Loading...
55 results
Search Results
Now showing 1 - 10 of 55
- Feromonas: comunicação por meios químicosPublication . Brenhas, Maria José; Silva, Carla Sousa eFeromonas são sinais químicos produzidos por um organismo que, mesmo em pequenas quantidades, influenciam o comportamento ou a fisiologia de outros indivíduos da mesma espécie. Teoricamente, todos os organismos libertam feromonas, que têm grande importância a nível da atracção sexual, mas são os insectos que utilizam estes mensageiros químicos como principal forma de comunicação. As feromonas são compostos orgânicos, geralmente voláteis e hidrofóbicos, que podem ser simples hidrocarbonetos ou incluírem grupos funcionais como álcoois, aldeídos, cetonas, entre outros. Pheromones are chemical signals produced by an organism that, even in small quantities, can elicit a behavioural or physiological response in another individual of the same species. In theory, every living organism release pheromones, with great impact in sexual attraction, but these chemical signals have special emphasis on insects, as the chief communication method. Pheromones are organic compounds, usually volatile and hydrophobic, that can be relatively simple hydrocarbons or compounds that include functional groups, such as alcohols, aldehydes, ketones, and so on.
- Nutraceuticals based on portuguese grape pomaces as a potential additive in food productsPublication . Ferreira da Vinha, Ana; Silva, Carla Sousa e; Sousa, Gonçalo de Magalhães e; Moutinho, Carla; Brenha, João; Sampaio, RicardoPortuguese wine industry by-products are often undervalued but constitute a potential source of bioactive phenoliccompounds that can be applied as a natural additive in several industries. In this context, the present study aimed to evaluate the nutritional composition, and the phenolic profile of two Portuguese Vitis vinifera L. grape pomaces (Touriga Nacional (red variety) and Alvarinho (white variety), and to correlate their chemical characterizations with their antioxidant activities. Strong correlations were observed between the presence of phenolic compounds and antioxidant activities, which enhances the application of pomace extracts in food and pharmaceutical areas. The high content of total phenolic compounds (25 - 41 g/ kg dry extract) and of flavonoids (9.2 - 18 g/ kg dry extract) found in both samples make these pomaces excellent candidates as food additives in food products, as well as antioxidant agents, such as natural dyes. Some polyphenols were identified by High Performance Liquid Chromatography (HPLC), being rutin and catequin the highest compounds found in red grape pomace (Touriga Nacional) while quercetin was only quantified in white grape pomace (Alvarinho). Cis-resveratrol was quantified in both grape pomace, which opens horizons for its use since this compound has considerable chemopreventive effects in the three main gains of carcinogenesis. As expected, the anthocyanin content was significantly higher in red grape pomace (37 g/ kg dry extract), emphasizing its interest as a natural food additive. Based on the findings, it is possible to conclude that these by-products have additional value, making them potentially useful in the food, pharmaceutical, and cosmetic industries.
- Fishing industry by-products: further applications in food, pharmaceutical and cosmetic industriesPublication . Ferreira da Vinha, Ana; Barbosa, Joana; Silva, Carla Sousa eThe agro-food industries, including the fishing industry, annually produce large quantities of by-products, whose valuation is still minimal or practical null. Currently, it is known that only a small part is reused for direct animals feeding or for composting. Considering that these by-products contain important levels of nutrients and bioactive compounds, some alternative ways of using by-products from the fishing industry are mentioned, namely for pharmaceutical and cosmetic industries. Nevertheless, the importance of sustainability must be taken in consideration, once it is an overly complex concept that involves economic and social development, without causing major damage to the environment. Biotechnology advances for marine by-products conversion into products of interest are numerous. Despite this, the fish sector is facing several issues such as wild fish stocks reduction while, at the same time, aquaculture rises, augmentation of the importations on a global market, and consumers behaviors. All those influent parameters affect and complicate the definition of an upgrading strategy for the by-products as they directly depend to the raw material processed. In view of the importance that the fishing industry has at international level, this work has attempted to characterize and enhance the by-products generated by this activity, through a detailed description of the nutritional, chemical and biological properties presented in fisheries waste, which can benefit, in the near future, the food, pharmaceutical and cosmetic industries.
- High-value compounds in papaya by-products (Carica papaya L. var. Formosa and Aliança): potential sustainable use and exploitationPublication . Ferreira da Vinha, Ana; S.G.Costa, Anabela; Espírito Santo, Liliana; Ferreira, Diana Melo; Silva, Carla Sousa e; Pinto, E.; Almeida, Agostinho; Oliveira, M. Beatriz P.P.Background: Food waste is a global and growing problem that is gaining traction due to its environmental, ethical, social, and economic repercussions. Between 2022 and 2027, the worldwide papaya market is expected to have a huge increase, meaning a growth in organic waste, including peels and seeds. Thus, this study evaluated the potential use of peels and seeds of two mature papaya fruits as a source of bioactive compounds, converting these by-products into value-added products. Proximate analysis (AOAC methods), mineral content (ICP-MS), free sugars (HPLC-ELSD), fatty acid composition (GC-FID), vitamin E profile (HPLC-DAD-FLD), and antioxidant activity (DPPH and FRAP assays) were evaluated. Results: Both by-products showed high total protein (20–27%), and dietary fiber (32–38%) contents. Papaya peels presented a high ash content (14–16%), indicating a potential application as a mineral source. 14 fatty acids were detected, with α-linolenic acid (30%) as the most abundant in the peels and oleic acid (74%) in the seeds. Both by-products showed high antioxidant activity. Conclusion: Papaya by-products display great potential for industrial recovery and application, such as formulation of new functional food ingredients.
