SEPARATION OF L-ARGININE AND L-CITRULLINE IN RED AND YELLOW CRIMSON WATERMELON (Citrullus lanatus) JUICES EXTRACT USING HPLC GRADIENT MODE

Abstract

Watermelon (Citrullus lanatus) is a nutritious fruit that has attracted scientific interest due to its phytonutrient content including carotenoids and amino acids. Watermelon juice is the richest known source of amino acids including L-arginine and L-citrulline. For a complete separation of amino acids in watermelon juices, a gradient mode of reverse phase high performance liquid chromatography (RP-HPLC) with UV detection was utilised owing to its supremacy over isocratic mode. This present study was aimed at achieving good separation of chromatography profiles and baseline between L-arginine and L-citrulline in red and yellow crimson watermelon juice extract. The edible parts of watermelons were juiced, stored at-80 o C and freeze dried to obtain dried juice powder. Samples were analysed by gradient mode of RP-HPLC using 0.1% orthophosphoric acid in water (v/v) and acetonitrile as mobile phase A and B. The chromatograph separation was performed using Gemini C 18 column at a flow rate of 1.0 mL/min, maintained temperature at 25 o C while detection was made at four different wavelengths; 195 nm, 200 nm, 207 nm and 210 nm with total analysis time of 35 min. Excellent chromatographic separation was achieved at conditions of gradient elution (0%B-95%B, 0-18 minutes and 95%B, 18-23 minutes, 95%B-0%B, 23-25 minutes, 0%B, 25-35 minutes) with baseline between L-arginine and L-citrulline in both watermelon juice extracts. The gradient mode used in this RP-HPLC successfully achieved efficient separation of chromatographic profile for amino acids, L-arginine and L-citrulline in the red and yellow crimson watermelon juice extracts.

Recent trends in preprocessing and extraction of watermelon rind extract: A comprehensive review

“…It is often consumed in hot weather in tropical and subtropical climates, especially in Africa, Asia, the United States, Russia, and the Mediterranean (Neglo et al, 2021). Watermelon belongs to the family Cucurbitaceae, including several other fruits such as winter melon, muskmelon, squash, cucumber, bottle ground, and pumpkin (Ridwan et al, 2018). Watermelon comprises three main parts: flesh, rind, and seed.…”