Structural and mechanical properties of native and modified cush-cush yam and cassava starch edible films

T. GUTIÉRREZ; M.S. TAPIA; C.J. PÉREZ; L. FAMÁ

FOOD HYDROCOLLOIDS

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2015 vol. 45 p. 211 - 217

0268-005X

Different hydrocolloids, such as starch, have been proposed as basic material (matrix) for edible films suitable for food packaging. In this work, edible films from native and modified starch and plasticized with glycerol were developed. Dark-cush-cush yam (Dioscorea trifida) and cassava (Manihot esculenta C.) starches used are from Venezuela. Chemical modification was made by cross-linking with sodium trimetaphosphate. Tensile uniaxial, microstructural and barrier properties of the films were investigated to determine their potential as replacement of existing synthetic materials used in the food industry. The structure of the materials showed that the gelatinization process of cush-cush yam films was poorer than that of cassava. Films conformed by the modified starches had greater glycerol-starch interaction (glycerol-amylose), which was more marked in the film with cassava. All starch-based films developed exhibited important mechanical properties resulting in the highest values of Young's modulus and resistivity for cush-cush yam films. Cassava films, and modified starch materials presented maximum flexibility, reinforcing the idea that these materials have better glycerol-starch interaction. Crosslinking films tended to increase water vapor permeability due to their hydrophilic characteristics. The important features observed in these biodegradable materials strengthen the idea for their use as packaging in the food industry, thus replacing synthetic materials that contaminate the environment.