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- Enhancing oxidative stability of sunflower oil by supplementation with prickled broom (Pterospartum tridentatum) ethanolic extractPublication . Neves, Marta; Miranda, Andreia; Lemos, Marco F.L.; Silva, Susana; Tecelão, CarlaThis study aimed to evaluate the effect of ethanolic extract of Pterospartum tridentatum flowers in the stability of sunflower oil. The extract was characterized regarding to its antioxidant activity by the 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) scavenging method (EC50 = 76.3 ± 2.6 μg/mL) and total phenolic content (200 ± 8 mg GAE/g). Extracts were added at 500 mg/L (E1) and 1,000 mg/L (E2), and after 30 days of storage at room temperature, E2 oil showed improved quality parameters,with a reduction of 22.4%,17.2%,and 45.6% in the values of acidity,peroxide,and p-anisidine, respectively.The extract also increased oil stability at 180 °C.After 27 hr, the acidity (0.216 ± 0.016 mg KOH/g) and the total oxidation value (TOTOX) (69.30 ± 0.26) values of E2 oil were significantly lower than the control. These results showed that P. tridentatum effectively improved the shelf-life and thermal stability of sunflower oil,being a promising source of antioxidants for edible oils processing.
- Preservation of fresh-cut Rocha Pear using Codium tomentosum extractPublication . Augusto, Ana; Miranda, Andreia; Crespo, Daniel; Campos, Maria J.; Raimundo, Délio; Pedrosa, Rui; Mitchell, Geoffrey; Niranjan, Keshavan; Silva, Susana F.J.Rocha is a Portuguese pear cultivar with high economic importance in the Portuguese Western Region. Degradative processes following its manipulation can quickly lead to product rejection, especially when sold as a freshcut product. The efficacy of a marine-based edible coating to inhibit superficial browning development in freshcut Rocha pear slices was investigated over a storage period of 15 days. The aqueous extract of Codium tomentosum, an edible green seaweed, was incorporated in an edible coating (0.5 g 100 mL -1) for fresh-cut Rocha pear. This novel treatment effect on the quality parameters of the pears was compared with a commercial coating currently used by industry and a control (dipping in deionised water). After 15 days storage at 4 ◦C, samples treated with the seaweed extract exhibited fewer colour changes and lower rates of superficial browning than control and commercial samples. Seaweed extract treatment was also observed to inhibit yeast and mould development, which may further contribute to shelf-life extension.
- Preservation of fresh-cut Rocha Pear using Codium tomentosum extractPublication . Augusto, Ana; Miranda, Andreia; Crespo, Daniel; Campos, Maria J.; Raimundo, Délio; Pedrosa, Rui; Mitchell, Geoffrey; Niranjan, Keshavan; Silva, Susana F.J.Rocha is a Portuguese pear cultivar with high economic importance in the Portuguese Western Region. Degradative processes following its manipulation can quickly lead to product rejection, especially when sold as a freshcut product. The efficacy of a marine-based edible coating to inhibit superficial browning development in freshcut Rocha pear slices was investigated over a storage period of 15 days. The aqueous extract of Codium tomentosum, an edible green seaweed, was incorporated in an edible coating (0.5 g 100 mL -1) for fresh-cut Rocha pear. This novel treatment effect on the quality parameters of the pears was compared with a commercial coating currently used by industry and a control (dipping in deionised water). After 15 days storage at 4 ◦C, samples treated with the seaweed extract exhibited fewer colour changes and lower rates of superficial browning than control and commercial samples. Seaweed extract treatment was also observed to inhibit yeast and mould development, which may further contribute to shelf-life extension.
- A pilot plant scale testing of the application of seaweed-based natural coating and modified atmosphere packaging for shelf-life extension of fresh-cut applePublication . Augusto, Ana; Miranda, Andreia; Costa, Leonor; Pinheiro, Joaquina; Campos, Maria J.; Raimundo, Délio; Pedrosa, Rui; Mitchell, Geoffrey; Niranjan, Keshavan; Silva, Susana F. J.Codium tomentosum hydroethanolic extract was obtained using a pilot solid–liquid extractor to validate the anti-browning functionality of the extract under industrial conditions. Fresh-cut apple slices were coated by immersion in: (1) a seaweed extract solution (0.5% w/v) and (2) a commercial coating, and the two sets of samples were compared with a control (immersion in water). Packaged samples were stored, under ambient and modified atmosphere conditions at 4°C. After 30 days of storage, the samples that were coated with the seaweed extract and packaged under modified atmosphere, demonstrated lower peroxidase activity and polyphenol oxidation when compared with the samples treated with the commercial additive. These results confirm, at pilot scale and under industrial production conditions, the efficacy of the seaweed extract as a bio-based substitute for the synthetic coatings, which are currently used to prevent browning in fresh-cut apples. Novelty impact statement Fresh-cut fruits are subjected to processing operations leading to a decrease in nutritional and organoleptic properties. It is therefore necessary to adopt strategies to delay the degradative processes. In this study, the efficacy of a pilot-scale production and industrial application of a coating formulated with Codium tomentosum seaweed extract has been established for the first time. This seaweed extract possesses the potential to prevent browning development in fresh-cut apples under industrial operating conditions.
