Loading...
39 results
Search Results
Now showing 1 - 10 of 39
- Phenolic compounds: current industrial applications, limitations and future challengesPublication . Albuquerque, Bianca R.; Heleno, Sandrina A.; Oliveira, Beatriz; Barros, Lillian; Ferreira, Isabel C.F.R.Phenolic compounds are natural bioactive molecules found mainly in plant tissues that have shown interesting bioactivities, such as antioxidant, antimicrobial, anti-inflammatory, and antiproliferative activities, among others, which has led to great interest in their use by several industries. However, despite the large number of scientific studies on this topic, some issues still need to be studied and solved, such as the understanding of the main actions of these compounds in organisms. Besides their large potential applicability in industry, phenolic compounds still face some issues making it necessary to develop strategies to improve bioavailability, sustainable technologies of extraction and refinement, and stability procedures to increase the range of applicability. This review focuses on the most recent advances in the applications of phenolic compounds in different technological and medicinal areas. In addition, techniques to improve their sustainable resourcing, stability and bioavailability will be presented and discussed. This journal is
- Insights into the chemical composition and in vitro bioactive properties of mangosteen (Garcinia mangostana L.) pericarpPublication . Albuquerque, Bianca R.; Dias, Maria Inês; Pinela, José; Calhelha, Ricardo C.; Pires, Tânia C.S.P.; Alves, Maria José; Corrêa, Rúbia C.G.; Ferreira, Isabel C.F.R.; Oliveira, Beatriz; Barros, LillianThe industrial processing of mangosteen (Garcinia mangostana L.) generates high amounts of waste, as similar to 60% of the fruit is formed by an inedible pericarp. However, its pericarp has been explored as a source of xanthones; nevertheless, studies addressing the recovery of other chemical compounds from such biomass are still scarce. Hence, this study intended to elucidate the chemical composition of the mangosteen pericarp, including fat-soluble (tocopherols and fatty acids) and water-soluble (organic acids and phenolic compound non-xanthones) compounds present in the following extracts: hydroethanolic (MT80), ethanolic (MTE), and aqueous (MTW). In addition, the antioxidant, anti-inflammatory, antiproliferative and antibacterial potentials of the extracts were assessed. The mangosteen pericarp showed a composition with seven organic acids, three tocopherol isomers, four fatty acids and fifteen phenolic compounds. Regarding the extraction of phenolics, the MT80 was the most efficient (54 mg/g extract), followed by MTE (19.79 mg/g extract) and MTW (4.011 mg/g extract). All extracts showed antioxidant and antibacterial activities; however, MT80 and MTE extracts were more efficient than MTW. Only MTW did not show anti-inflammatory properties, whereas MTE and MT80 showed inhibitory activities towards tumor cell lines. Notwithstanding, MTE showed cytotoxicity towards normal cells. Our findings support the idea that the ripe mangosteen pericarp is a source of bioactive compounds, although their recovery is dependent on the extraction solvent.
