Browsing by Author "Silva, Joana Laranjeira"
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- Bioactive hydrolysates from chlorella vulgaris: optimal process and bioactive propertiesPublication . Cunha, Sara A.; Coscueta, Ezequiel R.; Nova, Paulo; Silva, Joana Laranjeira; Pintado, Maria ManuelaMicroalgae have been described as a source of bioactive compounds, such as peptides. Microalgae are easy to produce, making them a sustainable resource for extracting active ingredients for industrial applications. Several microalgae species have interesting protein content, such as Chlorella vulgaris with around 52.2% of protein, making it promising for peptide hydrolysate production. Therefore, this work focused on the production of water-soluble hydrolysates rich in proteins/peptides from the microalgae C. vulgaris and studied bioactive properties. For that, a design of experiments (DOE) was performed to establish the optimal conditions to produce hydrolysates with higher levels of protein, as well as antioxidant and antihypertensive properties. Four experimental factors were considered (cellulase percentage, protease percentage, hydrolysis temperature, and hydrolysis duration) for three responses (protein content, antioxidant activity, and antihypertensive activity). The optimal conditions determined by the DOE allowed producing a scaled-up hydrolysate with 45% protein, with antioxidant activity, measured by oxygen radical absorbance capacity assay, of 1035 µmol TE/g protein, IC50 for angiotensin-converting enzyme inhibition activity of 286 µg protein/mL, and α-glucosidase inhibition of 31% (30 mg hydrolysate/mL). The obtained hydrolysates can be used as functional ingredients for food and nutraceuticals due to their antioxidant, antihypertensive, and antidiabetic potential. Moreover, the antioxidant potential of the extracts may be relevant for the cosmetic industry, especially in antiaging formulations.
- Enzymatic hydrolysis allows an integral valorization of nannochloropsis oceanica resulting in the production of bioactive peptide extracts and an eicosapentaenoic acid enriched fractionPublication . Cunha, Sara A.; Coscueta, Ezequiel R.; Alexandre, Agostinho M. R. C.; Partidário, Ana Maria Carvalho; Fernández, Naiara; Paiva, Alexandre; Silva, Joana Laranjeira; Pintado, Manuela E.Nannochloropsis oceanica is a microalga with relevant protein content, making it a potential source of bioactive peptides. Furthermore, it is also rich in fatty acids, with a special focus on eicosapentaenoic acid, an omega-3 fatty acid mainly obtained from marine animal sources, with high importance for human health. N. oceanica has a rigid cell wall constraining protein extraction, thus hydrolyzing it may help increase its components' extractability. Therefore, a Box-Behnken experimental design was carried out to optimize the hydrolysis. The hydrolysate A showed 67±0.7% of protein, antioxidant activity of 1166±63.7 μmol TE/g of protein and an ACE inhibition with an IC50 of 379 μg protein/mL. The hydrolysate B showed 60±1.8% of protein, antioxidant activity of 775±13.0 μmol TE/g of protein and an ACE inhibition with an IC50 of 239 μg protein/mL. The by-product showed higher yields of total fatty acids when compared to “raw” microalgae, being 5.22 and 1%, respectively. The sustainable developed methodology led to the production of one fraction rich in bioactive peptides and another with interesting EPA content, both with value-added properties with potential to be commercialized as ingredients for different industrial applications, such as functional food, supplements or cosmetic formulations.
- Health benefits and bioavailability of marine resources components that contribute to health – what’s new?Publication . Nova, Paulo; Pimenta-Martins, Ana; Silva, Joana Laranjeira; Silva, Ana Machado; Gomes, Ana Maria; Freitas, Ana CristinaThe strict connection between nutritional intake and health leads to a necessity of understanding the beneficial and protective role of healthy nutrients and foods. The marine environment is a source of a plethora of many organisms with unique properties, extremely rich in bioactive compounds and with remarkable potential for medical, industrial and biotechnological applications. Marine organisms are an extreme valuable source of functional ingredients such as polysaccharides, vitamins, minerals, pigments, enzymes, proteins and peptides, polyunsaturated fatty acids (PUFA), phenolic compounds and other secondary metabolites that prevent or have the potential to treat several diseases given their cardiovascular protective, anti-inflammatory, anti-hypertensive, anti-oxidant, anti-coagulant, anti-proliferative and anti-diabetic activities. This review provides an overview on the current advances regarding health benefits of marine bioactive compounds on several diseases and on human gut microbiota. In addition, it is discussed a crucial factor that is related to the effectiveness of these compounds on human organism namely its real bioavailability.
