Tinkturenpresse

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Solanum tuberosum L. - Solanaceae - potato, **Kartoffel**

Perennial herb, 0.40-1m high, native to South America (Chile?), cultivated worldwide; leaves odd-pinnate; flowers white, pink, blueish or violet, with yellow lines; berries pale green.

"Several varieties and races are known. The plant parts (including the tubers) contain a poisonous alkaloid, solanine, which is soon lost on boiling the tubers; sprouting or green tubers should be ovoided for edible purposes. Apart from starch, the potato is also a rich source of protein and vitamin C. The berry is rarely produced." [[http://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=200020608]]

"The vacuum steam volatile components of //whole baked potatoes// have been analysed by the direct combination of capillary gas-liquid chromatography and mass spectrometry. Forty-two compounds, mostly pyrazines and aliphatic aldehydes were characterised with some certainty. Some information was obtained about the identities of an additional 12. In the authors' opinion the components most important to baked potato aroma include [[https://www.sciencedirect.com/science/article/pii/S0023643896901395|2-ethyl-3,6-dimethylpyrazine]], 3-methyl-mercaptopropanal (methional), deca-trans,trans-2,4-dienal and possibly [[http://www.thegoodscentscompany.com/data/rw1008281.html|2-ethyl-3,5-dimethylpyrazine]]. Qualitatively the pattern of components characterised is very similar to that found in potato chips (the English potato crisp). Comparison of the volatile oils obtained from the baked potato skins and the potato insides showed a considerably greater ratio of pyrazines to aldehydes in the skins indicating that the pyrazines are probably formed largely in the skins." \\
[Volatile components of baked potatoes., Buttery, R.G., Guadagni, D.G., Ling, L.C., Journal of the Science of Food and Agriculture, Vol.24(9), 1973, 1125-1131]

{{methional.jpg|methional}} methional 

The key odorants of //french fries// prepared in palm oil were 2-ethyl-3,5-dimethylpyrazine, 3-ethyl-2,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine, 3-isobutyl-2-methoxypyrazine, (E,Z)- and (E,E)-2,4-decadienal, trans-4,5-epoxy-(E)-2-decenal, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, methylpropanal, 2- and 3-methylbutanal, and methanethiol. When palm oil was replaced by coconut fat, a coconut note appeared in the profile - with γ-octalactone and γ-nonalactone as major contributors to that note. \\
[Wagner, Robert K., and Werner Grosch. "Key odorants of French fries." Journal of the American Oil Chemists' Society 75 (1998): 1385-1392]
  
"The potent odorants of //boiled potatoes// were screened by aroma extract dilution analysis, aroma extract concentration analysis, and gas chromatography-olfactometry of static headspace samples. Altogether 45 odorants were found of which 42 were identified. trans-4,5-Epoxy-(E)-2-decenal, methional, 2-acetyl-1-pyrroline, dimethyltrisulfide, 2,3-diethyl-5-methylpyrazine, vanillin, sotolon, decanal, (E,E)-2,4-nonadienal, (E,E)-2,4-decadienal, (E)-β-damascenone, furaneol, methanethiol, 3-isopropyl-2-methoxypyrazine, dimethylsulfide appeared in at least one of the three screening experiments with a higher flavour dilution factor." \\
[Potent odorants of boiled potatoes., Mutti, B., Grosch, W., Food/Nahrung, Vol.43(5), 1999, 302-306]

"Boiled potato off-flavour is a cardboard-like note, that develops within hours when boiled potatoes are stored. Using a panel of four professional judges, it was verified that a clearly detectable off-flavour develops during the storage of boiled potatoes. Two different isolation methods (direct extraction and vacuum distillation/extraction) in combination with GC-MS and GC-sniffing were applied to the same freshly boiled and stored boiled potatoes. Eight compounds, (pentanal, hexanal, nonanal, (E)-2-octenal, 2,4-heptadienal, (E)-2-nonenal, (E,E)-2,4-nonadienal and 2,4-decadienal) were appointed as potential contributors to the off-flavour, since these compounds could be detected during GC-sniffing, and increased in concentration during storage. The eight compounds, that most probably appear as a result of lipoxygenase initiated oxidation of linoleic and linolenic acid during the boiling process, were quantified in freshly boiled and stored boiled potatoes." \\
[Identification of compounds contributing to boiled potato off-flavour (‘POF’)., Petersen, M.A., Poll, L., Larsen, L.M., LWT-Food Science and Technology, Vol.32(1), 1999, 32-40]

"Four potato cultivars, Cara, Nadine, Fianna, and Marfona, were selected. Potatoes were baked in their skins prior to separating the skin and flesh and preparing extracts of the volatile flavor compounds using a modified Likens-Nickerson apparatus. The concentrated extracts were analyzed by gas chromatography-mass spectrometry. Volatiles were identified and classified according to their origin, that is, lipid, sugar degradation and/or Maillard reaction not involving sulfur amino acids, sulfur compounds, methoxypyrazines, and other compounds... For skin, sugar degradation and/or the Maillard reaction was by far the most important source in all cultivars except Nadine, for which 62% of the volatiles were accounted for by the sesquiterpene [[http://webbook.nist.gov/cgi/cbook.cgi?ID=C54878250|solavetivone]]. Lipid and sugar degradation and/or the Maillard reaction were the main origins of volatiles in flesh. Calculated aroma values for a selection of the key potato volatiles identified reinforce the effects of cultivar and growing site on baked potato flavor." \\
[Comparison of volatile compounds isolated from the skin and flesh of four potato cultivars after baking., Oruna-Concha, M.J., Duckham, S.C., Ames, J.M., Journal of Agricultural and Food Chemistry, Vol.49(5), 2001, 2414-2421]

