无线电波加热提高狭鳕鱼糜的解冻效率

Influence of Radio Frequency Heating on Thawing Efficiency of Pollack Surimi

应用传统的方法解冻鱼糜耗时长,为了加快冷冻鱼糜的解冻速率并保持鱼糜的品质,本实验以狭鳕鱼糜为研究对象,比较了空气解冻、流水解冻、无线电波直接加热和无线电波间歇加热4种解冻方式对冷冻狭鳕鱼糜解冻效率和品质的影响。结果表明:空气解冻和流水解冻过程中狭鳕鱼糜温度分布较为均匀。无线电波解冻过程中鱼糜边角部位会出现局部过热现象,采用无线电波间歇式加热能有效延缓鱼糜表面温度的过快升高。无线电波加热解冻速度快,仅需4.6 min就可以使狭鳕鱼糜的中心温度达到1.8℃。应用无线电波间歇加热后的狭鳕鱼糜的持水力为78.8%,白度值为61.7,无线电波加热在一定程度上能增加狭鳕鱼糜的弹性和抑制微生物的生长繁殖,解冻后的狭鳕鱼糜菌落总数仅为4.9×103 CFU/g。采用无线电波间歇式加热的物料温度分布均匀性较好,解冻效率高,又能最大限度地保持冷冻食品的品质,是一种极具潜力的解冻方式。

It takes a long time to defrost surimi using traditional methods. In order to rapidly thaw the frozen surimi and maintain its quality, in this paper, the effects of natural thawing, running water thawing, direct heating and intermittent heating of radio frequency on thawing efficiency and quality of frozen Pollock surimi were compared. The results showed that the temperature distribution of Pollock surimi was uniform by natural thawing and running water thawing. Local overheating occurred at the corner of the surimi during the radio frequency heating. Using radio frequency intermittent heating could effectively delay the excessive increase of the temperature of surimi surface. Radio frequency heating has features of rapidly raising temperature, it only cost 4.6 minutes to reach the central temperature over 1.8 ℃. The water holding capacity was 76.8% and the whiteness value was 61.7 for radio frequency heating. In addition, radio frequency heating could increase the elasticity of surimi and effectively inhibit the growth of the microorganism, the colony-forming unit of surimi was only 4.9×103 CFU/g. As a potential thawing method, radio frequency intermittent heating has a high efficiency of heating that can maintain the quality of frozen food.