Corn and cassava starch with carboxymethyl cellulose films and its mechanical and hydrophobic properties.

Autor: Tavares KM; Postgraduate Program in Biomaterials Engineering (PPGBiomat), Federal University of Lavras (UFLA), Lavras, Minas Gerais, Brazil. Electronic address: mansurtavares@yahoo.com.br., Campos A; National Laboratory of Agribusiness Nanotechnology (LNNA), Embrapa Instrumentação, São Carlos, São Paulo, Brazil., Mitsuyuki MC; National Laboratory of Agribusiness Nanotechnology (LNNA), Embrapa Instrumentação, São Carlos, São Paulo, Brazil., Luchesi BR; Postgraduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos, São Paulo, Brazil., Marconcini JM; National Laboratory of Agribusiness Nanotechnology (LNNA), Embrapa Instrumentação, São Carlos, São Paulo, Brazil.
Jazyk: angličtina
Zdroj: Carbohydrate polymers [Carbohydr Polym] 2019 Nov 01; Vol. 223, pp. 115055. Date of Electronic Publication: 2019 Jul 20.
DOI: 10.1016/j.carbpol.2019.115055
Abstrakt: The amylose and amylopectin content of starch influences its functional characteristics and its interaction with other materials. Thus, it is important to study the mechanical strength and hydrophilicity of starch films of different botanical origins to elucidate the influence of their constituents in the interaction with carboxymethyl cellulose (CMC). The objective of this work was to evaluate the mechanical and physico-chemical properties of corn and cassava starch films and their blends with CMC by casting. The addition of CMC improved the tensile, increasing the strength at 206% for its blends with corn starch and 51% for its blends with cassava starch, the rupture stress at 89% and 74%, respectively, and the rupture strain at 381% and 57%, respectively. The elastic modulus presented increase of 20% for corn starch/CMC and 18% for cassava starch/CMC and the water vapor permeability at 48 and 40%, respectively. The corn starch film was more hydrophobic due to its higher amylose content, which contributed to the interaction between starch and glycerol OH groups and CMC COOH groups. This interaction was evidenced by FTIR and contact angle analysis, turning corn starch/CMC films into less hydrophilic material and reducing its water vapor permeability rate, which made this material promising for several applications, including food packaging.
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Databáze: MEDLINE
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