Browsing by Author "Cabral, Lourdes M.C."
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- Fortification of coconut water with microencapsulated grape pomace extract towards a novel electrolyte beverage: biological, sensorial and quality aspectsPublication . Costa, Joana R.; Monteiro, Maria João; Tonon, Renata V.; Cabral, Lourdes M.C.; Pastrana, Lorenzo; Pintado, Manuela E.A bioactive grape pomace extract (GPE) rich in polyphenols was encapsulated into alginate (GPE-Alg) or chitosan (GPE-CS) microparticles, later incorporated into coconut water. Biological and sensory properties were evaluated. Storage was performed at 4 ˚C followed by quality assessment. Evaluation of coconut water after gastrointestinal digestion on the growth pathogens and probiotic bacteria showed that the fortification with GPE-Alg and GPE-CS decreased the growth rate of pathogens when compared to non-fortified water, while promoted the growth of different bifidobacteria and lactobacilli strains. Sensory analysis allowed to conclude that the incorporation of GPE-Alg and GPE-CS did not promote significant differences in most of evaluated attributes, including aroma and flavor. The storage at 4 ˚C allowed a reduced degradation rate of total phenolics and anthocyanins for GPE-Alg and GPE-CS fortified beverage, with the half-life time of phenolic acids higher for GPE-Alg beverage and the half-life time of anthocyanins higher for GPE-CS fortified water. This study opens the opportunity in the application of food by-products in the development of novel efficient functional foods and beverages.
- Polymeric nanoparticles as oral delivery systems for a grape pomace extract towards the improvement of biological activitiesPublication . Costa, Joana R.; Xavier, Miguel; Amado, Isabel R.; Gonçalves, Catarina; Castro, Pedro M.; Tonon, Renata V.; Cabral, Lourdes M.C.; Pastrana, Lorenzo; Pintado, Manuela E.Grape pomace (GP) is a major by-product from the wine industry, known for its bioactive compounds and their impact upon gastrointestinal (GI) health. However, bioaccessibility is often poor due to their degradation during digestion. This work aimed to encapsulate bioactive GP extract (GPE) into chitosan (CS) and alginate (Alg) nanoparticles (NPs) to mitigate degradation in the GI tract. Alg and CS NPs were optimized using a rotatable central composite design and NPs were characterized for their size, polydispersity, zeta potential and total phenolics (TP) association efficiency. The best formulations showed sizes ranging 523–853 nm, polydispersity indexes of 0.11–0.36, zeta potential of −15.0–14.9 mV and TP association efficiencies of 68 and 65%. FTIR confirmed that there was no formation of new chemical groups after association of the polymers with GPE. Both formulations improved the bioaccessibility of different phenolics following in vitro GI digestion, leading to in-creased antioxidant and antimicrobial activities. Moreover, the permeability of bioactive compounds through a Caco-2/HT29-MTX co-culture was reduced, suggesting a higher residence time in the intestine. Cy5.5 was used for tracking the CS NPs, which did not affect the metabolic activity of Caco-2 and HT29-MTX cells. Confocal microscopy images confirmed the adsorption of NPs to the cellular layer and suggested a reduction of the tight junction protein occludin when cells were incubated with Cy5.5-CS in solution. This study suggests that encapsulation of GPE can offer protection against along the GI tract and improve its biological activity with significant impact for oral delivery applications, including functional foods.