2011 (04) : "Development of maize flour materials: evaluation and understanding of the relationships between structure and kinetics of biodegradation "(thesis by Fouzia JBILOU)

Thesis defended on APRIL 29, 2011

Development of maize flour materials: evaluation and understanding of the relationships between structure and kinetics of biodegradation

Jury :

  • Pr. Anne BERGERET (School of Mines of Alès) Rapporteur     
  • Pr. Yves GROHENS (University of South Brittany, Lorient) Rapporteur     
  • Pr. Françoise SILVESTRE (ENSIACET, Toulouse) Rapporteur     
  • Pr. Pascal DEGRAEVE (IUT University Lyon1) Thesis director    
  •  Dr. Sophie GALLAND (IUT Université Lyon1) Thesis co-director     
  • Dr. Nadia OULAHAL (IUT University Lyon1) Examiner    
  •  Dr. Valérie DESJARDIN (INSA Lyon) Invited member   
  •   Dr. Patrice DOLE (CTCPA Bourg en Bresse) Invited member

Read the thesis online (French only)


In order to develop materials from a renewable resource at a lower cost than starch, materials based on corn flour have been developed by extrusion-injection. The characterization of the physicochemical properties of these materials revealed that the level of glycerol (added to corn flour as a plasticizer) and the profile of the shear zones used during extrusion significantly influence the rate of destructuring of l starch and protein from corn flour. This could be established by notably crossing the results of analysis by X-ray diffraction, by infrared spectroscopy with Fourier transform, from differential scanning calorimetry analysis to observations by confocal laser scanning microscopy of materials. In addition, monitoring the kinetics of hydrolysis into starch reducing sugars by amylolytic enzymes in the presence and absence of proteolytic enzymes could be linked to the destructuring of proteins. The materials obtained however have crippling drawbacks for certain applications such as high hygroscopy and rapid aging over time. The addition of polybutylene succinate (PBS) to the flour-glycerol mixture has however led to an improvement in the mechanical properties and a reduction in the hygroscopy of these materials. Observations of the morphology of these materials by scanning electron microscopy have shown that cornmeal and PBS are incompatible and have a morphology which varies according to the level of PBS in the mixture (30, 50 or 70%). The study of the hydrolysis kinetics of starch in maize flour by amylolytic enzymes made it possible to highlight the influence of several factors: (i) the crystallinity of the starch, (ii) the specific area, (iii) porosity and (iv) material morphology. In addition, the evaluation of biodegradation by microbial route in liquid and solid medium by aerobic or anaerobic route showed the same global trends as the results obtained by enzymatic route. Thus, the materials produced from the formulations having proportions of PBS exceeding 50% are not biodegradable within the meaning of standard ISO 14855/1999 and are also weakly hydrolysed by amylolytic enzymes.

Valorization :

Publications in peer-reviewed journals:

  • Fouzia Jbilou, Sophie Galland, Farouk Ayadi, Laurent Belard, Charlyse Pouteau, Patrice Dole, Valérie Desjardin, Rémy Bayard, Pascal Degraeve (2011). Biodegradation of corn flour-based materials assessed by enzymatic, aerobic, and anaerobic tests : influence of specific surface area. Polymer Testing, 30 , 131-139.
  • Fouzia Jbilou, Farouk Ayadi, Sophie Galland, Catherine Joly, Patrice Dole, Laurent Belard, Pascal Degraeve (2011). Effect of shear stress extrusion intensity on plasticized corn flour structure : proteins role and distribution. Journal of Applied Polymer Science, 123(4) , 2177–2186
  • Communications at national and international congresses:

    Fouzia Jbilou, Pascal Degraeve, Issam Sebti. Synthèse sur les différentes méthodes d’évaluation de la biodégradabilité des polymères à base de ressources renouvelables.Colloque National de la Recherche dans les IUT (CNRIUT) les 29 et 30 mai 2008 à l’IUT A et l’IUT B, Université Claude Bernard Lyon 1. Lyon-Villeurbanne. (Oral communication and 8-page article)

    Fouzia Jbilou, Sophie Galland & Pascal Degraeve. Estimation de la biodégradabilité d’un matériau d’emballage alimentaire à base de farine de maïs par voie enzymatique. Colloque National de la Recherche dans les IUT (CNRIUT) 8-10 Juin 2009 à l’IUT A de Villeneuve d’Ascq Lille1. (Oral communication and 8-page article)
  • Fouzia Jbilou, Sophie Galland, Laurent Belard, and Pascal Degraeve. Effect of corn flour extrusion on its enzymatic degradation : impact of shearing zone profile. Congrès Matbim : First International Meeting on Material / Bioproduct Interactions. 3-5 March 2010 AgroParisTech, Paris. (poster)
  • Fouzia Jbilou, Sophie Galland, Nadia Oulahal, Pascal Degraeve. Effet de la formulation et du procédé sur la biodégradation d’un matériau à base de farine de maïs. 15 éme journée scientifique de l’Ecole Doctorale Interdisciplinaire Sciences-Santé le 17 Mars 2010 à l’université Lyon1. (Poster)
  • Fouzia Jbilou, Sophie Galland, Laurent Belard, Valérie Desjardin, Rémy Bayard, Pascal Degraeve. Biodegradation of corn flour-based material intended for food packaging under aerobic and anaerobic conditions. Congrès Plovdiv, Bulgarie au Food Science Engineering and Technologies. 15 et 16 octobre 2010. (Oral communication )