Meeting current consumer needs, food makers are currently looking to low fat foods, (and equally those with an 'indulgent' feel), to feed bottom line growth.
Indeed, the total value of the low-fat/low-sugar food market in the UK, for example, rose by an estimated 5.3 per cent in 2002, lower than the 8.6 per cent growth pitched in 2001 but nonetheless relatively strong.
But swapping fat for protein or carbohydrates has a knock-on effect, particularly for flavour, and therefore acceptance, of the new healthier product.
"The presence of proteins in flavoured low-fat food products causes a great challenge for flavour scientists because many proteins are able to bind several flavour compounds tightly and influence the perceived aroma profile significantly," explained lead reviewer Janina Kuhn from the Riddet Centre, Massey University in New Zealand.
The new review, published in the Journal of Food Science (Vol. 71, pp. R72-R81), a publication of the Institute of Food Technologists (IFT), states that taking full advantage of this growing sector is dependent on a better understanding of the science behind protein-flavour interactions.
"In fat-reduced or "light" foods the dominant components are carbohydrates or proteins, which interact differently with aroma compounds compared with fat, and thus change the perceived flavour," said Kuhn.
The current problems arise from the different interaction between proteins and flavours and fats and flavours. Research to date has mostly focused on model systems using one protein and one aroma compound in a solution.
However, "food systems are much more complex, consisting of several food matrix components and flavor mixtures. Thus, further research on these complex systems is becoming increasingly important."
And the reviewers map out the way forward for flavour scientists by underlining the key areas of focus in future.
Research should target the expansion of understanding of the physicochemical interactions between aromas and proteins with the goal to make the product acceptable to the consumers sense of taste and aroma.
This has been a short-fall so far, suggest the reviewers, "because instrumental flavour-binding studies do not show if and how bound flavour is perceived during consumption."
This can be done by expanding the current techniques of solid-phase microextraction (SPME) and nuclear magnetic resonance (NMR): "SPME is fast, solvent-free, and very sensitive. The main advantages of NMR techniques are speed and insight into binding mechanisms and binding topology."
By following such fundamental approaches it is envisaged that significant improvements in the delivery of flavours from low-fat products can be achieved similar to those obtained from the normal high-fat product.
"The studies on milk proteins are of great importance because milk proteins are utilized in numerous food products, including dairy products, bakery and confectionary products, and meat products," stressed Kuhn.