Comparative study of instrumental properties and sensory profiling of low-calorie chocolate containing hydrophobically modified inulin. Part II: Proton mobility, topological, tribological and dynamic sensory properties

Abstract

The aim of the present work was to evaluate the changes in instrumental measurements and dynamic sensory properties of chocolate as affected by the partial and total substitution of sucrose by dodecenyl-succinylated inulin upon storage. The results of textural, surface topology, and tribological properties of non-stored chocolates were found to be a function of modified inulin replacement, where an increase in modified inulin ratio allowed an increase in hardness, roughness, and friction coefficient. Compared to non-stored samples, the deterioration of textural properties after storage was inhibited in chocolate containing higher levels of modified inulin. Higher modified inulin ratios did not also induce an important change in NMR proton mobility, roughness, and friction coefficient upon storage. Confocal Raman microscopy revealed modified inulin located around sucrose and cocoa particles dispersed in fat phase, especially at the higher ratios. Temporal Dominance of Sensations (TDS) curves of non-stored samples elucidated that firmness was a dominant perception at the beginning of mastication, followed by melting rate, while cocoa flavor was experienced at the end of evaluation. However, these attributes were not perceived in stored chocolate with the lowest modified inulin. A PCA was performed to compare TDS scores and instrumental readings, showing a high correlation between instrumental measurement of hardness, friction coefficient, and NMR relaxation times and TDS score of firmness, bitterness, astringency, and melting rate. This work shows a new perspective to use biopolymeric surfactant for producing low-calorie chocolate, considering that hydrophobically modified inulin can diminish production costs and facilitate low-calorie product development.