• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.352-357
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• 2019

In this study, we investigated the limit temperature range which is effective for dormancy release of 'Hongro' and 'Fuji' apples during the endodormancy period. The germination rate was 50% or more in all treatments except of 'Hongro' $-5^{\circ}C$ treatment. The germination rate of 'Fuji' was 86.3% at the temperature of $-5^{\circ}C$. The concentrations of carbohydrate and mineral components were significantly different between treatments but did not show any tendency or specific change. However, the sorbitol contents of 'Hongro' $-5^{\circ}C$ treatment were higher at 29.62 mg/g than those of 'Fuji', which was not affected for dormancy release. The results of hormone analysis showed that ABA(abscisic acid) and JA(jasmonic acid) in 'Hongro' $-5^{\circ}C$ treatment were respectively 176.48 and 15.72 ng/g. ABA, JA and SA(salicylic acid) contents in 'Fuji' apple tree were significantly lower than those of 'Hongro'. As a result of this study, the limit temperature range effective for dormancy release was different according to the varieties, and 'Hongro' did not affect with 30.3% of germination rate at $-5^{\circ}C$. However, 'Fuji' is 86.3% even at $-5^{\circ}C$ it was suggested that 'Fuji' had a chilling accumulation for dormancy release.

• Food Science and Preservation
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• v.17 no.5
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• pp.616-624
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• 2010

We compared the physicochemical properties of, and volatile components in various commercial fruit vinegars (made from apples, grapes, and persimmons). Total acidity was highest in grape vinegars. Significant between-sample differences were evident in total and reducing sugar contents. Brownness, turbidity, and overall color difference (the ${\Delta}E$ value) were highest in persimmon vinegars. Free sugars were composed mainly of fructose, glucose, sucrose, and maltose. Major organic acids were present in the (descending abundance) order acetic acid, oxalic acid, citric acid, malic acid, and succinic acid, among-samples difference were negligible. Nine-essential free amino acids were detected in nine types of grape and persimmon vinegars, and in six varieties of apple vinegar. Among 17 types of volatile compounds identified in apple vinegars, 12 in grape vinegars, and 33 in persimmon vinegars, the main volatile components were acetic acid, ethyl acetate, isoamyl acetate, isovaleric acid, isoamyl alcohol, propanoic acid and phenethyl acetate. Volatile chemicals in commercial fruit vinegars were effectively analyzed using a SAW e-nose.

• Journal of Life Science
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• v.29 no.7
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• pp.769-773
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• 2019

In this study, the migration route and the absorption rate of calcium and magnesium in apple leaves were compared and analyzed using plant nutrients prepared by wet nano-grinding technology. The plant nutrients were sprayed onto the leaves to confirm the component content and the movement route of the nanoized calcium and magnesium. At 2, 4, and 8 weeks after the plant nutrient treatment, the apple leaves were divided into petiole, lamina, and side, and SEM and EDS were used to measure the calcium and magnesium contents. The calcium and magnesium contents of the petiole increased from the 4th week after plant nutrient application to 1,115% at the 8th week. The calcium and magnesium contents of the lamina decreased after spraying but increased after 4 weeks. The calcium and magnesium contents increased in the side of the leaves compared to the control, reaching 673% after 4 weeks. The calcium and magnesium contents increased with increasing duration in all plots when compared with the control unsprayed leaves, suggesting that the usually poorly soluble calcium and magnesium were transferred from the petioles to the lamina. The results of this study indicate that improved calcium and magnesium absorption could be obtained in crops other than apples using plant nutrients produced through wet nano-processing technology. This technology is also expected to be applicable to natural products and bioindustries.

