Impact of Salts Mixtures on the Physicochemical and Sensory Characteristics of Spanish-Style Manzanilla Green Table Olives during Packaging.

Using response surface methodology (RSM), this study investigates the effect of NaCl substitution (50%) with KCl, CaCl 2 , and MgCl 2 in the packaging brines (controlled variables) on the characteristics (responses) of plain green Spanish-style Manzanilla olives, maintaining the salt-mixture level of 5%. The RSM showed that the increment of CaCl 2 caused a linear significant ( p -value ≤ 0.05) decrease in pH and a linear increase in firmness (instrumental), hardness (panel scores), and crunchiness . The models for bitterness and fibrousness also included quadratic (CaCl 2 ·MgCl 2 ) and cubic (the three salt) interactions, which led to areas of minimum and maximum scores around the central points of the CaCl 2 -MgCl 2 and KCl-MgCl 2 axes, respectively. In contrast, the increase in the KCl level linearly decreased bitterness scores. Optimisation resulted in a relatively low desirability (0.57) and the selection of a combination that may necessitate further refinement, such as increasing KCl or reducing CaCl 2 levels, especially for markets sensitive to bitterness . Interestingly, the overall score and buying predisposition positively correlate with salty , smell , acid , and appearance and negatively with bitterness . Furthermore, PLS-R analysis found that the pivotal attributes influencing overall appreciation were smell and crunchiness while buying predisposition was promoted by crunchiness . Conversely, bitterness had a detrimental impact on these appreciations. Cluster analysis grouped the experimental runs into four categories, with sensory profiles predominantly diverging in bitterness , salty , and kinesthetic characteristics. Ultimately, this study elucidates four distinct sensory profiles that consumers experience.