Abstract:
To investigate the formation of warmed-over flavor (WOF) in surimi gels and how the odorants changed during a two-step water-bath heating process and water-bath reheating process, surimi gels were prepared with a set of temperatures (heated at 85 ℃, 90 ℃, and 100 ℃ for 30 min) or lengths of time (heated at 90 ℃ for 5 min, 10 min, 15 min, 20 min, 25 min, 35 min, 40 min, and 45 min) for the two-step water-bath heating process after a pre-incubation at 40 ℃ for 60 min. Meanwhile, the surimi gels, which were prepared by heating them at 40 ℃ for 60 min and 90 ℃ for 30 min, were reheated at a series of temperatures (60 ℃, 70 ℃, 80 ℃, 90 ℃, and 100 ℃ for 30 min) or for a series of durations (2.5 min, 5.0 min, 7.5 min, 10 min, and 15 min at 90 ℃). Thereafter, sensory evaluation, electronic nose sensing, and gas chromatography mass spectrometry (GC-MS) were conducted to analyze the odor properties of samples before and after the heating strategy. In total, 74 volatile components were successfully identified via GC-MS in surimi gels made using different water-bath heating methods, including 15 aldehydes, six ketones, 15 alcohols, ten esters, four phenols, two acids, seven hydrocarbons, and 15 other compounds. According to the odor activity values (OAVs) and sensory evaluation, the key odorant compounds that could affect the warmed-over flavor in surimi gels were hexanal, nonanal, octanal, 1-octen-3-ol, heptanal, (E)-2-nonenal, (E,Z)-2,6-nonadienal, (E)-6,10-dimethyl-5,9-undecadien-2-one, (E)-2-octen-1-ol, acetophenone, and styrene. Additionally, the warmed-over flavor presented "rancid-like" and "stale-like" odors. Additionally, the steps to generate the warmed-over flavor included pre-incubation at 40 ℃ for 60 min and heating at 90 ℃ for 30 min, followed by a reheating process at 80 ℃ for 30 min. With the increase in temperature, the WOF became more intense. This study provides some theoretical references for controlling the formation of warmed-over flavor in the manufacture of surimi products.
