High moisture microwave treatment modulates functional and pasting characteristics of buckwheat flour

One of the pseudocereals, which could be used as a functional gluten-free alternative is buckwheat. Therefore, there is a considerable interest in buckwheat for the production of nutraceutical preparations; it is considered to have potential for “functional food” development as it can provide health benefits beyond basic nutrition. However, buckwheat is not only used to improve the nutritional profile of products, but also to improve their physical and sensory quality, especially in the gluten-free products. Buckwheat do not contain any gluten-type proteins, which results in serious technological problems in buckwheat-based bread manufacturing. Heat-moisture treatment (HMT) is used for improving of poor functional properties of native starch and is particularly favourable for food applications. Several studies have demonstrated that HMT significantly alters the molecular structure and physicochemical properties of chestnut, corn, rice, potato, and sorghum starches. The main objective of the study was to analyse the impact of microwave radiation in the conditions of preset initial moisture content at 20% and 30% and heated for 4 or 8 min in cycles of MW exposure/rest of 20/40 s for Polish and Spanish buckwheat varieties. The viscometric profiles of flours in correlation to techno-functional properties of hydration, and colour characteristic of flours were assessed. The important factor influencing the changes was initial moisture content. The more pronounced effects were observed for 30% of initial moisture and 8 min treatment. The peak and final viscosities were lowered. Heating resulted in changes in pigmenting by lowering luminosity and hue and increasing chroma.