Broadband acoustic resonance dissolution spectroscopy of natural edible salts: Visualization and interpretation for descriptive and diagnostic analysis

Broadband acoustic resonance dissolution spectroscopy (BARDS) has been recently introduced as a low-cost method for the analysis of powdered materials. In this study, ten Iranian natural table salts, each separated into five particle size fractions, were analyzed with BARDS. The compositions and crystalline structure of samples were investigated with inductively coupled plasma optical emission spectroscopy, flame photometry, and X-ray diffraction methods. Moreover, different linear and nonlinear dimensionality reduction methods were used to visualize the ten salt types. The analyses revealed the presence of halite, sylvite, and anhydrite in the rock salts, and halite, bischofite, and periclase in the sea salts. Subjecting bubble volume spectra to nonlinear dimensionality reduction using the t-distributed stochastic neighbor embedding algorithm, the salts were clearly distinguished in a two-dimensional space with the distances and positions relative to their composition, crystalline structure, and particle morphology. The results of this study provide a roadmap toward unraveling the underlying mechanisms behind the BARDS spectra for further applications in characterizing natural edible salts.