Ways to remove phytic acid from grains, nuts, seeds and legumes




 

Finally, got it done. A summary of ways to remove phytic acid from grains and other seed foods… This is beneficial to know if you are a raw vegan or just like to munch on nuts, seeds, grains and beans on a daily basis.

There are two major ways to remove phytic acid. Physically and chemically. Recall that removal (aka neutralization) of phytic acid releases any zinc, iron, calcium, manganese, magnesium or copper bound to the molecule and prevents new minerals from binding. Hence, it makes minerals bioavailable – your body can utilize them instead of dumping them out.

Physical removal of phytic acid is mechanical removal of bran*, germ** or both. In most seed foods, phytic acid resides in bran while in a few others, in germ. On the other hand, chemical removal involves enzyme phytase which, via a chemical reaction, breaks down phytic acid. Phytase is naturally found in seed foods themselves, other plants, and animals. We, humans, have it but too little to break any significant amounts of phytic acid.

 

 

Physical removal

 

Very likely this method won’t appeal to you since de-branned and de-germed, that is, milled foods are no longer “raw”. Plus removal of bran and germ along with phytic acid removes all the goodness found in these parts of a seed – fibers, B vitamins and minerals. Moreover, in some seed foods, phytic acid is stored in endosperm***, the very part that milling leaves behind for people to eat, so in this case milling is no use anyways. Commercially-wise, milling is the most widespread technique to get rid of phytic acid. My guess is because it is convenient. And why not, it does its job. Ever questioned why Asians have been eating white rice for centuries, not brown? Unlike other populations of the east, people in Asian countries do not have a bulging rate of phytic acid-related deficiencies. And you know what? In terms of minimizing phytic acid as much as possible, say if you are trying to remineralize your teeth, high-quality milled grains is a decent temporal choice. Just soak or ferment the grain before eating.

 

 

Chemical removal

 

Second way, chemical removal of phytic acid, is much more in line with beliefs of raw vegans. The key to it is enzyme phytase. It chemically breaks phosphate arms (the parts that bind minerals, contain phosphorous) from the rest of the molecule. This way phosphorous and any bound minerals are released while new minerals cannot longer bind to the resultant molecule. In dry seeds phytase is dormant. To make it capable of breaking phytic acid, it needs to be activated. The enzyme requires certain conditions for activation – presence of water, acidic pH and at the very least room temperature. There are three methods to meet these conditions – through soaking, sprouting and fermentation. Either one or combination of two or three of these has always been done by our grandgrandmothers in the past and is still done today by relatively untouched by the modern world cultures. By “past”, I refer to times before the World Wars – two of the most radical turning points in human history – they brought changes even to the kitchen.

Let’s take a closer look at soaking, sprouting and fermentation. A little theory, a little hands-on info.

 

Soaking

Ways to remove phytic acid from grains, nuts, seeds and legumes - soakingSoaking is self-explanatory, you submerge seed foods in water for a period of time. Some acid such as apple cider vinegar can be added as well. Water and acid activate naturally present phytase enzyme. Soaking is especially effective for grains and legumes. Overall, the removal rate is about 10-20%. For example, in mung beans, chickpeas and cowpeas, soaking removes up to 16% of phytic acid. Moreover, the longer the soaking period the more phytic acid removed. There is a small disadvantage to it though –  some minerals and proteins are released into the water. But not a big deal, you can compensate this just by eating greens.

For majority of seeds, 24 hours of soaking is enough.

 

Sprouting

Ways to remove phytic acid from grains, nuts, seeds and legumes - alfalfaSprouting or germination is extended soaking, so to say. You hold seeds partly in water, partly exposed to air until sprouts emerge. Again, you can add some acid. During this stage various enzymes including phytase are fully activated to unlock the nutrients needed for the emergence of a seed into a plant. At this point even more phytase is activated. Hence, it makes sense that sprouting removes more phytic than soaking alone. The removal rate can be as high as 90%. I will continue with the above example – germination of mung beans, chickpeas and cowpeas removes up to 46% of phytic acid. Sprouting works even better on grains – the reductions are in the high 80%s for most grains. Relative to grains and legumes, it is harder to remove phytic acid from nuts and seeds, hence at the very minimum they should be sprouted; however not a lot of research is done on either. Interestingly, this Nigerian 2011 study confirmed that phytic acid removal is better if germinating seeds are exposed to light. So, keep your little growing ones uncovered and away from dark places.