• Food Engineering Progress
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• v.21 no.4
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• pp.312-317
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• 2017

Weight loss that influences quality and farmer incomes is affected by the storage environment of agricultural products. The interior of storage should be maintained at high humidity to prevent the weight loss of products which contain a lot of moisture. The research had constantly proceeded with change in the heat exchanger surface areas, humidity systems, and weight loss forecast to maintain high humidity within storage. Relative humidity that exerts an effect weight loss of crop is influenced by storage temperature, leak state, and volume of product. When weight loss is predicted, different conditions of these factors are derived. In case of CA storage, ways of forecasting the weight loss become easier compared to cold storage due to sealed storage with external environment during storage period. In this study, apples were stored in purge-type CA storage and weight loss has been predicted by using operating characteristics and environmental conditions. As a result, humidity variation in the storage fluctuates with the operation of the unit-cooler. Furthermore, unit-cooler operation factor is influenced by outside temperature and respiration heat. Prediction value of weight loss according to temperature and humidity has been most accurately predicted. Prediction value through defrosting water measured shows unit-cooler work quality. K-value needs verification to calculate the VPD method.

• Journal of Microbiology and Biotechnology
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• v.31 no.10
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• pp.1409-1419
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• 2021

A growing number of healthy dietary ingredients in fruits and vegetables have been shown to exhibit diverse biological activities. Phloretin, a dihydrochalcone flavonoid that is abundant in apples and pears, has anti-inflammatory effects on ulcerative colitis (UC) mice. The gut microbiota and metabolism are closely related to each other due to the existence of the food-gut axis in the human colon. To investigate the interplay of faecal metabolites and the microbiota in UC mice after phloretin treatment, phloretin (60 mg/kg) was administered by gavage to ameliorate dextran sulfate sodium (DSS)-induced UC in mice. Gut microbes and faecal metabolite profiles were detected by high-throughput sequencing and liquid chromatography mass spectrometry (LC-MS) analysis, respectively. The correlations between gut microbes and their metabolites were evaluated by Spearman correlation coefficients. The results indicated that phloretin reshaped the disturbed faecal metabolite profile in UC mice and improved the metabolic pathways by balancing the composition of faecal metabolites such as norepinephrine, mesalazine, tyrosine, 5-acetyl-2,4-dimethyloxazole, and 6-acetyl-2,3-dihydro-2-(hydroxymethyl)-4(1H)-pyridinone. Correlation analysis identified the relations between the gut microbes and their metabolites. Proteus was negatively related to many faecal metabolites, such as norepinephrine, L-tyrosine, laccarin, dopamine glucuronide, and 5-acetyl-2,4-dimethyloxazole. The abundance of unidentified Bacteriodales_S24-7_group was positively related to ecgonine, 15-KETE and 6-acetyl-2,3-dihydro-2-(hydroxymethyl)-4(1H)-pyridinone. The abundance of Christensenellaceae_R-7_group was negatively related to the levels of 15-KETE and netilmicin. Stenotrophomonas and 15-KETE were negatively related, while Intestinimonas and alanyl-serine were positively related. In conclusion, phloretin treatment had positive impacts on faecal metabolites in UC mice, and the changes in faecal metabolites were closely related to the gut microbiota.

• Research in Plant Disease
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• v.26 no.4
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• pp.239-249
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• 2020

To find out the cause of the fire blight outbreak in apples and pears of Korea in 2019, we investigated disease appearing situation of thirty fire blight infected orchards, and interviewed farmers to determine the cultivation characteristics. Fire blight occurred mostly in orchards that had infected more than 2 years before. The cause of this were as follows: farmers did not know the symptoms of the disease properly. It is presumed that it has spread from the first occurrence to the surrounding orchards by flower-visiting insects or farmers and to a short distance or a long distance by the same cultivator or co-farmer. These series of processes repeated in the newly spreading area, and then disease reports increased as farmers became aware of fire blight. To minimize the spread of fire blight in Korea, it suggested that thorough education of farmers for early diagnosis and quantitative detection technology that can diagnose even in no symptom showing plants. And chemical or biological spraying systems suitable for domestic cultivation methods, which are producing large fruits, and molecular epidemiological studies of pathogens.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.123-133
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• 2021

