2017 (10) : "Development of antimicrobial materials based on caseins." (Thesis by Elodie CHEVALIER)

Thesis defended on 10/25/2017

Thesis supervisor:

Dr N. Oulahal (thesis co-director), Dr F. Prochazka (thesis co-director)
F. Prochazka is a teacher-researcher at Jean Monnet University (St Etienne), research unit: UMR Polymer Materials Engineering (IMP)

Funding:

Doctoral Research Grant from the Rhône-Alpes region within the framework of the ARC (Academic Research Community) Environment (1/10: 14-30 / 09/17).

Industrial partners:

Sté Labelys (Bellignat, 01),
Sté Lactips (Lyon, 69)

Doctoral school of registration:

EDSIS (Sciences, Engineering, Health), ED n ° 488, Jean Monnet University, St Etienne

Summary:

Development of innovative biodegradable, edible and functionalized material comes from a triple socio-economic expectation in the field of sustainable development (decrease in synthetic non-biodegradable polymers), of natural solutions for food preservation (trend of “clean label” by food protection through active and smart packaging to avoid over-use of food additives) and of food safety (microbiological safety and traceability). Development in that field, started few decades ago is slowed down by production process (wet process), which is not an easy scale up process. However, a few years ago industrial process technique as extrusion started developing. In the present work, the twin-screw extrusion process was successfully applied to produce polymer based on protein raw material: acid casein, rennet casein and sodium caseinate. Extracted from caw milk, these three caseins own different characteristics, which affect material properties (mechanical, water sensitive properties). Matrix functionalization through organic acid addition bring an interesting antimicrobial response against Escherichia coli. Blending hydrophobic molecules as waxes (beeswax, candelilla wax and carnauba wax) creates a complex composite material which increases the range of available properties as improved water vapor barrier allowed by beeswax addition. Water sensitive properties are key points to consider at each step of material development and to understand relationships between the different ingredients (protein, plasticizer, waxes, antimicrobial agents). This manuscript shows the feasibility in the development of casein based material as biodegradable, edible and antimicrobial material, to apply and use in the food packaging industry or other industries