To explore the quality changes of pre-made chicken chops under different liquid nitrogen flash-freezing temperatures,liquid nitrogen spray(-80,-100,-120℃)was used to freeze chicken chops,whereas fresh storage at 4℃ and slow freezing at 18℃ were used as controls.The evaluation indicators included freezing speed,sensory score,water holding capacity,pH,color,texture and oxidation index.The results showed that treating chicken chops with liquid nitrogen flash-freezing considerably shortened the freezing time.The sensory score of chicken chops treated with liquid nitrogen flash-freezing at-100℃(70.83 points)was the closest to that of chicken chops refrigerated at 4℃(84.00 points),whereas treatment with liquid nitrogen flash-freezing at-120℃ caused cracks on the surface of the chops.The water holding capacity of pre-made chicken chops can be effectively maintained by liquid nitrogen flash-freezing.The centrifugal loss rate of chicken chops treated with liquid nitrogen flash-freezing at-100℃ was 20.95％,whereas that of chicken chops treated with slow freezing at-18℃ was as high as 32.84％.A significant difference was detected in pH among the different groups(P<0.05),but not in color(P>0.05).The texture indices of the liquid nitrogen flash-freezing groups were generally superior to those of the-18℃ slow-freezing group.Compared with slow freezing at-18℃,the malondialdehyde content of chicken chops treated with liquid nitrogen flash-freezing at-80 and-100℃ decreased by 22.54％ and 15.02％,respectively,whereas their glutathione peroxidase activity increased by 66.13％ and 132.58％,respectively.In conclusion,compared with the slow freezing at-18℃,chicken chops treated with liquid nitrogen flash-freezing retained superior eating quality.It is recommended that the processing temperature be maintained between-80 and-100℃.
维普
万方数据
