSS, °Brix), titratable acidity (TA, % citric acid), TSS/TA ratio, pH, colors, sugar content, and sensory profiles. The antioxidant effects were estimated by total polyphenol and flavonoid content and radical scavenging activity. The results showed that the plum puree containing both the flesh and the peel had markedly higher red coloration (a⁎ value) than the puree without the peel, while yellow coloration (b⁎ value) and lightness (L⁎ value) were lower in the puree without the peel than with the peel. The sensory qualities including the plum taste and flavor, texture as well as overall acceptance showed no significant variation between the samples. Meanwhile, the total polyphenol/flavonoid content and radical scavenging activities were significantly improved by the presence of fruit peel and by frozen storage. These findings suggest that frozen plums could be a suitable ingredient for making a puree and concentrate for the food manufacturing industry.

• Food Science and Preservation
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• v.20 no.6
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• pp.846-853
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• 2013

We investigated the effect of the cell-wall-degrading enzyme and its skin contact time on the brewing characteristics of Cheongsoo grape. The easy of juice extraction was excellent at the cell-wall-degrading enzyme and skin contact treatments, and the aroma was best after five days of skin contact treatment. Furthermore, the juice yields of the Chengsoo grape were more dramatically increased by the cell-wall-degrading enzyme and skin contact treatments than by the control. The data on the pH, total acidity, and soluble solids did not significantly differ among the treatments, and the pH range from 3.1 to 3.4; the total acidity from 0.5% to 0.6% (as tartaric acid); and the soluble solids, from 6.7 to 7.1 $^{\circ}Brix$. The alcohol content of cell-wall-degrading enzyme treatment was highest with 13.3%. The total polyphenol was gradually increased with the longer skin contact time, and was highest after 10 days of skin contact treatment, at 306.4 mg/L. The main organic acids detected in the Cheongsoo wine were malic and tartaric acid, and citric, succinic and lactic acid were also detected. Our results show that the cell-wall-degrading enzyme and skin contact treatments were better in terms of the easy of juice extraction and significantly increased the juice yield and the volatile compound of the Cheongsoo wine.