Ammonium sulfate is usually the salt of choice because besides its high water solubility and high ionic strength, NH4þ and SO42_ are at the ends of their respective Hofmeister series and are known to stabilize protein structure (Krisna et al., 2014). It was observed that with an increase in ammonium sulfate concentration, the extraction yield of AP also increased. Maximum extraction yield of 25.73 mg/ g is obtained at 40% ammonium sulfate concentration. This is because sulfate ions act as dehydrating agent. When it is added to the aqueous phase, water molecules start attaching itself to the sulfate ions thus enhancing their effective radius.