Rutin and quercetin in common and Tartary buckwheat flour and dough

The concentration of flavonoids rutin and quercetin in flours of common and Tartary buckwheat was investigated. In Tartary buckwheat, concentration of rutin is much higher compared to common buckwheat. In Tartary buckwheat it was measured 1.17 to 1.75% rutin in dry matter, while in common buckwheat it was only 0.003%. After direct contact of buckwheat flour with water, different biochemical activities in Tartary buckwheat developed with rutin. After the time (5 minutes or two hours), the concentration of rutin is in the flour-water mixtures much lowered, and quercetin appeared. However, after quick initial changes, some rutin remained in flour-water mixtures even after 24 hours. In any way, after 24 hours of direct contact of flour particles with water, the concentration of quercetin is higher than that of rutin. It is established that the concentration of rutin in flour-water mixtures is the result of two processes. One is the release of rutin from grain structures and its dissolving in water, and the second is the release of rutin degrading enzymes from grain structures and their activity in solution.

New trends in preparing buckwheat dishes in Slovenia

Slovenian cuisine is traditionally related to the use of buckwheat, especially common buckwheat. At the Education Centre Piramida Maribor there are developing possibilities of using common and Tartary buckwheat in modern gastronomy. This paper presentings buckwheat dishes, which were developed and upgraded according to the trends in modern nutrition, along with market responses. Present varieties of buckwheat bread made with different leavening agents (e.g. yeast, sourdough, baking powder, cream of tartar, mineral water and without rising agents), confectionnery (e.g. cakes, pies, cream-pies, strudels, biscuits) from Tartary buckwheat, common buckwheat and other flours and also Tartary buckwheat pasta are presented. Buckwheat (either as gruel or as flour) can also be used as an ingredient in filling the chocolate pralines or in ice cream. In addition various buckwheat dishes with a touch of contemporary trends and culinary art are introduced. Furthermore, the possibilities of using common and Tartary buckwheat flour for gluten-free confectionery and for a variety of sweet and savory gluten-free dishes in the culinary will be presented. The latest speciality will be the presentation of buckwheat bread, confectionery and pasta combined with edible flowers.

The disappearance of vitexin from Tartary buckwheat flour-water mixtures after the hydrothermal treatment

Vitexin is an apigenin flavone glucoside with known biological functions. This research reported the effects of initial temperature treatments of Tartary buckwheat flour mixture with water and time of methanol extraction from the cooked doughs on the amount of extractable vitexin. The mixtures of flour and water were initially hydrothermally treated at temperatures from 25 °C to 95 °C. Afterward the mixtures were cooked at 95 °C for 20 min, and vitexin extracted at room temperature with 80% aqueous methanol for 20 min, 2 h and 8 h. The extractable vitexin was extracted during the same extraction times for the control in the nonhydrothermally treated Tartary buckwheat flour-water mixture samples. For the cooked dough samples, the hydrothermal treatments were important in terms of the extractability of vitexin. The extractable vitexin persisted in the control samples during the extraction time up to 8 hours, while in the hydrothermally treated and cooked dough samples, there remained none detectable vitexin. The high-temperature initial treatments during dough preparation appeared not to prevent the degradation of vitexin in Tartary buckwheat flour.

Response of common buckwheat and Tartary buckwheat from different elevations to selenium treatment

Common buckwheat and Tartary buckwheat were grown in Slovenia outdoors at different elevations – 300 m, 600 m and 1180 m a.s.l. Both species were foliarly treated with selenium twice (in the vegetative phase and in the flowering phase). The effects of Se treatment and different growing locations on selected biochemical, physiological and anatomical traits were monitored. In Se treated common buckwheat, amount of chlorophylls was higher in plants from Ljubljana (the lowest elevation – 300 m a.s.l.) than in plants grown in Podbeže (600 m a.s.l.), whereas in control group, plants grown in Ljubljana contained more chlorophylls than plants from Javorje (the highest elevation – 1180 m a.s.l.). In both buckwheat species, Se alone did not affect amount of chlorophylls in any of location. In Se treated common buckwheat plants, the amount of UV absorbing compounds was the highest in plants, grown at the highest elevation. In common buckwheat, Se lowered the number of CaOx in plants, grown in Javorje. Conditions at different elevations, as well as treatments with Se, did not affect potential and effective photochemical efficiency of Photosystem II. Keywords: common buckwheat, Tartary buckwheat, elevation, selenium, morphological characteristics, biochemical characteristics

Recent advances in the nutritional, functional, and agronomic traits of Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.)

