The use of whey protein microparticles and dietary fibre could help manufacturers replace fat in reduced calorie emulsion-based foods, say researchers.
Published in Food Research International, the new study investigated the potential of using microparticulated whey protein (MWP) in combination with either modified starch or locust bean gum (LBG) as fat mimetics to produce reduced calorie emulsion-based sauces and dressings.
Led by senior researcher David Julian McClements from the University of Massachusetts and in partnership with researchers from ConAgra Foods, the team behind the study noted that recent demand for reduced calorie foods has resulted in many low calorie versions of food products being available in the market - for example, sauces, salad dressings, yogurts, ice cream, milk and others.
“However, many of these low calorie products lack the complex sensory properties experienced in the conventional versions,” they said. “In view of this, the food industry is continually trying to improve product formulations by using alternative ingredients and processing methods.”
The new study showed that reduced calorie food emulsions with an appearance and consistency similar to those of commercial full fat products can be formulated using MWP in combination with polysaccharides.
McClements and his colleagues investigated the influence of food matrix composition (including the use of protein, polysaccharide, and fat content) on the properties of thermally processed model emulsions.
Model systems containing MWP (2.5, 5.0 or 7.5%) with either modified starch (3.75%) or locust bean gum (LBG) (1%) and with or without fat droplets (5%) were formulated.
In all systems, increasing the MWP concentration led to an increase in apparent viscosity, which was attributed to an increase in the effective volume fraction of the dispersed phase, said the team.
“All systems containing MWP had creamy whitish appearances with relatively high lightness (L*) values, which is an advantage for their application in products supposed to have a creamy appearance,” revealed the authors.
The addition of a relatively low concentration of fat droplets (5%) further increased the lightness of the systems due to enhanced light scattering, they said – noting that the further addition of starch granules or locust bean gum to the MWP suspensions increased their viscosity, leading to mixtures with similar consistencies as commercial sauces, dressings, or dips.
“Overall, the appearance and rheological properties of the mixed systems were similar to commercial sauces and dressings,” the team said.
Furthermore, the addition of calcium or pH adjustment had little effect on the physicochemical properties of the mixed systems, which was attributed to the fact that the protein in the MWP was already denatured, they added.
“This may be an advantage during product development as variations in salt and pH levels would cause fewer challenges,” wrote McClements and his team.
Source: Food Research International
Published online ahead of print, doi: 10.1016/j.foodres.2014.07.034
“Reduced Calorie Emulsion-based Foods: Protein Microparticles and Dietary Fiber as Fat Replacers”
Authors: Cheryl Chung, Brian Degner, David Julian McClements