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Pyeongchang, South Korea

Lee J.,Dankook University | Oh M.,Dankook University | Chang Y.H.,Kyung Hee University | Lee Y.,Dankook University | And 5 more authors.
Journal of the Korean Society of Food Science and Nutrition | Year: 2016

The market for potato chips has expanded due to increased consumption of seasoned potato chips. However, the deep-frying process facilitates development of a browning color and formation of acrylamide. The objective of this work was to minimize browning color and acrylamide formation by fermentation prior to deep-frying. Potato slices were fermented by using three Bacillus strains, B. licheniformis (BL), B. methylotrophicus (BM), and B. subtilis, for 6 h at 30°C. In all fermentation groups, contents of total sugars in potato slices decreased. The color of fermented potato chips improved compared to the control. BM potato chips showed the best color values (76.33 in L value, 5.67 in a value, and 34.79 in b value). All fermentation processes reduced levels of acrylamide in deep-fried potato chips. Fermentation of potato slices for 2 h by BL reduced up to 96.1% acrylamide content. It was concluded that the fermentation process can positively affect color development and acrylamide formation. © 2016, Korean Society of Food Science and Nutrition. All Rights Reserved.

Cho K.-S.,Highland Agriculture Research Institute | Han E.-H.,Gyeongnam National University of Science and Technology | Kwak S.-S.,Korea Research Institute of Bioscience and Biotechnology | Cho J.-H.,Highland Agriculture Research Institute | And 5 more authors.
Comptes Rendus - Biologies | Year: 2016

Potato (Solanum tuberosum L.) is generally considered to be sensitive to drought stress. Even short periods of water shortage can result in reduced tuber production and quality. We previously reported that transgenic potato plants expressing the sweet potato orange gene (IbOr) under the control of the stress-inducible SWPA2 promoter (referred to as SOR plants) showed increased tolerance to methyl viologen-mediated oxidative stress and high salinity, along with increased carotenoid contents. In this study, in an effort to improve the productivity and environmental stress tolerance of potato, we subjected transgenic potato plants expressing IbOr to water-deficient conditions in the greenhouse. The SOR plants exhibited increased tolerance to drought stress under greenhouse conditions. IbOr expression was associated with slightly negative phenotypes, including reduced tuber production. Controlling IbOr expression imparted the same degree of drought tolerance while ameliorating these negative phenotypic effects, leading to levels of tuber production similar to or better than those of wild-type plants under drought stress conditions. In particular, under drought stress, drought tolerance and the production of marketable tubers (over 80. g) were improved in transgenic plants compared with non-transgenic plants. These results suggest that expressing the IbOr transgene can lead to significant gains in drought tolerance and tuber production in potato, thereby improving these agronomically important traits. © 2016 Académie des sciences.

Kim J.,Highland Agriculture Research Institute | Kim J.,Max Planck Institute for Chemical Ecology | Cha D.J.,Highland Agriculture Research Institute | Kwon M.,Highland Agriculture Research Institute | Maharjan R.,Highland Agriculture Research Institute
Entomological Research | Year: 2016

Potato virus Y (PVY) (Potyviridae: potyvirus) is a serious emerging virus affecting seed potato worldwide. It affects the seed potato by transmitting non-persistently via aphids. Sometimes this virus induces symptomless infection and is hard to detect in potato. So, it requires a specific and quick diagnosis for efficient examination. Recently, a reverse-transcription polymerase chain reaction (RT-PCR)-based PVY detection method has been developed from plant as well as insect vectors. However, it is a complex and time consuming method. Here, we developed a simple PVY detection method that uses boiling for releasing the viral RNA from aphid stylets, and amplification by PVY-specific primers located in the viral coat protein gene. The method is suitable for various strains. This simplified method could save time compared to earlier detection methods because of the simplified RNA extraction step. Following this procedure, we tested this one-step RT-PCR-based PVY detection method by using three PVY vectoring aphid species (Myzus persicae, Aphis gossypii and Macrosiphum euphorbiae) as well as other sucking insects such as thrips, Frankliniella occidentalis. The reliability of a newly developed primer set was suitable for RT-PCR and procedures were successfully demonstrated for virus detection. This PVY detection method is rapid, easy to use and suitable for large-scale testing in laboratories of seed potato, and could potentially be applied to virus-free seed potato production. © 2016 The Entomological Society of Korea and John Wiley & Sons Australia, Ltd

Heo H.,Kyung Hee University | Won C.,Kyung Hee University | Jin Y.-I.,Highland Agriculture Research Institute | Chang D.-C.,Highland Agriculture Research Institute | And 3 more authors.
Journal of the Korean Society of Food Science and Nutrition | Year: 2015

The objective of this study was to investigate the rheological and pasting properties of potato flour dispersions at different concentrations (3, 4, 5, 6, and 7%, w/w). A potato cultivar ‘Goun’, used in this study, was developed by Highland Agriculture Research Center, RDA. Potato flour dispersions showed shear-thinning behaviors (n=0.44~0.51) at 25°C. Apparent viscosity (ηa,100), consistency index (K), and yield stress (soc) significantly increased with an increase in potato flour concentration. Storage modulus (G’) and loss modulus (G“) significantly increased, whereas complex viscosity (η*) was significantly reduced with increasing frequency (ω) from 0.63 to 63.8 rad/s. Magnitudes of G’ and G“ were significantly increased with elevation of potato flour concentration. G’ values were considerably greater than G“ over the entire range of frequency (ω) with a high dependence on ω. Cox-Merz rule was not applicable to potato flour dispersions. Rapid Visco Analyzer data showed that peak viscosity, trough viscosity, breakdown viscosity, final viscosity, and set back viscosity of samples significantly increased with an increase in potato flour concentration. © 2015, Korean Society of Food Science and Nutrition. All rights reserved.

Kim J.I.,Highland Agriculture Research Institute | Kwon M.,Highland Agriculture Research Institute | Maharjan R.,Highland Agriculture Research Institute
Journal of Asia-Pacific Entomology | Year: 2015

A new gregarine species (Eugregarinida: Gregarinidae) was previously reported from daikon leaf beetle, Phaedon brassicae at Daegwallyeong in Korea. Here, we reported another novel gregarine species from the striped flea beetle, Phyllotreta striolata (Coleoptera: Chrysomelidae). The beetles were collected from the three locations; Pyeongchang (760. m), Hoengseong (466. m), and Inje (290. m), Gangwon province during July to September. In this paper, we present the morphological and molecular-biological characteristics of Gregarine species associated to P. brassicae and P. striolata. The size and body shape at mature trophozoite stage were the main morphological diagnostic characteristics of those species. Gregarines from P. brassicae were bigger in size (100. μm) with square shaped body while Gregarines from P. striolata were slightly smaller in size (80. μm) with egg shaped body. Based on the partial 18S rDNA sequence, this gregarine species was also grouped in eugregarine, and showed 85% homology to Gregarina sp. associated to P. brassicae. However, histological section result showed that each species had their own gregarine parasite beetle association. Species-specific parasitism was confirmed in local populations' beetles. There was positive relationship between infection rates, and the elevation of locations for gregarine related to P. striolata. Therefore, we suggested that the gregarines and their coleopteran hosts have species-specific interaction via co-evolution. © 2015 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society.

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