What Is Leaf Concentrate?

Leaf Concentrate: A Nutritional Powerhouse!

Leaf concentrate is an extremely nutritious food, maybe the most nutritious of all foods. This chart gives you an idea of how it compares to other better known nutritious foods. It is especially rich in protein, iron, calcium, and vitamin A, but it is also a good source of many other vitamins and minerals.

Nutrients in Some High-Protein Foods
100 g (3-1/2 oz)	Protein (g)	Iron (mg)	Calcium (mg)	Vitamin A (mcg RAE)
Dried alfalfa leaf concentrate	51	54	3,380	3,835
Beef steak	29	2	22	0
Scrambled eggs	15	2	66	182
Dried whole milk	26	0.5	912	257
Dry pinto beans	21	5	113	0

We make leaf concentrate by grinding or pulping fresh leaves, then pressing the pulped leaves to extract as much juice as possible. Then we heat the juice, and a curd—like green cottage cheese—floats to the top. This curd contains most of the proteins, oils, vitamins, and minerals in the leaf. We then squeeze as much liquid from the curd as we can. What remains is leaf concentrate. Removing the fiber and water concentrates the nutrients in green leaves and makes them more digestible.

Some edible leaves don't make good leaf concentrate. And many plants with edible leaves are not economically suited for leaf concentrate production.

Here are some of the leaf crops that have been used successfully to make leaf concentrate:

Alfalfa or Lucerne — this is an ideal crop in the temperate zone. It is a highly productive perennial legume. This means that it doesn't need to be replanted every year and that it can make its own supply of free nitrogen fertilizer from the air. Alfalfa has been used more than any other crop to make leaf concentrate.
Cowpeas have been an important leaf concentrate crop in the tropics. Like alfalfa, they fix their own nitrogen, but they are annuals so they need to be replanted at least once a year.

Other leaf crops that have been used include:

Berseem clover — this is also a legume. It is commonly grown in South Asia and the Middle East.
Amaranth — This is a very fast-growing tropical annual
Barley and wheat — These are two well-known grain crops whose young leaves make excellent leaf concentrate.
Several members of the mustard family — These are mainly fast-growing temperate zone annuals
Nettles — This is a very high protein riverbank plant, that sometimes grows as a weed.
Moringa — Moringa is a super-productive tropical tree with extremely nutritious leaves

Brief History of Leaf Concentrate

Although the technique for making leaf concentrate was discovered almost 250 years ago, attempts to popularize it as a food have been more recent. Three NGO's (Find Your Feet in England, Leaf for Life in the US, and APEF in France) have tried to introduce local Leaf concentrate production in over a dozen countries in order to combat malnutrition.

Early efforts in India, Nicaragua, and Bolivia were small scale and relied heavily on manual labor. Later efforts used powered equipment to pulp the leaves, like this APEF machinery heading to Burundi. Scaling up the operation improved the economics. This women's cooperative in southern Mexico ran a semi-industrialized leaf concentrate operation for 9 years. And this French operation, run by a cooperative of alfalfa farmers, dwarfed the Mexican project. Here they process 150 tons of alfalfa per hour. That is a lot of alfalfa! Their focus has been on improved animal feeds rather than fighting human malnutrition.

How Leaf Concentrate Is Made

I'll walk you through the process on the semi-industrial scale.

First leaves are run through a forage chopper to make them easier to pulp. Some pulpers don't require pre-chopping.
Next, the leaves are washed to remove dirt and dust and lifted to the pulper. A double set of half-inch wide blades spinning at 3600 times a minute pulp the leaves quickly.
The women use a 20-ton hydraulic press to squeeze the juice from the pulped leaves.
The juice is then heated quickly in a 30-gallon cooker, while gently stirring.
When the juice reaches the boiling point a woman skims the curd off and drains it.
After the curd cools a bit the women use the same hydraulic press to remove as much liquid or "whey" as possible. The pressed curd is about 55% moisture.
The women then "granulate" the curd by rubbing it through a 1/4-inch sieve. This speeds up drying by making uniformly small pieces.
The women dry the pressed and granulated curd in simple solar dryers.
Finally, they grind the dried concentrate in an electric corn mill.

The entire process breaks the leaves into three parts; fiber, liquid or "whey," and leaf concentrate. 100 kilograms of leaves usually yields about 45 kilos of fiber; 50 kilos of "whey," and 5 kilos of fresh leaf concentrate.

The fiber makes a valuable cattle feed. The "whey" is put back on crops as a nitrogen and potassium fertilizer.

Although the concentrate is by far the smallest of the 3 leaf fractions, only a tablespoon of dried leaf concentrate a day can prevent or reverse serious malnutrition in children.

The potential of leaf concentrate to reduce childhood malnutrition is enormous. But there are still some economic and cultural issues to overcome.

Thanks for watching.