Advanced processes for extraction and enzymatic hydrolysis of flavonoids and tannins from fruit waste: yield, purification and bioactivity

• Grant number: 24/22824-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: September 01, 2025
• End date: February 28, 2029
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Engineering
• Principal Investigator: Maurício Ariel Rostagno
• Grantee: Isadora Lopes de Oliveira
• Host Institution: Faculdade de Ciências Aplicadas (FCA). Universidade Estadual de Campinas (UNICAMP). Limeira , SP, Brazil

Abstract

Flavonoids are natural compounds found in plant-based foods that are known for their antioxidant, anti-inflammatory, and anticancer properties. Grape and apple pomace, rich in flavonoids such as catechins and quercetin, offer potential health benefits, includingcardiovascular disease prevention and neuroprotective effects. However, these compounds are naturally associated with sugars, forming tannin structures in grape pomace and glycosidic structures in apple pomace. In the case of apple pomace, glycosylated flavanols, such as rutin and other quercetin glycosides, can be hydrolyzed to release the aglycones bybreaking the bonds with the sugars. In grape pomace, the enzymatic action of tanase can promote the hydrolysis of tannins, releasing flavanols, such as catechins. These hydrolysisprocesses can improve the bioavailability of flavonoids and, consequently, enhance theirbeneficial effects on health. In this sense, this study aims to develop an efficient process forthe extraction of flavonoids from grape and apple pomace and to promote simultaneous deglycosylation of them using the enzymes ¿-glucosidase and tanase, in order to optimize the obtaining of bioactive substances. The study aims to propose new extraction methods, combining the use of ¿-glucosidase and tanase enzymes, with advanced extraction techniques, such as ultrasound-assisted extraction (UAE), extraction using pressurizedliquids (PLE) and expansion gas-assisted extraction (GXE). After determining the best conditions for extraction and hydrolysis, a study of the solid phase extraction (SPE) will be carried out in order to concentrate the extract in flavonoids, removing sugars present in the extract. The concentrated extracts will be applied in commercial milk and analyzed when the bioavailability of flavonoids, antioxidant capacities and sensory analysis The extraction and separation methods will be developed in the two-dimensional system of extraction, separation and analysis, proposed by the FAPESP project (18/14582-5). In addition, it isproposed to carry out part of this project at the Instituto de Investigación Vitivinícola y Agroalimentaria (IVAGRO) - Universidad de Cádiz, under the supervision of Professor Gerardo Fernandez Barbero, who has extensive experience in analytical chemistry of waste and by-products of the food industry. Thus, the results of this thesis aim to value the biomass generated in large quantities by the juice, wine and cider industries, transforming them into products of high added value and with greater bioactive potential.