Sensitivity analysis of regression models of physicochemical and rheological properties of kashk containing flaxseed extract

In this study, the effect of different amounts of flaxseed extract (0, 2.5, 5, 7.5, 10, 12.5 and 15%) on the physicochemical and rheological properties of kashk was investigated Then, in order to better understand the effect of flaxseed extract on the evaluated properties, Sensitivity Analysis (SA) of selected regression models was performed. The results of analysis of variance showed that the effect of flaxseed extract concentration on moisture, fat, protein, pH and solubility of kashk samples was significant so that according to the results of sensitivity analysis for each one percent increase in flaxseed extract about 4.38% moisture, 11.82% fat and 0.78% pH of the samples increased. Also, for each increase of one percent of flaxseed extract, about 7.01% of protein and 2.72% of solubility of samples were reduced. Therefore, according to the results of sensitivity analysis, fat had the highest sensitivity and pH the lowest sensitivity compared to physicochemical properties to changes in flaxseed extract. Also, the results of analysis of variance of the samples showed that the effect of flaxseed extract concentration on all parameters of Herschel model (flow behavior index, consistency coefficient and yield stress) was significant So for each one percent increase in flaxseed extract about 9% consistency coefficient and 11.82% fat and 9.03% the yield stress of the samples increased.