Nonvolatile Taste Compounds in Cooked Chinese Nanjing Duck Meat Following Postproduction Heat Treatment

Taste-active compounds, including free amino acids, succinic acid and 5'-nucleotides, and chemical components including moisture, pH, protein, crude fat, and sodium chloride were evaluated in cooked and packaged Chinese Nanjing ducks following heat treatments including control, 99 degrees C for 40 min, 108 degrees C for 20 min, 92 degrees C microwave followed by water heating, 95 degrees C for 30 min, 121 degrees C for 25 min. Heat treatment decreased (P < 0.05) the content of Alamine and moisture and reduced the pH value in muscle, but increased (P < 0.05) the protein and 5'-nucleotides content. The 99 degrees C group had a significantly lower crude fat content compared with other groups (P < 0.05). The succinic acid content in the control group was significantly higher than in the 121 degrees C group (P < 0.05). Groups treated at higher temperatures (108 degrees C, 121 degrees C, and microwave) had similar equivalent umami concentrations and 5'-nucleotides, free amino acids content, as well as the derived bitter and sweet taste components compared with the groups treated at lower temperatures. It can be speculated that these differences account for the enhanced flavor of the meat in the 99 degrees C, 108 degrees C, 121 degrees C, and microwave groups compared with the untreated control. Therefore, heat treatment at lower temperature after packaging may prolong product shelf life without any detrimental effects on taste. The results of this study indicate that it is important to use lower temperatures in this type of food processing. However, it may be possible to modify the primary processing steps to improve the content of umami-like taste compounds such as 5'-nucleotides. Practical Application Heat treatment of packaged products is an effective method for eradication of microbes, therefore increasing the shelf-life. However, such treatment can result in major changes in the sensory perception of meat products, particularly the formation of off-flavors. This study investigated changes in taste-active compounds in duck meat following a number of types of heat treatment.