Chapters 8.26

8.26-Using Maize (Corn) Silk as a Source of Profits and Improved Human Health

Lianna van der Zalm , University of Guelph, Canada

Suggested citation for this chapter.

van der,ZL. (2022) Using Maize (Corn) Silk as a Source of Profits and Improved Human Health,In Farmpedia, The Encyclopedia for Small Scale Farmers. Editor, M.N. Raizada, University of Guelph, Canada. http://www.farmpedia.org

Background of Corn and Corn Silk

In 94 developing countries across the world, 4.5 billion people get at least 30% of their calories from corn making it a staple for many (International Maize and Wheat Improvement Centre, 2016). Corn is wind-pollinated: the pollen is caught by corn silks at the tip of each ear and they travel down corn silks where they reach and fertilize eggs to give rise to kernels (IPBO, 2017). Corn silks are usually discarded, but they represent a simple opportunity for smallholder maize farmers to obtain extra income from a product they are already producing.

Health Benefits of Corn Silk

Corn silk has been used for thousands of years as a traditional cure for a multitude of health issues by the Chinese and Native Americans (Hasanudin et al., 2012). Today, it is used in many parts of the world as a traditional medicine such as in Turkey, the United States and France (Hasanudin et al., 2012). There are many proposed health benefits such as a variety of nutrients and natural cures including urinary infections, cystitis, edema, prostate disorders, antioxidant, hyperglycemia, depression and fatigue (Hasanudin et al., 2012).

Mature corn silk contains a variety of nutrients, minerals and antioxidants. The chart below shows the approximate compositions of these components.

Table 1: Nutrient and mineral composition on mature corn silk (Rahman & Rosli, 2014).

For urinary infections, cystitis, edema and prostate disorders, corn silk has been used as an anti-inflammatory (Steenkamp, 2003). When the bladder and urethral walls are irritated it makes it more difficult to urinate (Steenkamp, 2003). When corn silk is consumed, it relieves the lining of the urinary system reducing irritation (Steenkamp, 2003).

When oxidation occurs in the body it can cause damage to cells which can eventually lead to diseases such as cancers, diabetes, atherosclerosis and aging (Hasanudin et al., 2012). Corn silk has been studied as a potential antioxidant to prevent the occurrence of oxidation reducing the probability of the above diseases or reducing their advancement (Hasanudin et al., 2012).

Hyperglycemia is a condition characterized with diabetes as it indicates an elevated level of blood glucose when the body is not utilizing insulin properly (American Diabetes Association, 2018). A test done on mice showed that corn silk reduced hyperglycemia by increasing insulin levels and recovering injured cells (Guo et al., 2009).

Corn silk has also been tested in its effectiveness as an anti-depressant and anti-fatigue supplement. The anti-depressant is based on the high levels of phenol and flavonoids and showed similar results as an anti-depressant drug (Mahmoudi & Ehteshami, 2010). For anti-fatigue, a test was done on mice showing that there was an inhibitory factor for blood lactic acid increasing hepatic glycogen concentration increasing the drive of the mice (Hu et al., 2010).

Making Corn Silk Powder

For corn silk products, the silk can be either dried or left as is but drying the silk will extend the shelf life. To begin, the silk should be washed to make sure no pests are present (Alterman, 2013). Once washed, pat dry with a towel and then place them in a drying rack. The drying area needs to be between 25°C-30°C for optimal conditions with minimal humidity and with no sunlight so that the nutrients do not get lost (Alterman, 2013). Link 1 in the Helpful Hints section leads to an option for a drying rack which is black, so the material will absorb more sunlight than the silk if it cannot be placed in the dark. After drying is complete (silk no longer has moisture), the silk can be chopped finely for easier use. This can be done with a knife or the device found in link 2 in Helpful Hints. After chopping, the silk should be put in an air tight container until use (Ness, 2018).

Value Addition as a Tea

Corn silk tea is the way Chinese people have been utilizing corn silk’s benefits for thousands of years (TCM World Foundation, 2015). The tea can be prepared either in tea bags to sell, or directly in a steeper to sell directly to the consumer. If tea bags are being made, place 2 teaspoons of dried corn silk into a bag such as the ones found in link 3 in Helpful Hints (Gale Encyclopedia of Alternative Medicine, 2018). To make the tea, the tea bag should be placed in boiling water and steeped for 15-20 minutes (Gale Encyclopedia of Alternative Medicine,2018). To be effective, the mixture should be drunk 3 times a day (Gale Encyclopedia of Alternative Medicine, 2018). If the fresh corn silk is being used, 1 tablespoon should be added to 1 cup of boiling water and left to steep for 20 minutes (Radhakrishnan, 2017). The tea should then be strained and sold for drinking (Radhakrishnan, 2017). Honey, agave or any natural sweetener can be added to add sweetness (Radhakrishnan, 2017). Other herbs can be added to the teas to increase their value such as dandelion leaves, nettle leaves and uva ursi for a bladder helper tea (Sun and Moon Dispensary, 2017).

