Physical distribution and characteristics of meat and bone meal protein

BACKGROUND: Use of meat and bone meal (MBM) in animal feed has been progressively restricted. Production of an MBM protein isolate would facilitate the development of new applications. Rational design of a process to produce such an isolate requires knowledge of MBM protein distribution and characteristics. RESULTS: MBM consists of varying proportions of bone and soft tissue particles, but the soft tissue particles contain > 80% of the protein. Under mild conditions only a small portion of MBM protein can be solubilized; the most aggressive non‐hydrolytic conditions fail to solubilize > 55% of the protein. Amino acid analysis reveals that collagen accounts for approximately 17% of the protein in soft tissue particles and 26% of that in bone particles. The extractable fractions of MBM protein are highly polydisperse and have weight‐average molecular masses of 71.1–86.7 kDa. CONCLUSION: MBM protein is a challenging substance to utilize functionally, largely due to its low solubility and intermingling with non‐protein substances. Results suggest that production of an MBM protein isolate will have to incorporate limited hydrolysis.