Estratégias de processamento e revalorização de matériasprimas alimentares para a produção de ingredientes funcionais e sustentáveis

Abstract

A considerable volume of agro-industrial by-products are produced daily from North to South of Brazil. Fruit by-products, consisting mainly of skins, seeds, and residual pulp, constitute up to 50% of the initial weight of the fruit. Although it has been demonstrated that fruit by-products are valuable sources of residual phytochemicals with potential applications in the food industry, there are only few products in the market made from this abundant raw material, especially in developing countries like Brazil. According to The Food and Agriculture Organization (FAO), innovation is a valuable tool against hunger and malnutrition, and this includes not only the development of new technologies, but also the rational use of existing products and procedures. Thus, this PhD dissertation demonstrates strategies for the revalorization of underexplored food materials to produce plant-based ingredients, that were assessed regarding their physicochemical, functional, and bioactive properties, polyphenol bioaccessibility, and environmental viability. Specifically, extraction protocols designed to obtain aqueous polyphenol-rich extracts recovered from tropical fruit residues (acerola and jambolan) using conventional (solid-liquid extraction) and emerging (ultrasound) techniques were evaluated performance-wise. In addition, the environmental viability of each one of the extraction methods was evaluated by the LCA tool. Furthermore, the production of proteinpolyphenol food ingredients was carried out by spray drying using different strategies: a) polyphenols recovered from American elderberry residue and juice encapsulated with soy protein isolate (SPI) and tapioca starch (TS) and b) polyphenols extracted from rosemary leaves or recovered from muscadine grape residue using a novel insect protein or a mixture of insect protein and pea protein isolate as drying carriers. The UAES protocol (Ultrasound Assisted Extraction and Stirring) after 90 min showed the highest total polyphenol content, and the LCA revealed that the UAES had the lowest environmental impact among all extraction protocols. For elderberry particles, those produced with SPI had greater solubility and flowability, as well as higher bioaccessibility, while those with TS had higher levels of bioactive compounds (total phenolics, anthocyanins and proanthocyanidin). The insect protein-polyphenol particles showed good functional characteristics and the best spray drying performance were observed when insect protein and pea protein blend was used while rosemary-derived particles were more bioaccessible. This work addresses issues of great interest worldwide in food science and technology and unveils important scientific results for the advance of alternative foods processing, new raw materials and repurposing of food waste. Furthermore, new applications for bioaccessible food ingredients with desirable functional properties using environmentally friendly approaches are shown here.