Abstract: The present invention provides a process for producing an enzyme, which includes recovering an enzyme by microfiltering an enzyme-containing solution, having a cell density of 1% (v/v) or less and an enzyme concentration of 1% (w/v) or more in terms of the amount of proteins, with a cationic surfactant added in an amount of 0.01 to 1% (w/v) to the enzyme-containing solution.

Abstract: The present invention provides an ester composition which can tenderize a stringy hard meat such as beef from abroad to a proper tenderness, the processing time, etc. and a meat tenderizer comprising said ester composition and protease without giving a special control over the amount of an enzyme. The present invention also provides a meat modifier which can provide a tender, juicy and less stringy meat that can be easily served and a food meat or meat product processed with such a meat modifier. A meat modifier is also provided, comprising an ester composition of a C.sub.12-22 saturated or unsaturated fatty monoglyceride with succinic acid or diacetyltartaric acid having an acid value of from 30 to 120. The present invention provides a meat modifier comprising the ester composition and a metalloprotease, which no longer causes round to be tenderized after 24 hours of storage at a temperature of 20.degree. C.