Caroline Pénicaud, INRAE, participated to the virtual live LCAFood2020 conference (https://lcafood2020.com/) to present the work performed with Camille Quentier (INRAE) and Esteban Gerbino (CONICET) during Esteban Gerbino’s secondment at INRAE in summer 2019. This work deals with the  environmental performance of new processes for the production of fructo- and galacto-oligosaccharides (FOS and GOS).

Abstract

The prebiotics like FOS and GOS are receiving special attention in the food industry due to their health benefits. They can be produced by enzymatic synthesis by using disaccharides or other substrates as raw materials or by extraction and hydrolysis from different natural sources (roots, legumes). The environmental footprints of these different production schemes are lacking to provide guidance for the ecodesign of such new production processes.

In this work, Life Cycle Assessment (LCA) was undertaken to analyse and compare the production of FOS and GOS by enzymatic synthesis from glucose (to get FOS) or lactose (to get GOS) and hydrolytic production from extraction of Yacon potato (to get FOS) or chickpea (to get GOS).

A cradle-to-gate approach was considered in the two scenarios under assessment (the phases of use and/or final disposal of FOS/GOS were not considered). The functional unit was defined as 100 g of FOS/GOS produced. LCAs were performed using data collected at the laboratory scale, supplemented with data from Ecoinvent database. SimaPro was used for the LCA modelling with the midpoint impact EF2.0 characterization method.

Results showed that the main environmental hotspot was the production of Yacon potato or chickpea used in the hydrolysis process. For this reason, the hydrolytic process caused higher environmental burdens than the enzymatic synthesis process. Chickpea production causing more impacts than Yacon potato production, GOS production generated more environmental impacts than FOS production. When produced by enzymatic synthesis, FOS and GOS were the sources of similar environmental impacts.

From a process point of view, special attention must be paid on three specific stages of production: time of synthesis, freeze-drying and purification of the final product. The environmental load of these stages was associated to high energy consumption and huge amount of ethanol requirement.

The results from this study helped to identify the stages requiring special efforts to ecodesign the production of FOS and GOS at pilot scale in the future. Further research should primarily be focused in the reduction of the biomass used and corresponding solid waste generated during the hydrolytic production. Furthermore, environmental assessment should be included at each development of the process to ensure its efficient eco-design.