• The Korean Journal of Pesticide Science
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• v.13 no.3
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• pp.185-189
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• 2009

A monoterpenoid compound, benzylideneacetone (BZA), is a metabolite of an entomopathogenic bacterium, Xenorhabdus nematophila. Its primary biological activity is an inhibitor of phospholipase $A_2$, which catalyzes the committed step of biosynthesis of various eicosanoids that are critically important to mediate insect immune responses. When BZA was applied to two-spotted spider mite, Tetranychus urticae, it exhibited a dose-dependent mortality in leaf-disc assay. Subsequently BZA was tested against T. urticae infesting apples in a field orchard, in which it showed a significant control efficacy, which was not statistically different with that of a commercial acaricide. BZA also had significant antibacterial activities against three species of plant pathogenic bacteria when it was added to the bacterial cultures, in which it showed the highest inhibitory activity against a bacterial wilt-causing pathogen, Ralstonia solanacearum. The bacterial pathogen caused significant disease symptom to young potato plants. However, BZA significantly suppressed the disease occurrence. This study suggests that BZA can be used to develop a novel crop protectant to control mite and bacterial pathogen.

• Food Science and Preservation
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• v.23 no.4
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• pp.585-590
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• 2016

In this study, the antioxidant and tyrosinase inhibitory activities of aqueous ethanolic extract from the immature fruits of Malus pumila cv. Fuji were evaluated. The antioxidant capacities of the extract was investigated employing radical scavenging assays using DPPH and $ABTS^+$ radicals. The skin-whitening effect of M. pumila cv. Fuji extract was tested using mushroom tyrosinase assay. In addition, the total phenolic content was measured by a spectrophotometric analysis. All tested samples showed a dose-dependent radical scavenging and tyrosinase inhibitory activities. Among the tested samples, the ethyl acetate (EtOAc)-soluble portion from the immature fruits of M. pumila cv. Fuji was showed the significant DPPH and $ABTS^+$ radicals scavenging activities. Also, the tyrosinase inhibitory activity of the ethyl acetate (EtOAc)-soluble portion from immature apples was higher than other solvent-soluble portion. These results suggest that unripe fruits of M. pumila cv. Fuji could be considered as a new valuable source of natural antioxidant and skin-whitening agents. Systematic investigation of immature fruits of Malus pumila cv. Fuji will be performed for the further development of its biological properties.

• Food Science and Preservation
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• v.16 no.3
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• pp.311-316
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• 2009

Changes in physiochemical properties and polyphenol activities of wine fermented with apples and Rosa rugosa Thun were investigated. To this end, four different mixing ratios of apple and R. rugosa, including R. rugosa:apple 2:1 (Apple 33), R. rugosa:apple 1:2 (Apple 67), R. rugosa:apple 1:5 (Apple 83), and apple alone (Apple 100), were prepared and fermented by Saccharomyces bayanus for 14 days at $24^{\circ}C$ with a further 14 days of post-fermentation at $20^{\circ}C$. The final ethanol content ranged from 8.2.10.2%, with no significant difference between the four groups after fermentation and post-fermentation. Final Brix, pH, and total acidity of the four samples ranged from 7.1.7.5 Brix, pH 3.85.4.07, and acidity 0.73.1.19%. As the proportion of R. rugosa increased, the anthocyanin content and color intensity of wine also increased, whereas the free amino acid concentration decreased.

• Korean journal of applied entomology
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• v.24 no.1 s.62
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• pp.19-24
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• 1985

Alternaria mali isolated from infected apples in storages and orchards of the four main apple growing areas of Taegu, Yesan, Jungup and Chungju in Korea was tested with various fungicides added in PSA medium. The fungal tolerance varied with little difference by orchard area and with great difference by king and concentration of fungicide. Minimum inhibitory concentration (MIC) of chlorothalonil and captafol was $100,238{\mu}g\;and\;81,000{\mu}g/ml$, respectively, showing low effects with high fungal tolerance; of iprodione and folpet was $3,285{\mu}g\;and\;3,000{\mu}g/ml$, respectively, showing moderate effects with moderate fungal tolerance; and of oxidong, polyoxin and polydong was $1,000{\mu}g,\;900{\mu}g\;and\;500{\mu}g/ml$, respectively, showing high effects with low fungal tolerance. Mycelial growth, conidia formation and conidia germination of the fungus showed a similar trend of response to the seven fungicides.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1305-1309
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• 2012

For functional enhancement of apples, the effects of CuEDTA and FeEDTA foliar spray were investigated on the antioxidant contents and antioxidant activities in 'Hongro' fruit, which is a representative early season harvesting apple cultivar, at 30 days before harvest. The polyphenolic content of peel was significantly higher in the CuEDTA (1,228.6 mg/100 g) and FeEDTA (1,210.0 mg/100 g) spraying treatment groups compared to the control group (998.8 mg/100 g). The flavonoid content of peel showed the same trend as that of polyphenolic content. The ascorbic acid content of peel as also significantly increased in the CuEDTA and FeEDTA spraying treatment groups, but anthocyanin content was the highest in the control group (560.6 mg/100 g). The ABTS and DPPH radical scavenging activities were higher in the CuEDTA and FeEDTA spraying treatment groups than in the control group, but reducing power was not significantly different between the treatments. As a result of this study, 3% CuEDTA and FeEDTA spraying treatments at 30 days before harvest can be used to effectively enhance antioxidant contents in 'Hongro' apple.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.51-57
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• 2008

