The good extraction method depend on the solvent type which is used, time, temperature and the purpose. Maceration with water may lead the extract rot and growth of microorganisms with long period

Dear Mac!

Definitely, this method is good for extraction of bioactives. In our lab, we used this method of extraction, in parallel with other methods. We got very good results, even better than for ultrasound-assisted extraction. Though in our experiment the maceration lasted 48h and the temperature was 30 C.

I hope this helps.

Good luck,

Yours sincerely,

Vitali

Vitalijs Radenkovs

Dear Vitalijs Radenkovs

Many Thanks!

Is it alright if I skip the washing of the plant part? and also how long should I freeze dry them? Is 24 hrs enough?

The reported methodology belongs to conventional extraction methods and the methodology seems to be o.k. Please think to increase the temperature to achieve better results and to decrease the extraction time. You use also try "green" extraction techniques like ultrasound-assisted or microwave-assisted extraction if you have the equipment.

Dear Mac,

You are very welcome!

Good luck in your endeavours.

Yours sincerely,

Vitali

Dear Mac,

What type of plant material you are talking about?

Freeze-drying time depends on the moisture content of the sample, the amount of loaded sample, and equipment characteristics (vacuum, temperature). In our lab, samples with approx. 30-40% moisture content usually undergo freeze-drying for 72 h at −51 ± 1 °C under vacuum of 0.055–0.065 mbar.

Vitalijs Radenkovs

Dear Vitalijs Radenkovs

Thanks again for the response.

currently I'm testing on ariel parts like leaves, stem, bark/wood, which are already quite dry. However I want to preserve them with maximum bioactivity for a longer time so that's why I decided to freeze dry them.

I was wondering whether washing of the plant really necessary prior to extraction?

Prodromos Skenderidis

Dear Prodromos Skenderidis

Thanks for your answer.

What would be the optimum temperature & time for solvent maceration?

Dear Mac,

Well, If you are considering the extraction of biologically active compounds using conventional techniques such as maceration and let's say as solvent water or 20, 30% EtOH, I would suggest you do not skip washing step. I suppose your samples are not sterile and do contain soluble and insoluble impurities and microorganisms so proper pretreatment needs to be performed. I guess you can try to use sodium chloride solution for cleaning. At least you'll remove physical particles from your samples.

In case you will decide to used more concentrated solvents, I should say you do not need to worry about microbiological contamination and possible spoilage of samples during maceration.

I hope this helps,

Yours sincerely,

Vitali

Vitalijs Radenkovs

Dear Vitalijs Radenkovs

I'm going to use absolute ethanol and absolute chloroform for maceration.

Do we have to add water to the plant material prior to freeze drying? I heard something like that from one of my colleagues.

Also do you think that 72 hrs of maceration is too long?

Dear Mac,

* Do we have to add water to the plant material prior to freeze drying?

**What's the point of this?

* Also do you think that 72 hrs of maceration is too long?

** Honestly, I do not know. You need to check the concentration of compounds at different points of time during maceration. Let's say after 12, 24, 48, and 72 h of maceration. Based on these data you could define the most appropriate time of maceration.

Vitalijs Radenkovs

Dear Vitalijs Radenkovs

Yes. I too thought adding water has no meaning.

Thats a good point. For your extract do you think that 48 hrs is the optimum time?

Dear Mac,

Yes, we found that 48 h is enough to extract bioactives using maceration. After that time we observed concentration of bioactives started to decrease, perhaps due to oxidation processes caused by light and oxygen exposure.

Yours sincerely,

Vitali

Vitalijs Radenkovs

Dear Vitalijs Radenkovs

Great. I will stick with 48 hrs then. Thank you so much!

Dear Mac!

It was a pleasure to help :)

Good luck,

Yours sincerely,

Vitali

The good extraction method depend on the solvent type which is used, time, temperature and the purpose. Maceration with water may lead the extract rot and growth of microorganisms with long period

Dear Dr Mac;

I agree with your method. We also use some extract (EtOH, methanol or acetone etc.) method in our laboratory for antimicrobial activity or another activity. Have a nice work.

Eda Altınöz

Dear Eda Altınöz

Thanks for your response.

Out of EtOH, methanol & acetone for which extract did you get good results for antimicrobial activity? particularly for bacteria like E. coli?

You’re welcome Dear Mac,

Polarity indices are as follows; Methanol>Acetone>EtOH. So you can choose methanol. In methanol, we get good results( for E.coli)

Eda Altınöz

Many Thanks!

You’re welcome Dear Mac..Have a nice study..

Eda Altınöz

Vitalijs Radenkovs

Dear Vitalijs Radenkovs & Eda Altınöz

Have you tried comparing the antimicrobial activity between air-dried & freeze-dried plant material?

Dear Mac;

I haven’t tried freeze-dried plant material. :(

Dear Mac!

Thank you for very practical question!

Unfortunately, such experiments haven't been done by our group. Though based on the study carried out by our colleagues one can conclude that freeze-drying and microwave-vacuum drying less affecting chemical composition, especially vitamin C content comparing with oven drying.

However, the temperature and time of drying are key factors determining the degree of bioactives loss during drying.

Yours sincerely,

Vitali

After extraction with adéquate solvant we use succefuly the adsoption desorption method to extract the antimicrobial substances from the plant extract. Now we work on selective extraction by this method under optimal conditions. A paper is in préparation.

Hello Mac,

Best of Luck. I agree with your method but In my suggestion is, if you take 20g of plant powder than you take 80 ml of Solvents. Solvents of evaporation time like Methanol, Ethanol, Acetone evaporates quickly from as much as DMSO.

if you Maceration with water sometimes may lead extract growth of microorganisms and Fungus in your extraction solvent and sometimes water Extraction has given the false and Unsatisfied Results.

Best of luck in your experiment.

Vitalijs Radenkovs

Avijit Banik

Eda Altınöz

Dear Vitalijs Radenkovs & Avijit Banik - Excellent. Thank you so much!

Dear Eda Altınöz - It is Ok. Thank you :)

Hi, I suggest to use magnetic stiring to reduce the time of meceration. But, you have to choose the solvent first. Be careful when evaporating the solevent, reduce as possible the temperature.

Yakoub Ladjal Ettoumi

I'm hoping to macerate within 48 hrs. Which one is better magnetic stirrer or rotary shaker?

I am not sure but, I prefere the rotary shaker!

Yakoub Ladjal Ettoumi : Thanks.

Dried plants grind and take a certain weight from them, then add an organic solvent such as ethanol, methanol or hexane, and determine the type of solvent depending on the active substances in the plant foe use anti-microorganism while plant in Frozen used to extracts enzymes and plant antibody with good look

Extraction of Natural Products Using Near-Critical Solvents book

Introductory Chapter: Plant Extracts bookBy Aman Dekebo

In general, the maceration procedure is the better approach for extracting many compounds. It is recommendable to be performed on magnetic stirrer to ensure better exchange of active molecules between plant material and used solvent (typically ethanol, methanol, hexane, ect). My experiance showed that using green extraction methods as ultrasound-assisted extraction accelarates the extraction of biactive molecules, save energy and reduce time.

Nadezhda Traycheva Petkova

Thanks for your response.

How about using the vortex mixer? Is it good as ultrasound-assisted extraction?

We usually prefer air dry instead of freeze dry and extraction with 150 mL of 70% methanol for 48 hour at max 40 C