• Preventive Nutrition and Food Science
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• v.22 no.3
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• pp.195-202
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• 2017

The objective of this study was to investigate the antioxidant and antimicrobial properties of quinoa cultivated in Korea and to compare it with imported quinoa from the USA and Peru. The highest amount of total flavonoid contents (TFC) with 20.91 mg quercetin equivalents/100 g was measured in quinoa seed extract cultivated in Korea, while the total phenolic contents (TPC) were significantly higher in quinoa from the USA (16.28 mg gallic acid equivalents/100 g). In addition, quinoa extracts cultivated in Korea displayed a superior antioxidant ability in both, ferric reducing antioxidant power and 1,1-diphenyl-2-picrylhydrazyl values. There was a high correlation between TFC and antioxidant activity and a low correlation between TPC and antioxidant activity. The antimicrobial activity of the quinoa extracts was determined using a disc diffusion assay and optical density method. In both assays, the quinoa seed extracts did not have strong antimicrobial activity against foodborne bacteria, including Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus, Escherichia coli, Salmonella Typhimurium, and Campylobacter jejuni.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.6
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• pp.688-694
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• 2017

The effects of heat treatments on the physicochemical properties and in vitro biological activities of quinoa (Chenopodium quinoa Willd.) were investigated. Quinoa grains were subjected to two different heat treatment methods: boiling and steaming plus roasting (steaming/roasting). Compared with raw quinoa, boiled quinoa samples had slightly lower crude protein, crude fat, crude ash, and starch contents. However, steaming/roasting treatment did not cause significant differences in proximate composition. Heat treatments reduced total phenolic and flavonoid contents in quinoa extracts, and higher reduction was detected upon boiling treatment. Heat treatments also reduced lightness and increased yellowness of quinoa samples. Heat treatments increased water absorption index but decreased water solubility index. In vitro starch hydrolysis increased substantially after both heat treatments, and slightly higher values were observed in the boiled quinoa samples. 1,1-Diphenyl-2-picrylhydrazyl free radical scavenging activity and nitrite scavenging activity were reduced by heat treatments, and the boiled quinoa sample showed the lowest activity likely due to loss of activities in cooking water.

• Research in Plant Disease
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• v.16 no.3
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• pp.238-246
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• 2010

In 2006 fall, a preliminary survey of viruses in two important medicinal plants, Cynanchum wilfordii and C. auriculatum, was conducted on the experimental fields at the Agricultural Research and Extension Services of Chungbuk province in Korea. On each experimental fields, percentage of virus infection was ranged from 20 to 80%, and especially an average of disease incidence propagated by roots was twice higher than that by seeds. The various symptoms were observed in Cynanchum spp. plants, such as mosaic, mottle, necrosis, yellowing, chlorotic spot and malformation etc. In electron microscopic examination of crude sap extracts, filamentous rod particles with 390-730 nm were observed in most samples. The virus particles were purified from the leaves of C. wilfordii with typical mosaic symptom, and the viral RNA was extracted from this sample containing 430-845 nm long filamentous rod. To identify the viruses, reverse transcription followed by PCR with random primers was carried out. The putative sequences of P3 and coat protein of potyvirus were obtained. From a BLAST of the two sequences, they showed 26-38% and 62-72% identities to potyviruses, respectively. In SDS-PAGE analysis, the subunit of coat protein was approximately 30.3 kDa, close to the coat protein of potyvirus. In bioassay with 21 species in 7 families, Chenopodium quinoa showed local lesion on inoculated leave and chlorotic spot on upper leave, but the others were not infected. RT-PCR detection using specific primer of C. wilfordii and C. auriculatum samples, all of 24 samples with virus symptom was positive, and five out of seven samples without virus symptom were also positive. On the basis of these data, the virus could be considered as a new member of potyvirus. We suggested that the name of the virus was Keunjorong mosaic virus (KjMV) after the common Korean name of C. wilfordii.