OHMIC THAWING OF FROZEN BEEF CUTS

Abstract

ABSTRACTIn this study, the application of ohmic heating to thaw the frozen beef cut samples was investigated. The center temperature of different sample sizes of beef cuts (2.5 cm × 2.5 cm × 5 cm; 2.5 cm × 5 cm × 5 cm; 3: 5 cm × 5 cm × 5 cm) was aimed to reach +10C from −18C. The ohmic thawing was performed by the application of different voltage gradients (10, 20 and 30 V/cm), whereas the conventional thawing was performed at controlled conditions (25C, 95% RH). The effects of sample size, thawing method and voltage gradient on thawing time, drip loss, color, temperature homogeneity and EUR were investigated. Significant differences were found between thawing methods in terms of the temperature homogeneity, the thawing time and the thawing loss (P < 0.05). The results indicated that as the voltage gradient increased, the thawing time decreased, while the thawing loss remained unchanged. There was a decrease in the EUR (47–70%) with the increase in the sample size and the voltage gradient applied during ohmic thawing.The results of this study will provide valuable data for the design of the industrial ohmic thawing systems and give useful insights to further studies on this subject.PRACTICAL APPLICATIONSIn meat processing, especially in thawing, there are several problems regarding the nonhomogeneities during thermal treatments due to heterogeneous structure of the sample, and the high energy consumption of conventional heating methods. To overcome all these problems, researchers focused on the alternative methods to replace or complement the traditional thawing process of meat products. Ohmic processing is used in a wide range of applications such as preheating, blanching, pasteurization, sterilization and extraction of food products. Although it has an approved technology for liquids and has industrial applications, there was no industrial application of ohmic technology in meat processing. In recent years, the researches on the usage of ohmic technologies in meat processing have been increased. This study focused on the applicability of ohmic thawing procedures for beef cuts with different sizes in terms of appropriate thawing attributes and energy utilization percentage.Results from this study will give important information to academic studies and industrial applications for the design of ohmic thawing systems for meat products. The main items required for system considerations were also discussed.