Fortification of chocolate bars by solid lipid nanoparticles of ferrous sulfate based on stearic acid and fat rich in monoacylglycerol and diacylglycerol from coconut stearin: study of physicochemical properties and sensory acceptability

Abstract

ABSTRACT Iron fortification in the form of ferrous sulfate is associated with several disadvantages, particularly related to the unpleasant after-taste. In this context, ferrous sulfate must be encapsulated by forming solid lipid nanoparticles (SLNs), which can be applied to fat-based foods such as chocolate bar. Therefore, this study aimed to provide chocolate bar fortified by SLN-ferrous sulfate with good physicochemical characteristics and sensory acceptability. The process was carried out by providing fats rich in monoacylglycerol (MAG) and diacylglycerol (DAG) from coconut stearin as a lipid matrix and emulsifier, fabricating SLN-ferrous sulfate, and fortifying SLN-ferrous sulfate in the chocolate bar at 0% (control), 2.5%, 5%, and 7.5%. The results showed that the fortification significantly affected texture, color, iron content, and sensory acceptability. The addition of SLN-ferrous sulfate of 2.5% produced chocolate bar with good physicochemical properties, which were preferred by the panelists. The chocolate bar contained iron reaching 79.23 mg/kg, a small spherulitic crystal microstructure, dominated by stable β-crystals, and no fat bloom was formed. Furthermore, SLN-ferrous sulfate based on fats rich in MAG and DAG from coconut stearin was compatible with good characteristics.