MicroGreens (micro greens) are a tiny form of young edible greens produced from vegetable, herb or other plants. They range in size from 1″ to 1 ½” long, including the stem and leaves. A MicroGreen has a single central stem which has been cut just above the soil line during harvesting. It has two fully developed cotyledon leaves and usually one pair very small, partially developed true leaves. The typical stem and leaf configuration for micro greens is about 1” to 1½” in height, and ½” to 1“ in width across the top. MicroGreens can have surprisingly intense flavors considering their small size though not as strong as mature greens and herbs.
MicroGreens are used as a fresh flavor ingredient primarily in fine dining restaurants. These restaurants place a strong emphasis on both the creative presentation and flavor of their dishes. MicroGreens’ delicate, fresh appearance adds beauty and dimension combined with a range of distinct flavor elements.
No longer a novelty item, MicroGreens have been popular in upscale culinary establishments for well over 15 years. MicroGreens have become a solid ingredient in our finest restaurants, and Fresh Origins has grown from a tiny start-up to America’s leading producer. Fresh Origins prides itself on providing the most consistent supply available. In addition, we regularly introduce new and exciting MicroGreen varieties to the culinary world.
MicroGreens have been produced in the United States since about the mid 1990′s beginning in Southern California. Initially, there were very few varieties offered. The basic varieties are Arugula, Basil, Beets, Kale, Cilantro and a mixture called Rainbow Mix. They are now being grown in most areas of the country with an increasing number of varieties being produced. Although many people who are learning about Microgreens for the first time assume they are used in salads, they very rarely are.
A form of MicroGreens sold in a specialized growing medium, cellulose (paper) pulp, has been produced in Europe since about 2002. Recently, living MicroGreens have been offered for sale in the United States as well. There are a few reasons why this format has not been widely utilized. This method requires more packaging in terms of either boxing or heavy plastic trays and growing medium resulting in a much higher cost for a significantly smaller yield. The quality is often soft and stringy with this method. It is also more costly to deliver in this form. For those who care about sustainability, living MicroGreens are the least sustainable and the most wasteful of our resources. The other major issue is that the product, may start out fresh and vibrant just as it is removed from the ideal growing conditions of a greenhouse, but once they are put in a restaurant kitchen or restaurant cooler, the quality and flavor quickly declines. While they can still be considered alive and growing, once removed from the greenhouse, they rapidly begin to get even more soft, stretched, and stemmy as they lose color and flavor.
Microgreens versus Sprouts
MicroGreens are not the same as sprouts. Some articles about MicroGreens characterize them as being very much the same as sprouts. There are several important differences. Understanding the different production methods of each can help clear up any confusion between them.
Sprouts are simply germinated seeds. What is eaten consists of the seed, root, stem and pale, underdeveloped leaves. The FDA seeks to regulate all businesses that produce sprouts due to numerous outbreaks of food poisoning (11 recalls/alerts in the past year alone). In 2011, 52 people died and thousands got sick from consuming organic sprouts in Europe. The European Food Safety Authority (EFSA) has now warned consumers against eating sprouts or sprouted seeds unless they are thoroughly cooked. Salmonella and Escherichia coli O157: H7 have been the major causes of sprout-associated illness outbreaks. Commercial sprout processors must follow rigorous FDA Guidelines for the production that include multiple laboratory tests of each batch for the presence of pathogenic bacteria, to minimize the threat of foodborne illness. Despite rigorous efforts to reduce foodborne illness caused by sprouts, more and more restaurants are no longer able to cope with the risk and have removed sprouts from their menus. In October 2012 one of the nation’s leading food retailers; Kroger announced that it would no longer sell sprouts in its supermarket chains because of the potential for foodborne illness. “Sprouts are unavoidably unsafe products” said Caroline Smith DeWaal, Food Safety Director of the Center for Science in the Public Interest. Walmart Stores discontinued selling sprouts in 2010.
