Abstract:Soy protein concentrate was used as raw material, and two characteristic flavor compounds from beef (4-hydroxy-2,5-dimethyl-3(2H)-furanone and 2,5-dimethyl-pyrazine) and three characteristic flavor compounds from spices (geraniol, linalool, and citral) were added during the extrusion process to improve the flavor of soy protein extrudates. Headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) and a sensory preference evaluation method were used to evaluate the flavor changes of extrudates. The results showed that the addition of exogenous volatile compounds caused significant changes in the types and concentrations of flavor compounds in the extrudates. After the addition of 2,5-dimethyl-pyrazine, furaneol, and linalool, the mass fraction ratio of off-flavor compounds to pleasant-flavor compounds in the soy protein extrudates decreased from 87∶13 in the control group to 83∶17, 57∶43, and 80∶20, respectively. Consumer preferences scores for the extrudates increased from 3.25 in the control group to 7.65, 6.34 and 5.62, respectively. Additionally, the evaporation of water during extrusion reduced the concentrations of three furan compounds in the extrudates by 67%~100% and two aldehyde compounds by 15%~83%, while the concentrations of other higher-boiling-point compounds remained unchanged.
