Importance of Soaking, Sprouting, Roasting, and Fermenting

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Importance of Soaking, Sprouting, Roasting, and Fermenting

Whole grains, legumes, nuts and seeds are some of the healthiest foods to include in your diet. Studies on eating styles like the Mediterranean diet have evidenced the health benefits of increasing the intake of these types of foods, together with lots of fresh fruit and vegetables, and a moderate intake of red meats.1 The risk of heart disease, diabetes type 2, hypertension and stroke can be reduced just by following a balanced plant-based diet.1 The American Heart Association also suggests the inclusion of these foods in a heart-healthy diet and they are part of the DASH (Dietary Approaches to Stop Hypertension) eating plan.2

Unfortunately, there’s BIG problem with these foods and it’s one that most people are not aware of. Grains, legumes, seeds and nuts contain anti-nutrients. The most notable one is called phytic acid or phytates. Humans (and animals with one stomach) are not able to digest phytic acid and together with other enzyme inhibitors present in these foods, it can wreak havoc on digestion.3 Phytic acid is how phosphorus is stored in plants, stopping them from germinating too early. Phytic acid inhibits the release of phosphorus and the absorption of other minerals like magnesium, iron, calcium and zinc. This can drastically affect the bio-availability of these nutrients. The phytate form of phytic acid is responsible for inhibiting the absorption of minerals and is found in the protein bodies of nuts, seeds and legumes and in the bran or endosperm of grains.3

The most common industrial method to remove phytic acid and its compounds is by milling it at high temperatures. This process also removes most of the nutritional fiber and minerals, leaving only a heap of nutrient-void carhohydrates.3 The promotion by health and wellness shops these days to eat more ‘raw’ and ‘unprocessed’ foods are not entirely beneficial either, as these foods still contain phytic acid, enzyme inhibitors and other anti-nutrients like tannins, oxalates, pectins, gluten and indigestible complex sugars.4

Is there a way to reduce anti-nutrient content in grains, legumes seeds and nuts and improve their bio-availability and digestion? Yes, there is! And it’s easier than you think – by mimicking the germination process that occurs in nature. The processes of soaking, sprouting, roasting and even fermentation has been used by our ancestors to properly prepare these foods, something that we forget to do in our busy modern-day lives.3,4  

How does it work?

In the natural world most plants need moisture, warmth and a light acidic environment to grow and germinate. These plants also contain an enzyme called phytase that is its natural way to neutralize phytic acid, releasing the phosphorus compounds.7

When we mimic this natural process through soaking, sprouting and roasting, we make these foods much easier to digest and increase nutrient bioavailability for absorption. It also helps to activate phytase which can assist in the reduction of phytic acid.7 Studies performed on legumes like chickpeas and mung beans have shown that sprouting, longer germination times and applied heat were successful in reducing the amount of phytates and tannins and increasing the availability of minerals like iron, zinc and calcium.5 Studies have also shown that soaking cereal can increase the solubility of iron and zinc and the soaking of beans and grains can improve mineral bioavailability and reduce phytic acid concentrations.3

Historically our ancestors have used these processes, usually a combination of all three, to prepare these ingredients for cooking. Some of these traditional preparation methods are still used today by native tribes in Africa, Indian cooking, Mexican cooking and Asian cooking.4

  • Traditional South Asian culture recommends eating soaked almonds for improved memory8
  • In traditional Indian cooking lentils and rice are fermented before preparing dosas4
  • Scottish and Welsh traditions call for oats to be soaked and fermented before eating4
  • Injera bread are made by the Ethiopians by fermenting teff7
  • Soaking, heat, and fermentation has been used throughout Europe and America to prepare sourdough bread for centuries4,7
  • Traditional Ezekiel bread, or manna bread from the bible, is made from milling sprouted grains

Soaking

Soaking is the process of covering legumes, grains, seeds and nuts with water. It is also the first step in sprouting. Nuts and seeds can be soaked in saltwater and then dried, as done by the Native Americans. For grains and legumes, a more acidic solution will be needed to help remove the phytic acid.3,7 Soaking activates phytase that helps to deactivate phytic acid.3