- In vitro gastrointestinal digestion impact on the antioxidant activity of extracts produced from the microalgae chlorella vulgaris and nannochloropsis oceanicaPublication . Cunha, Sara A.; Salsinha, Ana S.; Silva, Joana Laranjeira; Pintado, ManuelaMicroalgae are rapidly cultivable growing photosynthetic organisms rich in compounds with high biological values, such as antioxidants, with interest for food industry. Although microalgae extracts may present several health benefits, it is necessary to understand if their properties are maintained throughout the gastrointestinal (GI) digestion, after the exposure to enzymes and different pH ranges. Thus, this work studied the impact of in vitro gastrointestinal digestion on the antioxidant activity of extracts produced from the microalgae Chlorella vulgaris and Nannochloropsis oceanica, with the goal of evaluating their potential as functional food ingredients. Chlorella extract was produced by acid and enzymatic hydrolysis (cellulase and subtilisin) and Nannochloropsis extract by enzymatic hydrolysis (cellulase and subtilisin). Both were submitted to simulated GI conditions. The antioxidant activity was determined by ORAC and ABTS assays in four stages of GI simulation (before digestion, and after mouth, stomach and intestine digestion). Both extracts showed increased ORAC and ABTS values throughout the GI digestion. This increase was statistically significant for Chlorella in terms of ABTS values in all phases, and in ORAC after stomach and intestine digestion. For Nannochloropsis, only the increase in ABTS values was statistically different after stomach and intestine digestion (pThis study showed that both extracts maintain their antioxidant activity throughout in vitro GI digestion, with a little increase being observed, which may be explained by the formation of smaller and more bioactive peptides. These results shows that Chlorella and Nannochloropsis extracts may be considered sustainable antioxidant ingredients for the development of functional food.
- Microalgae, a potential source of protein and bioactive peptidesPublication . Cunha, Sara; Coscueta, Ezequiel; Castro, Rita de; Silva, Joana Laranjeira; Pintado, Manuela
- Nannochloropsis oceanica: a source of bioactive peptidesPublication . Cunha, Sara; Coscueta, Ezequiel; Silva, Joana Laranjeira; Pintado, Manuela
- Optimization of bioactive peptides extraction from chlorella vulgarisPublication . Cunha, Sara; Coscueta, Ezequiel; Silva, Joana Laranjeira; Pintado, Manuela
- Optimization of bioactive peptides extraction from chlorella vulgarisPublication . Cunha, Sara; Coscueta, Ezequiel; Silva, Joana Laranjeira; Pintado, ManuelaChlorella vulgaris may be a source of several interesting compounds, as bioactive peptides with anticancer, antioxidant, anti-hypertensive activities. Furthermore, microalgae peptides may also be of great interest due to their functional properties as solubility, emulsifying and foaming properties, which could be beneficial for industrial application. The microalgae cell wall is rich in polysaccharides making it rigid and difficult to digest and, consequently, limiting the extraction of proteins and generation of peptides. Whereby it is important to break cell wall to achieve a more efficient peptide extraction. Therefore, this work aimed to obtain an optimized microalgae extract rich in bioactive peptides, through the combination of acid and enzymatic hydrolysis. Chlorella vulgaris was submitted to several extraction conditions, with variable factors including temperature, pH values, enzymes type, enzymes concentration, incubation time, use of salts and acids. The best factors were chosen after the determination of protein concentration (Bicinchoninic acid assay) and hydrolysis degree (2,4,6-Trinitrobenzene-l -Sulfonic Acid Method). A combination of an acid and an enzymatic hydrolysis, with a cellulase and a protease, appeared to be the best method to achieve protein and peptide extraction. The antioxidant and anti-hypertensive activities of peptides were tested by Oxygen-radical absorbance-capacity assay and ACE-inhibitory activity assay, respectively. To confirm the optimal extraction conditions, an experimental design was performed using statgraphic centurion software. Factorial design allowed an evaluation of the effect of three factors (protease concentration, temperature and hydrolysis time) on protein release and extracts bioactivities. The best extracts showed high antioxidant (34 μmol Trolox Equivalent/mg sample) and anti-hypertensive (IC50 of 12,75 μg protein/mL) activities. Thus, the factorial design allowed to confirm the combination of experimental factors that leads to the most efficient extraction of antioxidant and anti-hypertensive peptides, validating the studied extraction method. The obtained peptide extract may be further tested toward the development of functional foods.