Influence of Cooking Technique on Bioactive Compounds Bioaccessibility of Vegetable Lentil Soup

Vegetables and legume soups contain various essential and bioactive constituents such as vitamin C, carotenoids, and phenolics. Antioxidant activity characteristics related to those compounds are well known to contribute profusely to human health. The cooking technique affects the bioavailability of nutrients and bioactive compounds, making it crucial to explore the optimal alternative to maximize them. The objective of this study was to explore the influence of different cooking techniques (boiling, pressure cooking, sous-vide, and cook-vide (CV)) on the physicochemical and compositional properties of a ready-to-eat vegetable lentil soup. For this, the bioaccessibility of those compounds was assessed through in vitro simulated gastrointestinal methodology. The firmness of vegetables was established to define treatments’ cooking times, allowing subsequent comparison of nutritional and functional soup’s properties. The color of vegetables was also evaluated as a quality parameter, which contributed to providing a global vision of the process impact. The results revealed that in vitro digestion (IVD) caused a decrease of all bioactive compound determinations for all cooking treatments. Additionally, thermal treatment improves the antioxidant activity of the soups measured by the DPPH method. This study highlights the importance of considering the digestion process when comparing cooking techniques. After IVD, traditional cooking reached the maximum total carotenoids and lycopene content; CV and pressure cooking techniques provided the highest total phenol content, showing these three techniques to have the maximum antioxidant capacity.