Soaking times:7,9

  • Nuts – soak for 8–12 hours
  • Legumes (adzuki beans, black beans, chickpeas, mung beans) – soak for 8–12 hours
  • Grains – soak for 6 hours
  • Seeds – soak for 8–12 hours; sunflower seeds can be soaked for up to 24 hours

Benefits:3

  • Soaking can remove phytic acid
  • Increases digestion
  • Increases bioavailability of minerals
  • Increases absorption of minerals
  • Can easily be done at home

Studies3 have shown that soaking chickpeas for 12 hours decreased the phytic acid content by 55%. Soaking grains for 6 hours at a temperature between 45–65˚C at a slightly acidic pH (5–6), showed a considerable decrease in phytate components.3

Use: Use soaked legumes, grains, nuts and seeds for further sprouting, making pastes or nut butters or cooking. Studies have shown that soaking followed by cooking can reduce the phytic acid in these foods even more.3,7

Best used for: Nuts, followed by dehydration if necessary. Studies have shown that overnight-soaked raw almonds have increased vitamin E content and eating a hand full of them can improve memory.5 Soaking of certain spices is also recommended, to improve flavor profiles.

Soaking of grains, seeds and legumes will usually be followed by growing nutritious sprouts, fermentation, or milling and adding yeast for baking bread.

Sprouting

Sprouting is the process of allowing grains, seeds, nuts and legumes to germinate and form shoots and small leaves. Sprouting follows soaking and can further enhance the nutritional content, and digestibility of these foods.10 A sprouted grain, for instance, will contain the bran, germ and endosperm and can be consumed whole.10 Studies have shown that sprouting can reduce phytic acid up to 40% and this can be increased by adding a phytase-rich medium to the sprouting process.3,7 Consumption and cultivating of sprouts have been a long tradition in Eastern countries and were popularized in the West in the 1980s. The rich nutrient profiles of sprouts, their earthy taste and pleasing aesthetic look on salads made them even more popular.10 They are also cheap to produce with low-processing and almost no additives needed.10

The sprouting process is easy to do in the comfort of your own home without the need for lots of equipment. Here is the basic method of sprouting:1

  • Soak your legumes, grains, seeds or nuts for about 12–24 hours. If soaking for longer than 12 hours, rinse with fresh water every twelve hours
  • Strain off the water when you are ready to sprout
  • Spread them in a single layer on a clean tray
  • Cover with a damp cloth, or cling film with a few air holes punched in
  • Leave in a dark place until they begin to sprout
  • Refrigerate and eat within 3–4 days
  • If you want to make sure there’s no bacterial or moldy growth, you can rinse the sprouts every day in fresh water

Sprouting times:7,9

Sprouting times are usually a few days and can vary from the variety you are trying to sprout.

  • Nuts – Nuts aren’t really ideal for sprouting and should rather be soaked. Almonds are the best nuts to use for sprouting and requires 2–3 days
  • Legumes and beans – most 2–3 days; kidney beans 2–7 days
  • Grains – most 2–3 days; wild and black rice 3–5 days
  • Seeds – most 2–3 days; alfalfa 3–5 days

Benefits:6,10,11,12

  • Reduces phytic acid concentration
  • Increases digestion
  • Increases bioavailability of minerals
  • Increases absorption of minerals
  • Can easily be done at home
  • Decreases enzyme inhibitors
  • Increases fiber content
  • Increases digestibility of gluten
  • Increases protein content

Studies on sprouting have reported that phytic acid in sprouted millet is reduced by 45% after 96 hours3 and the sprouting of lentils on an industrial scale has proved a notable decrease in antinutrients.13 Another study done on chickpeas, mung beans and cowpeas showed that phytic acid was reduced after sprouting for 24–60 hours.5 After the sprouting process the sprouts were cooked and that improved the bioavailability of mineral content (iron, calcium, zinc) even more. The sprouting of kidney beans at 30˚C for 96 hours reduced phytates by 85.9%.5

Use: enjoy on salads or cooked, use to make sprout bread (Ezekiel bread)