Tartary buckwheat (Fagopyrum tataricum(L.) Gaertn.) is considered a functional food because its seeds contain higher amounts of polyphenols (e.g., rutin) compared to common buckwheat. However, because of its highly bitter taste and difficulties in cultivation, the agricultural production and usage of Tartary buckwheat in food products remain limited. The nutritional and functional ingredients of Tartary buckwheat include quercetin, which causes its bitterness and is generated by rutinosidase (rutin-degrading enzyme). A nonbitter Tartary buckwheat variety with trace levels of rutinosidase has recently been developed. Despite such research, there is still a lack of agronomic information on Tartary buckwheat. Lodging can be a significant problem during its cultivation, and a lodging-resistant, semidwarf variety has been developed. This paper summarizes recent advances in our knowledge regarding the nutritional and agronomic traits of Tartary buckwheat. The information extends our understanding of the health benefits of Tartary buckwheat and the solutions to challenges in its agricultural production. Keywords: agronomic traits, nutrient function, Tartary buckwheat

Mechanical characteristics of buckwheat noodles made with blue-green alga, ishi-kurage (Nostoc commune Vauch.)

The present study was conducted to clarify the effect of a kind of blue-green algae, i.e., ishi-kurage , on the mechanical characteristics of buckwheat noodles. Mechanical analysis of buckwheat noodles with ishi-kurage showed that incorporation of ishi-kurage into buckwheat noodles enhanced breaking stress and energy. Sensory evaluation with human panels showed that buckwheat noodles with ishi-kurage were more preferred when compared with noodles without ishi-kurage. On the other hand, incorporation of ishi-kurage into buckwheat noodles enhanced decreased solubility of the albumin plus globulin fraction. The present study finding suggests that the endogenous protein may be an important factor responsible for the mechanical characteristic of buckwheat noodles with ishi-kurage.

Extraction of rutin and quercetin from Tartary buckwheat grains, hydrothermally treated at different temperatures

Tartary buckwheat grains were hydrothermally treated to establish the conditions under which rutin remains in the grain. Tartary buckwheat grains were soaked in water at the temperatures 51 °C, 61 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 93 °C, 97 °C and 99 °C, and a control group at 21 °C. During 20 minutes soaking at 51 °C or 61 °C the concentration of rutin decreased. This effect was mostly pronounced by soaking at 70 °C and 75 °C, where instead of missing amount of rutin, some quercetin appeared. After soaking at 80 °C, 85 °C, 90 °C, 93 °C, 97 °C and 99 °C concentration of rutin was not significantly different in comparison to the concentration of rutin after soaking 20 minutes at 21°C. It is suggested that exposure to water at 21°C is similar to natural conditions, where rutin degrading enzymes remain mainly inactive and in grain separated from its potential substrate. Further is suggested that at the soaking temperatures 51 °C, 61 °C, 70 °C and 75 °C, grain structures are partly degraded and rutin degrading enzymes got contact to the substrate. By soaking at 80 °C, 85 °C, 90 °C, 93 °C, 97 °C and 99 °C, rutin degrading enzymes lose their activity. Thus wet treatment of Tartary buckwheat grains for 20 minutes at temperature at 80 °C or above, this threshold is enough to preserve the content of rutin in the samples. This is of importance for nutritional quality of Tartary buckwheat food products.

Application of micro-PIXE (particle induced X-ray emission) to study buckwheat grain structure and composition

Tartary buckwheat (Fagopyrum tataricum Gaertn.) is a gluten-free pseudo-cereal crop with a grain nutrient profile that makes it an excellent alternative foodstuff. The distribution of calcium (Ca), magnesium (Mg), phosphorus (P) and sulphur (S) was investigated by micro-PIXE (particle induced X-ray emission) to resolve allocation and concentration of the elements in nine distinct grain tissues. Magnesium, P and S were preferentially allocated to the cotyledons and the embryonic axis (both inner and outer tissues), and Ca was predominant in the pericarp where two Ca-rich layers were observed. Allocation of P and S to aleurone suggests that this layer of cells, although not as prominent as in cereal grain, is rich in phytate and proteins. Quantitative information on spatial distribution of mineral elements in the edible grain may be useful in the technological processing of the grain and particularly in reducing the amount of mineral-element loss during milling.

Toshiko Matano

Obituary On March 22, 2020, our dear friend and teacher Toshiko Matano, Professor Emeritus of Shinshu University, Nagano Prefecture, Japan, passed away at her home in Ina, Japan.

Note on the 14th International Symposium on Buckwheat at North-Eastern Hill University, Shillong, India from Sept. 3 to 6, 2019

The Department of Botany, North-Eastern Hill University (NEHU), Shillong, India in collaboration with ICAR-Na- tional Bureau of Plant Genetic Resources (NBPGR), India, and DBT-Institute of Bioresources and Sustainable De­velopment (IBSD), India organized the 14th International Symposium on Buckwheat at North-Eastern Hill Univer­sity, Shillong from Sept. 3 to 6, 2019 at North Eastern Hill University, Shillong ...