Microgreens:
A Drought Tolerant Super Food?
I have been growing microgreens for the last four months and I think they are well poised to be a drought busting superfood based on their low water use and their nutritional punch. From my experience microgreens use about 90% less water to produce than their mature versions which is a significant reduction in water use. In this post I unveil the nutritional aspects of these little known emerging food product.
At this point you might also be wondering what microgreens are. They are basically baby plants that are not more than a month old and can range from the more common sunflower microgreens to spicy radish to herb microgreens. Microgreens started being used in the 1980s by Californian chefs to jazz up their creations due to the beautiful and colorful nature of these little beauties.
When I started I had no idea what microgreens are and how best to grow them. All I knew was that producing a quick food product became intoxicating. I began by giving microgreen samples to family and friends. People really liked the pick me up they felt after eating these little magical foods, but I still wasn’t sure how the nutrients in a 1 to 3 ounce portion compared to mature vegetable version.
Being a scientist at heart (10 years in water quality science) I was desperate to know just how nutrient dense microgreens were, so I did a standard literature search. I was pretty surprised that there were not many studies about the nutrient profile of microgreens. There were many vague claims on the internet but nothing substantial until I read “The Assessment of Vitamin and Carotenoid Concentration of Emerging Food Products: Edible Microgreens” by Zhenlei Xiao, Gene E. Lester, Yaguang Luo, & Qin Wang” published in 2012.
Man was I blown away! What follows is a summary of their findings related to a phytochemical nutrient anaylsis of microgreens (meaning micronutrients) with a quick water requirement recap of microgreen versus mature plant water use at the end.
The authors analyzed 25 commercially available microgreens for Vitamin C (antioxidant), Provitamin A (free radical scavenger antioxidant), Vitamin K (important blood coagulator) & Vitamin E (antioxidant). If you want to skip the analysis below, the authors concluded that “microgreens contain considerably higher concentrations of vitamins and carotenoids than their mature counterparts”.
Starting with Vitamin C, the authors found that red cabbage microgreens has 6 fold higher concentration than mature cabbage. You read that right, a 6 fold increase in vitamin C when compared to the mature leaf in published data. Not to be outdone garnet amaranth microgreens have a between a 3 fold and an 11 fold increase in vitamin C compared to their mature counterpart. The difference to a Californian in a drought was pretty staggering from a nutritional perspective considering how low water usage microgreens need. The recommended dietary allowance (RDA) for vitamin C is 60mg/100g so a small bite of microgreens gets you to the RDA pretty quick.
The authors concluded their analysis of vitamin C content by stating that “fresh microgreens” are “good to excellent” sources of vitamin C which agrees with studies conducted by Bergquist, et al. on baby spinach (greens that are 30–60 days old) that concluded that baby spinanch leaves packed more nutrition than the mature version.
Provitamin A is the next set of molecules the researchers studied. The researchers looked at B-carotene, lutein/zeaxanthin, violaxanthin, & tocopherols (Vitamin E). These exotic sounding nutrients are class of molecules in the Carotenoid family. You probably know this family of molecules best by their association with carrots which provide nutrients for our eyes.
Researchers found that red cabbage microgreens had a 260 fold increase in B-carotene when compared to their adult counterpart. Yes, 260 times greater nutrient content. Cilantro microgreens was next but paled in comparison by only a 3 fold increase. It is interesting to note that wasabi, green basil, pea tendrils, & garnet amaranth had B-carotene content that was comparable to carrots and sweet potatoes. To me that means less water resources to produce similar or greater nutrients for human consumption.
Another set of carotenoids were the lutein/zeaxanthin group. Cilantro microgreens were 11.2 times greater than the mature counterpart while red cabbage was 28.6 times greater than the mature version. Mature spinach is considered an excellent source of leutin/zeaxanthin at 7.2mg/100g which was much lower than the top 5 microgreens as displayed in the chart below.
The next group of carotenoids that the researchers looked at were violaxanthin. Cilantro had the highest concentration of violaxanthin which was a 5 fold increase compared to mature cilantro leaves and 2.8 fold increase of mature spinach. Most microgreens in the survey had higher levels of violaxanthin than mature cilantro while 40% had levels equal or greater than mature spinach.
The last group of carotenoids were the tocopherols or “Vitamin E”. And again microgreens do not disappoint with red cabbage microgreen containing over 40 times the nutrient than the mature version.
Garnet amaranth had the largest concentration of phylloquinone or “Vitamin K” and 18 of the 25 microgreens studied had vitamin K densities equal or higher than broccoli which is the “most commonly consumed vegetable in he U.S.”
Before I started my microgreen adventure I was really only familiar with lettuce, kale, and spinach as salad components. My views on what constitutes a salad is drastically changing. Oh et al. (J. Am. Hort. Science) found that 7 day old lettuce (Lactuca sativa) seedlings had the highest total phenolic concentration and antioxidant capacity compared to the older leaves. My crisphead lettuces use about a half of gallon of water to produce about a half of pound of microgreens. With a head of lettuce (about a pound) using 11 gallons of water to grow to maturity, microgreens not only can be a viable route to provide the nutrients we need in a much smaller water footprint. If you can get similar or greater nutrition using 90% less water, wouldn’t that be an obvious food choice?
There are a lot more studies needed to look at the macro level nutrients of microgreens compared to their mature counterparts but I contend that if the micronutrients are so high I would assume the macronutrients would be on par with these results. And if most vegetables are water then doesn’t it make more sense to drink more water and eat microgreens for their nutritional benefits?
Are microgreens the next drought tolerant superfood, what are your thoughts?
P.S. — I plan on producing an e-book soon that will help people start their own microgreen business or easily grow microgreens in their home to boost their own nutrition, so stay tuned!