Best used for: Legumes, grains and seeds

Fermentation

Many foods are produced through the process of fermentation. Vinegar, bread, cheese, yogurt and even coffee are just some of the foods we make by adding natural yeasts and bacteria to start the process of fermentation. Fermentation is described as a metabolic process where carbohydrates are converted to energy, forming alcohol or other organic acids as by-products. 3

In grains, legumes and seeds fermentation causes enzymatic degradation of phytic acid by creating a more acidic environment, it naturally lowers the pH. 3 Fermentation also stimulates phytase, which helps to break down phytic acid and is an ideal process to use for grain high in phytase (wheat, rye). 7

Alcoholic and lactic acid fermentation are the two types of fermentation. Depending on the recipe and what needs to be fermented, a starter culture, salt, sugar or whey will be added to the food.18The quickest way to ferment grains and legumes at home is to soak them in water with something acidic like apple cider vinegar or lemon juice. Ferment up to two days and rinse thoroughly.4

Benefits: 3, 7,19

  • Reduces phytic acid concentration
  • Increases bioavailability of minerals
  • Increases digestibility of protein and fiber
  • Reduces antinutrients
  • Acts as a natural preservative
  • Has probiotic effects that can improve gut health

Uses: use fermented grains for making bread, mash fermented beans into dips and sauces or eat on salads.

Studies have shown that fermentation of millet for 12–24 hours can significantly decrease phytic acid and tannins. 3 The fermentation of corn using a traditional Sudanese lactic acid fermentation method successfully reduced the levels of antinutrients and increased the bioavailability of minerals like iron and phosphorus.17 Sourdough fermentation of wheat for just 4 hours showed a 60% reduction in phytic acid, with increased reduction at longer fermentation times. 7

Roasting

The research on roasting is somewhat limited but has proven to be effective, especially after soaking, to remove a large portion of phytic acid and phytate.7 Roasting can be done in the oven, or in a pan as dry frying. Research on the roasting of groundnut showed the effective reduction of antinutrients and improved bioavailability of minerals like calcium, potassium, phosphorus, sodium and magnesium.14 Another study also showed that roasting chickpeas significantly reduced their phytic acid content.15

Roasting times: Roasting times can vary and can be anything from 15–45 min at a moderately high temperature. When the nuts, legumes, seeds or grains start to turn golden brown, they can be removed from the heat.

Benefits:

  • Reduces phytic acid concentration
  • Increases bioavailability of minerals
  • Can easily be done at home
  • Low cost
  • Enhances taste

Use: eat roasted nuts and seeds as snacks, use on salads, ground down to a flour for baking

Best used for: nuts, seeds, spices

A note on spices

Spices and aromatic herbs are flavorful additions that can be used in cooking. They are also packed with phytonutrients that are well known for having medicinal effects.16 Soaking spices can enhance their flavors, while sprouting others like mustard seeds can be a delicious crunchy addition to salads. Spices do contain some anti-nutrients like tannins and oxalates, but research relating to the preparation methods of spices and its effect on anti-nutrients are scarce. Traditionally, spices have been roasted or more conveniently just heated on a pan prior to incorporating into various dishes. Not only does this enhance the flavors but is an effective method of neutralizing the anti-nutrients for optimal bio-availability.

Conclusion

They health benefits of ingesting foods like whole grains, legumes, nuts, seeds and spices are numerous. When implementing any of these preparation processes, the antinutrient content of these foods can successfully be reduced and they are more easily digestible. Most of the studies mentioned in this article suggest that a combination of all three of these processes will be the most beneficial. It may seem time consuming to implement all three of these processes, but if you would like to get the most out of your beans and nuts you should at least commit to trying one of them.

