Structure design for perception of sweetness in food gels

Licentiate thesis, 2008

The production of foods with reduced sugar contents is desired and asked for. However, when reducing the sugar concentration, sweetness and structure and texture properties are altered. There is thus a need for a deeper understanding of the complex relations between a food’s structure, texture and taste. The use of structure design for control of sweetness intensity was utilized in this work for two different model systems; pectin and gelatin. By mixing low-methoxyl (LM) and high-methoxyl (HM) pectins in different ratios and with 30% sugar it is possible to build gels with controlled rheological properties. The sweetness intensity tended to be enhanced when the LM/HM pectin ratio, and G´, increased, due to higher diffusion. Perceived glueyness and thickness increased with pectin concentration. Higher HM/LM pectin ratios increased the glueyness and higher LM pectin proportions increased the thickness. When producing gelatin gels with the sugar unevenly distributed throughout the structure, the perception of sweetness was enhanced in a layered gels compared to a homogeneous gel with the same total mean sugar concentration (9%). The gel layers had similar rheology (G´ and G´´), and the differently layered gels were perceived as equally hard. For the homogeneous samples, hardness decreased and the pieces during breakdown became smaller when the sugar concentration increased, probably due to a lower total gelatin concentration and higher viscosities in the water phase of these gels.