Strawberry guava is a fruit with a high viscosity due to presence of soluble sugars, pectic substance, and other soluble solids in the pulp (Haminiuk and others 2006), as a result of which aqueous extracts are also highly viscous. Therefore, it was necessary to precipitate these constituents with methanol; for example, to avoid any possible interference in the analysis (Vriesmann and others 2009). Extracts for HPLC analysis were prepared with methanol.