For the study, researchers used Mankai, the branded duckweed ingredient produced by Israeli startup Hinoman.
This new research is a sub-study of the Dietary Intervention Randomized Controlled Trial – Polyphenols Unprocessed (DIRECT PLUS) which explores the effects of green-Mediterranean diet.
Duckweed contains the complete amino acid protein profile of eggs
Duckweed has been consumed for hundreds of years in Southeast Asia due to its high-protein content – more than 45%. According to researchers, it includes the complete protein profile of eggs, containing all nine essential and six conditional amino acids.
Other nutritional findings of duckweed:
A previous duckweed study conducted by Alon Kaplan, a Ph.D. student in Prof. Shai's lab, published in Clinical Nutrition, showed that the absorption of the essential amino acids from Mankai was similar to the soft cheese and peas equivalent in protein content.
Another study by the researchers in the Journal of Nutrition published earlier this year by BGU Ph.D. student Anat Yaskolka Meir R.D., indicates that a Mediterranean diet with Mankai, elevates iron and folic acid levels, despite low quantities of red meat. This study also determined that iron from Mankai was efficient in treating iron-deficiency anemia in anemic rats to the same degree as the common treatment.
In addition, mankai is very rich in polyphenols, mainly phenolic acids and flavonoids (including catechins), dietary fibers, minerals (including iron and zinc), vitamin A, vitamin B complex, and vitamin B12 , which is rarely produced by plants, noted researchers.
Hinoman is growing Mankai on a commercial scale in Israel and other countries such as the US in a closed sustainable environment, which requires a fraction of the amount of water to produce each gram of protein compared to soy, kale, or spinach. The duckweed variety can also be grown year-round using hydroponic cultivation, said researchers.
Participants felt more full consuming duckweed green shake vs. yogurt shake
While duckweed’s sustainability advantage and high protein content have become more well known, less is known about how mankai is metabolized when consumed as a whole food ingredient.
In the study, researchers compared mankai shake consumption to a yogurt shake equivalent in carbohydrates, protein, lipids, and calories.
The randomized controlled crossover trial was conducted with twenty “abdominally obese” participants (average age of 51.4) who were instructed to replace dinner with either a green shake (containing mankai duckweed) or the yogurt shake.
Following two weeks of monitoring with glucose sensors, participants who drank the duckweed shake showed a much better response in a variety of measurements including lower glucose peak levels, morning fasting glucose levels, later peak time, and faster glucose evacuation. The participants also felt more full after consuming the mankai shake vs. the nutritionally equivalent yogurt shake.
“It is the aggregation of all of these properties which seem to make the easily integratable, tasteless, and odorless plant, a good candidate to become a superfood,” said researchers of the study.
The new green shake?
Mankai is available as a dry milled powder and works well in a number of applications from bakery and meat analogues to beverage and sports nutrition protein powders. The aquatic protein is also available in fresh or frozen formats for used in smoothies and shakes, according to Hinoman.
The company's entry into the market has been through the foodservice channel primarily and Harvard University recently introduced Mankai smoothies in the Harvard School of Public Health cafeteria.
