White wheat has emerged as the top performer for both flavour and functionality in wholegrain food production.
This is the finding of a review published as a feature paper in the scientific journal Foods by the Grains & Legumes Nutrition Council (GLNC).
As sensory acceptance of wholegrains is an important factor influencing consumption, the GLNC team focused on analysing current scientific literature to identify the sensory differences between red and white wheats for making wholegrain and high-fibre foods.
Of the research examining the suitability of red and white wheats for inclusion in wholegrain and high-fibre foods, the review analysed 16 studies. This included 13 sensory studies, and the remainder were quantitative analysis studies.
White wheat preference
The analysis showed a predominant preference for white wheat in 10 of these studies.
Another three studies showed a preference for red wheat and preferences in the rest of the studies were neutral, or difficult to determine.
Individual studies looked at a broad range of grain food categories, such as wholegrain breads, crackers, noodles, tortillas, flour, intact grains and bran.
Seed coat colour was identified as the main difference between red and white wheats. But there were also variations observed in bran colour - which can influence the colour of refined flour.
The research found that polyphenol oxidase activity was responsible for the differences in refined flour colour, with white wheat less likely to cause 'browning' of flour in products, such as noodles. This is an important consideration in Asian markets.
Despite the colour differences in seed coat and refined flour, the analysis showed that red and white wheat grains are nutritionally almost identical, with only minor differences between micronutrient content (iron, zinc, phosphorus and potassium).
In terms of sensory perception, however, 'bound' versus 'free' phenolic compounds were found to be variable in white and red wheats.
For example, the analysis showed white wheat was higher in bound phenolic compounds. This may contribute to its perceived sweeter taste.
Bound phenolics are also beneficial because they can survive digestion in the upper digestive tract and, when they subsequently reach the colon, they are released by intestinal microflora - providing bowel health benefits.
Consumer behaviour changes
In Australia and internationally, changes to consumer behaviour to help increase wholegrain consumption requires a range of tactics, such as:
- the manufacture of appealing products;
- clear product labelling; and
- communication highlighting dietary benefits.
This is particularly important in countries where refined grain intake is the status quo and white bread and white rice are staple products.
The variety of wheat used for making wholegrain products is also a pertinent consideration because white wheat tastes less bitter than red wheat.
Studies in this review showed that even children could perceive these taste differences.
Promotion of the beneficial attributes that characterise white wheat is encouraged in Australian domestic and international grain markets because it is the main type of wheat grown Australia-wide - and wholegrain market demand has increased globally.
To read the full paper, visit the GLNC website