"Tubers of five cultivars of potato were stored at 4 °C for 2, 3, and 8 months and baked in a conventional oven. The flavor compounds from the baked potato flesh were isolated by headspace adsorption onto Tenax and analyzed by gas chromatography-mass spectrometry. On a quantitative basis, compounds derived from lipid and Maillard reaction/sugar degradation dominated the flavor isolates, with sulfur compounds, methoxypyrazines, and terpenes making smaller contributions... Overall, of the compounds monitored, those most likely having the greatest flavor impact were 2-isopropyl-3-methyoxypyrazine, 2-isobutyl-3-methoxypyrazine, dimethyl trisulfide, decanal, and 3-methylbutanal, with methylpropanal, 2-methylbutanal, methional, and nonanal also being probable important contributors to flavor. " \\
[Effect of cultivar and storage time on the volatile flavor components of baked potato., Duckham, S.C., Dodson, A.T., Bakker, J., Ames, J.M., Journal of agricultural and food chemistry, Vol.50(20), 2002, 5640-5648]

"Extrusion cooking processing followed by air-drying has been applied to obtain low-fat potato snacks. Optimal parameters were developed for a dough recipe. Dough contained apart from potato granules 7% of canola oil, 1% of salt, 1% of baking powder, 5% of maltodextrin, and 15% of wheat flour. After the extrusion process, snacks were dried at 85 °C for 15 min followed by 130 °C for 45 min. The potent odorants of extruded potato snacks were identified using aroma extract dilution analysis and gas chromatography-olfactometry. Among the characteristic compounds, methional with boiled potato flavor, benzenemethanethiol with pepper-seed flavor, 2-acetyl-1-pyrroline with popcorn flavor, benzacetaldehyde with strong flowery flavor, butanal with rancid flavor, and 2-acetylpyrazine with roasty flavor were considered to be the main contributors to the aroma of extruded potato snacks. Several compounds were concluded to be developed during extrusion cooking, such as ethanol, 3-methylbutanal, (Z)-1,5-octadien-3-one with geranium flavor, and unknown ones with the flavor of boiled potato, cumin, candy, or parsley root. Compounds such as methanethiol, 2,3-pentanedione, limonene, 2-acetylpyrazine, 2-ethyl-3,5-dimethylpyrazine, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 3-hydroxy-4,5-dimethyl-2(5H)-furanone, 2-methyl-3,5-diethylpyrazine, 5-methyl-2,3-diethylpyrazine, and (E)-β-damascenone were probably developed during air-drying of the potato extrudate." \\
[Identification of potent odorants formed during the preparation of extruded potato snacks., Majcher, M.A., Jelen, H.H., Journal of agricultural and food chemistry, Vol.53(16), 2005, 6432-6437]

"Vegetable flavor is an important factor in consumer choice but a trait that is difficult to assess quantitatively. The purpose of this study was to assess the levels of the major umami compounds in boiled potato tubers, in cultivars previously assessed for sensory quality. The free levels of the major umami amino acids, glutamate and aspartate, and the 5′-nucleotides, GMP and AMP, were measured in potato samples during the cooking process. Tubers were sampled at several time points during the growing season. The levels of both glutamate and 5′-nucleotides were significantly higher in mature tubers of two Solanum phureja ([[http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?101304|Solanum tuberosum L. subsp. andigenum (Juz. & Bukasov) Hawkes]], yellow potato) cultivars compared with two Solanum tuberosum cultivars. The equivalent umami concentration was calculated for five cultivars, and there were strong positive correlations with flavor attributes and acceptability scores from a trained evaluation panel, suggesting that umami is an important component of potato flavor." \\
[Umami compounds are a determinant of the flavor of potato (Solanum tuberosum L.)., Morris, W.L., Ross, H.A., Ducreux, L.J., Bradshaw, J.E., Bryan, G.J., Taylor, M.A., Journal of agricultural and food chemistry, Vol.55(23), 2007, 9627-9633]

Omission experiments showed that 2-methylbutyraldehyde, 2-ethyl-3,5-dimethyl-pyrazine, methional, phenylacetaldehyde, (E,E)-2,4-decadienal, trans-4,5-epoxy-(E)-2-decenal, 2,5-dimethyl-4-hydroxy-3(2H)-furanone, hexanal, octanal, nonanal, (E)-2-heptenal, 2-ethyl-3-methyl-pyrazine, and 1-octanol have a significant effect on //french fries aroma//.  \\
[Xu, Lirong, et al. "Sensory-directed flavor analysis of key odorants compounds development of French fries and oils in the break-in, optimum and degrading frying stage." Food Science and Human Wellness 12.1 (2023): 140-150] [[https://www.sciencedirect.com/science/article/pii/S2213453022001392]]

{{:solanum_tuberosum.jpg?600}} \\
Masclef,A., Atlas des plantes de France, vol.3 t.234 \\
[[http://plantgenera.org/species.php?id_species=958623]]


{{http://www.botanische-spaziergaenge.at/Bilder/Konica_4/PICT1954.JPG}} \\
Solanum tuberosum / Bisamberg / Broschäcker \\ © Rolf Marschner (2007),  
[[http://botanische-spaziergaenge.at/viewtopic.php?f=70&t=214| www.botanische-spaziergaenge.at]]