Preparation and characterization of puffed rice sticks produced via extrusion using indigo carmine-calcium carbonate lake

This study utilized the oriented crystal structure of calcium carbonate (CaCO 3 ) to develop indigo carmine (IC) lakes, specifically IC-amorphous calcium carbonate (IC-ACC), IC-vaterite, IC-calcite, and IC-aragonite lakes, as novel pigments for colored puffed rice sticks obtained via extrusion. The IC-CaCO 3 lakes exhibited superior blueness stability during storage compared to IC alone. The moisture content of the all samples was below 5.92 g/kg, while the IC-ACC and IC-vaterite lakes showed moisture levels similar to the blank group. Analysis of the sodium and calcium content showed that the use of lakes enabled the production of extruded puffed rice sticks with reduced sodium and added calcium. Textural assessment indicated that although IC-CaCO 3 lake addition increased hardness, they minimally affected brittleness and elasticity, with chewiness varying by lake type. Sensory evaluation showed that the samples with added lake yielded lower color scores than the IC group, with no significant differences from blank group regarding other attributes such as appearance, olfactory characteristics, texture, and impurities. GC-MS analysis revealed that the IC-ACC and IC-vaterite lakes preserved core flavors of puffed rice produced via extrusion, while also introducing new volatile compounds and enhancing the aroma diversity. E-nose and E-tongue evaluations confirmed that lake addition did not adversely impact the odor or taste profiles. IC-CaCO 3 lakes are viable IC substitutes since they improve blueness stability without compromising product quality. • Crystal structure of IC-CaCO 3 lake influenced properties of puffed rice sticks. • Replacement of IC with IC-CaCO 3 lake enhanced color stability of puffed rice stick. • No significant sensory differences were found between groups, except for color. • Complexity of volatile profile in IC, IC-ACC, and IC-vaterite groups enhanced. • E-nose/tongue proved IC-CaCO 3 lakes preserved inherent flavor profile of rice sticks.