Fat reduction in chocolate: a multidisciplinary approach considering emulsion science and consumer expectations

Norton, Jennifer Elizabeth (2012). Fat reduction in chocolate: a multidisciplinary approach considering emulsion science and consumer expectations. University of Birmingham. Ph.D.

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Abstract

Chocolate is consumed in large quantities, but is high in fat and calories, and has limited nutritional benefits. Producing reduced-fat chocolate offers a way of reducing energy consumed, if the consumer will accept the product. The aims of the research presented in this thesis were: i) to investigate consumer response to reduced-fat chocolate; ii) to investigate formulation routes for producing a reduced fat chocolate.

Focus group data indicated ambivalence towards chocolate, with some negativity towards the concept of a reduced-fat indulgent product. By manipulating label information it was shown that whilst consumers expected to like chocolate labelled ‘reduced-fat’ less than the standard chocolate, ratings of actual liking and of sensory attributes were similar. Thus, personal experience plays a greater role than expectations. This suggests that if the sensory characteristics of a reduced-fat chocolate can be matched to a standard chocolate, actual liking should not be affected. Packaging concepts indicated how different components of the package affect liking.

Water in oil cocoa butter emulsions were produced using a high shear mixer and a margarine line. Formulation changes (emulsifier type and concentration, and gelatin concentration) and processing parameters (shaft speeds and temperatures, and flow rate) were considered. All emulsions had small droplets (typically 1-5μm) and little ‘free water’. When produced on the margarine line fat crystals in polymorphic form V were produced. Crystalline shells were also observed at the droplet interface. Pilot plant experiments resulted in comparable emulsions, with small droplets and fat crystals in form V. Although a full chocolate was not produced, the potential for margarine technology to produce a reduced-fat chocolate was demonstrated.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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