Encapsulation of allyl sulfide with middle-chain triglyceride oil and cyclodextrin by spray drying

Abstract

Volatile sulfur compounds are very important in the contribution or sensory analysis of flavors in many foods. The molecular inclusion of flavor in cyclodextrin (CD) is one technique to protect against the degradation of labile flavor. Encapsulation of diluted allyl sulfide in middle-chain triglyceride (MCT) oil with cyclodextrin as a wall material was investigated using a spray dryer. A carrier solution was prepared by dissolving α-, β-, or γ-CD in distilled water. Allyl sulfide (10,000 ppm) in an MCT and CD solution was homogenized and incubated at 30℃ for 8 h. This incubated solution was spray dried in a mini spray dryer. Spray-dried powder containing allyl sulfide was obtained with an allyl sulfide content of 0.78 mg/g CD for α-CD, 0.17 for β-CD, and 0.63 for γ-CD at an inlet air temperature of 200℃. The content of allyl sulfide in the powder was affected by the concentration of allyl sulfide in the MCT oil and the content of MCT oil in the feed solution. The inlet air temperature did not affect the content of allyl sulfide in the CD powder. The incubation of allyl sulfide in the MCT oil and CD solution formed an inclusion complex of allyl sulfide in the CD powder. It was also shown that the lettuces under supercooled conditions keep the initial state of the water and sugar contents by reducing the respiration rate, and that the risk of foodborne illness is improved by keeping the number of the bacteria in low level even after the supercooled storages for three weeks.