Traditional (low temperature, long time) and novel (low temperature, short time) sous-vide cooking of lean tuna were characterized by analyzing the effects of thermal protein denaturation (TPD) on quality attributes, such as color, appearance, shrinkage, drip loss, and texture. TPD was analyzed by differential scanning calorimetry and estimated for several thermal schedules by kinetic analysis, following the dynamic method. When heated at a rate of 10 8C/min, myosin began to denature at around 35 8C. Actin did not denature, even when the temperature rose to approximately 51 8C, until the denaturation of myosin was complete. However, actin began to denature at approximately 58 8C and was completely denatured at 76 8C. Actin denaturation had a stronger effect than myosin denaturation on texture changes, whereas myosin denaturation was responsible for changes in color and appearance. A better preservation of tuna quality was obtained by novel sous-vide cooking over the traditional sous-vide method.
Practical applicationsThe results of this study are useful to both the research community and industry because they provide quantitative characterization of the consequences of sous-vide cooking method on food quality explained by estimating TPD. Moreover, the kinetic parameters of the denaturation rate collected for kinetic modeling of the TPD of tuna, not only have application to simulate denaturation of actin and myosin under different thermal schedules of sous-vide cooking, but also they can be used for the analysis of additional thermal treatments.
| I N TR ODU C TI ONSous-vide is a method of cooking food in vacuumized plastic pouches at precisely controlled temperatures (Baldwin, 2012). The benefits of the sous-vide method have been reported in several articles (Baldwin, 2012;Sampels, 2015;Schellekens, 1996), including the production of foods with better color, texture, and nutrient retention. The sous-vide technique includes a combination of barrier technologies such as vacuum packaging and cold shock (after thermal processing), where the products are quickly cooled and stored at temperatures below 4 8C for a few hours or days, depending on nature of the product. During sousvide heating, the food in the bag is heated to the exact optimal cooking temperature, using a water bath or a steam convection oven (Schellekens, 1996). The food is eventually reheated before serving.Sous-vide cooking enables a precise, even temperature maintained throughout the food, resulting in an overall homogeneous appearance (Provost, Colabroy, Kelly, & Wallert, 2016). Thus, the food is cooked to the same temperature throughout, without excess heat being applied to the surface of the food. These results are obtained under traditional sous-vide process, using low temperatures and prolonged processing times (Ibarra et al., 2013;Schellekens, 1996). However, in the past decade, some delicatessen products have been processed by a novel sousvide-cooking method, using reduced processing times. Under these conditions, the inner part of th...