Overall, sprouting needs much more time than soaking – some seeds may need up to 10 days to sprout.

 

Fermentation

Ways to remove phytic acid from grains, nuts, seeds and legumes - fermentationNow fermentation. Remember that fermentation is a process of beneficial microorganisms converting carbohydrates to acids and gas. Similarly to soaking and sprouting you can add some apple cider vinegar or lemon juice to speed up the process. To ferment your seed foods, you simply throw in bacterial/yeast culture and wait until bubbles develop. During the process, the quantity of phytase enzyme is increased via two main routes. First, organic acids produced by bacteria create favorable pH for phytase activation. Second, the bacteria contributes its own phytases. Yes, phytase from sources other than seed foods themselves can contribute to breaking the phytic acid. For this reason fermentation is the most effective way to reduce the naughty acid. In fact, combination of sprouting and fermenting can eliminate nearly 100% of phytic acid. For example, fermentation alone gets rid of 96% of phytic acid in brown rice. A tasty, teeth-friendly milk can be made from properly prepared rice seeds.

Fermentation usually takes several days.

 

Adding exogenous phytase

Like I just mentioned, phytase from other organisms can successfully be used to break phytic acid. But not only friendly bacteria harbours phytase. Obviously plants have it. Some plants have more than others though. For example, rye and barley have lots of it. A whole array of other critters have it as well – yeast, fungi, mammals, amphibians, reptiles, fish. Majority of it is detected in the blood. Blood is out of the topic, won’t make your life better but you can certainly benefit from rye, bacteria and yeast phytases. There are many options – you can either make your own bacterial culture, use brine from previous ferment or any vegetable starter culture, grind some rye grain into flour… Add either of these while soaking or after sprouting your seed foods. Make emphasis on seeds and nuts in order to remove the maximum phytic acid possible. Commercially, in terms of using phytase on the large scale, isolating it from microrganisms is much more possible than animals or plants. However, it will take awhile before you see something like that on store shelves. Until then, the above methods should suffice.

 

Controversial ways to banish phytic acid

There are two other ways to remove phytic acid chemically – cooking and microwaving. And you are certainly trying to stay away from both, right? (I hope you know the flaws). But just like phytase enzyme, high heat and microwaves chemically tear phospate arms from the rest of the molecule. Don’t worry, not much to miss as neither is particularly good at removing phytic acid. In fact, neither removes more phytic acid than soaking.

Sadly, attempts to remove phytic acid on the genetic scale have been done as well. Scientists aim at both, phytic acid-containing foods AND phytase-containing organisms. That’s right, phytic acid problem is that significant! See for yourself – one third of the world population suffers from anemia and zinc deficiency. And all because of too much phytic acid in the diet. The thing is, these nations are poor and have little alternatives. They can’t just switch to foods with no or little phytic acid, from corn to potatoes, for example. By and large, genetic modification is convenient and cheap way to get rid of phytic acid on the large scale – so that’s why it is being dig into. However, no matter how great these genetic ideas look like, millions are against messing up with genes. Not just health-conscious people. Why? Although there is just a handful of studies on how GMO foods affect health, the data that is already in is intimidating…

 

Hope this wasn’t confusing. If you learned something important for yourself, share it with other vegans!

I will prepare step-by-step “how to” soak, sprout and ferment for the next post.

 

 


 

*bran – the outermost layer of a seed
**endosperm – the layer in a seed that lies between bran and germ
***germ – the innermost layer of a seed

 

Main references:

http://link.springer.com/article/10.1007/s13197-013-0978-y
https://www.ncbi.nlm.nih.gov/pubmed/24803714
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3551043/

 

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