Encapsulation of L-carvone for burst release in chewing gum application

Delarue, Juliette Marie Caroline (2021). Encapsulation of L-carvone for burst release in chewing gum application. University of Birmingham. Ph.D.

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Abstract

It was desired to use microencapsulation to extend the perception of a spearmint flavour (L-carvone) in chewing gum products by providing a flavour burst delivery.
Core-shell capsules were first synthesised by complex coacervation using gum arabic in combination with chitosan. The stability of the emulsion was investigated by experimental design. It was identified that the best conditions were achieved for a polymer ratio of 6:1 (w/w), using highly concentrated gum arabic (12 wt%), without emulsifier, mixed at 3000 rpm, with a coacervation pH of 3.6, and using physical crosslinking (sodium tripolyphosphate).
The obtained capsules were further coated with an extra layer of gum arabic/chitosan 6:1 (w/w) by spray coating/drying. The final capsules with double coating were characterised by SEM, size distribution, UV-Vis and micromanipulation techniques to assess their mechanical stability. The capsules were finally incorporated in a chewing gum matrix and their release profile was quantified by UV measurements.
Capsules with different mechanical properties can have the potential to produce different bursting profiles, and release flavour at different times. It was proposed that zeta potential measurements should be used in association with turbidity measurements in order to efficiently identify the mixing polymer ratio and optimum coacervation pH for new polymer combinations. The use of corn starch combined with chitosan 3:2 (w/w) at pH 5.2 was identified as a promising alternative.
It is thought that this work offers a useful insight to understand better the critical steps which can influence the complex coacervation process. The proposed methodology of systematically using zeta potential measurements in association with turbidity measurements for investigating new polymer combinations for use in the complex coacervation process can be very beneficial for future work in the food industry as well as in other industrial fields, as it can reduce the necessity for time consuming trials.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):