Dry fractionation as a tool to sustainably innovate the legume value chain and support the valorization of marginal areas.

Factors that negatively affect the legume supply in European Union involve the low productivity gains and the high variability of economic returns (Ferreira et al., 2021), which makes farmers not motivated to cultivate legumes. The development of legume-based ingredients such as protein concentrates, may promote the legume market expansion in the European Union and it is an object of different EU research calls. In fact, EU does not sufficiently produce legumes to meet the increasing demand of plant-proteins (Ferreira et al., 2021). From this perspective, simple and sustainable methods of protein production must be implemented. Dry fractionation is the most sustainable technology for protein extraction (Lie-Piang et al., 2023), as it is based on physical processes, e.g., a cyclonic fractionation or an electrostatic separation of a finely milled flour into two fractions mainly containing i) large starch granules and/ or non-protein components; and ii) protein bodies, without any use of water or chemicals (De Angelis et al., 2021). We suggest that dry fractionation might also be a strategy to valorize the neglected and underutilized grains, facing the problems related to the loss of the genetic resources and of the biodiversity. In fact, neglected and minor grains are well adapted to local environments, require low input for their growth and they tolerate stresses in a way that they can be grown in marginal lands. This is a relevant and modern objective of the Italian scientific community which aims at the development of marginal areas enhancing agroecological and socio-economic sustainability (https://agritechcentre. it/). This would also promote the protein diversification and increase the self-sufficiency of protein production. The aim of this contribute is to review the use of the dry fractionation to produce legume-based ingredients, highlighting its versatility from the perspective of promoting the valorization of minor and neglected legumes. The bibliographic research was carried out considering studied published in the last 10 years, using Scopus and Web of Science scientific databases, including keywords e.g., “dry fractionation”, “legumes”, “ingredients”, “protein”, and their combinations. A total of 89 articles, composed of 16 reviews and 73 research papers were collected. The number of research articles concerning the application of the dry fractionation has increased over the years, with more applications on legumes compared to cereals and other crops. Moreover, the majority of the studies are focused on pea and faba bean and pea (Figure 1). However, a total of 10 different legume crops have been studied, confirming the versatility of the dry fractionation process and its potential in supporting the valorization of the minor crops. Overall, the protein obtained with dry fractionation are characterized by peculiar functional properties, including a high protein solubility, high foaming ability and foam stability, high gelling ability. Such properties have been exploited in the formulation of different food, such as bakery products, pasta, as well as other innovative food products such as meat and dairy analogues. In conclusion, our review highlight as the dry-fractionated protein needs to be improved, from the perspective of promoting the utilization of a wider range of plant materials. Moreover, the presence of antinutrient compounds and the intense sensory profile characterized by legume notes appear to be the most relevant factors to overcome.