Dry fractionation and bioprocessing for novel legume ingredients

PhD defended by Qinhui Xing at Wageningen University on 9 February 2021

Conventional ingredient manufacturing processes from legumes rely on wet separation processes to obtain purified ingredients. Drawback of these processes is that they consume copious amounts of energy and water and have often a detrimental effect to the native functionality of components. Dry fractionation relies on the combination of dry milling and dry separation methods such as air classification and electrostatic separation. As no water is used, this route is much more energy efficient and components are retained in their native state. Dry-enriched legume ingredients or specifically protein concentrates can be applied directly in product manufacturing. However, it needs further processed to enhance ingredient functionality and/or nutritional value. This could done in different ways by using either physical treatment or fermentation. During physical treatment or bioprocessing proteins will be cleaved into peptides which promotes digestibility and allergens can be reduced or even beneficial components such as antioxidants may be formed. The preference would be to apply a step that requires relative little water and still provides the before-mentioned advantages. Finally, the ultimate value of a novel ingredient should be demonstrated in a product. This is either completely new products or may be partial replacement of an existing recipe with the novel ingredient.

Project aim: To deliver novel functional and healthy legume ingredients and foods that have added value. Specifically, (a) optimisation of dry fractionation, to seek for a good balance between purity and yield; (b) to investigate to what extent fermentation can be used to enhance the functional and nutritional properties of selected legume flours; (c) to demonstrate and indicate the potential use and application of enriched and bioprocessed fractions in food preparation; (d) to direct the development of the novel dry process.