Pilot scale production of dietary fibers from Tunisian tomato and red pepper by-products

Abstract

This research aims to valorize the by-products of tomato and red pepper processing underrated despite their richness in valuable compounds, essentially dietary fibers extracted from canning industry by-products using water as solvent. Therefore, varying operating conditions were tested on a laboratory scale, and the obtained fibers were characterized to choose the appropriate conditions for applying fiber extraction on a pilot scale. The selected parameters were applied (60 °C, 3 h) and the produced fibers were recovered. The Fourier Transform Infrared (FTIR) analysis indicated that the obtained by-products fibers were mainly cellulosic with similar structures, which proved that the scaling up did not affect the chemical structure of the fiber samples. These observations were confirmed by the X-ray diffraction (XRD) analysis and the Thermogravimetric analysis (TGA). The Scanning Electron Microscopy (SEM) analysis showed arranged fibrous forms for the pilot scale extracted fibers. The analysis of extraction solvents and the regenerated liquid corroborated the choice of operating conditions for the scaling up. The outcome of this study established that the extrapolation of the dietary fiber extraction from tomato pomace and red pepper pomace was carried out successfully on a pilot scale and might be feasible at an industrial scale. This green dietary fiber extraction encourages using this valuable extract in several fields, such as cosmetic and nutraceutical applications.