Effects of Stewing Modes on Physicochemical Quality and Formation of Flavour Compounds of Chinese Dagu Chicken Soup

This study aimed to evaluate the influences of stewing modes, including high fire short time (HFST, 100°C/1 h), medium-high fire mid-length time (MFMT, 98°C/2 h), medium fire long time (MFLT, 90°C/3 h), and low fire ultra-length time (LFUT, 83°C/4 h) processing, on physicochemical parameters and flavour compound profile of Chinese Dagu chicken soup. The chicken soup prepared under the stewing mode of MFMT had smaller particle size (d 3,2 of 2.56 μm and d 4,3 of 1.73 μm), higher zeta potential (8.66 mV), and viscosity than the soups stewed under the other conditions. The umami-taste compounds, such as inosine 5'-monophosphate, and umami free amino acid were the most abundant in the soup stewed by MFMT (53.47 and 59.91 mg/100 mL, respectively). GC-MS results showed that the volatile compounds were mainly hexanal, octanal, heptanal, ( E,E )-2,4-decadienal, nonanal, and 1-octen-3-ol. Additionally, the results of measurements made with the electronic nose and electronic tongue indicated that the overall flavour of the four chicken soups varied significantly. In general, considering the stability and umami taste of chicken soup, as well as the time-saving need, it is recommended to use the MFMT mode to prepare the chicken soup.