The review, published in Food Hydrocolloids, investigated the uses of inulin in dairy systems as a fat replacer, exploring how the soluble fibre ingredient can be used to replace fats by mimic the features such as mouth feel and creaminess – and how these effects may be related to changes in rheology of the food system in liquid, semi-solid and solid dairy products.
The reviewers said the inclusion of long-chain inulin in a dairy product as fat replacer “can have different effects on the rheological properties and on texture depending on the structure and composition of each product.”
“Understanding the underlying mechanisms inducing the behaviour of inulin as fat replacer is important to design and develop low-fat inulin-enriched products with good sensory quality,” said the reviewers, led by Sensus’ Diederick Meyer in the Netherlands.
“This type of information can also be useful to gain a better understanding of the effect of inulin on oral processing and breakdown of the structure of dairy products,” they added.
Inulin – a fructose-based oligosaccharide – is a type of soluble fibre found in onions, garlic, banana, and chicory roots. The fibre is being increasingly used in processed foods because due to its adaptable characteristics, which make it suitable to replace sugars, fats, and carbohydrates.
It is also reported to have several health benefits, including increasing calcium and magnesium absorption, in addition to having a prebiotic effect by promoting the growth of intestinal bacteria.
The authors noted that when inulin is added to food in low concentrations “the rheological properties and the sensory quality of the product will not be affected strongly.”
However, they noted that to make inulin-based dietary fibre claims, inulin should be added in amounts that range from three to six grams per 100 g or 100 ml, whilst between three and eight grams per portion must be added in order to assure a Bifidogenic effect.
Meyer and his CSIC colleagues noted that the product structure and the presence of other ingredients especially hydrocolloids, can modify the rate and the extent of inulin crystallisation and thus influence its functionality as fat replacer.
“It appears that the competition for moisture is a determining factor as they may determine whether starch can gelatinise completely or inulin can dissolve completely or form microcrystals or aggregates,” they said.
Meyer and colleagues concluded that the effect of inulin on rheological behaviour and on texture in different dairy products “clearly and not surprisingly not only depends on the concentration but also on the degree of polymerisation of the inulin.”
Source: Food Hydrocolloids
Published online ahead of print, doi: 10.1016/j.foodhyd.2011.04.012
“Inulin as texture modifier in dairy products”
Authors: D. Meyer, S. Bayarri, A. Tárrega, E. Costell