Spectral study of heat treatment process of wheat flour by VIS/SW-NIR image system

• Wheat flour was treated with heat at 80, 100, 130 °C for 10, 20 and 30 min.
• Reflectance spectra of treated flours were obtained by SW-NIR imaging analyses.
• Pattern differentiation according to treatments intensity was noted for spectral data.
• Cakes were processed and modifications in cake features were noted.
• Relationship between cake features and spectral data were observed.

The capability of the VIS/SW-NIR (visible/short wave near infrared) hyperspectral imaging system to characterize the heat treatment process of cake wheat flour was studied. Combinations of heat treatments of flour were run at different temperatures (80, 100 and 130 °C) and for various times (10, 20 and 30 min). The resulting treated flours were analyzed by the imaging technique. The hyperspectral results, studied by multivariate statistical methods, showed a pattern evolution of the flours treated by different heat treatments. The wavelengths that contributed the most, and implied in the differentiations, were detected. The selection of wavelengths allowed us to optimize the analysis, which reduced from 54 to 6 wavelengths. To ensure that the VIS/SW-NIR information depended on the heat treatment influence on flours, cakes were produced and characterized according to height, mass loss during the baking process, crumb structure and textural properties. The VIS/SW-NIR imaging analysis was capable of following the changes that occurred during the different heat treatments of flours. VIS/SW-NIR was applied to determine and adjust the heat treatment process variables to improve the features of flours during the cake production process.