Value Addition as a Tincture

A tincture is a higher concentration of an extract of an herb or plant (Wong, 2018). The herb is soaked in alcohol to extract the nutrients for a few weeks where it is then strained and bottled (Wong, 2018). To make a corn silk tincture, a mason jar or something similar should be filled ¼ full with chopped fresh corn silk and the rest filled with a high proof alcohol such as vodka (Radhakrishnan, 2017). After 4-6 weeks in a cool dark place the mixture can be strained (Radhakrishnan, 2017). ¼ to ½ a teaspoon can be taken 3 times a day (Radhakrishnan, 2017).

Value Addition as a Powder for Soups/Stew Type Meals

Since corn silk has a light taste, if added to meals the benefits would be present without a flavor change (Ness, 2018). Dried corn silk can be used directly in meals and sold as a spice (Ness, 2018). Even fresh corn silk can be added to meals after being chopped if it is used within a couple of days after harvesting.

Cost Analysis

The typical post harvest stages for corn involves husking the corn before storing it so instead of throwing the husks out, the corn silk can simply be separated from the husks in this step adding only seconds to the process (Shepherd, 1999). To rinse the corn silk, the cost of labour to get the water and containers for water need to be considered. To dry, the drying net in link 1 costs between $2-$15 depending on the location. The labour only needs to be considered for chopping unless the food chopper in link 2 is used which costs $4-$10. If tea bags are being created, then the cost of the bags range from $0.06-$0.11 per bag found in link 3. For the tincture, alcohol would most likely be sold at local markets. The only other unknown costs would be the type of packaging it would be sold in and the transport.

Market Analysis

As prices for produce and products change everyday and not a lot of information is available on where the best places to sell products is, connecting with an organization is probably the best opportunity for subsistence farmers. One organization called Farm Africa (a link can be found in link 4 in Helpful Hints) assists farmers in optimizing their growing and selling strategies (Farm Africa, 2018). They assist in increasing yields and quality and connect farmers together to sell in bulk and aid in marketing efficiency (Farm Africa, 2018). This organization knows local markets the best, making them a valuable connection to create. Some other potential selling areas would be at local markets, to local doctors or physicians to give as a treatment for the ailments discussed above or at grocery stores as a health product. By using the health benefit information provided, packaging and marketing can be created to promote the use of the products for health concerns.

Potential Issues

For the tincture, it should be made apparent on the bottle that it does contain alcohol so pregnant women should not consume it. To reach toxicity levels of corn silk, one would have to consume more than 500 mg/kg of corn silk to body weight, which is a very high concentration (Ha et al., 2018). If the weather is poor, the corn silk can be dried in an oven or dehydrator as the moisture would be too high otherwise. One other issue could be that the corn silks may not form properly during drought or other types of stress (Nielsen, 2016).

Helpful Hints

Link 1: Source for herb drying device https://www.alibaba.com/product-detail/factory-price-hot-sale-black-herb_60778736385.html?spm=a2700.galleryofferlist.normalList.33.42184e57dqM5IU

Link 2: Source for food processor https://www.alibaba.com/product-detail/2017-Creative-Kitchen-Pulling-Food-Chopper_60760225664.html?spm=a2700.galleryofferlist.normalList.294.62b73777Taidco

Link 3: Source for tea bags https://www.alibaba.com/product-detail/Transparency-PLA-Biodegradable-Folding-Corn-Fiber_60787347001.html?spm=a2700.7724838.2017115.215.2bb17c60t1nap6

Link 4: Organization for crop and marketing aid https://www.farmafrica.org/agriculture/agriculture-1

Link 5: YouTube video on how to make corn silk tea https://www.youtube.com/watch?v=h5uiheCH01c

Link 6: Link for a variety of corn silk recipes https://thenerdyfarmwife.com/uses-for-corn-silk/

Link 7: YouTube video on what corn silk can help health wise and how https://www.youtube.com/watch?v=MV5kZUFbSEs

Link 8: How to make corn silk spice https://delishably.com/spices-seasonings/Making-Homemade-Corn-Silk-Spice

