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- Fish processing industry residues: a review of valuable products extraction and characterization methodsPublication . Ideia, Pedro; Pinto, Joana; Ferreira, Rui; Figueiredo, Leandro; Spínola, Vítor; Castilho, Paula C.Fish processing industry has experienced significant growth, playing an important role in the world economy. The increased exploration of marine resources contributes to the generation of considerable amounts of biowaste, which ends up as discards. In the face of the resultant disposal and environmental problems, many efforts have been made to deal with the fishery waste in more efficient ways. Nowadays, these by-products are regarded as important sources of high added value compounds, such as hydroxyapatite, collagen, gelatin, lipids, enzymes, hydrolysates and bioactive peptides, with great potential for human health applications. The present paper aims to review the current methods of extraction and characterization of added value products from fish by-products, as well as their actual and potential applications.
- Hypoglycemic, anti-glycation and antioxidant in vitro properties of two Vaccinium species from Macaronesia: A relation to their phenolic compositionPublication . Spínola, Vítor; Pinto, Joana; Castilho, Paula C.Vaccinium cylindraceaeum (Azores blueberry) and V. padifolium (Madeira blueberry) are two Portuguese endemic species, which phytochemical composition and beneficial properties lack scientific validation. In this work, their potential in vitro inhibitory effects against key enzymes linked to type 2 diabetes and obesity and glycation of proteins were evaluated. Anthocyanins were predominant in fruits, while hydroxycinnamic acids (in particular 5-O-caffeoylquinic acid) and flavonoids were the main compounds in leaves. Vaccinium extracts showed effective inhibitions of glucosidases and glycation of proteins and mild activity towards α-amylase and pancreatic lipase (by comparison with reference compounds). Phenolic composition was strongly correlated with reported bioactivities. In fact, 5-O-caffeoylquinic can be considered one of the main hypoglycemic and anti-glycation agents of analysed extracts. Consumption of both Vaccinium species should be encouraged since berries could offer a dietary option in the prevention and control of diabetes and obesity, while leaves are good candidates for development of nutraceuticals.
- Identification and quantification of phenolic compounds of selected fruits from Madeira Island by HPLC-DAD–ESI-MSn and screening for their antioxidant activityPublication . Spínola, Vítor; Pinto, Joana; Castilho, Paula C.Five fruits species commonly cultivated and consumed in Madeira Island (Portugal) were investigated for their phenolic profile by means of reversed phase high-performance liquid chromatography coupled to diode array detection and electrospray ionisation mass spectrometry (HPLC-DAD-ESI/MS(n)) and antioxidant potential. A large number of compounds were characterised, flavonoids and phenolic acids being the major components found in target samples, 39 compounds (flavonoids, phenolic acids, terpenoids, cyanogenic glycosides and organic acids) were identified in cherimoyas, lemons, papayas, passion-fruits and strawberries for the first time. Furthermore, all samples were systematically analysed for their total phenolic and flavonoid contents along with two radical scavenging methods (ABTS and ORAC) for antioxidant activity measurement. Target fruits presented high phenolic contents which is responsible for most of the antioxidant activity against radical reactive species (R(2)>0.80). Quantitative data showed that anthocyanins, in particular pelargonidin-3-O-hexoside (>300 mg/100 mL), present only in strawberries were the compounds in largest amounts but are the ones which contribute less to the antioxidant activity.
