1. AMSA. (1995). Research guidelines for cookery, sensory evaluation and instrument tenderness measures in fresh meats. Chicago: American Meat Science Association.
2. Effects of papain and a microbial enzyme on meat proteins and beef tenderness;Ashie;Journal of Food Science,2002
3. Two improved and simplified methods for spectrophotometric determination of hydroxyproline;Bergman;Analytical Chemistry,1963
4. CFR (Code of Federal Regulations) (2009). Use of food ingredients and sources of radiation (No. 9, Section 21). Washington, DC: CFR.
5. CFR (Code of Federal Regulations) (1999). Bacterially-derived protease enzyme preparation (No. 21, Section 1150). Washington, DC: CFR.