To create new knowledge in the area of pigment stability in raw and processed purple wheat. Such information is essential in processing purple wheat. The project will also result in the delivery of improved anthocyanin-pigmented wheat based on anthocyanin composition and stability.
The spring wheat cultivar CDC Primepurple is considered a good source of anthocyanin pigments. The pigments are more stable in the bran matrix compared to a solubilized form when subjected to heat treatments at various pH values. The purple wheat pigments are more stable at a pH of 1. At a high temperature (e.g. 90 oC) the pigments could undergo thermal degradation resulting in a drop in their content and intensity. There was a reduction in anthocyanins during bread-making or muffin-making processes. Despite the loss of anthocyanins during the baking process, up to 38%, bread and muffin products made from purple wheat, particularly those made from bran-enriched formulas, had high anthocyanin levels. These products could be used to improve the daily consumption of anthocyanins and polyphenols. Currently there is no recommended daily intake of anthocyanins or polyphenols but the consumption of 3 servings of these products per day could provide about 7.8-9.5 mg anthocyanins per day with a serving size of 50 mg. Addition of phenolic acids such as ferulic acid or natural polyphonic extracts (e.g. resveratrol) to anthocyanin extracts from purple wheat or to pure anthocyanins (e.g. cyanidin-3-glucoside) solutions was found to improve stability and DPPH radical scavenging capacity during storage at ambient temperature. This suggests that co-pigmentation could be used as a new approach to improve stability of purple wheat products. The total anthocyanin content of purple pericarp wheat lines differed in expression and stability over growing environments. The cultivar CDC Primepurple was intermediate in terms of stability of anthocyanin expression. A majority of the purple wheat germplasm in advanced stages of testing had a soft kernel and lower flour yield. The baking quality was, on average, similar to that of the CPSR wheat cultivar AC Crystal. Future breeding efforts should focus on the selection of cultivars with improved milling and baking properties.