We´re trying to evaluate coffee pulp as biomass for production of lactic acid with bacillus in an "artesanal way". We don´t have HPLC or GC-MS. We evaluated a protocol with precipitation of ZnSO4 and spectrophotometric identification with FeCl3 (425nm), but we do´nt have good results. Previously, we tried with an extraction with Ca(OH)2 without a good result.
Any suggestions?
Thanks in advance!
Hi Pilar,
you could go for an enzymatic assay using lactate dehydrogenase and glutamate-pyruvate transaminase. Kits for this are comercially availibile or you buy enzymes and co-factors and set-up the system as you wish.
Best,
Ruben
Hi Pilar,
without HPLC or GC/MS the determination will be a little bit difficult.
I've found three other methods:
http://www.jbc.org/content/82/1/23.full.pdf
https://www.sciencedirect.com/science/article/pii/S0039914018308385
http://www.chemikinternational.com/wp-content/uploads/2015/05/chemik_2015_04-9.pdf
Regards
Markus
Article Fermentative lactic acid production from coffee pulp hydroly...
Good luck
Hi Nikolay,
you've read that Pilar has no access to HPLC or GC/MS?
Your link is good but in that case useless.
Regards
Markus
Hi Pilar,
you could go for an enzymatic assay using lactate dehydrogenase and glutamate-pyruvate transaminase. Kits for this are comercially availibile or you buy enzymes and co-factors and set-up the system as you wish.
Best,
Ruben
As the question is about recommending a protocol (essay) to determine lactate in coffee (pulp) I recommend using a specific liquid chromatographic approach after sample preparation. As coffee, and coffee pulp is loaded with "tons" of larger MW organics, I would recommend either to use a RP-type of guard column to trap the organics, or an offline matrix removal with disposable ultra filtration vials. The filtrate should be clean for any chromatographic determination, and ion exclusion chromatography in conjunction with suppressed conductivity should do the job.
As an example please have a look here:
https://www.thermofisher.com/de/en/home/industrial/chromatography/ion-chromatography-ic/ion-chromatography-columns/ion-exclusion-ic-columns.html
Alternative approaches are available (e.g. ion exchange chromatography) and you should check with your local distributors for the respective capabilities.
Please let me know in case of further questions.
Cheers,
Detlef.
Try the BI enzymatic procedure for lactose in cheese. It uses the enzyme lactase. Be sure you use a spike and recovery study.
You can choose the enzymatic way. It is the best one if you haven't instruments.
Thanks a lot to everyone!!!
I really appreciate your advice about it!!!
In my opinion, the enzymatic test also is the best choice... Just that in my country there aren`t providers, so I`m waiting for the importation (3 months!!!)...
I`ll try to be patient!! :)
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