Solid lipid nanoparticles of mangosteen peel extract based on monoacylglycerol-diacylglycerol-rich fat and stearic acid: Study on physicochemical properties and encapsulation efficiency

Mangosteen peel (Garcinia mangostana L.) contains phenolics and high antioxidant activity, but encapsulation including solid lipid nanoparticles (SLN), is required to provide stability and a good delivery system. Therefore, this study aimed to determine the characteristics of SLN of mangosteen peel extract produced using the double emulsion method based on monoacylglycerol (MAG) and diacylglycerol (DAG)-rich fat from coconut stearin and stearic acid. The results showed that higher concentrations of MAG-DAG-rich fat led to smaller particle sizes and increased entrapment efficiency (EE). However, the application of higher mangosteen peel extract increased the particle size and decreased EE. The use of 40 % MAG-DAG-rich fat and 15 % mangosteen peel extract produced the best SLN characteristics, with EE of 97.73 ± 0.33 %, particle size of 373.00 ± 20.30 nm, polydispersity index (PI) of 1.52 ± 0.08, total flavonoid content of 3.19 ± 0.29 mg QE/g, and antioxidant activity (IC₅₀) of 235.12 ± 2.93 ppm. SLN showed spherulite-shaped particles, where mangosteen peel extract was trapped and dispersed in the nanosphere system. The preparation of SLN-mangosteen peel extract based on MAG-DAG-rich fat from coconut stearin and stearic acid effectively provided encapsulated bioactive compounds of mangosteen extract with good physicochemical properties.