Recent Advances for Rapid Freezing and Thawing Methods of Foods

Freezing is one of the most effective and widely used preservation methods in the food industry. Freezing process means that the temperature of foods is reduced until the microbial growth and enzymatic activity are not possible; thus, the long-term preservation of foods is achieved. Since the rate of freezing is known to affect the distribution and size of ice crystals, the freezing rate is very important in the freezing process. In addition to the freezing process, it is known that the thawing process is also very important for the food quality. Similar to freezing, the rapid thawing method is preferred due to reduced weight loss, better texture, and prevention of microbial growth. For rapid freezing and thawing of food materials, various new technologies such as ultrasound, high pressure, and electric field are proposed instead of the traditional technologies currently used. These technologies provide to control ice crystal size, accelerate heat and mass transfer rates, and reduce tissue damage and weight loss. This review examines the effects of new technologies such as ultrasound, high-pressure, microwave, radiofrequency, magnetic field, and electric field on rapid freezing and thawing of foods while taking into account all the benefits and drawbacks. Additionally, this review is aimed to give guidance regarding the future research to enhance and, if required, combine current and developing technologies (high-pressure, ultrasound, microwave, radiofrequency, magnetic field, and electric field) to preserve foods with properties as near to fresh sample state as possible after freezing and thawing.