RHEOLOGICAL CHARACTERISTICS OF EXTRUDATES FROM CORN SEMOLINA ENRICHED WITH TAPIOCA FLOUR

Apostol Simitchiev; Mariya Dushkova; Nesho Toshkov; Georgi Dobrev; Anna Koleva; Ventsislav Nenov

doi:10.9755/ejfa.2016-03-230

Authors

Apostol Simitchiev University of Food Technology, Department of Machines and Apparatus For Food Industry, Plovdiv, Bulgaria
Mariya Dushkova University of Food Technology, Department of Process Engineering, Plovdiv, Bulgaria
Nesho Toshkov University of Food Technology, Department of Process Engineering, Plovdiv, Bulgaria
Georgi Dobrev University of Food Technology, Department of Biochemistry and Molecular Biology, Plovdiv, Bulgaria
Anna Koleva University of Food Technology, Department of Technology of cereal, bread and confectionary products, Plovdiv, Bulgaria
Ventsislav Nenov University of Food Technology, Department of Machines and Apparatus For Food Industry, Plovdiv, Bulgaria

DOI:

https://doi.org/10.9755/ejfa.2016-03-230

Keywords:

Corn, Rheology, Tapioca, Viscosity

Abstract

The rheological characteristics of extrudates from corn semolina and mixture of corn semolina and tapioca flour were examined by rotational viscometer "Brookfield” RV-DV II + Pro. A non-linear relationship between the shear stress and the shear rate was established. The model of Ostwald–de Waele was applied and flow and consistency indexes were calculated and used to analyse the rheological behavior of the tested samples. The change of the effective viscosity as a function of the shear rate, depending on the moisture of the mixture, temperature and tapioca content was studied. In this study the addition of tapioca flour to corn semolina increased the viscosity of the extrudates by 60 %. The results suggest that tapioca flour influence the rheological properties of food products and can be used as a thickening additive to various kinds of food.