Infrared spectra of pumpkin protein concentrate in comparison with wheat flour and prospects for its use in bakery products technology

Abstract

The research was carried out using the method of infrared spectroscopy in the near-infrared region. It was established that the spectrum of wheat flour had a lower reflection intensity than the spectrum of pumpkin protein concentrate. The first minimum of reflection intensity for wheat flour was at 1460 nm, and for pumpkin protein concentrate this extremum shifted to 1510 nm. The next extremum for both types of raw materials was at the same wavelength – 1650 nm, and the next minimum for pumpkin protein concentrate was at a wavelength of 1720 nm, which does not appear at all in the spectrum of wheat flour. This length is related to lipid components and indicates absorption of carbonyl esters of fats. Thus, this extremum was expressed for pumpkin protein concentrate, which is explained by the presence of more lipid components in this raw material than in wheat flour. The minimum moisture reflection characteristic lies at a wavelength of 1930 nm and indicates approximately the same moisture content in the studied raw materials. In the range of wavelengths from 2030 nm to 2100 nm, the spectrum of pumpkin protein concentrate showed several extrema that characterize the protein groups of the raw material with the maximum extremum at 2100 nm. This indicates the presence of a large amount of protein, that does not contain gluten proteins. The obtained results indicate a different composition of structural units of wheat flour compared to pumpkin protein concentrate, so it is possible to predict the influence of this raw material on the redistribution of the main structural units in bread and dough with it in the recipe as well as on the physical and chemical, structural and mechanical characteristics and quality indicators of bread.