Sprouts are produced entirely in water. The seed is not actually planted. A high density of seed is placed inside of sprouting equipment or enclosed containers. The seed germinates rapidly due to the high moisture and humidity levels maintained in the enclosures. Seeds can also be sprouted in cloth bags that are repeatedly soaked in water. For most sprouts, the seeds are soaked and placed in a rotating drum or container, kept at or near 100% humidity and maintained at a temperature of about 80 degrees F. When this processing is finished, usually after about 48 hours, the sprouts are ready for packaging and sale. The sprouting process occurs in dark or very low light conditions. These dark, warm, wet, crowded conditions are ideal for the rapid proliferation of dangerous pathogenic bacteria.
After this process of soaking and repeated rinsing (2-6 or more times per day to prevent spoilage), the sprouted seeds are ready for consumption. This is long before the expansion of any leaves. These sprouted seeds are generally sold as a tangled mass of very pale roots, stems, and leaf buds. MicroGreens cannot be grown using these methods.
Microgreens are not processed in the water. Microgreen seeds are planted and grown in soil or a soil substitute such as peat moss or other fibrous materials. They are ideally grown in high light conditions with low humidity and good air circulation. The seed density is a fraction of what is used in sprout processing so each individual plant has space in which to grow and develop. Most varieties require 1-2 weeks growing time, some 4-6 weeks. After the leaves are fully expanded the microgreens are ready for harvest. They are cut above the soil surface and packed without any roots. Some MicroGreens are sold while still growing, rooted in the soil or another growing medium so that they can be cut by the end user.
If the stem is cut leaving root behind, and it is not produced in water, it is a microgreen, not a sprout. MicroGreens that are grown in sunlight with plenty of space and good ventilation have increased vigor resulting in more color and flavor compared to those grown under artificial lights.
The conditions that are ideal for growing MicroGreens do not encourage the growth of dangerous pathogens. These growing methods would not work for the production of sprouts.
Various MicroGreens Ready For Harvest
To minimize confusion, it is important to avoid using words like “sprouting” or “sprouts” when writing about or describing MicroGreens. FDA inspectors do not always understand the differences, potentially putting a MicroGreen grower in the position of explaining them or being shut down. There could be confusion if the grower has described MicroGreens as being in any way similar to sprouts. The FDA will consider enforcement actions against any party growing sprouts commercially, who does not have effective preventive controls in place, involving extensive microbial testing and FDA oversight.
The potential for food safety issues with MicroGreens may be increasing due to the number of indoor MicroGreen growing operations in which excessive seed density, low light intensity, low air circulation or most commonly, a lack of GAP (good agricultural practices) and GMP (good manufacturing practices) based food safety procedures. Certain provisions of the FDA’s Guidance for Industry: Reducing Microbial Food Safety Hazards For Sprouted Seeds may be beneficial and prudent for growers of MicroGreens to follow.
MicroGreens have much stronger, more developed flavors than sprouts making them an ideal flavor component with a broad range of leaf shapes, textures and colors.
General Specifications of a MicroGreen
A MicroGreen is a seedling having a a central stem which has been cut just above the soil line during harvesting. It has two fully developed cotyledon leaves, and usually one pair very small, partially developed true leaves. Differences in the size and leaf configuration are based upon the specific plant variety. For example, Micro Borage is a very large MicroGreen. At 1″ in height, it has a pair of very large cotyledon leaves and no true leaves. By comparison, Micro Mint has extremely tiny cotyledon leaves and will have 3-4 sets of true leaves at about 1″ in height. More typical in size and leaf configuration for micro greens is Micro Basil at about 1-1 1/2″ in height, and 1/2″ to 1″ in width across the top and includes the cotyledon leaves and one set of very small true leaves.
MicroGreens and Nutrition
It has become an urban legend that MicroGreens possess high concentrations of various nutritional and beneficial compounds. As people read and parrot the misinformation, it spreads. More and more people see the claims, and the myth just continues to snowball until it is accepted as fact by most people without any question.
Numerous articles and websites claim that MicroGreens are the latest nutritional miracle-food. The fact is, there have been no studies done on MicroGreens to substantiate any of these claims so at this point it is all just wishful thinking; new-age mumbo jumbo.* No evidence of MicroGreens’ nutritional value means the numerous claims have no scientific basis. It would, of course, be to our benefit to claim that MicroGreens are some kind of super-food. Most likely, MicroGreens actually have a lower nutritional value than full-sized vegetables and herbs.
