Ingredient replacement in low fat mayonnaise: Going with the flow
Posted: 30 June 2015 | | No comments yet
We discuss the microstructure and some rheological aspects of commercial mayonnaises, ranging from a traditional mayonnaise to lower fat content mayonnaises and finally a low cost supermarket own brand mayonnaise…
Mayonnaise is a common and popular condiment, consumer acceptance of which, like most food products is primarily driven by flavour. However, other criteria including texture, ease of dispensing and spreadability are important. The product needs to flow out of the bottle with relative ease yet maintain its structure once dispensed. This functionality is determined by the rheological properties of the product, which are due to the interactions between ingredients at a macromolecular level and by the microstructure of the product.
Mayonnaise is an emulsion and consists primarily of water and a dispersed oil phase, traditionally consisting of olive oil, though other vegetable oils are also very common. As such, mayonnaise can be classed as a concentrated emulsion or a high internal phase emulsion and often as a soft solid. The oil droplets are usually stabilised by egg yolk derived amphiphiles, namely phospholipids such as lecithin. In particular, lecithin is a highly effective stabiliser, which prevents the emulsion from phase separating or splitting.
Global trends continue to see promotion of healthy lifestyles through regular exercise, balanced diet and avoidance of high calorie and fat content foods. Therefore, the drive towards ‘light’ food products has become a common theme with all food manufacturers providing products to an increasingly aware consumer population. Furthermore, the desire for higher profit margins stimulates efforts to reformulate food products using cheaper ingredients, which nonetheless maintain all the sensory characteristics of the original formula. To address these trends, mayonnaise recipes have moved to products with lower fat content. To maintain the texture and rheological properties of the ‘light’ products, water soluble polymers such as bean and bacterial derived guar and xanthan gum, respectively, are employed. When dissolved in water these polymers hydrate and form networks. The result is a high viscosity product at low concentrations of additive. The networks these ingredients form also share similar rheological characteristics to many foods, such as yield stress and shear thinning behaviour. As such, they are excellent alternatives to more expensive standard ingredients. In changing the ingredients, the formulator can dramatically change the microstructure of the product, but it has to exhibit similar sensorial attributes.
Here we discuss the microstructure and some rheological aspects of commercial mayonnaises, ranging from a traditional mayonnaise to lower fat content mayonnaises and finally a low cost supermarket own brand mayonnaise. To distinguish between the original and modified product, a closer look at the microstructure and its mechanical properties is required…