Fermentation as an Extraction Method

Although most cultures have fermented food as a staple in their dietary patterns, little has been reported on the use of fermentation as an herbal extraction method. The process may contribute more than just modifying solvent pH. Rizzello et al. (2013) reported using a lactic acid fermentation with specific yeast strains that improved the antioxidant activity of Echinacea purpurea. They compared fermentation extraction to either a methanol or water extract without fermentation. The greatest antimicrobial activity was associated with low molecular mass compounds negated in the presence of digestive enzymes, suggesting small peptides as the active agent.  The authors cited other experiments with grapes, soy and cereal grains where the fermentation process increased bio-availability of  certain compounds and produced novel chemical species.

This process is worth exploring by both herbal supplement companies and herbalist as a new medicine making method. Traditional texts provide some guidance.  Enzymatic processes can optimize extraction of plant cellular content at lower temperatures. And research (Mishra et al., 2010; Mulay and Khale, 2011) applying traditional Ayurvedic methods of  fermented extraction found reduced toxicity in the final product. This opens up a little explored market around functional foods as well.

Reference:

  1. Mishra AKGupta AGupta VSand RBansal P2010Asava and arishta: an Ayrvedic medicine – an overview. Int J Pharm Biol Arch. 1(1):2430.
  2. Mulay SKhale A2011Asavarishtas through improved fermentation technology. Int J Pharma Sci Res. 2(6):14211425.
  3. Rizzello, CG et al. (2013) Lactic acid fermentation as a tool to enhance the functional features of Echinacea spp. Microbial Cell Factories. 12:44-59.

 

It’s in the Dirt

Arbuscular mycorrhiza seen under microscope. F...
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Well, dirt plus nutrient content. Organic farmers know that it’s really about the soil. In particular, the “living” component of the soil. Researchers are now catching up with findings that help explain why soils on organic farms and in native woodland ecologies have greater concentrations of fungal spores in the soil and greater levels fungal colonization of plant roots – particularly the symbiotic or helpful fungi.

Mycorrhizal fungi form a symbiotic relationship with plant roots, each exchanging benefits with the other. The plant gains phosphorous from the extended “root-like” threads of fungal hyphae, while the fungi absorb glucose stored in plant root cells, which was originally metabolized (made) by the plant during photosynthesis. Additional benefits these fungi provide the plants include enhanced disease resistance, soil stability and structure, as well as nitrogen fixation.

However, the fungus cannot be cultivated in the absence of a host plant root. Commercial farming often suffers from dead soil. The USDA’s Eastern Regional Research Center (ERRC) focuses research on the use of mycorrhizal fungi to improve crop quality and yield. Researchers at this facility try to understand the necessary chemical signal exchanged between plant and fungus required during the various stages of fungal development. Their aim is to grow the fungus on artificial media without the presence of plant roots. Because of the numerous benefits that mycorrhizal fungi provide, commercial farmers hope that a fungal inoculum could then be used to limit the amount of fertilizers applied to large scale crops while still improving plant growth and health.

I’ll come back to the way plant and fungus woo each other, whispering sweet chemical cross talk…