Pig bone extract as the main raw material,the change of protease activity,amylase activity,xylanase activity,amino acid nitrogen,reducing sugar and red index were investigated during solid-state fermentation by Monascus and double strains of Monascus and Aspergillus oryzae. At the same time,the protein degradation products were analyzed by SDS-PAGE electrophoresis. The results showed that in the process of Monascus fermentation,enzyme activities increased to its peak and then decreased. Neutral、alkaline pro...