For estimation of tryptophan, the samples were hydrolysed using 4.2 M NaOH at 110◦C (Allred and MacDonald, 1988). The hydrolysates were dissolved in methanol and loaded into Ultra-HPLC Dionex RSLC (Dionex Corporation,USA). Detection was done at 263 nm and 338 nm (Meussen et al.,2014).