An investigation into the application of konjac glucomannan as a flavor encapsulant

摘要

The application of konjac glucomannan (KGM) in flavor encapsulation in the spray-dry method was investigated in this paper using sweet orange oil as the model. KGM provided the highest encapsulation yield when the apparent viscosity of the KGM solution was reduced to 200 mPa S by cellulase hydrolysis. In the presence of emulsifier Tween 80, the hydrolyzed KGM offered comparable encapsulation yield with Arabic gum and starch sodium octenyl succinate (SSOS), but provided significantly higher encapsulation yield than maltodextrin. Besides, the combination of KGM with Arabic gum, SSOS, and maltodextrin, were also studied. The combination could significantly (P < 0.05) increase the encapsulation yield in the KGM content up to 80% compared with pure KGM; when the KGM content was reduced to 20%, the combination with maltodextrin resulted in a significant (P < 0.05) decrease in encapsulation yield, possibly due to the poor emulsifying capability of both KGM and maltodextrin. The effect of encapsulation on flavor composition was investigated by using the fingerprint technique and the vectorial angle method was adopted to assess the similarity between the chromatographs. The comparison showed that KGM had similar flavor retention with SSOS and Arabic gum, but provided a significant (P < 0.05) higher retention than maltodextrin. The encapsulated flavors exhibited few pores and smooth surface under TEM with the size ranging from 5 to 15 μm. It was concluded that KGM provided comparable flavor retention capability as the most widely used Arabic gum and SSOS and had great potential as a flavor encapsulant.