Evolution of the nutritional value of tomato products from the field to the cans: impact of harvesting and processing methods on macro- and micro-element contents and lycopene bioaccessibility.

摘要

Nutritional value of food is mainly determined from the metabolites contained in the crops and food products and is among the quality parameters retained and emphasis for consumers. Fresh fruits benefit from a positive feeling of consumers while processed fruits are often considered as low-nutritional because processing is generally considered as deleterious for most health-benefit components. However fruit matrix provide protections explaining that a proportion of sensitive molecules remains even after heat treatments. Processing may also have positive impact by enhancing bioaccessibility of nutrients. In order to have a critical view of how the nutritional value of tomato products evolve during the classical industrial routes, we designed a pilot-scaled experimentation for tomato puree and paste preparations, including various harvesting and processing methods. Every product was evaluated for their vitamin C, main sugars, main acids and fibre content. Lycopene content and bioaccessibility was also evaluated. Vitamin C was the most impacted element by harvesting and processing methods (up to 80% loss), but surprisingly, only 10% of the initial vitamin C was lost during the cold break processing (100 degrees C for 15 min). As was sugars, acids and fibres, lycopene content was little affected by the process. However, its bioaccessibility was enhanced when tomato was prepared with hot break methods.