• Korean Journal of Medicinal Crop Science
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• v.27 no.2
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• pp.108-114
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• 2019

Background: Rutin is decomposed by rutin-degrading enzymes (RDE) during the processing of buckwheat groats, resulting in a decrease in rutin content and a further increase in the bitterness of processed products. Thus, the present study aimed to examine RDE activity in groats and various tissues of domestic buckwheat varieties and to develop a method to reduce the loss of rutin during the groat processing. Methods and Results: RDE activity and isozymes patterns were determined in Tartary and common buckwheat. RDE activity, measured by quercetin production rate, was 273 and $70{\mu}g/g$ fresh weight/min in mature Tartary and common buckwheat groats, respectively. A total of six RDE isozymes were detected in mature groats of Tartary buckwheat on a non-denaturing gel. In Tartary buckwheat groats, RDE activity decreased by approximately 81 or 71% with roasting or steaming for 5 min respectively. As the roasting or steaming time increased to 30 min, RDE activity decreased by over 95%. These results indicated that RDE was inactivated in groats by roasting or steaming. When untreated Tartary buckwheat groats were kneaded with powder, RDE was activated and the quercetin production rate increased by 62%. However, when roasted groats were kneaded with powder, the quercetin production rate decreased by 93%, mainly due mainly to inactivation of RDE, as indicated by a decrease in band intensities of the six isozymes. Conclusions: These results suggested that the loss of rutin, due to RDE activity during processing, may be reduced by 71 to 100% by roasting or steaming groats for 5 to 30 min, due in large part to the inactivation of RDE isozymes.

• Journal of the Korean Society of Food Culture
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• v.23 no.1
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• pp.121-129
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• 2008

To produce buckwheat sprouts, buckwheats were germinated at $23{\pm}2^{\circ}C$ up to 8 days in total darkness. In proximate analysis, moisture content increased from 13.87% of buckwheat groats to 93.75% of buckwheat sprouts on the 8th day of germination. On dry weight basis, lipid and ash contents increased like as protein content increased from 13.45% to 21.82% while carbohydrate content decreased due to enzyme hydrolysis. Amino acids were rich in glutamic acid, aspartic acids, and lysine, and also the ratio of the essential amino acids to total amino acids increased from 26.84% to 36.84%. Vitamin C did not exist in buckwheat groats but its content has continued to increase as far as 99.56 mg/100 g buckwheat sprouts. Rutin continued to increase by HPLC analysis from 4.71 mg/100 g buckwheat groats to 1,524 mg/100 g buckwheat sprouts. In analysis of organic acids, oxalic, maleic, and citric acids were commonly found in buckwheat sprouts. Fagopyrin was found almost none in buckwheat sprouts. In conclusion, the conversion of buckwheat seeds into sprouts through germination in darkness results in physically different final product with nutritional changes such as higher content of rutin, generation of vitamin C, abundance of the essential amino acids, and the existence of fagopyrin on very little.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.175-180
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• 2005

This study was carried out to determine total contents of phenol and flavonoid in common and tartary buckwheat for the purpose of developing new kind of functional food with buckwheat materials. Total content of phenol and flavonoid in seeds of tartary buckwheat were higher than that of common buckwheat. It showed same tendency in groats and hulls. Total content of phenol and flavonoid in groats showed higher than hulls in tartary buckwheat while those of hulls was a little higher than groats in common buckwheat seed. Rutin content in common buckwheat was higher in odor of the hulls (25.2 mg/100 g)>dehulled seed(19.8 mg/100 g)>groats (12.8mg/100 g). But tartary buckwheat was higher in oder of the groats(2042.1 mg/100 g)>dehulled seed (1375.8 mg/100 g)>hulls(138.7 mg/100 g). Flavanol content in dehulled seeds of the tartary and common buckwheat did not show the difference. However, flavanol contents in leaf, stem and spouts of tartary buckwheat were respectively higher than in those of common. Among the flavanols, catechin content was highest in all plant parts of their buckwheat and also was higher in odor of epicatechin>epicatechingallate. However, epicatechingallate content in sprouts of both buckwheat species was about 30-40 times higher than seeds.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.271-271
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• 2017

Tartary buckwheat is known for its high rutin (quercetin 3-rutinoside) content which has antioxidant, anti-inflammatory, and anticarcinogenic effects. The buckwheat tea which is popular in Korea, is dependent on the quality of applied processing methods (steaming, dehuling, and roasting). This study focused on the evaluation of changes in rutin and anti-oxidant contents during the processing of tartary buckwheat tea. Raw tartary buckwheat seeds contains the highest quantities of rutin (2,212 mg/100 g D.W.). Soaking in water and steaming the whole seeds of tartary buckwheat significantly decreased its rutin and quercetin contents. Whereas the contents of rutin and quercetin in dehulled groats increased after steaming. The process of roasting with $70-80^{\circ}C$ for 2-3 min significantly decreased the contents of rutin (992 mg/100 g D.W.) and quercetin (12.8 mg/100 g D.W.). In the processing of tartary buckwheat tea, rutin content dropped about 45% in comparison with raw whole seeds.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.732-737
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• 1990