- Flavonoid composition and in vitro anti-proliferative activity of the hydroethanolic extract of Garcinia mangostana L. pericarpPublication . Albuquerque, Bianca R.; Dias, Maria Inês; Calhelha, Ricardo C.; Oliveira, Beatriz; Ferreira, Isabel C.F.R.; Barros, LillianGarcinia mangostana L., known as mangosteen, is a tropical fruit belonging to the Clusiaceae family, native from South Asia but can also be found in other tropical territories, such as South America [1,2,3]. The fruit comprises an inedible dark purple epicarp (> 60%) that encases an edible succulent pulp [2]. Nowadays, mangosteen pulp and pericarp have been used in beverages as food supplement by virtue of the traditional knowledge about its health benefits. However, correlation studies between the folk medicine usage and its chemical composition are scarce in the literature [2,3]. Aiming to elucidate part of the chemical composition, the present study carried out the determination of the main flavonoids, including anthocyanin compounds, present in mangosteen pericarp by High Performance Liquid Chromatography coupled to a diode array detector and mass spectrometry by electrospray ionization (HPLC-DAD-ESI/MSn). Furthermore, the cytotoxicity effects of its hydroethanolic extracts were evaluated on four human tumor cell lines (NCI-H460 - lung carcinoma, MCF-7 - breast carcinoma, HepG2 - hepatocellular carcinoma, and HeLa - cervical carcinoma) by the Sulforhodamine B (SRB) assay. Mangosteen pericarp presented nine non-anthocyanin flavonoid compounds, most of which belonging to the procyanidin class (seven compounds), one taxifolin derivative (taxifolin-O-rhamnoside, found in low concentrations), and one quercetin derivative (quercetin-3-O-rutinose, found in trace amounts). Regarding the anthocyanin flavonoids compounds group, two were found and tentatively identified as cyanidin-Odihexoside and delphinidin-O-dihexoside. Regarding the total amount of flavonoids, the extracts presented 53 ± 1 mg of non-anthocyanin flavonoids/g of extract, 3.66 ± 0.02 mg of anthocyanins/g of extract. Concerning the cytotoxic activity, the hydroethanolic extracts presented activity against all tumor cell lines studied (GI50 < 75 μg/mL). The results obtained from the present study showed that mangosteen pericarp could be an interesting natural source of high added value and bioactive compounds, with the potential to the applied in several industrial fields including pharmaceutical, nutraceutical, among others.
- Development of a natural preservative based on catechin and derivatives from plant originPublication . Albuquerque, Bianca R.; Prieto Lage, Miguel A.; Pereira, Celeide; Barros, Lillian; Ferreira, Isabel C.F.R.The controversy and ambiguity related with chemical additives, allied to the sporadic scares, have paved the way for natural additives to gain interest and funding. Today, most consumers prefer foods added with natural additives, which is seen by the food industry as an opportunity to find new and more efficient natural‐based solutions. Polyphenols constitute some of the most interesting groups of natural compounds in the vegetable kingdom and due to their antioxidant capacity, they have been used to develop natural additives in the class of preservatives. They can be added as plant extracts, taking advantage of the synergistic effects between compounds, or as individual molecules. Catechin, a widely known flavon‐3‐ol, is also known for its antioxidant activity. The discovery of new alternative sources of natural additives is also a very important topic, therefore the aim of this study was to obtain an extract enriched in catechins (natural preservative), from fruits of Arbutus unedo L., as an alternative source to the already well studied Camellia sinensis (L.) Kuntze. However, the catechin stability during the extraction and storage processes requires essential conditions that need to be examined cautiously. Therefore, a stability study of the enriched catechin extract powder was performed, evaluating the main affecting conditions involved in the obtaining and storage of the extract and its stability in mimitized food matrices. To determine these effects three main variables (time, temperature and pH) affecting catechin function were considered, being the catechin content monitored by HPLC‐DAD. Mechanistic and phenomenological equations were used to describe the responses and optimal conditions for catechin stability. Overall, with this study the best stability conditions for catechin enriched extracts were established (information protected by a submitted patent) in order to allow its use as a natural preserver by the food industry.
