| Beide Seiten der vorigen Revision
Vorhergehende Überarbeitung
Nächste Überarbeitung
|
Vorhergehende Überarbeitung
Nächste Überarbeitung
Beide Seiten der Revision
|
allium_cepa_l [2017/11/09 08:43]
andreas |
allium_cepa_l [2018/10/02 18:04]
andreas |
| "The most important compound found in the headspace of sliced onions by SPME-GC-MS after 1 min emission of volatiles was thiopropanal S-oxide. Also, some dipropenyl disulphides and propenyl propyl disulphides were identified. After 30 min, most of the thiopropanal-S-oxide disappeared, and other sulphur and non-sulphur compounds appeared in the GC chromatograms. The major constituents were diprop(en)yl disulphides. Similar constituents were also found in the water-slurred onions by headspace and direct SPME." \\ | "The most important compound found in the headspace of sliced onions by SPME-GC-MS after 1 min emission of volatiles was thiopropanal S-oxide. Also, some dipropenyl disulphides and propenyl propyl disulphides were identified. After 30 min, most of the thiopropanal-S-oxide disappeared, and other sulphur and non-sulphur compounds appeared in the GC chromatograms. The major constituents were diprop(en)yl disulphides. Similar constituents were also found in the water-slurred onions by headspace and direct SPME." \\ |
| [Determination of fresh onion (Allium cepa L.) volatiles by solid phase microextraction combined with gas chromatography-mass spectrometry., Järvenpää, E.P., Zhang, Z., Huopalahti, R., King, J.W., Zeitschrift für Lebensmitteluntersuchung und-Forschung A, Vol.207(1), 1998, 39-43] | [Determination of fresh onion (Allium cepa L.) volatiles by solid phase microextraction combined with gas chromatography-mass spectrometry., Järvenpää, E.P., Zhang, Z., Huopalahti, R., King, J.W., Zeitschrift für Lebensmitteluntersuchung und-Forschung A, Vol.207(1), 1998, 39-43] |
| | |
| | The lachrymatory factor thiopropanal-S-oxide is not released spontaneously as a by-product following the action of the enzyme alliinase, but is specifically synthesized from the intermediate sulphenic acid by a previously undiscovered enzyme, lachrymatory-factor synthase. \\ |
| | [Imai, S., et al. "Plant biochemistry: an onion enzyme that makes the eyes water." Nature 419.6908 (2002): 685] |
| |
| "Various Allium hybrids, obtained by the crossbreeding of Allium cepa (onion) as the mother plant and six taxonomically distant wild species obtained by embryo rescue, were investigated with special respect to their individual profiles of cysteine sulfoxides as well as enzymically and nonenzymically formed aroma substances. Alliinase (EC 4.4.1.4) catalyzes the conversion of odorless (+)-S-alk(en)yl-l-cysteine sulfoxides into volatile thiosulfinates. These thiosulfinates were converted to a variety of sulfides by steam distillation... Cysteine sulfoxides as well as alliinase activity were found in all investigated samples at different levels, but (+)-S-methyl-l-cysteine sulfoxide (methiin) was the most abundant sulfoxide present. (+)-S-(trans-1-Propenyl)-l-cysteine sulfoxide ([[https://de.wikipedia.org/wiki/Isoalliin|isoalliin]]) is typical for onion and was found in all investigated hybrids. The pattern of the other cysteine sulfoxides depended strongly on the parent plants used... \\ | "Various Allium hybrids, obtained by the crossbreeding of Allium cepa (onion) as the mother plant and six taxonomically distant wild species obtained by embryo rescue, were investigated with special respect to their individual profiles of cysteine sulfoxides as well as enzymically and nonenzymically formed aroma substances. Alliinase (EC 4.4.1.4) catalyzes the conversion of odorless (+)-S-alk(en)yl-l-cysteine sulfoxides into volatile thiosulfinates. These thiosulfinates were converted to a variety of sulfides by steam distillation... Cysteine sulfoxides as well as alliinase activity were found in all investigated samples at different levels, but (+)-S-methyl-l-cysteine sulfoxide (methiin) was the most abundant sulfoxide present. (+)-S-(trans-1-Propenyl)-l-cysteine sulfoxide ([[https://de.wikipedia.org/wiki/Isoalliin|isoalliin]]) is typical for onion and was found in all investigated hybrids. The pattern of the other cysteine sulfoxides depended strongly on the parent plants used... \\ |
