Novel Microemulgel Based on Persian Gum Hydrochlorides Containing Garlic Essential Oil: Rheological, Mechanical, and Antimicrobial Properties and In Vitro Sustained Release Modeling

The research aimed to produce microemulsions loaded with garlic essential oil (5, 10, and 15% w/w) to improve the mechanical and antimicrobial properties of Persian gum and k-carrageenan-based microemulgels against food pathogens. Microemulsions loaded with 10% garlic essential oil had an average particle size of 88.59 ± 2.59 mm and an encapsulation efficiency of 95.61 ± 1.38%. Microemulsions loaded with 10% garlic essential oil with levels of 3, 5, and 7% were used in the structure of hydrogels. Using garlic essential oil microemulsion (up to 50%) in microemulgels structure led to an increase in viscosity and consistency index. The rheological data were well-fitted by the power law model, and all samples had pseudoplastic (shear-thinning) behavior. The mechanical properties of microemulgels were improved by using microemulsions, and a 5% microemulsion of garlic essential oil was associated with an increase in hardness, cohesiveness, and chewiness indices. FTIR analysis confirmed that garlic essential oil is well placed in the microemulsion structure, and microemulsions containing garlic essential oil will strengthen the mechanical properties of microemulgels by establishing hydrogen bonds with the hydrogel matrix. The modeling of the release of garlic essential oil in food simulants showed that the highest amount of release occurs in aqueous media, and the Peleg model is the best description of the release behavior of the essential oil from the structure of microemulgels. The dominant mechanism involved in the garlic essential oil release in the food simulants was the Fickian release mechanism. Staphylococcus aureus showed the highest sensitivity against microemulgels loaded with garlic essential oil.