In this study, the rutin contents in buckwheat and buckwheat foods were determined. Rutin in buckwheat and buckwheat foods was extracted with methanol and separated by High Performance Liquid Chromatography(HPLC) equipped with Lambda-Max Model 481 detector set at 355 nm using a ${\mu}$ Bondapak $C_{18}$ column and a 2.5% acetic acid:methanol:acetonitrile (35:5:10, v:v:v) solvent. There were differences in the rutin contents among the different species of buckwheat. The rutin contents in buckwheat groats were ranged from 8.84 mg to 24.77 mg/100g. The rutin contents in commercial buckwheat groats and flours were ranged from 15.04 mg to 20.92 mg/100g. The rutin contents in commercial dried buckwheat noodles, steamed buckwheat noodles, and buckwheat cookies were ranged from 1.76 mg to 10.84 mg/100g.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.4
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• pp.38-44
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• 1979

$^14$C-sucrose was labeled on detached panicles and $^14{CO}_2$ on flag leaves or panicles of intact plants to study grain sink activity in spring oats cultivar Pennfield. Defoliation and emasculation experiment was conducted to study source-sink relationship during grain filling. Specific activity of groat rose up to 15 days after anthesis and declined rapidly to 18 days. Daily gain of groat wt. matched closely with specific activity of. groat during grain filling. Primary groats were higher in specific activity of groat than secondary groats.$^14{CO}_2$ exposure on panicle was three times higher in specific activity of groat than $^14{CO}_2$exposure on flag leaf. In the defoliation and emasculation experiment, groat wt. of Pennfield oats decreased as ratio of source/sink decreased. Half number of spikelets with half leaf area was no different in groat wt. compared to control, but normal number of spikelets with zero leaf area was decreased 16% in groat wt., indicating a significant compensation by green area on panicle.

• Korean journal of food and cookery science
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• v.10 no.3
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• pp.249-253
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• 1994

In this study, total dietary fiber contents, acid detergent fiber contents lignin, water binding capacity (WBC), iron binding capacity of ADF and rutin contents from Korean buckwheats were determined. Total dietary fiber (TDF) content was 3.14% in kyungbuk rice buckwheat, 5.65% in kangwon hull buckwheat and 3.35% in kangwon rice buckwheat. Acid detergent fiber (ADF) content was 2.47, 4.46 and 2.94%, respectively and lignin content was 1.14, 1.60 and 1.08% respectively. The water binding capacity of these three sample dietary fiber showed that TDF were in the range of 2.87~3.88 g %H_2O$/g DF and ADF were in the range of 4.62~5.26 g %H_2O$/g DF. The iron binding capacity of ADF at pH 5.0, 6.0, 7.0 were 79.11, 78.01, 46.16% in kyungbuk rice buckwheat, 70.63, 63.83, 53.60% in kangwon hull buckwheat and 77.67, 76.33, 50.25% in kangwon rice buckwheat. The rutin contents of these samples and their hulls were 13.54~16.41 mg/100 g groats and 12.13~14.24 mg/100 g in hulls. The rutin content of kyungbuk rice buckwheat was the highest.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11a
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• pp.43-46
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• 2002

The first record of buckwheat in Korea was revealed from an old Korean book, "Hyangyakguguebbang(鄕藥救急方)" written in the era of king 'Gojong' who governed the country from AD 1236 to 1251 in the Korea dynasty. Buckwheat in Korea has been known to be introduced from China in 5th -6th century. One of the most famous buckwheat noodles, 'Naengmyeon' had been used popularly among the people in the Korea dynasty. It is true that buckwheat had been cooked and sold in temples during the Korea dynasty, and was regarded it as one of the temple foods at that time. Buckwheat has been cultivated as an alternative crop and buckwheat grains have been used as a hardy plant when the food situation for people was lacking in Korea. Buckwheat was an important crop in a slash-and-burn field(shifting cultivation) of the mountainous area in Kangwon province. A written history of the shifting cultivation in Korea was found in an old book "Taekriji" which was written by Lee, Jung-Hwan in the Chosun dynasty. The area and number of households of shifting cultivation in Korea was 40,000 ha and 135,000 household, respectively in 1973. Fifty to sixty kilogram of buckwheat grains per la was harvested at an altitude of 600 - 800m. Folk songs which have been sung among the people in shifting areas include buckwheat meal. One of the folk songs for buckwheat is as follows; "they do not eat rice with or without waxy property but eat buckwheat mixture." Since 1974, shifting cultivation has been legally prohibited to allow revegetation of destroyed mountains and rehabilitation of woodlands in Korea. Buckwheat has been traditionally marketed as noodle or flour for the manufacture of noodles, and also as groats for food in Korea. Consumption in markets has increased over the past several years. Buckwheat grains are mainly consumed in the form of noodles in Korea. However, many people have recently pursued a desire to make food products of high quality in processing buckwheat materials for health reasons.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.185-195
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• 2022

To enable the widespread use of buckwheat and create novel consumer demands through improved food processing techniques, we compared the quality characteristics of roasted groats following different processing and brewing methods for common and tartary buckwheat. The various processing steps resulted in significant reductions in rutin content for both buckwheat species, while the quercetin content increased in the tartary buckwheat. The fully processed tea products showed dramatic differences in rutin content, which varied based on the buckwheat species, formulation, and brewing method. Tartary buckwheat contained an average of 61 times more rutin than common buckwheat. The tartary buckwheat variety, Hwanggeum-miso, was used to determine an optimal roasting temperature of 70-80℃. Finally, we suggest that consumers who want buckwheat tea rich in rutin would prefer hand-drip-extracted tea, while those who want tea with less bitterness, sweetness, and good flavor would prefer the cold-brewed method.