Drying Kinetics of Biofilms Obtained from Chestnut Starch and Carrageenan with and without Glycerol

• Type: Article in International Scientific Journal
• Date: 2011

Authors

R. Moreira (Author) FEUP; F. Chenlo (Author) FEUP; M.D. Torres (Author) FEUP; C. Silva (Author) Other; D.M. Prieto (Author) FEUP; A. M.M. Sousa (Author) FEUP; L. Hilliou (Author) FEUP; M. P. Gonçalves (Author) FEUP

Journal

Title: Drying Technology

Vol. 29

Pages: 1058-1065

ISSN: 0737-3937

Publisher: Taylor & Francis

Indexing

ISI Web of Knowledge - 16 Citations

ISI Web of Science

Scopus - 30 Citations

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

Other information

Authenticus ID: P-002-XA1

DOI: 10.1080/07373937.2011.563000

Abstract (EN): Drying kinetics of biofilms from chestnut starch and hybrid carrageenan were experimentally determined and modelled. The biofilms were obtained by mixing the respective solutions (4.0% w/w) of both substances in the proportion 80/20 of chestnut starch/hybrid carrageenan. Glycerol (at 5.0% w/w) was added to some biofilms. Biofilms were prepared using a casting method. Drying kinetics were performed at 30, 40, and 50 degrees C for forced air convection (1.8 +/- 0.1 m/s) and 30 and 50 degrees C for natural convection. Constant drying rate period, above critical moisture content (5.4 and 4.2 kg water/kg d.b. without and with glycerol, respectively) allowed the evaluation of the heat transfer coefficients. The water diffusion coefficients were determined in the falling rate period assuming a semi-infinite slab with variable thickness. Water sorption isotherms of biofilms at 25 degrees C were determined and fitted with the GAB model. Mechanical properties of different biofilms showed no significant differences for Young's modulus values (44.0 +/- 4.6 MPa). Nevertheless, films prepared at 30 degrees C under natural drying showed the lowest values of tensile strength and elongation (32.2 +/- 4.9MPa and 0.85 +/- 0.11%).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8