- Perfil fenólico e propriedades bioativas do epicarpo de jabuticabaPublication . Albuquerque, Bianca R.; Calhelha, Ricardo C.; Pereira, Carla; Pires, Tânia C.S.; Barros, Lillian; Oliveira, Beatriz; Ferreira, Isabel C.F.R.A jabuticabeira é uma árvore frutífera nativa do Brasil, sendo encontrada principalmente na Mata Atlântica. Os seus frutos, denominados por jabuticabas, são pequenas bagas de aproximadamente 2 – 3,5 cm que possuem uma coloração preta a roxa, quando maduros. São muito apreciados para consumo in natura devido ao agradável sabor da sua polpa; no entanto, o epicarpo, que é rígido e possui um sabor adstringente, não é comumente consumido, sendo responsável por grande parte do resíduo gerado no processamento de produtos derivados de jabuticaba [1]. A intensa coloração desta parte dos frutos é devida à concentração de pigmentos presentes na sua composição, nomeadamente antocianinas, que são compostos de grande interesse devido à sua coloração atrativa e às suas propriedades benéficas para a saúde [2]. Além disso, a presença de outros compostos fenólicos também tem sido relatada no epicarpo de jabuticaba [1,3]. Com o objetivo de valorizar este biorresíduo, o presente estudo teve como foco a determinação do seu perfil fenólico e a avaliação das suas propriedades bioativas, nomeadamente a atividade antioxidante, antimicrobiana e antiproliferativa. Os compostos fenólicos presentes no extrato do epicarpo de jabuticaba (EEJ) foram detetados por HPLC-DAD- ESI/MS. Os ensaios de bioatividade foram realizados por métodos in vitro: a atividade antioxidante foi determinada através da inibição da formação de substâncias reativas do ácido tiobarbitúrico (TBARS) e da inibição da hemólise oxidativa (OxLHIA); a atividade antimicrobiana foi avaliada pelo método da microdiluição contra oito bactérias patogénicas; e a citotoxicidade foi analisada pelo ensaio da sulforrodamina B com quatro linhas celulares tumorais e uma cultura primária de células não-tumorais. O epicarpo de jabuticaba apresentou um perfil fenólico constituído por catorze compostos fenólicos não antociânicos e dois antociânicos, sendo a cianidina-3-O-glucósido o composto mais abundante. Em relação às propriedades bioativas, o EEJ apresentou uma elevada atividade antioxidante, atividade antiproliferativa contra três linhas celulares tumorais e atividade antimicrobiana contra todas as bactérias avaliadas. Não foi observada hepatotoxicidade em células não-tumorais na maior concentração de extrato avaliada. Conclui-se, assim, que o EEJ apresenta uma composição rica em compostos fenólicos, principalmente em antocianinas, e que possui consideráveis propriedades bioativas, o que potencia o interesse da exploração deste biorresíduo para a obtenção de compostos de interesse para a indústria alimentar e farmacêutica.
- Anthocyanin-rich extract of jabuticaba epicarp as a natural colorant: Optimization of heat- and ultrasound-assisted extractions and application in a bakery productPublication . Albuquerque, Bianca R.; Pinela, José; Barros, Lillian; Oliveira, Beatriz; Ferreira, Isabel C.F.R.Heat- and ultrasound-assisted extractions of anthocyanins from jabuticaba epicarp were optimized and the colouring potential of the developed extract was tested on macarons. The independent variables time (t), solvent concentration (S), and temperature (T) or power (P) were combined in a five-level central composite design coupled with response surface methodology. The delphinidin-3-O-glucoside and cyanidin-3-O-glucoside levels monitored by HPLC-DAD-ESI/MS were used as response criteria. The developed models were successfully fitted to the experimental data and used to determine optimal extraction conditions. HAE was the most efficient method yielding 81 ± 2 mg/g extract under optimal conditions (t = 21.8 min, T = 47.1 °C and S = 9.1% ethanol, v/v). Macarons were then produced using the optimized anthocyanin-rich colouring extract and their colour parameters and nutritional profile were monitored during shelf-life. The obtained results provided useful information for the development of anthocyanin-rich extracts from a bio-waste with potential use as natural food colorants.
