Carbohydrate Polymers 87 (2012) 1302–1310 Contents lists available at SciVerse ScienceDirect Carbohydrate Polymers j ourna l ho me pag e: www.elsevier.com/locate/carbpol Properties of baked foams based on cassava starch, sugarcane bagasse fibers and montmorillonite Ana E.S. Vercelheze a , Farayde M. Fakhouri b , Luiz H. Dall’Antônia c , Alexandre Urbano d , Elza Y. Youssef b , Fábio Yamashita b , Suzana Mali a,∗ a Department of Biochemistry and Biotechnology, CCE, State University of Londrina, PO BOX 6001, 86051-990, Londrina – PR, Brazil b Department of Food Science and Technology, CCA, State University of Londrina, Brazil c Department of Chemistry, CCE, State University of Londrina, Brazil d Department of Physics, CCE, State University of Londrina, Brazil a r t i c l e i n f o Article history: Received 2 June 2011 Received in revised form 25 August 2011 Accepted 6 September 2011 Available online 12 September 2011 Keywords: Biodegradable Packaging Trays Composites Nanocomposites a b s t r a c t The objectives of this work were to develop biodegradable trays from cassava starch, sugarcane fibers and Na-montmorillonite (Na-MMT) using a baking process and to study the effects of these components on the microstructure and physicochemical and mechanical properties of the trays. All formulations resulted in well-shaped trays with densities between 0.1941 and 0.2966 g/cm 3 . The addition of fibers and Na-MMT resulted in less dense and less rigid trays. As observed in the water sorption isotherms, the increase in the equilibrium moisture content was more pronounced when the samples were stored at RH (relative humidity) above 75%. The foams had high water absorption capacities (>50%) when immersed in water (1 min). The studied processing conditions resulted in good nanoclay dispersion, leading to the formation of an exfoliated structure. The trays developed in this study represent an alternative for the packaging of foods with low water contents. © 2011 Elsevier Ltd. All rights reserved. 1. Introduction The development of biodegradable packaging based on starch has attracted an increasing amount of attention; however, materi- als produced from this biopolymer have some problems, including poor mechanical properties and hydrophilicity. Water solubility increases the degradability and the speed of degradation; however, moisture sensitivity also limits the applications of the material. The use of composites and nanocomposites from these materials can also aid in the development of new low-cost products with better performances (Yu, Dean, & Li, 2006). Fiber-reinforced composites have been studied in various appli- cations and reviewed by many authors because they have excellent specific properties, such as high strength, low weight and good barrier properties. In that respect, natural fibers are generally inter- esting because they not only have the functional capability to substitute for the widely used glass fibers but also have advantages from the point of view of weight and fiber–matrix adhesion, specif- ically with polar matrix materials, such as biopolymeric matrices. These agro-based materials are abundant in nature and frequently are wastes from various industrial processes. For example, sugar- ∗ Corresponding author. Tel.: +55 43 3371 4270; fax: +55 43 3371 4054. E-mail address: smali@uel.br (S. Mali). cane bagasse fiber, which is a poorly valorized waste residue from the sugar and alcohol industries in Brazil, is often used as fuels in households or is sometimes burned in the fields as a means of dis- posal. Sugarcane bagasse fiber consists of about 40–50% cellulose (Satyanarayana, Arizaga, & Wypych, 2009; Sun, Sun, Zhao, & Sun, 2004). Nanocomposites are systems that contain fillers with at least one nanosized dimension and represent a new class of materials that exhibit improved mechanical, thermal, barrier and physic- ochemical properties compared with the starting polymers and conventional (microscale) composites. Although several nanoparti- cles have been recognized as possible additives to enhance polymer performance, most intensive studies are currently focused on layered silicates, such as montmorillonite (MMT), due to their availability, versatility, low cost and respectability towards the environment and health (Azeredo, 2009). The montmorillonite crystal lattice consists of 1-nm thin layers with an octahedral alumina sheet sandwiched between two tetrahedral silica sheets. The layers are negatively charged, and this charge is balanced by alkali cations, such as Na + , Li + or Ca 2+ , in the gallery space between the aluminosilicate lay- ers. Na-montmorillonite (Na-MMT) clay is hydrophilic with a high surface area and is miscible with hydrophilic polymers, such as starch (Ardakani, Mohseni, Beitollahi, Benvidi, & Naeimi, 2010; Ray & Okamoto, 2003). The properties of the resulting 0144-8617/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.carbpol.2011.09.016