As a point of reference, some sprouts (which are not MicroGreens), have been said to contain particularly high concentrations of a certain chemo-protective compound, Sulphoraphane Glucosinolate (SGS), however the highest concentration of this is actually found in the seed. Since sprouts are consumed with the seed still attached, this may explain the presence of this compound in sprouts. If people feel they really want more of this compound, they should simply eat the seed before it is sprouted to get the highest concentration. Of course, MicroGreens are not sprouts. MicroGreens are cut at the stem, and have no roots or seed attached so there would be no reason to think this compound exists in any particularly high amount. There have not been any studies done on MicroGreens to determine the presence of SGS or any other compound.
People should not rely on unsubstantiated claims to make dietary decisions, nor should any company attempt to sell a product or book using these fake nutritional claims. Fresh Origins does not rely on unsubstantiated claims to sell its product.
If anyone makes the claim that MicroGreens are “packed with nutrition”, don’t take their word for it, ask for the nutritional analysis to back it up. If at some point there are reliable nutritional studies done on microgreens, and they do show high values, Fresh Origins will be very pleased to promote it.
The USDA has weighed in on the situation for sprouts: Although research suggests a promising role for in promoting health, the research results do not permit definitive scientific conclusions on specific health benefits. At this time, the FDA has not reached any such conclusions or authorized any claims specifically for SGS or broccoli sprouts. There is no mention of microgreens.
Regarding the nutritional value of sprouts, the USDA has listed the nutritional value of sprouts compared to full-sized broccoli. In summary, broccoli sprouts are significantly lower in nutritional value when compared to full-sized broccoli. Of note: the sprouts were lower in protein (1.4 compared to 2.324 mg.), Vitamin A (561 compared to 1,082.64 IU), Riboflavin (none found in sprouts compared to .043 mg.), Vitamin B-6 (.07 compared to .112 mg.), Vitamin C (20 compared to 58.188 mg), and Iron (.22 compared to .665 mg.). The idea that sprouts are high in nutrition originated from when the sprouted seeds were analyzed and compared to dry unsprouted seeds. There is a significant difference which has led to unfounded claims that they are high in nutrition compared to anything else.
This relates to MicroGreens in that since sprouts which are the youngest form of broccoli have lower nutritional value than mature broccoli, it stands to reason that microgreens have lower nutritional value than their full-sized counterparts as well.
MicroGreens certainly have a lot of flavor considering their tiny size, however, they do have less flavor than their full-sized counterparts. The flavors definitely increase in vegetable and herb plants as they grow larger. It is logical to conclude that the nutritional value also increases as the plant matures.
Varieties of MicroGreens
The seeds used to grow MicroGreens are the same seeds that are used for full sized herbs, vegetables and greens. MicroGreens are simply seedlings that are harvested before they develop into larger plants.
Commonly grown varieties of microgreens include: Amaranth, Arugula, Beets, Basil, Cabbage, Celery, Chard, Chervil, Cilantro, Cress, Fennel, Kale, Mustard, Parsley, Radish, and Sorrel.
Several varieties can be mixed together to create combinations of tastes, textures and colors.
Fresh Origins has contributed a summarized version of our original content to the Wikipedia page for “MicroGreens”.
*August 2012; Finally the first nutritional analysis of MicroGreens has been done! While the results seem promising, there are some concerns with the study. The primary issue is that they did not do the analysis of the mature versions used for the comparisons with the MicroGreens. This comparison, of course, is the whole basis for making the claim that the MicroGreens are more nutritious than the mature versions. Instead, they relied upon data from the analysis done by others probably a very long time ago, so it is unlikely the same methods of analysis could have been done. Another concern: some of the comparisons were not correct such as comparing one type of amaranth in the micro form to a completly different type (and color) in the mature form or comparing a Micro Radish top to a mature Radish Root. In addition, some of the items tested were not actually MicroGreens, but shoots. We are hoping there might be a future study done where there is first a clear definition of what MicroGreens are and that there would be nutritional analysis done of both the MicroGreen and the mature leaf in the same study using the same methods, rather than relying on outside data and variable varieties grown under different conditions to compare.