The study – published inFood Hydrocolloids – investigated the effects of altering the distribution of fat on the perception of sensory attributes, finding a significant enhancement of mouth feel attributes in gels with an uneven (inhomogeneous) distribution of fat throughout the product.
“Inhomogeneous samples with large differences in fat content between layers were perceived more spreadable and melting than the sample in which fat was homogeneously distributed,” noted the authors, led by Dr Markus Stieger of Wageningen University and TI Food and Nutrition, the Netherlands.
They reported that inhomogeneous samples with large differences in fat content between layers had higher intensity ratings of mouth feel and after feel attributes than homogeneous samples at the same overall fat content.
As a result Stieger and his team suggested “that the modulation of the spatial distribution of fat can be used to reduce the fat content of food products without causing undesirable changes in the sensory properties.”
The researchers noted that the excessive consumption of fat has been linked to the increased risk of several health problems, including obesity and cardiovascular diseases.
“As a consequence, there is an increasing demand for low-fat products in an attempt to decrease fat intake,” said Stieger and his team.
“Given that the reduction of fat usually causes undesirable changes in the properties of foods, the development of low-fat products remains a challenge for food manufacturers,”
The effect of fat content – including the size, concentration and distribution of fat – on the mechanical and sensory properties foods has been suggested to play an important role in consumer liking, they noted.
“Therefore, a successful fat reduction strategy should not cause prominent changes in the physical-chemical and sensorial properties of the low-fat product,” said Stieger.
The researchers used a model system made up of layered agar and gelatin gels – containing an oil-in-water emulsion droplets dispersed in the gel matrix. The team used four layers of gel, varying in the amount of emulsion droplets in each, to prepare samples with homogeneous and inhomogeneous distributions of fat – in the form of emulsion droplets.
Using a Quantitative Descriptive Analysis (QDA) panel, the team assessed the sensory attributes of the different gel samples.
Stieger and his colleagues, noted that the position of the high-fat layers in the sample affected the perception of fat-related attributes. They reported that ‘creaminess’ ratings tended to increase as the difference in fat content between layers increased in the inhomogeneous samples.
“The sample with high-fat layers on the outside had the highest ratings for all mouth feel and after feel attributes,” said the researchers.
The team concluded that modification of the distribution of fat in a gel based food system could be of use in reducing fat content in food products – without altering important sensory properties of such foods.
Source: Food Hydrocolloids
Published online ahead of print, doi: 10.1016/j.foodhyd.2011.11.002
“Inhomogeneous distribution of fat enhances the perception of fat-related sensory attributes in gelled foods”
Authors: A.C. Mosca, J.A. Rocha, G. Sala, F. van de Velde, M. Stieger