Browsing by Author "Castro, Maria Leonor"
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- Bromelain-catalyzed hydrolysis of fish and poultry by-products: a sustainable approach to biopeptide productionPublication . Borges, Sandra; Ribas, Tânia C. F.; Castro, Maria Leonor; Campos, Débora; Mota, Maria João; Almeida, André; Pintado, ManuelaThis study aimed to develop bioactive protein hydrolysates from fish and poultry by-products using bromelain, an enzyme obtained from pineapple by-products, with potential applications in food and biotechnology. The global rise in protein-rich food consumption has led to increased generation of animal by-products from the meat and fish industries. These by-products are rich in protein, making them suitable for producing bioactive compounds. A multifactorial design was employed to optimize the hydrolysis process, evaluating key parameters such as enzyme-to-substrate (E/S) ratio and hydrolysis time. The optimal conditions were identified as 1.3 % (E/ S) for 240 min for fish by-products, and 2.0 % (E/S) for 180 min for poultry by-products. These conditions were scaled up to produce fish (FH) and poultry (PH) hydrolysates. The hydrolysates showed high protein content (70.8 ± 0.1 % for FH and 56.3 ± 1.0 % for PH), potent antioxidant activity (ORAC: 249.02 ± 4.71 µmol eq. Trolox/g for FH and 144.41 ± 11.62 µmol eq. Trolox/g for PH), and notable ACE inhibitory effects (IC₅₀: 693 ± 12 µg protein/mL for FH and 1585 ± 6 µg protein/mL for PH). Furthermore, hydrolysates promoted probiotic strains’ growth, with 1 % (w/v) FH or PH showing comparable performance to conventional culture media in supporting Lactobacillus casei 01 (p > 0.05). These results highlight the potential of bromelain-derived hydrolysates as sustainable, cost-effective alternatives to traditional nitrogen sources in functional fermented food or microbiological culture media. This study contributes to value creation from agro-industrial by-products and aligns with global sustainability initiatives by promoting circular bioeconomy approaches.
- Elevating skincare science: grape seed extract encapsulation for dermatological carePublication . Castro, Maria Leonor; Azevedo-Silva, João; Valente, Diana; Machado, Adriana; Ribeiro, Tânia; Ferreira, João Paulo; Pintado, Manuela; Ramos, Oscar L.; Borges, Sandra; Baptista-Silva, SaraThe skin is the largest organ in the human body and serves multiple functions such as barrier protection and thermoregulation. The maintenance of its integrity and healthy structure is of paramount importance. Accordingly, technological advances in cosmetic sciences have been directed towards optimizing these factors. Plant-derived ingredients have been explored for their bioactivity profiles and sustainable sources. Grape by-products contain a group of bioactive molecules that display important biological activities. Nonetheless, many of these molecules (e.g., phenolic compounds) are unstable and susceptible to degradation. So, their encapsulation using nano/microsystems (i.e., microdispersions) has been explored as a promising solution. In this work, two grape seed extracts were obtained, one from a single grape variety (GSE-Ov) and another from a mix of five grape varieties (GSE-Sv). These extracts were analysed for their antioxidant and antimicrobial activities, as well as their chemical composition and molecular structure. The extract that showed the most promising properties was GSE-Ov with a DPPH IC50 of 0.079 mg mL−1. This extract was encapsulated in soy lecithin microdispersions coated with pectin, with an encapsulation efficiency of 88.8%. They showed an in vitro release of polyphenols of 59.4% during 24 h. The particles displayed a zeta potential of −20.3 mV and an average diameter of 13.6 µm. Microdispersions proved to be safe under 5 and 2.5 mg mL−1 in HaCaT and HDF cell models, respectively. Additionally, they demonstrated anti-inflammatory activity against IL-1α when tested at 2 mg mL−1. This work enabled the valorisation of a by-product from the wine industry by using natural extracts in skincare products.
- Endowed polyphenols in advanced delivery systems for vaginal infectionsPublication . Apolinário, Eduardo; Castro, Maria Leonor; Pintado, Manuela; Ferreira, João Paulo; Baptista-Silva, Sara; Borges, SandraVaginal infections (VIs) are the result of the nefarious vaginal polymicrobial universe (i.e., Gardnerella vaginalis, Prevotella spp., Staphylococcus spp., Candida albicans, etc.), the inhabitants of which multiply and infect the surface of the vaginal epithelium, which serves as a scaffold for the adhesion of pathogenic poly-complexes with interactive abilities. VIs affect over 1 billion women per year and have a stunning annual relapse rate of 30%. These conditions impact women’s quality of life and fertility and cause oncogenic Human Papillomavirus (HPV) persistence. VIs are typically treated with oral (i.e., Flagyl®) and localized drug tablets and creams/gels (i.e., Clindesse®), with potential leakage from the vaginal tract upon administration leading to the failure of the treatment. This study intends to highlight polyphenols as potential therapeutic agents in terms of their benefits and limitations and suggest strategies to increase their effectiveness. Polyphenols are natural compounds rich in phenolic structures which have an impact on this type of pathology and deserve the utmost attention from researchers. Natural polyphenols have several advantages: renewability, biodegradability, low environmental impact, biocompatibility, application versatility, bioactive properties, and the potential for sustainable applications. These compounds, formulated in advanced delivery systems, may natively exhibit antioxidant, anti-inflammatory, and antimicrobial activities. The main objective of this review is to highlight the importance of researching new and effective formulations to prevent and treat VIs based on natural, controlled, and sustainable systems.
- Grape by-products in sustainable cosmetics: nanoencapsulation and market trendsPublication . Castro, Maria Leonor; Ferreira, João Paulo; Pintado, Manuela; Ramos, Oscar L.; Borges, Sandra; Baptista-Silva, SaraThe largest human organ, the skin, serves a variety of essential functions including protection, preservation of water and electrolytes, regulation of body temperature, and fat storage. Its maintenance and preservation are supported by cosmetic products, whose functions include cleaning, protection, and modulation. The market for these products is predicted to increase from 100.13 billion USD in 2021 to 145.82 billion USD in 2028. Recently, it has been suggested that grape by-products (totalling 14.5 million tons per year just in Europe) has a great potential to be used in the creation of new cosmetic products. In this regard, this article aims to provide a comprehensive overview of the current state of knowledge regarding the bioactive compounds in grape pomace, the advantages of applying them to the skin, and the main cosmetic products already on the market incorporating these bioactives. Most of these compounds are derived from the Vitis vinifera L. species, and exhibit several biological properties, such as antioxidant, antimicrobial, anti-inflammatory, inhibition of skin degrading enzymes, protection from UVA damage, increased cell viability, and skin whitening effect. On the other hand, nanoencapsulation techniques can provide a significant improvement in the stability of grape-derived bioactive compounds, in particular of resveratrol, and this issue is also addressed in a critical manner in this review.