Abstract

In this research, garlic essential oil (GEO) was microencapsulated by spray drying, and the use of the encapsulated powder in Nem chua Hue (a traditional fermented pork product) was studied. The experiments were carried out with three parameters: carrier types (α-cyclodextrin, γ-cyclodextrin, maltodextrin–α-cyclodextrin, and a maltodextrin–γ- cyclodextrin [MD–γ-CD]), added GEO 2–8% (w/w), and spray drying temperature 160–180°C. The formulation having 5% (w/w) GEO and a MD–γ-CD carrier with spray-dried temperature of 170°C gave the highest encapsulation efficiency and encapsulation yield of 91.86% and 80.53%, respectively. Fourier-transform infrared, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy analyzes confirmed the formation of an inclusion complex and showed a good structural stability of the microcapsules. The release behavior at humidity levels of 6–98% RH and temperature from 30 to 100°C fitted closely with the Avrami model (n ≈ 0.30–0.44). When adding 0.01–0.02% (w/w) microencapsulated GEO into Nem chua Hue, the total aerobic count and total yeast and mold were significantly reduced, while lactic acid bacteria maintained at an appropriate level to support the fermentation process. There was also slowed acidification and increased product firmness. The 0.015% level could provide the best balance between sensory quality and microbiological safety. Its shelf-life was extended by at least 2 days. The MD–γ-CD is effective for controlled release and potential for meat product preservation.

Key words: Garlic essential oil, Microencapsulation, Spray drying, Cyclodextrin, Controlled release, Shelf-life extension, Nem Chua Hue