Trehalose boost fruity aroma in strawberry creams

The new research, published in the Journal of Food Engineering , reports that adding trehalose to strawberry cream, improvements in colour, aroma, and the anthocyanin content of the finished fillings.

"The biological importance of trehalose, a non-reducing disaccharide, is currently of much interest.

Because of its existence in organisms and bacteria, and its exceptional ability to create their dormant state under dry conditions, trehalose is currently being considered as a potentially beneficial food additive," wrote the authors from the Faculty of Food Technology (Osijek, Croatia) and the Biotechnical Faculty (Ljubljana, Slovenia).

"It was found that the addition of trehalose had positive effect on colour retention.

The retention of anthocyanin was also higher in both evaporated and freeze-dried samples, and the extent of retention was proportional to the amount of trehalose added," they added.

The researchers investigated the potential of trehalose at three different concentrations - three, five and ten per cent as a partial replacement of sucrose - to influence the quality of a strawberry cream filling.

They also used the freeze-drying technique as an alternative to the more common evaporation technique for the production of the cream fillings.

Lead author Mirela Kopjar and co-workers report that, in addition to improvements in colour and aroma levels, compared to the control cream filling, trehalose also had a positive effect on the levels of fruity esters.

Moreover, the level of trehalose addition was proportional to the increases observed in anthocyanin content, added the researchers.

"It can be concluded that aroma compounds retention depends not only on the process selected, but also on the structure of the aroma compounds.

The degree of retention depends on the complexity of the food matrix and interactions that can occur within it, especially in the presence of additives, in this case trehalose," wrote Kopjar.

Putting the results into context, the researchers stated: " Commercial strawberry cream fillings are normally prepared by evaporation and without adding trehalose, so its values of texture parameters were used as reference for the purpose of comparison.

"If the fillings are too hard, like the freeze-dried samples obtained in this work, it is very difficult to apply them on the base of product.

Also, if the fillings are too sticky, they adhere to the roller during application and additional problems can occur.

"[From our results] it can be seen that only evaporated samples with trehalose addition had lower values of stickiness index, which means that they were stickier than normally prepared samples, but this difference was not too pronounced."

This is not the first report of the aroma-boosting potential of trehalose.

Last year, researchers from the Faculty of Food Technology and Biotechnology at the University of Zagreb reported that the sugar could improve the aroma and quality of dried fruit ingredients.

Indeed, the Croatian researchers reported in the journal LWT - Food Science & Technology (doi: 10.1016/j.lwt.2006.12.011), that adding trehalose to dehydrated pear cubes could improve aroma retention by 15 per cent.

Source: Journal of Food Engineering Published online ahead of print, doi:10.1016/j.jfoodeng.2007.12.011 "Influence of trehalose addition and storage conditions on the quality of strawberry cream filling" Authors: M. Kopjar, V. Pilizota, J. Hribar, M. Simcic, E. Zlatic and N. Nedi Tiban