- Natural resources with sweetener power: phytochemistry and antioxidant characterisation of Stevia Rebaudiana (Bert.), sensorial and centesimal analyses of lemon cake recipes with S. Rebaudiana incorporationPublication . Silva, Carla Sousa e; Oliveira, Adriana; Pinto, Sara Vanessa; Manso, M. Conceição; Ferreira da Vinha, AnaStevia rebaudiana leaf extracts are calorie-free sweeteners of natural origin, derived from the Stevia rebaudiana plant known as a natural sweetener, which contains steviol glycosides and others bioactive compounds recognized by their biological properties. The present study was designed to evaluate the total phenolics (26.0 mg gallic acid/g) and total flavonoids contents (9.7 mg catechin/g) of a hydroalcoholic extract of Stevia rebaudiana dried leaves. A similar hydroalcoholic extract of commercial powder steviol sweetener was also evaluated, showing lower contents of bioactive compounds (11.9 mg/g and 5.1 mg/g, for total phenolics and flavonoids, respectively). The hydroalcoholic extract of dried Stevia rebaudiana leaves also showed high in vitro antioxidant activity, besides a positive correlation between total phenolic compounds and the DPPH and FRAP assays. Moreover, Stevia rebaudiana leaves have sensory and functional properties superior to those of many other high-potency sweeteners and is likely to become a major source of natural sweetener for the growing food market. Thus, four different lemon cakes formulations were studied (a traditional cake control recipe with sugar, two cakes with incorporation of Stevia rebaudiana fresh leaf and a cake with commercial powder steviol), using a sensory analysis covering 100 untrained consumers. Centesimal composition analyses of the four lemon cakes showed significant differences in fat, ashes, proteins and carbohydrates contents (p<0.05). Also, the raised energy value observed for the cake control was superior to the cake with Stevia rebaudiana leaves incorporation (309.8 Kcal/100 g, 268.0 Kcal/100 g,142 respectively). Sensorial analysis results showed that Stevia rebaudiana leaves were accepted and, in the future, they can be a natural option to replace some or all the saccharose in cakes formulations.
- Cannabis for chronic pain: mechanistic insights and therapeutic challengesPublication . Matos, Carla; Pereira, Ana Teresa; Dias, Maria João; Silva, Carla Sousa e; Ferreira da Vinha, Ana; Carvalho, MárciaChronic pain represents a complex and debilitating condition that affects millions of people worldwide, significantly compromising their quality of life. The conventional approach to treating this type of pain often relies on the use of opioid analgesics and anti-inflammatory drugs. While these agents are effective in the short term, they present several limitations, including the risk of dependence, severe side effects, and, in some cases, ineffectiveness in reducing pain. In this context, medical cannabis has emerged as a promising therapeutic alternative, given its potential ability to relieve pain effectively with a favorable safety profile. This work aims to provide a comprehensive and up-to-date review of the existing literature on the effects of medical cannabis in the treatment of chronic pain. Cannabis sativa contains several pharmacologically active compounds, the most prominent of which are delta-9-tetrahydrocannabinol (∆9-THC) and cannabidiol (CBD), which interact with the body’s endocannabinoid system, thereby modulating the pain response. Clinical evidence has shown that cannabinoids can significantly reduce the intensity of chronic pain, particularly in cases of neuropathy, multiple sclerosis, arthritis, and other painful conditions that are unresponsive to conventional treatments. However, the full integration of medical cannabis into clinical practice faces significant obstacles, including the need for standardized dosing, long-term safety data, and regulatory frameworks. These issues, alongside concerns over adverse effects and drug interactions, must be addressed to unlock the full therapeutic potential of cannabinoids, particularly for chronic pain patients, who endure both physical suffering and the added burden of stress.
- Invasive plants and their possible applications - phytochemical profile and biological properties: a reviewPublication . Ferreira da Vinha, Ana; Silva, Carla Sousa e; Moutinho, Carla; Matos, CarlaInvasive species are distinguished by their simplicity in reproductive and ability to adapt to adverse environments. Biological invasion has been identified as the primary driver of global change, responsible for biotic interchange and, as a result, habitat homogenization. It is well recognized that invasive species have been one of the primary causes of native species loss in recent centuries, affecting the natural ecosystem of each geographic area. Furthermore, the number of invasive species is fast increasing in all countries and taxonomic groupings, thus it is critical to implement more effective measures than those that have been used, which may include their phytochemical evaluation and, biological activities for future applications in phytotherapy and pharmacy. This review intends to show the phytochemical potential of three known invasive species, commonly present in the Portuguese maritime coastal zones, specifically, Agave americana, Carpobrotus edulis and Arundo donax. This study can be extended to other similar situations involving invasive species from other countries with the goal to enhance the efficiency of potential future projections for these species, particularly on the phytotherapeutic and pharmaceutical levels. Technological and scientific comprehension of these species' chemical and biological qualities will serve improve the efficiency of the management strategies will be implemented, emphasizing a sustainable economy.
