Sous-vide meat properties as a function of physical and surface changes during processing

Abstract

Sous-vide is a method of cooking of vacuum-packed samples at relatively low temperature for longer periods than practiced with conventional cooking. Sous-vide is applicable to a wide variety of foods, and optimized sous-vide processing of meat can result in more tender products with less cooking loss. In this study, chicken breast and Thai local beef round were compared under sous-vide (vacuum-packaged and cooked at 60 to 80 °C for 1 to 7.5 h) and traditional cooking temperatures. The physical properties and surface texture of meat during sous-vide cooking were determined. It was found that the L^* (lightness) and a^* (redness) of cooked chicken breast were not affected by cooking temperatures or times (p >0.05), while the color of cooked beef depended on both temperature and time (p ≤0.05). It was found that cooking at higher temperature and for longer time resulted in meat with lower cooking yield and higher sous-vide loss, but with less re-heating loss (p ≤0.05). These results were supplemented with surface texture images which showed that larger spaces developed between the fibers after cooking at higher temperatures for longer time than those for samples cooked by sous-vide. Sous-vide chicken breast cooked at 60 °C for 2 h and 80 °C for 0.5 h, as well as beef cooked at 60 °C for 2.5 h and 80 °C for 2 h, were the most tender as measured by the lowest shear force values.