Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

--- cydonia_oblonga_mill [2021/02/28 09:19] – andreas
+++ cydonia_oblonga_mill [2021/02/28 09:40] (aktuell) – andreas
@@ Zeile 25: / Zeile 25: @@
 "Ripe quince fruits are not edible raw because of their hardness and bitterness, but they nevertheless emit a floral odor so strong that they are sometimes used as household room refreshers." Oils obtained from the peel of quince fruit consisted mainly (GC 77%) of esters, mostly ethyl esters. \\
 [Volatile constituents of peel of quince fruit, Cydonia oblonga Miller., Umano, K., Shoji, A., Hagi, Y., Shibamoto, T., Journal of Agricultural and Food Chemistry, Vol.34(4), 1986, 593-596]
+Theaspiranes A/B (fresh green-woody/cassis-like) are formed at natural pH of the quince fruit pulp under acidic conditions (pH 3.5-3.8) from the labile precursor 4-hydroxy-7,8-dihydro-beta-ionol. \\
+[Winterhalter, Peter, and Peter Schreier. "4-Hydroxy-7,8-dihydro-beta-ionol: natural precursor of theaspiranes in quince fruit (Cydonia oblonga, Mill.)." Journal of Agricultural and Food Chemistry 36.3 (1988): 560-562]
 Main volatile components (HS-GC-MS) of freeze-dried fruit puree were ethanol (~50%), ethyl acetate (35.4%), ethyl hexanoate (2.8%), the theaspiranes (2.2%), ethyl octanoate (1.4%), and ethyl 2-methylbutyrate (~1%). Minor components were e.g. limonene, trimethylbenzol, alpha ionene, farnesene, acetoin, safranal, and vitispirane; esters like propyl acetate, ethyl butyrate, and ethyl (E)-2-octenoate; alcohols like isobutanol, 2-methylbutanol and hexanol; and aldehydes like hexanal, octanal and nonanal. \\