Nowadays, depending on the progress of science and technology, our eating habits have changed. The shape and quality of nutrition is important for human health. Especially, some food components have various effect on central nervous system such as depression, anxiety, sleep, appetite. Food constituents are transported into the central nervous system via the neutral amino acids such as phenylalanine, leucine, isoleucine, tyrosine and valine. Amino acids have an important role in human nutrition. It cannot be synthesized in the body and one of the essential amino acids that must be taken outside, trytophan, is indispensable in human nutrition because of it has the many functions. In recent years, scientific community concentrated on the various functions of L-Trytophan (L-Trp) as pioneer in the secretion of the hormones serotonin and melatoninin in the human body. The hormones serotonin and melatonin is responsible for activities such as psychology, sleep, body temperature, blood pressure balance, antioxidant effect, cancer inhibitor, sexuality, autism and circadian rhythms in human body that they are available in various foods such as milk, kefir, yogurt, orange, strawberry, grape, olive oil, walnut, prune, nut, pomegranate, coffee, kiwi and banana. In this study, L-Trp, serotonin and melatonin biosynthesis and metabolism, food profiles and in terms of their physiological and biological effects on human health has been compiled.

The plankton communities are important source of food for the aquatic organisms, and if any undesirable changes in aquatic environment may affect plankton diversity and density. Therefore, assessment of planktonic communities in the freshwater ecosystems is essential because they serve as bio-indicators of water quality parameters. Hence, the present research was focused to evaluate the freshwater phytoplankton and zooplankton diversity and their abundance in Valankulam Lake (Lat. 10.59° N and Long. 76.57° E), at Coimbatore city, Tamil Nadu, India. Results from the study revealed that a total of 77 species of phytoplankton and zooplankton were recorded, under 37 families and 46 genera. In addition to that, a total of 43 phytoplankton species were recorded under 25 families and 30 genera, (which includes; 15 species of Cyanophyceae, 17 species of Chlorophyceae, 08 species of Bacillariophyceae, 03 species of Euglenophyceae). and a total of 34 species of zooplankton were recorded under 12 families and 17 genera, (which includes 13 species of Rotifera, 09 species of Cladocera, 08 species of Copepoda and 04 species of Ostracoda). The maximum plankton diversity was observed during the monsoon season and the minimum in the summer season. Results from study revealed the ecological status of the lake is categorized as moderately polluted due to the presence of municipal waste and industrial discharges into the lake water. Therefore, the assessment of planktonic communities in water bodies will be useful to monitor and maintain the water quality parameters and wealth of aquatic biota in the aquatic ecosystem.