- In vitro studies on the effect of watercress juice on digestive enzymes relevant to type 2 diabetes and obesity and antioxidant activityPublication . Spínola, Vítor; Pinto, Joana; Castilho, Paula C.Inhibition of enzymes involved in carbohydrate and lipids metabolism is an important strategy against type 2 diabetes and obesity, by suppressing dietary sugar and fat absorption. This work reports, for the first time, the in vitro inhibition of a-glucosidase, a-amylase and lipase by water cress juice (WJ). Juice was analyzed for qualitative and quantitative composition and in vitro antioxidant activities. Several components were identified, namely hydroxycinnamic acids, flavo nols, and other minor water-soluble phytochemicals. Quantitative data revealed a dimer of caffeoylmalic acid (0.73 mg mL21 of juice), disinapoylgentibiose (0.64 mg mL21 ), ferulic acid (0.56 mg mL21 ), and isorhamnetin-O-sophoroside-O-malonyl(hexoside) (0.38 mg mL21 ) as the pre dominant polyphenols. The results showed that WJ had dose-dependent inhibitory potential against targeted enzymes, displaying a more potent inhibitory effect against a-glucosidase relative to a-amylase and lipase. WJ can be considered a potential complementary dietary approach to control hyperglycaemia and hyperlipidaemia, through inhibition of digestive enzymes. Practical applications Currently, raw watercress is widely consumed in liquid form, alone or together with other fresh vege tables, as an ingredient of the “detox juices.” Studies on watercress phenolic composition and antidiabetic properties have been performed on extracts, but not on juice, which is closer to the edi ble form. The present study supports consumption of watercress juice as source of phytochemicals potentially capable of inhibiting digestive enzymes linked to diabetes and obesity prevention/control.
- Changes in the phenolic compositions of Elaeagnus umbellata and Sambucus lanceolata after in vitro gastrointestinal digestion and evaluation of their potential anti-diabetic propertiesPublication . Spínola, Vítor; Pinto, Joana; Llorent-Martínez, Eulogio J.; Castilho, Paula C.In this work, the phenolic composition of E. umbellata leaves and berries is reported. Berries were rich in flavonols, whereas leaves presented abundant flavonols and ellagitannins. Then, the enzyme-inhibitory properties, anti-glycation and antioxidant activities of E. umbellata and Sambucus lanceolata (its phenolic profile has been already established in a previous work) were tested by several in vitro assays and compared. The simulated gastrointestinal digestion resulted in a decrease on their phenolic composition. Nevertheless, both species still had the ability to inhibit aldose reductase activity and protein glycation and scavenge free radicals at the end of the process. Thus, the potential beneficial effects of E. umbellata and S. lanceolata seems to be kept to some extent after passage throughout the digestive system. Altogether, this study provides further insight into investigation of these species as dietary sources of bioactive compounds to lower the risk of type-2 diabetes and obesity.
- Estudo da composição e das propriedades bioactivas de plantas produtoras de bagasPublication . Pinto, Joana Carolina Nunes; Castilho, Paula Cristina Machado FerreiraO consumo de frutas e vegetais tem sido associado à prevenção de várias doenças crónicas, nomeadamente doenças cardiovasculares, diabetes, cancro e outras que envolvam processos inflamatórios. As bagas destacam-se pelo seu elevado conteúdo em polifenóis, cujas propriedades antioxidantes contribuem para a manutenção da saúde humana. O presente trabalho teve como alvo de estudo as diferentes partes morfológicas (bagas e folhas) de espécies produtoras de bagas, nomeadamente Elaeagnus umbellata, a Rubus grandofolius, a Sambucus lancolata, a Vaccinium padifolium e a Vaccinium cylindraceum, tendo em vista a sua valorização como produtos alimentares e/ou nutracêuticos. A caracterização físico-química destas espécies permitiu determinar que o teor total de sólidos solúveis (TSS) das bagas varia de 4,4 a 16,5 °Brix. As bagas demonstraram ser a parte morfológica com teor de humidade mais elevado. A análise do perfil fenólico por HPLC-DAD-ESI/MSn, no modo negativo, dos extractos metanólicos mostrou que as folhas apresentam maior conteúdo de compostos fenólicos, comparativamente às bagas. Os ácidos hidroxicinâmicos (derivados dos ácidos cafeicos, cumárico e ferúlico), os ácidos cafeoilquínicos, bem como os flavonóis-O-glicosilados (derivados da quercetina e canferol) predominam nestas espécies. A análise pelo modo positivo permitiu a identificação de antocianinas glicosiladas (delfinidina, cianidina, petunidina, peonidina e malvidina) nas bagas e folhas jovens da espécie Vaccinium padifolium. Os ensaios in vitro de simulação da digestão gastrointestinal permitiram compreender a sua influência na actividade antioxidante dos extractos. Após a digestão, as folhas continuam a apresentar maior capacidade antioxidante do que as bagas. Adicionalmente, concluiu-se que as enzimas presentes neste processo têm menor influência do que o pH e a força iónica dos sucos digestivos. O estudo do efeito inibitório in vitro dos extractos sobre a actividade de enzimas responsáveis pelo metabolismo dos hidratos de carbono permitiu determinar que os viii Joana Pinto (2016) extractos foram mais eficientes na inibição da actividade da α-glucosidase do que na inibição da actividade da α-amilase.
