Innovative technological applications of plant-based ingredients

Concerns regarding climate change and the increasing of the world population have grown the demand for sustainable, healthier, and ethical food products. As a consequence, the market of animal-based food shifts towards plant-based products. The substitution of meat involves using plant protein ingredients, and among the crops, legumes have been identified as one of the most promising protein sources. Wet fractionation is the most commonly applied technology for obtaining protein and starch ingredients. Compared to the wet process, dry fractionation is a more efficient alternative that saves chemicals, energy and water. Indeed, dry fractionation involves a combination of milling and dry separation, through air classification or tribo-electric separation of starch and proteins. Dry-fractionated ingredients are characterized by lower purity than wet-fractionated ones, since dry fractionation allows to separate a fine fraction richer in proteins from a coarse fraction enriched in starch. The latter is often considered a co-product of protein production, destined to feed industry. Being a solvent-free technology, dry fractionation can retain the native structure and functionality of macromolecules, making it advantageous for tailoring the ingredients in food development. In this doctoral thesis the technological properties of dry-fractionated ingredients and their applications in innovative food products were explored. Those activities are related to the mission M2C1 of Italian PNRR “Sustainable agriculture and circular economy” and the 12 Goal established by the 2030 United Nations’ Agenda “Responsible consumption and production”. Activities begin with an in-depth study of techno-functional properties of dry-fractionated ingredients. Information was collected from the available literature and converted into an overview of the best application in food products, based on the properties of the dry fractionated ingredients (Chapter 1). Indeed, dry-fractionated ingredients have some peculiar properties linked to their native preserved structure that could help in tailoring food products. Then, in order to clearly establish a difference between dry and wet fractionated proteins, a comparison of their techno-functional, rheological and chemical properties was carried out (Chapter 2). Those properties were explored in real, innovative food products, specifically a sponge cake with a dry-fractionated egg-replacer (Chapter 3), which was submitted to rheological, textural and sensory characterization. The main objective was to explore the suitability of dry-fractionated protein-rich fractions from lentil, chickpea and mung bean to be used as egg replacer. The effect of species and concentration on the cake properties was evaluated. Dry fractionation technology could also be suitable for valorising food by-products, such as the defatted cake generated during the extraction of the oily fraction from durum wheat (Triticum turgidum L. var. durum) bran and germ. Indeed dry-fractionated durum wheat cake protein was explored to produce a snack bar rich in protein and fibers (Chapter 4). Chapter 5 describes the use of the same by-product, in combination with pea protein isolate, in the production of texturized vegetable protein (TVP) using a low-moisture extrusion-cooking process. TVPs are generally applied in meat alternative products. To complete these studies, considering that the dry-fractionated starch-rich fraction is still underutilized, its use in plant-based jelly candies has been explored, taking advantage of the gelling ability of starch (Chapter 6).