- Avaliação da utilização da espectrofotometria de UV/Vis na quantificação de antibióticos em extractos de leite de vacaPublication . Guedes, Cátia; Matos, Carla; Moutinho, Carla; Silva, Carla Sousa eA comercialização da maior parte dos alimentos é precedida por um processamento complexo,o qual necessita de ser devidamente monitorizado, de forma a controlar a presença de substâncias nocivas. no entanto, estas substâncias, designadamente antibióticos, são necessárias no combate de diversas patologias veterinárias, pelo que são administradas aos animais de consumo. este estudo foi desenvolvido com o objectivo de testar e optimizar um método de extracção de resíduos de antibióticos do leite de vaca gordo pasteurizado. The marketing of most food is preceded by a complex process, which needs to be properly monitored in order to supervise the presence of harmful substances. However, these substances, including antibiotics that are administrated to consumption animals, are necessary in combating of various veterinary diseases. this study was developed with the aim to test and optimize a method for extraction of antibiotic residues in cow’s pasteurized milk.
- Agro-food wastes: valorization of lychee (Litchi chinensis) peelsPublication . Ferchal, Clemence; Silva, Carla Sousa e; Ferreira da Vinha, AnaBackground: Tropical fruits represent one of the most important crops in the world. Moreover, currently, food security is a growing problem due to the depletion of natural resources and increasing population, which has led to a gap between production and consumption (1). Nowadays, medicine has started to pay great attention to functional food, which displays an additional function related to health promotion or disease prevention. In fact, phytochemicals present in fruit byproducts (peel and seeds) are generally significantly higher than in their respective edible tissues (pulp), suggesting these wastes to be potential sources for isolating bioactive compounds or as nutraceuticals ingredients for new food products (2). Methods: Lychee (Litchi chinensis) is a very popular fruit, currently consumed worldwide. The peel and seed represent 50% of the fruit, which is considered high. However, when processed properly, such waste can generate other products as extracts and flours, contributing to its use in food, pharmaceutical and cosmetic industries. Selected fruits were washed, weighed and separated into peel, pulp and seed. The peel was lyophilized, ground, and stored protected from light until the time of analysis. Proximate composition of lychee peel flour was performed according to the methods AOAC (3), and dietary fiber, determined using enzymatic kit Sigma®, followed the technique proposed by (3). The total energy value (TEV) was also calculated. Results: Total carbohydrates and TEV were high (60 g/100 g and 318 kcal/100 g, respectively), presenting low content of proteins and lipids. Lychee peel flour presented 20 g/100 g dietary fiber. The Reference Daily Intake (RDI) is 25 g fiber (4); thus, this flour may be considered a potential fiber source, to be integrated in new products. Conclusions: It is desirable to find proper food applications for fruits peel for helping the environment through sustainability and creating new value-added food products.
- Vitamina C em cascas de citrinos: sua determinação e potencial utilização na terapia periodontalPublication . Silva, Carla Sousa e; Teixeira, Fabiana Gonçalves; Mesquita, Rita; Moutinho, Carla; Salgado, Abel; Ferreira da Vinha, AnaA doença periodontal, de etiologia bacteriana, é de ocorrência e progressão multifatorial. Os fatores derivados do hospedeiro podem ser relacionados com causas genéticas, hormonais e nutricionais. Entre estas últimas, o ácido ascórbico tem assumido um papel importante na terapia desta patologia, uma vez que a sua deficiência pode provocar defeitos na estrutura do colagénio, aumentar o stress oxidativo e a inflamação. O ácido ascórbico é uma vitamina hidrossolúvel, com importantes características antioxidantes e terapêuticas, que pode ser encontrada nos citrinos. As cascas resultantes do processamento alimentar transformam-se geralmente em desperdício, o que tem impacto ambiental. Contudo, os resíduos resultantes dos citrinos podem ser utilizados como uma fonte de compostos funcionais. O objetivo deste trabalho experimental recaiu na quantificação da vitamina C nas cascas de três citrinos selecionados, a laranja (Citrus sinensis), o limão (Citrus limon) e a tangerina (Citrus reticulata), tendo em vista o reaproveitamento das mesmas e a sua possível aplicação na criação de suplementos dietéticos de ácido ascórbico, que possam ser considerados como um complemento à terapia periodontal. A concentração de vitamina C nas cascas dos citrinos avaliados mostrou-se superior na tangerina, seguida imediatamente da laranja e, por último, do limão, apresentando estas valores entre 137,1 mg e 99,5 mg por 100 g.