- Polyphenolic profile and antioxidant activities of Madeiran elderberry (Sambucus lanceolata) as affected by simulated in vitro digestionPublication . Pinto, Joana; Spínola, Vítor; Llorent-Martínez, Eulogio J.; Fernández-de Córdova, María Luisa; Molina-García, Lucía; Castilho, Paula CThe aims of this study were twofold: a) to provide a detailed report on the phenolic composition and antioxidant activity of fresh berries and leaves of Sambucus lanceolata (Madeiran elderberry); b) to study the effects caused by a simulated in vitro digestion on the composition and antioxidant activity of the berries and leaves. Seventy-seven phytochemicals, mainly polyphenols, were identified in the methanol extracts of fresh berries and leaves, with the content of polyphenols higher in berries (27.2mg·g-1 dry extract, DE) than in leaves (25.9mg·g-1 DE). Anthocyanins were dominant in berries, while hydroxycinnamic acids (HCAs) and flavonols were abundant in leaves. Higher antioxidant activities were found in leaves than in berries, using several in vitro assays. After the simulated in vitro digestion, the levels of polyphenols were significantly reduced, in particular those of berries (81.8% decrease). Anthocyanins were the most affected compounds during the simulated digestion. However, despite the significant loss of phenolic compounds during digestion, methanol extracts of digested berries and leaves were still able to scavenge free-radicals. Hence, the consumption of leaves and/or berries of S. lanceolata may help prevent oxidative stress.
- Evaluation of Rubus grandifolius L. (wild blackberries) activities targeting management of type-2 diabetes and obesity using in vitro modelsPublication . Spínola, Vítor; Pinto, Joana; Llorent-Martínez, Eulogio J.; Tomás, Helena; Castilho, Paula C.Rubus grandifolius Lowe (wild blackberries) is an endemic species from Madeira Archipelago (Portugal) used in folk medicine for alleviating diabetic complications. In this work, R. grandifolius methanolic extracts were analysed for in vitro inhibitory effect on digestive enzymes linked to type-2 diabetes, as well as aldose reductase activity and protein glycation. The phenolic composition, antioxidant and cytotoxic activities were also determined. Methanolic extracts exhibited strong inhibition of glucosidases (α- and β), but were less potent for α-amylase and pancreatic lipase when compared to current pharmaceutical drugs. The total phenolic content determined by HPLC-DAD varied between 92.96 - 97.47 and 118.01-137.41 mg g-1 of dry extract for berries and leaves, respectively. Fifty polyphenols were quantified, anthocyanins and ellagitannins being the main compounds. Cyanidin-3-glucoside was identified as one of the main hypoglycaemic and hypolipidemic agents in all extracts. R. grandifolius also prevented glycation of bovine-serum albumin (BSA) and showed strong radical scavenging activity against tested free radicals. At low concentration, the extracts were not cytotoxic against Caco-2 cells. Based on the results of this study, wild blackberry extracts demonstrated a potential beneficial effect on the control/management of type-2 diabetes mellitus, validating their use in folk medicine.