Untitled

Funder

Organizational Unit

Publications

Biological protein precipitation: a green process for the extraction of cucumisin from melon (Cucumis melo L. inodorus) by-products

Publication . Gómez-García, Ricardo; Campos, Débora A.; Aguilar, Cristóbal N.; Madureira, Ana R.; Pintado, Manuela

Cucumisin (CUC) from industrial melon by-products was separated for the first time through biological precipitation using carrageenan (CRG). This approach could represent a cost-effective and environmentally friendly process for the industries, avoiding the use of expensive equipment and toxic salts or solvents, such as butanol and ethanol. In this study, biological precipitation of proteins from melon by-products using CRG was studied and compared with conventional precipitation with ammonium sulphate. Different methods were applied for the identification and characterization of isolated proteins, including SDS-PAGE gel, FPLC and proteolytic activity assays. The isolated CUC confirmed a molecular weight of 68 kDa and showed highly stable proteolytic (PA) and milk-clotting (MCA) activities in a wide range of CaCl2 (20 to 60 mM), pH (5 to 7) and temperatures (30 to 85 ºC). Melon peel extract demonstrated to possess significant PA (4.24 U/mg protein) and MCA (191.50 MCU/mg protein), but such values were increased by ammonium sulphate precipitation (1.60 and 2.06-folds, respectively), and specially a noticeable increment was observed by biological precipitation with 2.11 and 17.65-folds, respectively, demonstrating the capability to be an effective strategy to isolate and purify CUC, allowing a yield of 0.17 g CUC/100 g of by-products and keeping its biological properties.

2021Journal article

Open access

The use of emergent technologies to extract added value compounds from grape by-products

Publication . Coelho, M. C.; Pereira, R.; Rodrigues, A. S.; Teixeira, J. A.; Pintado, M.E

Background: The current circular economy system-based sustainability and the social lifestyle trends, have led to a developed structure that is restorative or regenerative by purpose and innovation. It substitutes the end-of-life idea of a by-product adding value to it, shifts towards the usage of environmentally friendly solutions, elimi-nating the harmful chemicals, which impair reuse. Scope and approach: Considering the wine production, which is one of the most critical agro-industrial sectors worldwide, generating large amounts of by-products with environmental impact, but also with high economic and nutritional potential. This review aims to evaluate the effects of alternative green technologies on the functionality and recovery of bioactive compounds (BCs) from wine by-products. Key findings and conclusions: These agro-industrial by-products, e.g., skins and pulp remnants, are rich in BCs with health benefits such as supporting the immune system, anti-tumoral, and preventing cardiovascular diseases. Besides, the consumer has increased interest in diet and health, demanding suppliers to consider the reuse of agro-food by-products. Thus, the application of green recovery technologies eliminates the harmful effects comparing to conventional technologies, can be recycled into the food chain as functional additives for different products and applications, guaranteeing the sustainability and reducing the winemaking by-products.

2020Journal article

Restricted access

Incorporation of olive pomace ingredients into yoghurts as a source of fibre and hydroxytyrosol: antioxidant activity and stability throughout gastrointestinal digestion

Publication . Ribeiro, Tânia B.; Bonifácio-Lopes, Teresa; Morais, Pilar; Miranda, Arménio; Nunes, João; Vicente, António A.; Pintado, Manuela

Liquid-enriched powder (LOPP) and pulp-enriched powder (POPP) obtained from olive pomace were incorporated into yoghurt, not only, to increase its content in dietary fibre, hydroxytyrosol and unsaturated fatty acids, but also to understand the lipids-phenolics interaction by simultaneous incorporation of olive oil. POPP (2%) and LOPP (1%) addition to yoghurt allowed fulfilling the condition of being a “source of fibre” and provided 5 mg of hydroxytyrosol and derivatives in a standard yoghurt (120 g), respectively. Yoghurts’ unsaturated fatty acids profile was positively influenced by the addition of only POPP and olive oil + LOPP or + POPP. All OP powder-fortified yoghurts exhibited higher total phenolic content and antioxidant activity than the control (p<0.05). After in vitro digestion the bioaccessibility of total phenolics (more 25.58%) and hydroxytyrosol (more 68.71%) in LOPP-yoghurts was improved by the addition of olive oil. In conclusion, OP powders´ incorporation gave additional and essential healthy properties to yoghurt.

2021Journal article

Open access

Prebiotic effects of olive pomace powders in the gut: In vitro evaluation of the inhibition of adhesion of pathogens, prebiotic and antioxidant effects

Publication . Ribeiro, Tânia; Costa, Célia Maria; Bonifácio-Lopes, Teresa; Silva, Sara; Veiga, Mariana; Monforte, Ana Rita; Nunes, João; Vicente, António A.; Pintado, Manuela

Olive pomace is a biowaste rich in polyphenols and insoluble dietary fibre with high potential to develop new value chains towards a sustainable and circular bioeconomy. Regarding gut health, olive pomace phenolics and insoluble dietary fibre (after possible fermentation) could act as antioxidants, antimicrobial and prebiotic agents. These potential beneficial effects on the gut were analysed for two powders from olive pomace: liquid-enriched powder (LOPP) - mostly source of phenolics - and pulp-enriched powder (POPP) - main source of insoluble dietary fibre. LOPP and POPP were subjected to an in vitro simulated gastrointestinal digestion followed by in vitro faecal fermentation. The undigested fraction retained in the colon was analysed regarding its potential antioxidant, antimicrobial and prebiotic effects. LOPP and POPP did not impact the gut microbiota diversity negatively, showing a similar ratio of Firmicutes/Bacteroidetes compared to a positive control (FOS). LOPP exhibit a positive (similar to FOS) effect on the Prevotella spp./Bacteroides spp. ratio. Both powders promoted more the production of short-chain fatty acids (mainly acetate > butyrate > propionate) than FOS and showed also significant total phenolic content and oxygen radical absorbance capacity during faecal fermentation until 48 h. Besides that, these powders showed mucin-adhesion inhibition ability against pathogens, principally POPP against Bacillus cereus (22.03 ± 2.45%) and Listeria monocytogenes (20.01 ± 1.93%). This study demonstrates that olive pomace powders have prebiotic effects on microbiota, including the stimulation of short-chain fatty acids production, potential antioxidant and antimicrobial activity which could improve the human gut health.

2021Journal article

Restricted access