Preparation and properties of thermal responsive 2,3-diethyl-5-methylpyrazine fragrance microcapsules with β-CD/CS as wall materials

Int J Biol Macromol. 2024 Nov 19;283(Pt 3):137853. doi: 10.1016/j.ijbiomac.2024.137853. Online ahead of print.

Abstract

2,3-Diethyl-5-methylpyrazine (DEMP) is recognized for its unique nutty scent but faces limitations due to rapid evaporation. The primary objective of this study was to explore the effect of incorporating DEMP with β-cyclodextrin (β-CD) and chitosan (CS) as wall material on the microstructure and thermal release behavior, antibacterial, and antioxidant characteristics. Initially, the microcapsules preparation process underwent optimization with embedding rate of 78.03 % through response surface by ultrasonic technique. The characterization of microcapsules was confirmed through SEM, FT-IR and TEM, with the majority exhibiting smooth and shell core structures that overlapped. Through sustained release kinetics analysis, the release of microcapsules under 80 °C, 50 °C and room temperature was more in line with the first-order kinetic and Avrami kinetic equation. The heat release kinetics analysis yielded a well-matched linear fitting curve. Additionally, microcapsules effectively suppressed the growth of S. aureus and E. coli germs, and demonstrated strong antioxidant properties, compared with DEMP. Adding 10 mg microcapsules to the Heat Not Burning (HNB) cigarette, the sensory quality was significantly improved. This discovery has the potential to pave a new route for the encapsulation of fragrance molecules, and expanding their multifunctional usages for enhancing the flavor of cigarettes and food.

Keywords: Thermal responsiveness; Ultrasound method; β-CD/CS.