Sterilization is the most relevant technique to guaranty safety of shelf-stable food products at ambient temperature. However, these thermal processes are often optimised to microbiological aspect and consequently are not without consequences on quality. Only few studies are focussed on the simultaneous management of these two aspects. Ascorbic acid is of interest due to its vulnerability and health benefits. Its degradation at sterilization temperature (> 100 °C) is poorly documented. The aim of this work is to model thermal processes in a risk/benefit approach, taking in account the nutritional aspect. Its final objective is to design new thermal processes which will be efficient to inactivate heat-resistant microorganisms, but not too drastic in order to maintain the maximum quality. Using a new instrumented reactor (thermoresistometer Mastia®), the behaviors of ascorbic acid food model solution at pH = 3.5, in aerobic and anaerobic conditions, was measured. The obtained data have shown that degradation of ascorbic acid does not follow classical kinetics in conditions of appertization, it follows 0.5-order kinetics in aerobic conditions and zero-order kinetics in anaerobic conditions.