In order to use Osmia cornifrons more effectively in apples, we investigated the pollination effect and nesting activity of O. cornifrons on 'Hongro', the middle-season cultivar, and 'Fuji', the late-season cultivar. There was a significant difference in the nesting activity and pollination effect of O. cornifrons depending on the apple cultivar. The nesting activity, rate of trap nesting, and reproduction in 'Fuji' were 2.5, 1.5, and 3.8 times greater than in 'Hongro', respectively. The pollination effect according to cultivar 'Fuji' was 1.6 times greater than that of 'Hongro' in the central fruit set. In terms of the quality of fruit, the asymmetry index of 'Fuji' was 2.5 times lower than that of 'Hongro', and the number of apple seeds of 'Fuji' was 1.9 times greater than that of 'Hongro'. The main reason for this result was the air temperature. The activity of O. cornifrons was most affected by air temperature (R2 = 0.578). It is expected that the nesting activity and pollination effect are great in 'Fuji' (17.4-24.1℃) when the temperature during the blooming period is higher than that of 'Hongro' (12.5-20.2℃). Our study provides important information on stable apple production for apple cultivators, and can be used as an evidence for changes in flora and insect fauna caused by climate change.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.201-207
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• 2022

In this paper, the relationship between RGB, HSV, La^*b^* colors and sugar content was analyzed using linear regression on apples harvested in the same region. First, as a result of examining the correlation coefficient with sugar content according to each color level, it was found that the (+) region having a positive coefficient and a (-) region having a negative coefficient were separated according to the color level. Also, the correlation coefficient between color and sugar content, represented by the average value, was 0.342 in the La^*b^* color space, which was higher than the coefficient in the RGB and hsv space. That is, this means that the sugar content is related to the color in the La^*b^* space. Also, in the complex color composed of regions with high sugar content, it was found to be R²=0.3627, indicating that it is related to sugar content. In all nine color spaces, it was found to be R²=0.3668. In this case, it was found that the coefficients of v and b^* had an effect on the sugar content. Due to this, it was possible to confirm the validity of the empirical prediction that the higher the b^* representing yellow, the higher the sugar content.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.421-430
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• 2022

Crop load management in apple trees is important for achieving optimum productivity and crop value. Hence, we investigated the influence of different crop loads on the fruit quality, mineral content, and yield of the 'RubyS' apple variety. After 4 weeks of full bloom, the crop load was adjusted by hand thinning to different (5, 10, and 15 fruits·cm^-2) trunk cross-sectional areas (TCSA), representing low, medium, and high crop loads. The low crop load increased the fruit size and weight, the development of the red-blushed area, and the peel color a^* at harvest; however, it reduced the total number of fruits·tree^-1 and yield compared with that of the other crop loads. The medium crop load improved the fruit weight, flesh firmness, and soluble solids content and reduced the fruits·tree^-1 but did not affect the fruit size and yield. However, there were no significant differences in the titratable acidity and starch index among the crop loads. The fruit mineral content (phosphorus and potassium) was higher in the low and medium crop loads compared to the high crop load. However, the nitrogen, calcium, and magnesium contents in the fruits were not affected by the crop loads. Overall, this study suggests that a low crop load improves the fruit size and weight, but its effect on the quality and fruit mineral content is similar to that of a medium crop load. Therefore, the optimum crop load level for the 'RubyS' apple trees was approximately 10 fruits·cm^-2 TCSA.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.943-951
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• 2022

In this study, 8 kinds of fruits and vegetables such as apples, pears and radishes were cut and hot water extracts and Steamed hot water extract from fruits and vegetables were prepared and used as experimental substrates. As a result of fermenting with 1% (W/V) red ginseng extract (W/V) and 8 types of lactic acid bacteria mixed starter added to the lactic acid bacteria fermented extract, the pattern and content of ginsenosides were almost unchanged in the fruit and vegetable extract group and the steam treatment group. However, in the lactic acid bacteria fermented group, the TLC pattern was changed according to the fermentation process and treatment, and the content of ginsenosides converted into Rg₃(S) and Rg₅ increased. No change in the number of lactic acid bacteria (cfu) was observed in all four types of fruit and vegetable extracts. The number of lactic acid bacteria CFU was slightly decreased in the four fermented groups of fruit and vegetable extracts, but the growth inhibitory effect of beneficial bacteria was not significant. The growth inhibitory effect of the three harmful bacteria was not affected by the growth of E. coli and Pseudomonas in the four fruit and vegetable extracts. However, the proliferation of Salmonella was inhibited, which was confirmed as the growth inhibitory effect of the fruit and vegetable extract regardless of whether the steamed hot water extract or red ginseng extract was added.