This study demonstrates a variability in efficacy of mating disruption against the oriental fruit moth, Grapholita molesta, populations infesting apples cultivated in differential environmental conditions. Throughout the growing seasons, trap catches of G. molesta male moths and damaged leaf and fruit were examined to evaluate the efficacy of a commercialized mating disruptor. Treatment of the mating disruptor significantly reduced the trap catches of male moth in treated plot, compared to those of the untreated plot. This reduced trap catches were significantly correlated with leaf and fruit damage. Moreover, the highest host damage occurred in June just after the highest overwintering adult peaks in both plots. The treatment of mating disruptors in Chungsong effectively disrupted the overwintering population in April and May, resulting in no noticeable host damage during the following growing seasons. However, there was a marked difference in host damage between two plots, especially in late seasons. Variation in the efficacy of mating disruption technology in terms of host damage appeared to be related with nearby pheromone-untreated orchards, which may result in the immigration of gravid females.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.37-44
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• 2008

Oriental fruit moth, Grapholita molesta, is a serious pest on apples. To control this pest in an environmentally friendly method, mating disruption strategy using sex pheromone has been developed. Area-wide application of mating disruption has been needed to be effective, with little understanding on how much size of apple cultivating area should be treated in one time application of the mating disruption technique. On this matter, we needed to determine a minimal mating active zone of G. molesta that should be applied with mating disrupters to be effective. Molecular markers to discriminate a specific population should be developed to trace population migration for reproductive behaviors. Here we developed two effective molecular markers using random amplified polymorphic DNA (RAPD) technique. Different field populations of G. molesta, based on locations and seasons, were analyzed with these markers. In a specific location, G. molesta populations varied in genetic composition with different seasons. Different local populations showed differential variation according to their relative distances among apple orchards. In overall, genetic variation among different populations became lessen with progression of seasons.

• Journal of Life Science
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• v.27 no.6
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• pp.688-693
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• 2017

Antifungal bacterium against Colletotrichum coccodes causing black dot disease of potatoes and anthracnose of tomatoes was isolated from sewage sludge. The isolate showed a 99% sequence homology of partial 16S rRNA of Bacillus methylotrophicus CBMB205 and Bacillus amyloliquefaciens subsp. plantarum FZB42. The isolate was identified as Bacillus sp. SW29-2, using the neighbor-joining phylogenetic tree, BlastN sequence analysis, and morphological and cultural characteristics. Bacillus sp. SW29-2 is an aerobic, Gram-positive, endospore-forming bacterium, of which the morphological and physiological characteristics were the same as those of type strain B. lichniformis CBMB205, except for the cell growth of over 4% NaCl. The cell growth of the temperature and the initial pH of the medium was shown at $18-47^{\circ}C$ (opt. ca. $38^{\circ}C$) and 3-9 (opt. ca. 6.0), respectively. The inhibition size (diameter) of Bacillus sp. SW29-2 against four strains of C. coccodes ranged from 23 to 29 mm. Also, the isolate showed antifungal activity against penicillium rot-causing Penicillium expansum in apples. Thus far, any report on the antifungal activity of Baciilus spp. against C. coccodes has not been found. These results suggest that the Bacillus sp. SW29-2 isolate could be used as a possible biocontrol agent against C. coccodes, and further applied to other plant pathogenic fungi.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.406-413
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• 2011

This study was carried out to investigate antioxidative properties of various extracts and antibrowning effects of extracts in apple slices were investigated by ${\Delta}E$ value and PPO relative activity. Apples were cut into 1.5 cm thickness and they were dipped in 1% extract solutions(OW: water extracts of onion, OE: 80% EtOH extracts of onion, AW: water extracts of apple, AE: 80% EtOH extracts of apple, MW: water extracts of mandarin orange peel, ME: 80% EtOH extracts of mandarin orange peel) for 1 min. OW showed higher than the other treatments for total phenolic contents(94.35 mg/g), PPO inhibition(74.00%). And the highest DPPH free radical scavenging activity(40.27%) measured in ME. ${\Delta}E$ value of apple slices dipped in MW was 2.37 whereas ${\Delta}E$ value of apple slices dipped in AW was 12.12. These results suggest that onion and mandarin orange peel extracts should be a potential source for controlling browning during storage of apple slices.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.786-789
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• 1996

An image processing system was built to evaluate the color properties of apple and meat. The system consisted of video camera, video card, 32 bit microcomputer and an optical illuminator. The operating software was developed to carry out capturing, analyzing, displaying and storing of the 8 bit digitized images of food. The images of apples at various maturing stages were investigated to obtain the color histogram of R, G, B and Hunter value. RGB histogram showed a major difference in G value, 35.01, the minor change in R value, 6.16, and the negligible difference in B value. The image of beef cut was separated into two parts, fat and lean tissue, by applying threshold value method based on the digital value of color. The threshold value for fat was over 240 and for lean under 230 in R value, respectively. The resulting non fat image showed 2% decreased color difference value, ${\Delta}E$, than whole meat cut.