The organic residues used in the experiment were analyzed for the following chemical components:
Total C by wet oxidation with potassium dichromate Walkley and Black, total N by micro Kjeldahl distillation, lignin by the acid-detergent lignin determination Goering and van Soest. Polyphenols were extracted from 0.75 g sample in 20 ml hot 77 oC 50% aqueous methanol and determined colormetrically using the Follin-Denis reagent with tannic acid as a standard Anderson and Ingram 1993. Protein binding capacity PBC of polyphenols was determined in the same extract of polyphenols through the reaction of the polyphenols with bovine serum albumin BSA Handayanto et al. 1994.