by David Kennedy and Leaf for Life 1993 ABOUT THIS MANUAL It is the purpose of this manual to help people interested in health, nutrition, agriculture and environmental is1sues to be able to begin making and using leaf concentrate in towns and villages in developing countries. This manual is an ongoing work that will be periodically updated. It deals almost exclusively with small or village scale production systems. There is very little information on industrial scale production. This manual should be useful to anyone involved in a small leaf concentrate program, but is not intended to substitute for hands on training. Eventually, the manual will be matched with a training film on videocassette and a 3 - 5 day training course offered at least once a year. You may want to photocopy some of the information and charts in this manual for people who need to refer to one aspect of leaf concentrate work, but who do not need the entire manual. Throughout the manual I use the terms "leaf concentrate", "LC", or occasionally "leaf curd" to describe a food made from coagulating green plant leaf juice. This food has also been called "leaf protein" and "leaf protein concentrate". Most of the references relate to projects linked with or run by a small voluntary organization called Find Your Feet in Great Britain and Leaf for Life in the USA. Information and ideas for this manual came from a lot of people, most importantly Walt Bray, Glyn Davys, and Boone Guyton. Drawings and help with layout also came from several people, including Beth Rosdatter, Alison Craig, Susan Lynn, Therese and Sherri Hildebrand, Jose Leon and Danne Lakin. You are most cordially invited to join in the development of this exciting 'Food for the Future'. Leaf For Life appreciates any criticisms or suggestions that may help to improve this course. We also like to hear of problems, solutions, recipes, or good ideas that people run into while working with leaf concentrate. Thank you and the best of luck. INTRODUCTION In the last half of the 18 th Century a Frenchman named Rouelle discovered that a vegetable curd could be made by simply heating the juice squeezed from hemlock leaves. Little was done with this information until World War II when the British, fearing that their food supplies could be cut off, began searching for alternative sources of protein. N.W. Pirie led a team of scientists in the development of equipment to extract protein from green leaves. Using alfalfa, wheat leaves, mustard greens, and other plants, the team did a great deal of research on the use of these leaf concentrates. While this team and a few other individuals continued working on leaf concentrates, it wasn't until the 1960's that interest in making curd from leaves picked up again. Work began advancing on two quite different fronts. In several highly developed countries work began on using dried leaf curd to enrich animal feeds. At the same time Find Your Feet ( LEAF FO R LIFE), a small voluntary organization based in London, England, began promoting the use of leaf concentrate to counter malnutrition in children living in tropical villages and towns. Several studies were undertaken to establish the safety and nutritional value of the leaf concentrate in the diets of children. Find Your Feet ( LEAF FOR LIFE) has since started programs to teach women how to prepare leaf concentrate for malnourished children in Mexico, India, Bolivia, Sri Lanka, Ghana, Nicaragua and Bangladesh.* These programs have received financial support from the United Nations, the European Economic Community, Mexico's DIF, the British Overseas Development Agency, the Rotary Club International, employee programs from Delta Airlines and Sun Microsystems, as well as many private trusts and individual supporters. In all of its projects Leaf For Life has worked to train women to make high quality leaf concentrate from local leaves, with the aim of improving the diet of members of their communities who are vulnerable to malnutrition. Usually this means children, pregnant and nursing mothers, and the elderly. Through the work done in these projects and work done in England, the U.S., India and Sweden the process of making and using leaf concentrate is gradually becoming easier and more economical Machinery is constantly being improved and new recipes are tried every year The workshops where leaf concentrate is made are becoming more efficiently organized and the cost of starting a program is dropping. * We know of two other organizations using leaf concentrate in small nutrition programs. Leaf Nutrient Program has begun a project in Coahuila, Mexico and the Pakistan Council for Scientific and Industrial Research did the same type of work at an orphanage near Lahore, Pakistan. Their addresses, along with those of other sources of information on subjects related to leaf concentrate are listed in the back of this manual. WHAT IS LEAF CONCENTRATE? Leaf concentrate is an extremely nutritious food made by mechanically separating indigestible fiber and soluble anti-nutrients from much of the protein, vitamins, and minerals in certain fresh green plant leaves. Because it is so rich in beta-carotene, iron, and high quality protein, leaf concentrate is very effective in combating malnutrition, especially the anemia and vitamin A deficiency which are prevalent among children and pregnant women in most developing countries. It is easily combined with a variety of inexpensive foods to make culturally acceptable dishes. Because it takes more direct advantage of solar energy, a leaf crop can produce more nutrients per hectare than any other agricultural system. Leaf crops can usually be produced with less environmental impact than grains. The simple technology of making leaf concentrate offers a means of capturing a much greater part of the leaf harvest for direct human consumption. The fiber that is separated can be used to feed animals, and the left over liquid, or "whey" can be used to fertilize plants, so nothing is lost. WHY LEAF CONCENTRATE WORKS Agriculture is basically a biological system for collecting the energy of the sun in ways that are useful to humans. Green leaves are the solar energy collectors. The more surface area of green leaves exposed to the sun's light, the more energy can be captured from a given parcel of land. Chlorophyll, the pigment that makes leaves (and leaf concentrate) so green, converts carbon dioxide from the air, water and sunlight into simple carbohydrates. These combine with each other to make sugars and starches, which supply our bodies with energy. They also combine to make fibers like cellulose and lignin that make useful things like paper, cotton cloth, and wood possible. These simple carbohydrates formed in the plant's green leaves also combine with nitrates from the soil to make proteins, which are often called the building blocks of life. The basic foods that we eat are almost all created in the green leaves of plants. They are then translocated to be stored in seeds, tubers, and fruits. When we eat a tortilla, a sweet potato, or a banana we are eating food made by the green leaves of the corn plant, the sweet potato plant, and the banana plant. Moving the food from the leaf to the seed or the tuber or the fruit costs the plant energy. This reduces the amount of available food because the plants burn their own sugars and starches to get this energy. Of course, much more of this food becomes unavailable when the seeds or tubers are fed to animals. This explains why animal products like meat, milk, and eggs are usually more expensive than plant products. When we grow wheat or other basic grains the young leaves of the plant are relatively efficient at converting the sun's energy to food. However, for much of the time that the grain occupies our best farmland it is producing very little food. As the leaves turn yellow and brown they stop producing food and the plant is simply drying the seed so that it will be a very compact food storage container. These grains are certainly convenient food. Because the grains have far less water and fiber than the green leaves, as well as generally milder flavor, they have been a more useful and popular food. The leaf concentrate technology offers a simple means of removing much of the water and almost all of the fiber from the green leaves. This can make green leaves a much more attractive food. While leaf concentrate will never replace grains, it does offer a major new source of food in the human diet. Combining inexpensive easily grown starchy crops like cassava, bananas, and breadfruit with leaf concentrate could provide superior nutrition to a grain based diet for millions of people in the tropics. By more directly tapping the tremendous productivity of leaf crops, leaf concentrate can produce more protein and most other important nutrients per hectare than other agricultural systems. How quickly this food technology is put into widespread practice will depend mainly on economics. The economics of leaf concentrate production is closely tied to the scale of operation and how well the fiber that remains when the concentrate is separated from the leaves is utilized. Usually the most economical use of this fiber is to feed it to cows, goats, sheep, horses, rabbits, or guinea pigs.. Because the fiber is so finely chopped up animals can absorb the nutrients in it more readily than they can from hay or forage crop. In a sense, the grinding of the leaves for making leaf concentrate acts in the same way as the animals chewing the leaves for a long time.