A review of paramylon processing routes from microalga biomass to non-derivatized and chemically modified products

Frédérica Feuzing (1, 2) , Jean Pierre Mbakidi (1) , Luc Marchal (2) , Sandrine Bouquillon (1) , Eric Leroy (3, 2)

1 ICMR - Institut de Chimie Moléculaire de Reims - UMR 7312
2 GEPEA - Laboratoire de génie des procédés - environnement - agroalimentaire
3 GEPEA-MAPS2 - Matrices Aliments Procédés Propriétés Structure - Sensoriel

Paramylon is a linear β-1,3-glucan, similar to curdlan, produced as intracellular granules by the microalga Euglena gracilis, a highly versatile and robust strain, able to grow under various trophic conditions, with valorization of CO2, wastewaters, or food byproducts as nutrients. This review focuses in particular on the various processing routes leading to new potential paramylon based products. Due to its crystalline structure, involving triple helices stabilized by internal intermolecular hydrogen bonds, paramylon is neither water-soluble nor thermoplastic. The few solvents able to disrupt the triple helices, and to fully solubilize the polymer as random coils, allow non derivatizing shaping into films, fibers, and even nanofibers by a specific self-assembly mechanism. Chemical modification in homogeneous or heterogeneous conditions is also possible. The non-selective or regioselective substitution of the hydroxyl groups of glucosidic units leads to water-soluble ionic derivatives and thermoplastic paramylon esters with foreseen applications ranging from health to bioplastics.

Mots clés: processing; chemical modification; β-1 3-glucan; crystallinity; solvents

Domaines: Polymères

Frédérica Feuzing, Jean Pierre Mbakidi, Luc Marchal, Sandrine Bouquillon, Eric Leroy. A review of paramylon processing routes from microalga biomass to non-derivatized and chemically modified products. Carbohydrate Polymers, 2022, 288, pp.119181. ⟨10.1016/j.carbpol.2022.119181⟩. ⟨hal-03575459⟩