Review of the Sensory and Physico-Chemical Properties of Red and White Wheat: Which Makes the Best Whole Grain?

Establishing sensory and physico-chemical differences between products made from red and white wheat may guide the choice of wheat for use in whole grain and high fibre products. As sensory acceptance is key to consumption, this scoping review aimed to document sensory and physico-chemical research demonstrating quantitative differences in red and white wheat and the associated bran. The following databases were systematically searched following the PRISMA protocol: PubMed, Medline, Scopus, CINHAL and ScienceDirect (1990-2019). Of 16 studies, 13 were sensory studies with 529 participants (six of which included quantitative analysis) and three additional quantitative studies. Overall, 10 studies were in favour of white wheat (seven sensory studies, two focused on quantitative analysis and two with additional quantitative studies). Whole grain (wholemeal) bread, pita bread, crackers, noodles, tortillas, flour, intact grains and bran were examined. Aside from the seed coat colour, levels of bound versus free phenolic compounds and polyphenol oxidase activity appeared most responsible for the differences in red and white wheat. Ensuring the sample size for sensory studies are large enough to detect between-group preferences and linking to physico-chemical analysis are recommended. Attention to blinding techniques in sensory testing and use of food products realistically and consistently prepared with commercial potential are also suggested. This scoping review provides confidence in preference for white wheat for whole grain products, particularly for breads, tortillas and in the choice of white wheat for products suitable for the Asian market.