References

1. Alterman, T. (2013, February). Drying Herbs: Easier Than You Think - Real Food. Retrieved from https://www.motherearthnews.com/real-food/drying/drying-herbs-zm0z13fmzmat

2. American Diabetes Association (2018). Hyperglycemia (High Blood Glucose). Retrieved November 10, 2018, from http://www.diabetes.org/living-with-diabetes/treatment-and-care/blood-glucose-control/hyperglycemia.html

3. Farm Africa (2018). Agriculture. Farmafrica.org. Retrieved from: https://www.farmafrica.org/agriculture/agriculture-1

4. Gale Encyclopedia of Alternative Medicine (2018). Cornsilk. Encyclopedia.com. Retrieved from https://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/cornsilk

5. Guo, J., Liu, T., Han, L., & Liu, Y. (2009). The effects of corn silk on glycaemic metabolism. Nutrition & Metabolism,6(1), 47. Retrieved from https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/1743-7075-6-47.

6. Ha, A. W., Kang, H. J., Kim, S. L., Kim, M. H., & Kim, W. K. (2018). Acute and Subacute Toxicity Evaluation of Corn Silk Extract. Preventive Nutrition and Food Science,23(1), 70-76. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5894788/.

7. Hasanudin, K., Hashim, P., & Mustafa, S. (2012). Corn Silk (Stigma Maydis) in Healthcare: A Phytochemical and Pharmacological Review. Molecules,17(8), 9697-9715. Retrieved from https://www.researchgate.net/publication/230665731_Corn_Silk_Stigma_Maydis_in_Healthcare_A_Phytochemical_and_Pharmacological_Review.

8. Hu, Q., Zhang, L., Li, Y., Ding, Y., & Li, F. (2010). Purification and anti-fatigue activity of flavonoids from corn silk. International Journal of Physical Sciences,5(4), 321-326. Retrieved from http://www.academicjournals.org/app/webroot/article/article1380726309_Hu et al.pdf

9. International Maize and Wheat Improvement Centre (2016). Why Maize. CGIAR. Retrieved November 29, 2018, from https://maize.org/why-maize/

10. IPBO. (2017). Maize in Africa. International Plant Biotechnology Outreach. Retrieved from http://www.vib.be/en/about-vib/Documents/VIB_MaizeInAfrica_EN_2017.pdf

11. Mahmoudi, M., & Ehteshami, S. (2010). P.2.d.002 Antidepressant activity of Iranian Corn Silk. European Neuropsychopharmacology,20(3), 392. Retrieved from https://www.sciencedirect.com/science/article/pii/S0924977X10705563.

12. Nielsen, B. (2016). Silk Development and Emergence in Corn. Purdue University. Retrieved from https://www.agry.purdue.edu/ext/corn/news/timeless/silks.html

13. Ness, V. V. (2018, August 04). Making Homemade Corn Silk Spice. Delishably.com Retrieved from https://delishably.com/spices-seasonings/Making-Homemade-Corn-Silk-Spice

14. Radhakrishnan, M. (2017, September 19). 10 Amazing Health Benefits of Corn Silk Tea. Stylecraze.com. Retrieved from https://www.stylecraze.com/articles/health-benefits-of-corn-silk-tea/#gref

15. Rahman, N. A., & Rosli, W. I. (2014). Nutritional compositions and antioxidative capacity of the silk obtained from immature and mature corn. Journal of King Saud University - Science,26(2), 119-127. Retrieved from https://www.sciencedirect.com/science/article/pii/S1018364713000773.

16. Shepherd, A.W. (1999) A guide to maize marketing for extension officers. Drying and storage. FAO, Rome. Retrieved from http://www.fao.org/docrep/005/x0530e/X0530E05.htm

17. Steenkamp, V. (2003). Phytomedicines for the prostate. Fitoterapia,74(6), 545-552. Retrieved from https://www.sciencedirect.com/science/article/pii/S0367326X03001552?via=ihub.

18. (2017, August 15). Summer Harvest: Corn Silk. Sunandmoondispensary.com. Retrieved from https://www.sunandmoondispensary.com/single-post/2017/08/15/Summer-Harvest-Corn-Silk

19. TCM World Foundation. (2015, August 24). Corn Silk Tea. TCMworld.org. Retrieved from https://www.tcmworld.org/recipes/corn-silk-tea/

20. Wong, C. (2018, August 1). What you Need to Know About Herbal Tinctures. Verywellhealth.com. Retrieved from https://www.verywellhealth.com/herbal-tinctures-8939