Phenolic compounds are found in foods as soluble and insoluble
forms, the latter being linked to structural cell components
through ester and glycosidic bonds. Insoluble phenolics are not
extractable by water or organic solvents, being released only upon
alkaline, acid or enzymatic hydrolyses. Alkaline hydrolysis is the
main step of the insoluble phenolics extraction procedure while
acid hydrolysis is applied to release compounds not removed in
the previous step. To the best of our knowledge, soluble and insoluble phenolic compounds of fresh guava fruit and guava powders
were investigated for the first time in the present study