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Influence of Aging Time on the Structural Changes of Cassava Thermoplastic Starch

  • José H. Mina (a1), Alex Valadez (a2), Pedro J. Herrera-Franco (a2) and Tanit Toledano (a2)

Abstract

In this work the change in the structural properties of cassava (manihot sculenta Crantz) thermoplastic starch (TPS) under controlled environment (humidity and temperature) was studied. Fourier Transform Infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results showed an evident increasing in the amorphous phase of the TPS regarding the native starch. There was a relative decrease of the band at 1047 cm-1 associated to crystalline structure of starch compared to the amorphous peak at 1022 cm-1. The X-ray diffraction patterns confirmed the increment of the amorphous phase in the TPS samples. Likewise the X-ray diffraction patterns shows evidence of residual type C crystallinity and the formation of a new crystalline phase type VH due to the orientation induced in plasticization process. In first stage of conditioning the tensile yield stress drops from 7.5 drops to 0.5 MPa and the break strain increases 1000%. At the same time it seems that the crystallinity of the samples increases as was evidenced by the gradually increasing of the FTIR band at 1047 cm-1. In a second stage, the yield stress increases, the break strain drops and the crystallinity continue growing steadily. These findings suggest that coexist two phenomena simultaneously in the samples. A phenomenon of re-crystallization (retrogradation) that tends to make the material more stiff and a process of plasticization that tends to softening it. It seems that the latter mechanism predominates in the first stage, at short times, and the former in the second stage, at older times.

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1. Guan, J., Eskridge, K. and Hanna, M., Industrial Crops and Products 22, 109 (2004).
2. Huang, M., Yu, J. and Ma, X., Polymer Degradation and Stability 90, 501 (2005).
3. Villada, H., PhD. Thesis, Universidad del Valle (2005).
4. Lai, S., Don, T. and Huang, Y., Journal of Applied Polymer Science 100, 2371 (2006).
5. Nara, S. and Komiya, T., Starch/Stärke 35, 407 (1983).
6. Smits, A., Ruhnau, F., Vliegenthart, J. and Van Soest, J., Starch/Stärke 50, 478 (1998).
7. Rindlav, A., Hulleman, S. and Gatenholm, P., Carbohydrate Polymers 34, 25 (1997).
8. Van Soest, J., Hulleman, S., De Wit, D. and Vliegenthart, J., Industrial Crops and Products 5, 11 (1996).
9. Van Soest, J. and Knooren, N., Carbohydrate Polymers 29, 1411 (1996).
10. Wurzburg, O., Modified Starches: Properties and Uses (CRC Press, Boca Raton Florida, 2000) pp. 47.
11. Mina, J., Valadez, A., Herrera-Franco, P. and Toledano, T., Ingeniería y Competitividad 11, 95 (2009).
12. Mina, J., Valadez, A., Herrera-Franco, P., Zuluaga, F. and Delvasto, S., Dyna 78, 185 (2011).

Keywords

Influence of Aging Time on the Structural Changes of Cassava Thermoplastic Starch

  • José H. Mina (a1), Alex Valadez (a2), Pedro J. Herrera-Franco (a2) and Tanit Toledano (a2)

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