Challenging DESs and ILs in the valorization of food waste: a case study

Angelica Mero; Nicholas R Moody; Elena Husanu; Andrea Mezzetta; Felicia D'Andrea; Christian Silvio Pomelli; Nathalie Bernaert; Francesca Paradisi; Lorenzo Guazzelli

doi:10.3389/fchem.2023.1270221

Challenging DESs and ILs in the valorization of food waste: a case study

Front Chem. 2023 Oct 24:11:1270221. doi: 10.3389/fchem.2023.1270221. eCollection 2023.

Authors

Angelica Mero^{1

2}, Nicholas R Moody³, Elena Husanu¹, Andrea Mezzetta^{1

2}, Felicia D'Andrea^{1

2}, Christian Silvio Pomelli^{1

2}, Nathalie Bernaert⁴, Francesca Paradisi^{3

5}, Lorenzo Guazzelli^{1

2}

Affiliations

¹ Department of Pharmacy, Università di Pisa, Pisa, Italy.
² Consorzio INSTM, Firenze, Italy.
³ Department of Chemistry, University of Nottingham, Nottingham, United Kingdom.
⁴ Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Technology and Food Science Unit, Melle, Belgium.
⁵ Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.

Abstract

In this study, the efficacy of two of the best performing green solvents for the fractionation of lignocellulosic biomass, cholinium arginate (ChArg) as biobased ionic liquid (Bio-IL) and ChCl:lactic acid (ChCl:LA, 1:10) as natural deep eutectic solvent (NADES), was investigated and compared in the pretreatment of an agri-food industry waste, apple fibers (90°C for 1 h). For the sake of comparison, 1-butyl-3-methylimidazolium acetate (BMIM OAc) as one of the best IL able to dissolve cellulose was also used. After the pretreatment, two fractions were obtained in each case. The results gathered through FTIR and TG analyses of the two materials and the subsequent DNS assay performed after enzymatic treatment led to identify ChArg as the best medium to delignify and remove waxes, present on the starting apple fibers, thus producing a material substantially enriched in cellulose (CRM). Conversely, ChCl:LA did not provide satisfactorily results using these mild conditions, while BMIM OAc showed intermediate performance probably on account of the reduced crystallinity of cellulose after the dissolution-regeneration process. To corroborate the obtained data, FTIR and TG analyses were also performed on the residues collected after the enzymatic hydrolysis. At the end of the pretreatment, ChArg was also quantitatively recovered without significant alterations.

Keywords: biomass valorization; cellulose saccharification; deep eutetic solvent; food waste; ionic liquids.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. Era-Net Cofund SUSFOOD2 Call 2017, MIUR, DEFRA UK, and VLAIO.