Chelated amino acids: biomass sources, preparation, properties, and biological activities

Abstract Micronutrients such as Zn, Cu, Fe, and Mn are required metals for plant crops to increase their yield and quality. Metals are included in numerous biochemical reactions as enzymes, co-enzymes, and co-factors. Copper, zinc, and manganese are essential for the development and growth of animal as pigs and broiler chicks. Amino acids are of significant importance and are used in many applications, fields, and industries such as food, animal feed, supplement, pharmaceutical production, and as biofertilizers. Fertilizers of inorganic mineral structure are hardly diffused from the leaf surface into the plant, while chelated minerals with amino acids provide a great advantage in increasing the absorption efficiency and translocation of minerals within the plant. Also, it was known that derivatives of free or chelated amino acids have marked antioxidant activity and are able to inhibit the development of tumor tissues and leading to increase immune protective abilities of the organisms. Nanotechnology increased the application efficiency of metal-amino acid complexes. Using nano fertilizers to plants is one of critical importance due to their unique properties in size and increased surface areas. It released the nutrients on demand and regulates plant growth (such as wheat, rice, barley, and rapeseed plants). Metal chelating complexes have found extensive applications in various fields of human interest. Chelators are used in medical applications; water softeners are included as ingredients in many commercial products such as shampoos and food preservatives and control heavy metal pollution in aquacultures. Amino acids may be used separately in chelation process as free amino acids or can be separated from plant or animal wastes. It can be separated by hydrolysis of plant or agricultural crop wastes as thrones of tomato and sugar beet plants. Also, it can be separated from animal origin as leather wastes and chicken feather waste or from whey of cow milk after mozzarella cheese formation. So, amino acid production from wastes decreases the cost of metal-chelated complex formation.