What is the best temperature & conditions needed for long term maintenance of a plant extract containing flavonoids?

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Aly R Abdel-Moemin

Dear Sony

There are more than 5000 flavonoids have been identified, what type of flavonoids you working on? I would not recommend keeping extracted flavonoids chilled or frozen apart from doing study on the effect of chilling or freezing on the extracted flavonoids. It is assumed that after extraction of flavonoids to be injected freshly onto HPLC, or measured colorimetrically. Also to preserve the extracted flavonoids for several months it depends on the compounds you gonna to analyse and the method of extraction. According to our results we found that 17% of quercetin were decreased in lettuce samples kept at 4°C for a week compared to extracted flavonoids and injected freshly onto HPLC at the same day.

Best regards

I have attached 2 documents will help you

A.R. Abdel-Moemin, To investigate the antioxidant properties of dietary flavonoids in human metabolism. PhD Thesis, The Queen's University of Belfast, United Kingdom, 2004.

Thesis Chapter 2-TO INVESTIGATE THE ANTIOXIDANT PROPERTIES OF DIETA...

Thesis Chapter 3: TO INVESTIGATE THE ANTIOXIDANT PROPERTIES OF DIET...

Biswapriya Biswavas Misra

-20 C or as dissolved in DMSO. Freeze-dried at -20 C or -80 C also works fine. All storage will decay some amount- so the earlier you work and finish it is better. For bio-activities, you would not notice much difference but for isolation and quantification afterwards, there would be sea changes, as said above! : )