Colour and roughness influence whole grain bread liking: Study

Lightening the colour of whole grain breads could make products more appealing to consumers who would otherwise be more inclined to buy refined wheat bread products, indicates a new study.

While the benefits of consuming whole grain products have been well-researched and communicated, consumer liking can be a major barrier to consumption. Researchers from the University of Minnesota in the US decided to investigate consumers’ bread preferences in a bid to understand sensory factors that could influence their inclination to buy whole grain goods.

People’s perception of tastes and textures varies wildly and can be down to the functioning of certain taste receptors. For instance, the functioning of the T2R38 taste receptor determines perception of bitter compounds like 6-n-propylthiouracil (PROP).

Whether people are non-PROP tasters, medium tasters or supertasters is thought to be linked to fungiform papillae density – the taste structures on the tongue that house taste cells and mechanoreceptors.

The study involved 78 participants, who were rated according to their PROP intensities, fungiform papillae densities, and preference for whole or refined wheat breads. The participants were then asked to rate their liking of bread samples that were manipulated to vary in bitterness, roughness, and darkness.

The bitterness of the bread was altered by the addition of wheat germ, while bleached bran provided roughness, and caramel colour provided a darker colour.

The researchers saw that overall the participants preferred a less bitter but more rough loaf. The preference for roughness was larger in those participants with a higher fungiform papillae densities, and larger for those that were less sensitive to PROP.

Contrary to expectations, however, PROP intensity and fungiform papillae densities did not seem to have a great part to play in bitterness preference – although those in the supertaster group did tend to show bigger differences in liking between breads with different wheat germ levels.

These findings indicate that rougher bread with less bitterness compounds are most likely to be well-received.

Colour code

As for colour, participants who said they preferred refined bread liked a lighter colour, whereas those who preferred whole wheat liked their bread dark.

The researchers said this finding, which was highly polarised, could present an opportunity for food manufacturers to lighten the colour of whole grain bread in order to attract a wider consumer base.

Source

Food Quality and Preference (online ahead of print)

DOI: 10.1016/j/foodqual.2010.11.006

Effects of bitterness, roughness, PROP taster status and fungiform papillae density on bread acceptance

Authors: Bakke, A; Vickers, Z