Hello,

For many spectra my go to is usually https://spectra.chem.ut.ee/ , and you might be more interested in https://spectra.chem.ut.ee/paint/binders/ which leads to https://spectra.chem.ut.ee/paint/binders/starch/ the ATR-IR spectrum of starch.

All the best,

Pól

Suitable papers on FTIR of starch-glucose mixtures could not be readily found. [In fact, I found the paper by Bartosova et al. on FTIR of starch hydrolysates (attached) not very clear: for example, the labels in their Fig. 5 do not correspond to the scale of the horizontal axis.] If you do not succeed in finding some well comparable spectra of starch, glucose, and SHS (starch hydrolysis products) in the literature and you want to stick to FTIR, you have no other choice than doing some calibration experiments by yourself, preferably in the dry state.

1. A few commercial starches (at comparable water content) to establish whether botanical origin has an effect on FTIR-spectra (only slight effects are expected).

2. Some selected starch hydrolysis products (SHP), like pure glucose and SHP of various DE (= dextrose equivalent), looking for characteristic bands, i.e. for reducing end groups not occurring in starch.

3. A range of synthetic mixtures of starch + glucose and starch + SHP, and looking whether calculated DE from FTIR correspond to DE from reducing sugar analysis.

If so, FTIR can be used as a reliable tool to assess whether you are dealing with pure starch or with partially degraded starch. Please note that FTIR is not sensitive at low degrees of hydrolysis.

Altogether, for assessing starch degradation, I would rather recommend to rely on wet chemical analytical assays like those for DE, glucose content, or iodine binding.