- Jabuticaba residues (Myrciaria jaboticaba (Vell.) Berg) are rich sources of valuable compounds with bioactive propertiesPublication . Albuquerque, Bianca R.; Pereira, Carla; Calhelha, Ricardo C.; Alves, Maria José; Abreu, Rui M.V.; Barros, Lillian; Oliveira, Beatriz; Ferreira, Isabel C.F.R.The main environmental issue associated with compost production is the production of a liquid leachate. Leachate from municipal wastes contains carbon, nitrogen, phosphorus, potassium and trace elements that can be used as nutrients by plants. The advantages of the use of organic wastes such as compost leachate as fertilizers are evident. Their use would reduce the consumption of commercial fertilizers, which need, with their production, high cost and energy. This work aims to determine the physical and chemical properties of a specific leachate with a variable composition, collected from the composting line of a mechanical and biological treatment facility. The goal is to assess if the leachates can be used as a potential source for fertilizers, and thus develop and design a sequence of processes which could effectively convert the leachates to commercial fertilizers according to the requirements of the proposal of regulation of the European Parliament of 2016 for fertilizers. Preliminary results show that the leachate samples qualitatively meet the requirements established for the composition of commercial fertilizers, especially organo-mineral fertilizers. Furthermore, there is no production cost of leachate as a raw material. The results show that the leachate is characterized by manageable concentrations of heavy metals which can be removed by adsorption processes, and it presents suitable amounts of organic carbon after a water removal procedure. However, the establishment of the conditions for suitable conversion processes are still under investigation considering the high composition variability due to factors like storage and environmental conditions.
- Food bioactive compounds and emerging techniques for their extraction: Polyphenols as a case studyPublication . Câmara, José S.; Albuquerque, Bianca R.; Aguiar, Joselin; Corrêa, Rúbia C.G.; Gonçalves, João L.; Granato, Daniel; Pereira, Jorge A.M.; Barros, Lillian; Ferreira, Isabel C.F.R.Experimental studies have provided convincing evidence that food bioactive compounds (FBCs) have a positive biological impact on human health, exerting protective effects against noncommunicable diseases (NCD) including cancer and cardiovascular (CVDs), metabolic, and neurodegenerative disorders (NDDs). These benefits have been associated with the presence of secondary metabolites, namely polyphenols, glucosinolates, carotenoids, terpenoids, alkaloids, saponins, vitamins, and fibres, among others, derived from their antioxidant, antiatherogenic, anti-inflammatory, antimicrobial, antithrombotic, cardioprotective, and vasodilator properties. Polyphenols as one of the most abundant classes of bioactive compounds present in plant-based foods emerge as a promising approach for the development of efficacious preventive agents against NCDs with reduced side effects. The aim of this review is to present comprehensive and deep insights into the potential of polyphenols, from their chemical structure classification and biosynthesis to preventive effects on NCDs, namely cancer, CVDs, and NDDS. The challenge of polyphenols bioavailability and bioaccessibility will be explored in addition to useful industrial and environmental applications. Advanced and emerging extraction techniques will be highlighted and the high-resolution analytical techniques used for FBCs characterization, identification, and quantification will be considered.
