Ageing of Starch Based Systems as Observed with FT-IR and Solid State NMR Spectroscopy

Abstract

The retrogradation and physical ageing of model starch systems with respect to their glass transition temperatures Tg have been investigated by Fourier transform infrared Spectroscopy and solid state NMR spectroscopy. Diffuse reflectance Fourier transform infrared (DRIFT) spectra demonstrate the commencing retrogradation of starch materials stored above their Tg by changes in peak lineshapes and intensities in the characteristic area between 995 cm−1 and 1020 cm−1. Solid state NMR proton relaxation times in the rotating frame (proton T1ρ) show a characteristic course in relation to the storage conditions (time, humidity), for which a distinction is made between physical ageing which occurs below the Tg, and recrystallisation (retrogradation) which takes place above Tg. The proton T1ρ's of materials stored below Tg increase asymptotically in time due to physical ageing, whereas the proton T1ρ's of materials stored above Tg increase until a moisture content is reached that rises them above Tg, decrease due to further water absorption and then increase due to recrystallisation (retrogradation).

Physicochemical, Rheological and Structural Characteristics of Starch in Maize Tortillas

“…FTIR Spectroscopy X-ray diffraction is a long-range technique and this information should be complemented with other methodologies such as FTIR spectroscopy, where the conformational changes at starch molecular level may be analyzed. In this technique, the bands at 1047 and 1022 cm −1 are characteristic of the crystalline and amorphous zones of the starch, respectively [22]. The band at 1040 cm −1 is related to the development of double helices that are formed in the early hours of storage of starchy products, while the band at 1053 cm −1 increases with longer storage times and is due to aggregation and crystallization of starch chains [23].…”

A novel size-exclusion high performance liquid chromatography (SE-HPLC) method for measuring degree of amylose retrogradation in rice starch

“…X-ray diffraction studies clearly showed that the development of crystallinity occurred in an aging starch gel . Nevertheless, the sensitivity of this method was too low to detect the minor extent of recrystallization during a rapid storage (Smits, Ruhnau, Vliegenthart, & van Soest, 1998). Differential scanning calorimetry (DSC) was apparently used for measuring retrogradation of starch and proved to be a valuable tool to quantify the crystallinity of amylopectin rather than amylose recrystallite since this recrystallite was transformed at much higher temperature (120-160°C), at which the pans would be leaked before the transition occurred (Eerlingen, Jacobs, & Delcour, 1994;Russell, 1987).…”

Analysis of Bioactive Olygosaccharide-Metal Complexes by Modern FTIR Spectroscopy: Copper Complexes

“…These findings also suggest that the band can be considered as characteristic for the type of Metal-Ligand links. The band at about 1042 and 1019 cm -1 found for polysaccharide in the spectra of RLMP and the complex were shown to relate to the crystalline and amorphous phases, respectively (Smits et al, 1998). The changes in intensity of these bands are strongly associated with the alterations in the macromolecular order.…”