DSC studies of retrogradation and amylose–lipid complex transition taking place in gamma irradiated wheat starch
✍ Scribed by K. Cieśla; A.C. Eliasson
- Publisher
- Elsevier Science
- Year
- 2007
- Tongue
- English
- Weight
- 337 KB
- Volume
- 265
- Category
- Article
- ISSN
- 0168-583X
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✦ Synopsis
The effect of gamma irradiation ( 60 Co) with doses of 5-30 kGy on the amylose-lipid complex transition and retrogradation occurring in gels containing ca. 50% and ca. 20% wheat starch was studied by differential scanning calorimetry (DSC) during heating-cooling-heating cycles (up to three cycles). Transition of the amylose-lipid complex occurs in all the irradiated samples at a lower temperature as compared to the non-irradiated starch. That effect was larger when the radiation dose was higher. A further thermal treatment causes a decrease of the transition temperature in the irradiated samples, with no effect or increase of that temperature observed for the nonirradiated ones. Irradiation hinders retrogradation taking place in 50% gels but facilitates the process occurring in 20% gels. The differences between the irradiated and the non-irradiated samples are more evident in the every next heating or cooling cycle as well as after storage and in the case of ca. 50% suspensions as compared to ca. 20% suspensions. The results point out to the deterioration of the structure of the complexes formed in the irradiated starch as compared to the non-irradiated one.