The effects of extraction condition and freshness of raw materials on the quality and mutagenicity of hot-water extracts prepared from livestock bones

Hot-water extracts prepared from beef, pork, and chicken bones have been manufactured for a long time, and are used in many types of products, and have a large annual production. However, a detailed examination on the manufacturing conditions has not yet been carried out. In this study, we prepared the extracts at 100 degrees C, the most common temperature for industrial purposes, and 10 degrees C higher and lower than that. We compared mutual relationships among these extracting conditions, on their free amino acid compositions, and their sensory evaluation of basic taste qualities and overall preference. Fluctuation in mutagenicity of each extract was also inspected in connection with their extraction conditions. In conclusion, an extraction at a lower temperature than that generally used in the seasoning industry provided us with better results not only in recovery of free amino acids and sensory properties, but also in long term safety in regard to mutagenicity levels, regardless of the species of raw materials.