Upcycling plant side streams using mild processing

Summary

Food loss and waste (FLW) is an important aspect of food production and contributes significantly to the environmental impact of food. Next to prevention and reduction, valorisation of unavoidable FLW aids to improve the resource efficiency of the food chain.

To support food processing experts in the demand for feasible valorisation options, the Processtimator tool is developed within FOX – FOod processing in a Box. The tool combines flow charting and knowledge databases, to explore different process routes for side stream fractionation and valorisation, while accounting for the impact on overall value, costs and greenhouse gas (GHG) emissions. Based on side stream characteristics, the tool advises on possible processing routes. Side streams are characterized by daily availability and yearly volume, and on composition, both on major and valuable minor nutrients. After optimizing the operational window and equipment employment, the impact on mass balances and Opex/Capex is estimated.

In this study, the tool was used to evaluate an additional washing step in the industrial production of ginger and carrot juice to optimize production costs, waste streams and GHG-emissions. The results showed that for carrots the additional step is not economically feasible and does not reduce the GHG-emissions per kilogram of product. Whereas for ginger extraction, an additional washing step is economically feasible and if the primary production is considered also the GHG-emissions per kg of concentrated juice is lower. The different outcome can be explained by the total use of the carrots. From carrots, both juice and fibres are suitable to be used as food ingredient, whereas for ginger only the juice is used. The washing step recovers more solids for the juice thereby reduces the fibre fraction.

This case demonstrates the benefits of using the Processtimator tool to evaluate process changes before starting expensive and time-consuming tests.