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avena_sativa_l

Avena sativa L. - syn.Avena byzantina K. Koch; Avena orientalis Schreb. - Poaceae - oat, Hafer, Saathafer

Annual grass, up to 180cm tall, native to the Middle East, cultivated worldwide without tropics.
„This species is cultivated as a cereal crop (oats) in north-temperate regions of the world, and also as a green fodder crop. Genetic evidence points to Avena sterilis as the wild ancestor of A. sativa, and A. fatua as a weedy derivative. Hybrids between A. sativa and A. fatua with hairy florets or well-developed awns may occur where the two species grow together.“ http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200024905

„Oat β-glucan (OβG) consists mainly of the linear polysaccharide (1→3), (1[→4)-β-D-glucan and is often called β-glucan. This soluble oat fiber is able to attenuate blood postprandial glycemic and insulinemic responses, to lower blood total cholesterol and low-density lipoprotein (LDL) cholesterol, and to improve high-density lipoprotein (HDL) cholesterol and blood lipid profiles as well as to maintain body weight. Thus, OβG intake is beneficial in the prevention, treatment, and control of diabetes and cardiovascular diseases. In addition, OβG can stimulate immune functions by activating monocytes/macrophages and increasing the amounts of immunoglobulin, NK cells, killer T-cells, and so on, which will improve resistance to cancer and infectious and parasitic diseases, as well as increase biological therapies and their prevention. All these health benefits of OβG may be explained by its physicochemical properties (such as viscosity, molecular weight) which can be affected by extraction methods and its behavior in gastrointestinal tract.“
[Oat Beta‐Glucan: Its Role in Health Promotion and Prevention of Diseases., Daou, C., Zhang, H., Comprehensive Reviews in Food Science and Food Safety, Vol.11(4), 2012, 355-365] http://onlinelibrary.wiley.com/doi/10.1111/j.1541-4337.2012.00189.x/full


„To identify the compounds evoking the characteristic cereal-like, sweet aroma of oat flakes, an aroma extract dilution analysis (AEDA) was applied to a distillate prepared by solvent extraction/vacuum distillation from commercial oat flakes. Among the nine aroma-active compounds detected by gas chromatography−olfactometry and AEDA in the flavor dilution (FD) factor range of 4−1024, eight odorants, for example, (E)-β-damascenone, (Z)-3-hexenal, and butanoic acid, showed only low FD factors. However, one odorant eliciting the typical cereal, sweet aroma of the flakes was detected with the highest FD factor of 1024. By mass spectrometry and nuclear magnetic resonance measurements followed by a synthesis, (E,E,Z)-2,4,6-nonatrienal, exhibiting an intense oat flake-like odor at the extremely low odor threshold of 0.0002 ng/L in air, was identified as the key odorant of the flakes. By means of a newly developed stable isotope dilution analysis using synthesized, carbon-13-labeled nonatrienal as the internal standard, a concentration of 13 μg of (E,E,Z)-2,4,6-nonatrienal per kilogram of the flakes was measured. Model studies suggested linolenic acid as the precursor of nonatrienal in oats.“
[Characterization of (E,E,Z)-2,4,6-nonatrienal as a character impact aroma compound of oat flakes., Schuh, C., Schieberle, P., Journal of agricultural and food chemistry, Vol.53(22), 2005, 8699-8705]

 (E,E,Z)-2,4,6-nonatrienal (E,E,Z)-2,4,6-nonatrienal

„In order to assess the effect of heat treatment procedure on the flavor and volatile compounds of oats, raw oats, kiln and dried oats, dehulled oats and oat flakes were analysed. A sensory profile method was used to monitor changes in flavor. It changed from hay-like for raw oats into nutty, bread-like for oat flakes. Headspace solid phase microextraction (SPME) and solvent assisted flavor evaporation (SAFE) techniques were applied for isolation of aroma compounds. The most abundant compound in headspace was hexanal – its concentration varied from 176 to 1671 μg/kg depending on the processing stage. The key aroma compounds of oat flakes identified using gas chromatography – olfactometry and aroma extract dilution analysis (AEDA) were 2-methyl-3-furanthiol with roast/cooked oatmeal flavor together with methional, dimethyl trisulfide, 1-octen-3-ol, 2-methyl-3,5-diethylpyrazine.“
[Effect of heat treatment on the flavor of oat flakes., Klensporf, D., Jeleń, H.H., Journal of cereal science, Vol.48(3), 2008, 656-661]

Through application of AEDA the most important aroma active compounds of an extract from oat biscuits were identified and their flavor dilution (FD) factors and odour activity values (OAV) were determined. Most active compounds were 2-acetyl-1-pyrroline (popcorn-like, FD 4096, OAV 2400), 4-hydroxy-3-methoxybenzaldehyde (vanillin, FD 2048, OAV 1200), 2-acetyl-3,4,5,6-tetrahydropyridine (roasted, FD 1024, OAV 5700) , methional (boiled potatoes, FD 8192, OAV 370), methanthiol (sulfur-cabbage-like, OAV 290), 2-propionyl-1-pyrroline (roasted, FD 1024, OAV 190), 1-octen-3-one (earthy-musty, FD 1024, OAV 99), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (cotton candy, FD 1024, OAV 59), (E,E)-2,4-decadienal (fatty, OAV 56), and (E,E,Z)-2,4,6-Nonatrienal (oat-like, FD 1024, OAV 34).
[Charakterisierung der Schlüsselaromastoffe in einem Hafergebäck., Dach, A., Schieberle, P., Deutsche Forschungsanstalt für Lebensmittelchemie, Jahresbericht 2013, 40-43]

avena_sativa.jpg
Thomé,O.W., Flora von Deutschland Österreich und der Schweiz, Tafeln, vol.1, t.66 (1885)
http://plantgenera.org/species.php?id_species=120722

www.botanische-spaziergaenge.at_bilder_konica_2_pict8376.jpg
Avena sativa
© Rolf Marschner (2006), www.botanische-spaziergaenge.at

avena_sativa_l.txt · Zuletzt geändert: 2017/10/18 15:45 von andreas