References:

  1. Polak, R., Phillips, E. and Campbell, A. (2015). Legumes: Health Benefits and Culinary Approaches to Increase Intake. Clinical Diabetes, [online] 33(4), pp.198-205. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4608274/ [Accessed 8 Jan. 2020].
  2. The American Heart Association (2019). The American Heart Association Diet and Lifestyle Guidelines. [online] The American Heart Association. Available at: https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/nutrition-basics/aha-diet-and-lifestyle-recommendations [Accessed 8 Jan. 2020].
  3. Gupta, R., Gangoliya, S. and Singh, N. (2013). Reduction of phytic acid and enhancement of bioavailable micronutrients in food grains. Journal of Food Science and Technology, [online] 52(2), pp.676-684. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4325021/?report=classic [Accessed 8 Jan. 2020].
  4. Sally Fallon and Mary G. Enig PhD (2000). Be Kind to Your Grains … And Your Grains Will Be Kind To You – The Weston A. Price Foundation. [online] The Weston A. Price Foundation. Available at: https://www.westonaprice.org/health-topics/food-features/be-kind-to-your-grains-and-your-grains-will-be-kind-to-you/ [Accessed 8 Jan. 2020].
  5. Bains, K., Uppal, V. and Kaur, H. (2011). Optimization of germination time and heat treatments for enhanced availability of minerals from leguminous sprouts. Journal of Food Science and Technology, [online] 51(5), pp.1016-1020. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4008754/ [Accessed 9 Jan. 2020].
  6. Lorenz, K. (1980). Cereal sprouts: composition, nutritive value, food applications. – PubMed – NCBI. [online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pubmed/7002472 [Accessed 9 Jan. 2020].
  7. Nagel, R. (2010). Living With Phytic Acid – The Weston A. Price Foundation. [online] The Weston A. Price Foundation. Available at: https://www.westonaprice.org/health-topics/vegetarianism-and-plant-foods/living-with-phytic-acid/ [Accessed 9 Jan. 2020].
  8. Hassan Gil, A., Arslan, J. and Ahmed, T. (2017). Soaked Almonds Exhibit Vitamin E-dependent Memory Protective Effect in Rodent Models. International Journal of Pharmacology, [online] 13(5), pp.448-456. Available at: https://scialert.net/fulltext/?doi=ijp.2017.448.456 [Accessed 9 Jan. 2020].
  9. Masters, T. (2017). How to Soak & Sprout Nuts, Seeds, Grains, & Beans. [online] Vegetarian Times. Available at: https://www.vegetariantimes.com/skills/how-to-soak-sprout-nuts-seeds-grains-beans [Accessed 9 Jan. 2020].
  10. Benincasa, P., Falcinelli, B., Lutts, S., Stagnari, F. and Galieni, A. (2019). Sprouted Grains: A Comprehensive Review. Nutrients, [online] 11(2), p.421. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6413227/?report=classic [Accessed 9 Jan. 2020].
  11. Sur R., et al (1993). Storage changes in the quality of sound and sprouted flour. – PubMed – NCBI. Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pubmed/8332585 [Accessed 9 Jan. 2020].
  12. Chung TY., et al. (1989). Compositional and digestibility changes in sprouted barley and canola seeds. – PubMed – NCBI. [online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pubmed/2608636 [Accessed 9 Jan. 2020].
  13. Erba, D., Angelino, D., Marti, A., Manini, F., Faoro, F., Morreale, F., Pellegrini, N. and Casiraghi, M. (2018). Effect of sprouting on nutritional quality of pulses. International Journal of Food Sciences and Nutrition, [online] 70(1), pp.30-40. Available at: https://www.tandfonline.com/doi/abs/10.1080/09637486.2018.1478393?journalCode=iijf20 [Accessed 9 Jan. 2020].
  14. Ndidi, U., Ndidi, C., Aimola, I., Bassa, O., Mankilik, M. and Adamu, Z. (2014). Effects of Processing (Boiling and Roasting) on the Nutritional and Antinutritional Properties of Bambara Groundnuts (Vigna subterranea [L.] Verdc.) from Southern Kaduna, Nigeria. Hindawi. Available at: https://www.hindawi.com/journals/jfp/2014/472129/ [Accessed 9 Jan. 2020].
  15. Hussain B., et al. (1989). Effect of roasting and autoclaving on phytic acid content of chickpea. – PubMed – NCBI. [online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/pubmed/2755470 [Accessed 9 Jan. 2020].
  16. Jiang, T. (2019). Health Benefits of Culinary Herbs and Spices. Journal of AOAC International, [online] 102(2), pp.395-411. Available at: https://www.ingentaconnect.com/content/aoac/jaoac/2019/00000102/00000002/art00010 [Accessed 9 Jan. 2020].

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