Microgreens should be grown from special uncoated seeds (non thallium) vegetable green, harvested after sprouting as shoots, that are used both as a visual and super food as it has 4 to 40 times more nutrients . Fine dining chefs use microgreens to enhance the attractiveness and taste of their dishes with their delicate textures and distinctive flavors. Smaller than “baby greens,” and harvested later than sprouts, microgreens can provide a variety of leaf flavors, such as sweet and spicy. They are also known for their various colors and textures. Among upscale markets, they are now considered a specialty genre of greens that are good for garnishing salads, soups, plates, and sandwiches. Edible young greens and grains are produced from various kinds of vegetables, herbs or other plants. They range in size from, 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 fully developed cotyledon leaves and usually has one pair of very small, partially developed true leaves. The average crop-time for most microgreens is 10–14 days from seeding to harvest.
Microgreens began showing up on chefs’ menus as early as the 1980s, in San Francisco, California. In Southern California, microgreens have been grown since about the mid1990s. There were initially very few varieties offered. Those available were such as arugula, basil, beets, kale, cilantro and a mixture called Rainbow Mix. Having spread eastward from California, they are now being grown in most areas of the country with an increasing number of varieties being produced. Today, the U.S. microgreens industry consists of a variety of seed companies and growers.
Microgreens have three basic parts: a central stem, cotyledon leaf or leaves, and typically the first pair of very young true leaves. They vary in size depending upon the specific variety grown, with the typical size being in total length. When the green grows beyond this size, it should no longer be considered a microgreen. Larger sizes have been called petite greens. Microgreens are typically 2–4 weeks old from germination to harvest. Both baby greens and microgreens lack any legal definition. The terms “baby greens” and “microgreens” are marketing terms used to describe their respective categories. Sprouts are germinated seeds and are typically consumed as an entire plant (root, seed, and shoot), depending on the species. For example, sprouts from almond, pumpkin, and peanut reportedly have a preferred flavor when harvested prior to root development. Sprouts are legally defined, and have additional regulations concerning their production and marketing due to their relatively high risk of microbial contamination compared to other greens. Growers interested in producing sprouts for sale need to be aware of the risks and precautions summarized in the FDA publication Guidance for Industry: Reducing Microbial Food Safety Hazards for Sprouted Seeds (FDA 1999).
Growing microgreens is relatively easy; many small “backyard” growers have sprung up selling their greens at farmers’ markets or to restaurants. A shallow plastic container with drainage holes, such as a nursery flat or prepackaged-salad box, will facilitate sprouting and grow out on a small scale. Growing and marketing high-quality microgreens commercially is much more difficult.
In early 2014, researchers at the USDA Agricultural Research Service published several studies that identify the nutritional composition and shelf life of microgreens. Twenty-five varieties were tested, the main nutrients measured were ascorbic acid (vitamin C), tocopherols (vitamin E), phylloquinone (vitamin K) and beta-carotene (a precursor of vitamin A) and other carotenoids in the cotyledons. Of the 25 microgreens tested, red cabbage, coriander, garnet amaranth and green daikon radish had the highest concentrations of vitamin C, carotenoids, vitamin K and vitamin E, respectively. In general, the microgreens contained significantly higher levels of vitamins and carotenoids – about five times higher – than their mature plant equivalents, indicating that microgreens may be worth delivering them fresh for their short life. A nutritional study of microgreens was conducted in the summer of 2012 by the Department of Nutrition and Food Science, University of Maryland, indicating a promising potential that microgreens may indeed have a particularly high nutritional value compared to mature vegetables. Bhimu Patil, professor of horticulture and director of the Vegetable and Fruit Improvement Center at Texas A & M University, agrees that microgreens may have higher levels of nutrients than ripe vegetables. But he says that more studies are needed to compare the two side by side. “It’s a very good start, but there can be a lot of variations in nutrients depending on where you grow it, when you harvest, and in the middle of the soil,” says Patil. When choosing a micro-screen, researchers say they search the most intensely colored, which will be the most nutritious. Results from the University of Maryland’s and the USDA’s microchip research project attracted the attention of several national media outlets, including National Public Radio (NPR) and The Huffington Post.