Edible coatings on the basis of native starches for prolonging the shelf life of cassava tubers

Abstract
Cassava is one of the most important starch sources used in production of different foods in some African countries. Cassava is a highly perishable good. For prolonging the shelf life of cassava tubers different methods as coating the tubers with paraffin waxes are in use commercially. Paraffin wax, classified as a chemical preservative, is widely used on fruits, vegetables, and candy to make them shiny and pretty as well as to retard moisture loss and spoilage. The aim of this project is to study the feasibility of replacement of paraffin wax by materials of plant origin. These materials should be good available to indigenous farmers.

Edible coatings had been designed on the basis of native yam and cassava starches. A method to produce a starch-oil-emulsion and subsequently a dried film has been established. Physical properties of these films, as water retention, mechanical and optical characteristics, had been determined. The internal tension of films made from yam starch is high and leads to deformation and rupture of the coatings. Cassava starch is validated as a good film forming material. Impregnation of the films with plant oils in an appropriate concentration will reduce water vapor transport from a reservoir to the environment significantly and gives optimized mechanical properties.

Further activities will include the characterization of the chemical composition of cassava starches and application of the materials to coat fresh cassava tubers. A study concerning availability and pricing of the proposed coating method is recommended.

 

       
Cassava (Manihot esculenta) roots

Contacts:

North:

Dr. Michael Beyrer
Prof. Food Process Engineering
University of Applied Sciences Western Switzerland
Route du Rawyl 47
CH-1950 Sion
E-Mail: michael.beyrer@hevs.ch

South:

Dr. Charlemagne NINDJIN
Senior lecturer, Biochemistry/Food Technology
University of Abobo-adjamé / Swiss Centre of Scientific Research (Côte d’Ivoire)
01 BP 801 Abidjan 01
E-Mail: charlemagne.nindjin@csrs.ci