摘要：

The technique of Fourier transform infrared (FTIR) spectroscopy, in conjunction with new methods of sample presentation, has been used to study biopolymer functionality in aqueous systems. Changes in the spectra of kappa-carrageenan gels have been observed with both counter-ion and temperature. Most of these differences arise from conformational changes of the polysaccharide backbone, but there is also evidence of direct ion-sulphate interaction in certain ion forms, consistent with previous NMR results. An assignment of the region 1400-800 cm(-1) has been made for the carrageenan gels. In waxy maize and wheat starch gels, changes in the IR spectra are observed during storage. Some of these can be related to the development of crystallinity in the material. The time course of the observed FTIR measurements during retrogradation of waxy maize starch is very similar to those produced from other techniques, such as shear modulus. This process can also be in wheat starch gels and the possibility that it can be measured in real foodstuffs is demonstrated by the fact that the same techniques could be used to acquire a high-quality spectrum of bread.

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