Extraction of Protein from Common Plant Leaves for Use as Human Food

Abstract

Problem statement: Protein deficiency is one of the major nutritional problems in the developing world. The most disastrous consequences occur in children where protein malnutrition manifests itself in forms of two notorious diseases: Marasmus and kwashiorkor. Expansion of present agricultural practices into marginal lands is expected to solve this chronic protein shortage. The process of photosynthesis is the only non depletable protein source and can supply some essential amino acids as well as provide adequate nitrogen in the diet for synthesis of non essential amino acids in addition to vitamins and minerals. Approach: The aim of this study was to assess the nutritional values of common plant leaves and determine the feasibility of using them as a protein supplement. Six plants were cultivated and tested for their nutritional quality: amaranth, cowpea, sugar been, pumpkin, sweet potato and cabbage. Results: Pumpkin leaves recorded the highest protein yield (11.75%) followed by amaranth (10.5%) The protein contents in the leaves of sweet potato, cowpea, cabbage and sugar been were much lower (7.85, 6.95, 5.60 and 3.45%, respectively). Conclusion: Except for sugar bean, all plants had higher extractable protein content than cabbage. Proper use of the growing season can achieve high protein yield. Clean cutting will ensure that the leaves do not deteriorate within a few hours when kept in cool place and freezing leaves can improve protein extractability. The test plants should be given a trial as protein sources for human. Plant leaves have vitamins, minerals and essential amino acids and when consumed in adequate amounts they can supplement protein especially in areas where the environment is very hostile to livestock keeping or where fish protein is lacking. The optimum harvest age, fertilizer requirements and the possibility of combining two or more plants together to improve protein content should be studied. The amino acid, minerals and vitamins profiles should also be determined.