Quality improvement of the tomato-based products using infrared tool along the production chain

The tomato industry lacks tools to better characterize the technological potential of raw material, to monitor processes and to discriminate technological characteristics of industrial products. The objectives here were to evaluate the benefit of using mid-infrared spectroscopy (MIRS, 4000-650 cm(-1)) using databases collected on fresh fruits and on processed products over several years and from different French regions. Two-year models including spectral and reference data clearly indicated that MIRS accurately quantify soluble solids content (SSC), dry matter (DM) and titratable acidity (TA) of fresh tomatoes. The determination coefficients (R-2) were 0.93, 0.85 and 0.90, respectively. Those parameters are crucial to identify the technological potential of tomatoes and MIRS appears to be an available strategical tool to improve the dispatch of raw material between processing lines in factories. Factorial discriminant analysis (FDA) allowed a clear discrimination of cooked purees based directly on MIRS spectra according to the hot break (HB) or cold break (CB) processes, genotypes and production areas. Those results indicate that MIRS should be developed to monitor the product changes along the processing route (as a sensor) or to trace products through sample investigation at the industrial level. A preliminary study on tomato products delivered by two French plants and characterised by their own control laboratories showed significant correlations between MIRS and soluble solids (R-2 0.98) and viscosity (Bostwick reference values, R-2 0.76). Those results highlight that collaborations between research and industry should be organised to implement MIRS along the production chain of industry-tomato to improve their quality control as is already the case for other food industries such as cereals.