From: Jacob Zabicky (zabicky$##$bgumail.bgu.ac.il)
Date: Tue Oct 10 2000 - 09:43:31 EDT
Hello Bahman,
Without going too much into specifics, several things may have gone wrong
in your experiment.
1. As mentioned in a previous message, loss or decomposition of
flavor/aroma constituents.
2. You do not mention derivatization, but that may be necessary to convert
phenolic components (e.g., vanillin, caffeic acid, flavonoids) into
volatile compounds. Possibly you need developing an extraction and
derivatization procedure for your tracking routine.
3. The column may need conditioning, poosibly with a silylating agent, as
otherwise it may strongly adsorb certain species and spoil the
chromatogram.
It may be recommended to find in the literature some GC analytical routines
for wine phenolic components, to get a better idea obout how this
analytical technique should be applied.
All the best,
Jacob
>On Mon, 2 Oct 2000 14:03:33 +0300, Jacob Zabicky wrote:
>
>> Hello Bahman,
>>
>> Analysis related to organoleptic properties is a complicated business.
>One
>> particular flavor/aroma may be dependent on tens or even hundreds of
>> volatile and nonvolatile components, some of which appera in trace or
>> ultratrace concentrations. A sample kept under inadequate conditions may
>> radically change its flavor/aroma because part of the components
>decompose
>> evaporate or become adsorbed on the containers.
>>
>> All the best,
>>
>> Jacob
>>
>> >Hi all:
>> >
>> >I want to know that how we can detect off-flavor of cola flavor,
>> >I am an M.S. student,and i put cola flavor in different enviromental
>> >conditions-sunlight,tempeture=5,15,38'c,...
>> >I did GC test ,but unfortunately after 1 month and 2 month
>> >nothing have been seen,although the odor of flavor was changed!!
>> >Is GC capable for testing this matter?
>> >
>> >THANKS
>> >
>> >
>
>hi dear Jacob:
>
>oh your words can help me much,
> we put our flavors in different conditions:
>sunlight= ON ,OFF
>temperature=0'C,15'C,38'C
>oxygen=ON,OFF
>i detected my samples after 1,2 month and next week for the last time 3rd
>month.
>but our GC doesn't show anything,
>at least we can't see.
>our column is VITREOUS SILICA,
>but which samples were in sulight lost their color,
>and they got sharp smell.
>
>what can i do?
>does our GC act badly?
>
>thanks
>i am waiting for your reply like a thirsty
>
>Bahman
>
>
>
>>
>
>
>
>
>
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