Physicochemical characteristics as the markers in predicting the self-life of gluten-free cookies

The objective of this study was to investigate the effect of different storage conditions on physicochemical stability assessment of gluten-free rice-buckwheat cookies. Second order polynomial (SOP) models were developed to explore the effects of storage time (0-6 months), at ambient (23 ± 1 °C) and elevated (40 ± 1 °C) temperature, packaging condition (packed and unpacked samples), and cookie surface position on the level of water activity (aw), hydroxymethylfurfural content, peak force, and colour parameters (L*, a*, b*, h*, C*, ΔE*). The chemical characteristics of cookies were influenced by temperature, while the colour properties were mostly influenced by the position of the sample surface. The firmness was affected upon the synergy effect of temperature and packaging condition. The performance of the developed SOP models was to investigate the effect of storage conditions on the observed parameters, which showed a good fit to the experimental (r2 > 0.8). The obtained results demonstrated that the developed empirical models gave an appropriate fit to experimental data and predicted the physicochemical properties at a satisfactory level, and that they could be successfully implemented to cookie stability assessment.