INFLUENCE OF 3 COOKING METHODS ON SOME PR OPERTIES OF PORK ROAST

Pork roasting is compared using three different ovens : a conventional oven, a forced convection oven and a superheated steam oven. The evol ution of the central temperature and the roast weight are measured. A final cooking temperature of 70 degrees C in the center defines the co oking time. The sodium, potassium and thiamin content of the roasts at cooking time are measured. In the superheated steam oven, cooking tim e is reduced by 32% compared with the forced convection oven and by 48 % compared with the conventional oven for a 500 g pork roast cooked at 220 degrees C. The efficiency of the superheated steam cooking compar ed with conventional cooking is due to the condensation phenomenon obs erved during the first stage of cooking. After the condensation stage, heat is transfered by infrared radiations and free convection between the superheated steam and the roast surface. At T-70 degrees C, corre sponding to the time necessary to reach 70 degrees C in the center, th e weight of the roast cooked in the conventional oven is significantly lower than the weight of the roasts cooked in the two others ovens. S odium, potassium and thiamin retention in the meat are not significant ly different. The nutriment losses are about 30%. On the other hand, t here is a great difference of aspect between roasts cooked with the su perheated steam oven and the forced convection oven : roasts cooked wi th superheated steam are less intense in color. This result is linked with the shorter cooking time which limits the duration of the brownin g phase. A 44 consumers panel has found forced convection roast aspect to be more pleasant than the superheated steam roast aspect. However, to the consumers, the superheated steam roast texture is preferable.