- Composition in anthocyanins and bioactive properties of jabuticaba bioresiduesPublication . Albuquerque, Bianca R.; Dias, Maria Inês; Calhelha, Ricardo C.; Alves, Maria José; Pires, Tânia C.S.; Abreu, Rui M.V.; Pereira, Carla; Barros, Lillian; Oliveira, Beatriz; Ferreira, Isabel C.F.R.Myrciaria cauliflora (Mart.) O. Berg, known as jabuticaba, is a native species to Brazil, more specifically to Atlantic Rainforest biome. Its fruits are small berries with a diameter of 2.0 – 3.5 cm that contain between one and four seeds, with a sweet gelatinous pulp and thick dark purple epicarp when mature, which is not commonly consumed. Due to the properties of its pulp, the consumption and production of jellies and liqueurs from jabuticaba has increased. However, the epicarp that corresponds to about 50% of the fruit is not used, being converted into a bioresidue [1]. The intense colour of this part of the fruit is due to the pigments, namely anthocyanins, present in its composition. In addition to attractive staining, these molecules have been associated with bioactive properties, such as antioxidant activity, which makes their recovery interesting for application in various industrial segments, for instance, food and pharmaceutical [2,3]. With the objective of valorising this bioresidue, the present work aimed the determination of the main anthocyanins present in jabuticaba epicarp (by HPLC-DAD-ESI/MS) and the evaluation of the bioactivity of its ethanolic extract (through in vitro assessment of cytotoxic, antimicrobial, and antioxidant activities). Thus, cytotoxicity was evaluated in four tumour cell lines (NCI-H460 - lung carcinoma, MCF-7 - breast carcinoma, HepG2 - hepatocellular carcinoma, and HeLa - cervical carcinoma) and in a primary culture of non-tumour liver cells (PLP2), by the Sulforodamine B (SRB) assay. The antimicrobial activity was evaluated on five Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Morganella morgani, Proteus mirabilis, and Pseudomonas aeruginosa) and three Gram-positive bacteria (Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis). Lastly, the antioxidant activity was tested through the oxidative haemolysis inhibition assay (OxHLIA). The bioresidue of jabuticaba fruits presented two anthocyanins, identified as cyanidin 3-O-glucoside and delphinidin 3-O-glucoside, being the first one the most abundant. Regarding bioactivity, the ethanolic extract revealed antiproliferative activity in all tumour cell lines evaluated (GI50 < 300 μg/mL), except for NCI-H460, and did not show toxicity for PLP2 at the maximal tested concentration (400 μg/mL). It also exhibited bacteriostatic properties in all the analysed bacterial strains (ranging from 20 to 10 mg/mL). Regarding haemolysis inhibition, the extract was able to protect 50% of the erythrocyte population for 120 minutes in a lower concentration than the positive control (Trolox). The results obtained in this study allow to conclude that jabuticaba epicarp is a rich source of anthocyanins and also exhibits strong bioactivity, which makes it suitable for use as colorant.
- Recovery of anthocyanins from Eugenia spp. fruit peels: a comparison between heat- and ultrasound-assisted extractionPublication . Albuquerque, Bianca R.; Pinela, José; Pereira, Carla; Mandim, Filipa; Heleno, Sandrina A.; Oliveira, Beatriz; Barros, LillianNatural colorants have gained increased popularity among consumers and food producers due to their reputation as safer and healthier alternatives to commonly used artificial analogues. These natural pigments can be obtained from by-products resulting from food processing, such as the fruit peels of the Brazilian species Eugenia brasiliensis and Eugenia involucrata, thus contributing to the valorisation and circularity of these undervalued raw materials. Therefore, since these fruit peels present anthocyanin concentrations that justify their exploitation, this study aimed to optimize and compare the recovery of these pigments from these plant by-products using heat- and ultrasound-assisted extraction (HAE and UAE, respectively) methods. For process optimization, a central composite rotatable design coupled with response surface methodology was implemented, considering time, ethanol/water ratio, and temperature (for HAE) or ultrasonic power (for UAE) as relevant independent variables. While UAE resulted in higher extraction yields (40–42%, w/w), HAE led to higher anthocyanin contents (18 mg g−1 from E. involucrata and 323 mg g−1 from E. brasiliensis). Furthermore, the HAE global optimum involved only 2 min of processing. Both theoretical models were experimentally validated by applying the modelpredicted extraction conditions, and the obtained anthocyanin-rich extracts were analysed for colour and in vitro bioactive properties. In general, the extraction method did not greatly affect the colour or the antimicrobial and cytotoxic activities of the extracts. However, only E. brasiliensis extracts showed cytotoxicity on human tumour cell lines, which also stood out for their antioxidant activity, possibly due to the higher anthocyanin content. Thus, Eugenia spp. fruit peels could be an alternative renewable source of natural food colourants with bioactive properties. Nonetheless, since E. brasiliensis extracts displayed moderate toxicity towards normal cells, the toxicity threshold should be further investigated to ensure the safe exploitation of this raw material as a possible source of natural food colourants.