Microgreens are considered healthy food because they can provide many nutrients that are absolutely essential for humans to eat. Here is a list of 49 nutrients for a healthy human diet. The microgreens will be especially high in the last three columns.
Welch, Ross & Graham, Robin. (2004). Breeding for micronutrients in staple food crops from a human nutrition perspective. Journal of experimental botany. 55. 353-64. 10.1093/jxb/erh064.
Here is some of the nutritional content of broccoli microgreens according to Microgreen World and of mature broccoli according to the US Food and Drug Administration. You can see that the microgreens offer significantly higher levels of many important nutrients.
Macro-elements |
100g of broccoli microgreens |
100g of mature broccoli |
Calcium (Ca) |
88 mg |
47 mg |
Magnesium (Mg) |
51 mg |
21 mg |
Phosphorous (P) |
69 mg |
66 mg |
Potassium (K) |
326 mg |
316 mg |
Sodium (Na) |
52 mg |
33 mg |
Micro-element minerals |
100g of broccoli microgreens |
100g of mature broccoli |
Iron (Fe) |
0.67 mg |
0.73 mg |
Zinc (Zn) |
0.37 mg |
0.41 mg |
Copper (Cu) |
0.09 mg |
0.049 mg |
Manganese (Mn) |
0.37 mg |
21 mg |
Vitamin Content |
100g of broccoli microgreens |
100g of mature broccoli |
Vitamin A (ᵦ-carotene) |
221.80 mg |
31 µg |
Vitamin C (Ascorbic Acid) |
51.0 mg |
89.2 mg |
Vitamin E (tocepherol) |
24.1 mg |
0.78 mg |
Vitamin K (Phylloquinone) |
2.8 µg |
102 µg |
Other Nutrients |
100g of broccoli microgreens |
100g of mature broccoli |
Fiber |
410 mg |
260 mg |
Broccoli Microgreens Protein |
2.3 g |
2.82 g |
But there is still the question, are they tainted by the fertilizer? I found a brochure for the fertilizer in your question, MicroLife Liquid Organics Ocean Harvest liquid fertilizer. It lists these ingredients:
Homogenous, liquid concentrated All Organic fertilizer containing:
Ecklonia Maxima Kelp extracted through patented cell burst technology
process, Fish Hydrolysate manufactured via natural enzymatic
extraction, Blackstrap Molasses, Humic Acid, Fulvic Acid, Select Amino
Acids profile, Select Natural Plant Hormone/Natural Plant
Stimulator/Natural Vitamin profile, Calcium Phosphate, Arcanite,
Selected Sugars and Tryptic Soy Agar. No heat is used in the
manufacturing process to ensure purity of ingredients. Contains the
following Select Amino Acid profile: L-Alanine, L-Argine, L-Aspartic,
L-Cystine, L-Glutamic Acid, L-Glycine, L-Histidine, L-Isoleucine,
L-Leucine, L-Lysine, L-Methionine, L-Phenylalanine, L-Proline,
L-Threonine, L-Serine, L-Tryptophan, L-Tyrosine, L-Valine Contains the
following Plant Hormones, Plant Growth Stimulators and Vitamins:
Auxins, Cytokinins, Gibberellins, Abscissic Acid (ABA), Adenine,
Indole Acetic Acid (IAA), Adenosine, Zeatin, A (Carotene), B1, B12, C,
D, E, K, Biotin, Niacin, Choline, Pantothene, Folic Acid, Follinic
Acid. All MicroLife products are protected by patented technology and
proprietary manufacturing processes.
and to my ignorant eyes, there isn't anything I would consider a contaminant. There is also a material safety data sheet which does say that it isn't carcinogenic and recommends relatively mild first aid responses to over exposure. So I personally feel safe eating microgreens grown with this, although there absolutely are fertilizers and other agriculture chemicals that I am not comfortable with. In the end, it's about trusting the grower to follow responsible practices.