Assessment of L-Citrulline, L-Arginine and L-Glutamic Acid Content in Selected Fruits, Vegetables, Seeds, and Nuts Sold in Markets in Nairobi City County, Kenya

Background: L-citrulline, L-arginine, and L-glutamic acid are amino acids which are vital in the human body. L-citrulline boosts immunity, combats sarcopenia, detoxifies the liver, and enhances male fertility. L-arginine boosts internal production of nitric oxide, prevents abnormal blood clotting and accelerates healing of wounds. L-glutamic acid cleanses the central nervous system and improves overall brain health. Deficiency of these amino acids can lead to accumulation of ammonia and impact negatively to the nervous systems of the human body. This study aimed to identify and determine the levels of L-citrulline, L-arginine, and L-glutamic acid in selected fruits, vegetables, nuts, and seeds sold in markets in Nairobi City County, Kenya using Liquid Chromatography- Mass Spectrometry (LC-MS). Materials and Methods: Data was collected from 28 selected samples and data analysis was done using Statistical Analysis Software (SAS) version 9.4. Results: LC-MS showed the presence of both L-arginine and L-citrulline in most fruits, vegetables, and nuts while L-glutamic acid was present in the seeds. The levels of the amino acids in the fruits and vegetables were in the following range: L-citrulline (0.65- 19.41 mg/100g) in the button mushroom, cucumber, pumpkin, amaranthus, and kales, (3.16-3.79 mg/100g) in the watermelons and (1.57-10.21 mg/100g) in the nuts. L-arginine was in the range; 1.73 - 16.48 mg/100g in the amaranthus, kales, button mushroom, butternut squash, and cucumber, 5.44-6.56 mg/100g in the watermelons and 0.93-10.73 mg/100g in the nuts and L-glutamic acid (0.013-0.28 mg/100g) in the seeds of pumpkin, butternut, and watermelons. Conclusion: The results showed that locally available vegetables, fruits and nuts are rich in L-citrulline and L-arginine.