Abstract: An anti-denaturation agent for an edible paste product contains a protein decomposition extract obtained by decomposition of protein by proteinase and saccharides as essential active ingredients.

Abstract: A process for the preparation of fish and/or shellfish extracts having various pharmaceutical functions is provided. The process comprises decomposing raw fish and/or shellfish at a pH of 6.0 to 7.0 with a Bacillus subtilis derived proteinase and decomposing at the same pH range with a Koji mould derived proteinase. The product extracts contain peptide amino acids each having a molecular weight of substantially less than 3000 and free amino acids. According to the invention, medicines containing the fish and/or shellfish extracts are also provided such as nutrition balancing medicines, anti-ulcer medicines, diabetes relieving medicines, antilipemic medicines and rheumatism and arthritis relieving medicines.