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Tartary buckwheat (Fagopyrum tataricum Gaertn.) containing large amounts of functional compounds with antioxidant activity, such as rutin, has attracted substantial research attention due to its industrial applications. Particularly, the functional compounds in Tartary buckwheat bran, an unexploited byproduct of the buckwheat flour milling process, are more concentrated than those in Tartary buckwheat flour. Thus, Tartary buckwheat bran is deemed to be a potential material for making functional foods. However, a review that comprehensively summarizes the research on Tartary buckwheat bran is lacking. Therefore, we highlighted current studies on the chemical composition of Tartary buckwheat bran. Moreover, the processing method and food uses of Tartary buckwheat bran are also discussed. [ABSTRACT FROM AUTHOR]

We recently developed a novel Tartary buckwheat variety, 'Manten-Kirari', with trace-rutinosidase activity. The use of 'Manten-Kirari' enabled us to make rutin-rich food products with low bitterness. This study was intended to evaluate the physicochemical properties and in vitro digestibility of starch isolated from 'Manten-Kirari'. For comparison, the representative common buckwheat variety 'Kitawasesoba' and Tartary buckwheat variety 'Hokkai T8' in Japan were also used. The lowest content of amylose was found in 'Manten-Kirari' starch (18.1%) while the highest was in 'Kitawasesoba' starch (22.6%). 'Manten-Kirari' starch exhibited a larger median granule size (11.41 µm) and higher values of peak viscosity (286.8 RVU) and breakdown (115.2 RVU) than the others. The values of onset temperature for gelatinization were 60.5 °C for 'Kitawasesoba', 61.3 °C for 'Manten-Kirari', and 64.7 °C for 'Hokkai T8'. 'Manten-Kirari' and 'Hokkai T8' starches were digested more slowly than 'Kitawasesoba' starch. Our results will provide fundamental information concerning the expanded use of 'Manten-Kirari' in functional foods. [ABSTRACT FROM AUTHOR]

Rutin, a phenolic compound, has antioxidant, anti-dyslipidaemic, and body weight-reducing effects. We evaluated the anti-arteriosclerotic, antioxidant, and body weight-reducing effects of rutin-rich Tartary buckwheat. We randomly divided 144 adult subjects into an active test food group consuming products containing rutin-rich Tartary buckwheat and a placebo food group. Body composition measurements and haematological and urine tests were performed at weeks 0, 4, 8, and 12, and at 3 weeks after termination. Atherosclerosis index and ox-LDL did not significantly differ between the groups. However, TBARS levels, BW and BMI in the active test food group were significantly lower than those in the placebo group at week 8 (p = 0.027, p = 0.030, respectively). BFP in the active test food group at week 4 (p = 0.038) was lower than that in the placebo group. Thus, rutin-rich Tartary buckwheat intake may be effective for body weight due to its antioxidant properties. [ABSTRACT FROM AUTHOR]

Contamination of rutinosidase is a major problem for rutin-rich food due to the hydrolysis of the functional compound rutin and generation of strong bitterness caused by the hydrolyzed moiety quercetin. This problem sometimes occurs between the trace and normal rutinosidase Tartary buckwheat varieties. Here, we developed a simple and rapid method for rutinosidase detection in 'ripening seeds using UV light' and in 'dough using alum-flavonoid complexation' from Tartary buckwheat (Fagopyrum tataricum Gaertn.). Normal rutinosidase seeds can be distinguished from trace-rutinosidase mature seeds and ripening young seeds using a rutin solution by comparing the muddiness, which corresponds to quercetin generation. In dough, we detected a threefold relative increase in rutinosidase activity corresponding to 1% contamination of normal rutinosidase flour with trace-rutinosidase flour within 65 min. These methods do not require expensive apparatuses and toxic chemicals and are therefore promising for detecting and preventing contamination by rutinosidase, e.g., in food processing factories. [ABSTRACT FROM AUTHOR]

Tartary buckwheat is targeted as a healthy food because its food contains large amounts of polyphe-nols such as rutin and quercetin, especially. Quercetin is a substrate for POX activity, which sometimes plays important roles for quality changes in foods. Therefore, to obtain a basic understanding of the roles of Tartary buckwheat POX, we purified and characterized POX in Tartary buckwheat seeds. POX was purified (76.7 fold, final yield 4.77%). Tartary buckwheat seeds bore a single major POX (MW 46.8 kDa). Kinetic studies revealed that POX had lower Km values for quercetin (0.32 mM) and o-dianisidine (0.316 mM) than for ABTS (1.86 mM) and guaiacol (0.958 mM). POX showed greater activity under acidic pH conditions. Optimum pH of POX was the same pH as Tartary buckwheat dough. In addition, optimum temperature was around 20°C, corresponding to the temperature where dough is usually handled. Therefore, POX in Tartary buckwheat may play an important role in quality changes in food. [ABSTRACT FROM AUTHOR]

Tartary buckwheat bran, a byproduct of buckwheat milling, is commonly treated as waste. The present study examined the rutin content during successive infusions of roasted Tartary buckwheat bran and grain to develop a functional Tartary buckwheat tea. Samples (6 g) of roasted Tartary buckwheat bran and grain were rinsed with 300 mL of hot water (>95 °C) for 0.5 min. For the first infusion test, the tea infusion sample of roasted Tartary buckwheat bran contained a distinctly higher amount of rutin (389 mg/L) than that of the roasted Tartary buckwheat grain (68 mg/L). Overall, rutin was more effectively extracted from roasted Tartary buckwheat bran, as compared to roasted Tartary buckwheat grain. [ABSTRACT FROM AUTHOR]

• This is the first study of variety discrimination in a Polygonaceae family. • DNA markers based on RNA polymorphism can discriminate buckwheat varieties. • The marker is promising for rutin-rich foods to prevent rutinosidase contamination. • The method is suitable to detect contamination of variety in buckwheat flour/noodles. To discriminate the trace-rutinosidase variety of Tartary buckwheat 'Manten-Kirari', we developed DNA markers based on RNA polymorphism. Specifically, we mapped 17.76 GB RNA sequences, obtained using HiSeq2000, to create 11,358 large contigs constructed de novo from 'Manten-Kirari' RNA derived from GS-FLX+ titanium. From these, we developed eight DNA markers corresponding to single- to four-nucleotide polymorphisms between 'Manten-Kirari' and 'Hokkai T8', which is representative of normal rutinosidase content varieties in Japan. Using these markers, 'Manten-Kirari' was discriminated from 'Hokkai T8' by eight markers, from major Tartary buckwheat varieties by three markers, and from common buckwheats by two markers. We also performed direct PCR from flour and dried noodle made with 'Manten-Kirari' and 'Hokkai T8'. Based on the results, the DNA markers developed are promising for discriminating 'Manten-Kirari'. This is the first study to develop a DNA marker to discriminate varieties in the Polygonaceae family including buckwheat species. [ABSTRACT FROM AUTHOR]