超声波根据频率的不同分为功率超声波、高频超声波和诊断超声波。相比于高频超声波和诊断超声波,功率超声波具有更明显的空化效应,已经被证明是一种非常有效的食品加工新技术,适用于乳化、结晶、均质、切割、水解、生物活性物质提取等许多加工过程。功率超声波应用于提取、灭菌等食品加工过程时,会对食品中天然色素、抗氧化剂及部分多糖有降解改性的作用,同时,也会对食品中的农药残留有一定的降解作用,进而增强了食品的质量安全。该文简单介绍了超声波的作用原理,论述了功率超声波在食品加工过程中对于食品天然色素、抗氧化剂、多糖以及农药残留的降解作用,并分析了目前国内外食品领域中功率超声波降解应用于食品加工研究优势和存在的问题,以期为功率超声波在食品加工中的应用提供更全面的研究视角。
Ultrasound can be divided into three frequency ranges: power ultrasound, high frequency ultrasound and diagnostic ultrasound. Compared with high frequency ultrasound and ultrasonic diagnosis, power ultrasound generates larger cavitation bubbles resulting in higher temperatures and pressures in the cavitation zone. Power ultrasound has proven to be a very effective innovative technique of food processing, being applicable to many processes such as in the emulsification, crystallization, homogenization, cutting, hydrolysis and extraction of biologically active substances. However, some food products such as food natural pigments, antioxidants and some polysaccharides seem to present certain alterations after exposure to power ultrasound and these alterations may affect food quality and safety. At the same time, power ultrasound has also been applied to effective degradation of pesticide residues in food, increasing food quality and safety. In this paper, the principal mechanism and process parameters of ultrasound were summarized and the effects of power ultrasound on the degradation of food natural pigments, antioxidants, polysaccharides and pesticide residues in food processing were reviewed. The advantages and problems of applications of power ultrasound in food processing were analyzed to provide a comprehensive perspective for the applications of power ultrasound.