- Marine resources application potential for biotechnological purposesPublication . Lemos, Marco F.L.; Novais, Sara C.; Silva, Susana F.J.; Félix, Carina
- Argan oil as a rich source of linoleic fatty acid for dietetic structured lipids productionPublication . Simões, Tiago; Ferreira, Jessica; Lemos, Marco F.L.; Augusto, Ana; Félix, Rafael; Silva, Susana F.J.; Ferreira-Dias, Suzana; Tecelão, CarlaArgan oil is rich in long-chain unsaturated fatty acids (FA), mostly oleic and linoleic, and natural antioxidants. This study addresses the production of low-calorie structured lipids by acidolysis reaction, in a solvent-free system, between caprylic (C8:0; system I) or capric (C10:0; system II) acids and argan oil, used as triacylglycerol (TAG) source. Three commercial immobilized lipases were tested: Novozym® 435, Lipozyme® TL IM, and Lipozyme® RM IM. Higher incorporation degree (ID) was achieved when C10:0 was used as acyl donor, for all the lipases tested. Lipozyme® RM IM yielded the highest ID for both systems (28.9 +- 0.05 mol.% C10:0, and 11.4 +- 2.2 mol.% C8:0), being the only catalyst able to incorporate C8:0 under the reaction conditions for biocatalyst screening (molar ratio 2:1 FA/TAG and 55ºC). The optimal conditions for Lipozyme® RM IM in system II were found by response surface methodology (66ºC; molar ratio FA/TAG of 4:1), enabling to reach an ID of 40.9 mol.% of C10:0. Operational stability of Lipozyme® RM IM in system II was also evaluated under optimal conditions, after eight consecutive 24 h-batches, with biocatalyst rehydration between cycles. The biocatalyst presented a half-life time of 103 h.
- Seaweed fermentation within the fields of food and natural productsPublication . Reboleira, João; Silva, Susana; Chatzifragkou, Afroditi; Niranjan, Keshavan; Lemos, Marco F.L.Background: Seaweeds are promising substrates for biotransformation via fermentation, something that has been primarily utilized by the field of biofuels but focused less attention from other fields of research. Considering that the fermentation of abundant land resources has become an important means by which new added-value compounds can be obtained, exploring the same process for seaweeds can contribute to an effective and sustainable exploitation of marine resources. Scope and approach: In this review, recent advances demonstrating the potential behind the fermentation of seaweeds are evaluated. A breakdown of the most relevant seaweed compounds and their effect on potential bioprocesses is presented, along with pre-processing techniques that have become popular in biofuel fermentations. The applications of seaweed fermentation products in the fields of natural product research, functional foods and nutraceuticals, as well as the limitations and opportunities of seaweed fermentation are also highlighted. Key findings and conclusions: Research revealing that seaweed fermentation can be used to create novel food and nutraceutical products that demonstrate high bioactivity and sensory quality was presented. The studies included demonstrate the use of this process in algal tissues and extracts as an enhancer of antioxidant, antimicrobial, antiinflammatory and antidiabetic activities, among others. Many of the difficulties related to fermenting seaweed have been addressed by research within the field of biofuels, providing insight on the conditions and pretreatments necessary to improve seaweed fermentability. Food applications for seaweed fermentation products are still underdeveloped, but the nutritional, sensory and bioactive profiles collected so far highly encourage further developments.
- Oxidative Stability of Sunflower Oil Enriched with Fig Tree Leaves Bioactive Compounds at Frying TemperaturePublication . Pinteus, Susete; Neves, Marta; Tecelão, Carla; Silva, Susana; Cruz, Alexandra; Bernardino, Susana; Mendes, Vasco; Ribeiro, Vânia; Vaz, Daniela; Campos, Maria JorgeThe pressure imposed by the increase of world’s population and climate change makes it imperative to find sustainable strategies to optimize food resources and decrease waste production based on circular economy principles. This work evaluated the potential of fig tree leaves to reduce the oxidation of sunflower oil when exposed to frying temperatures. The bioactive compounds extracted directly from fig tree leaves were incorporated into the oil at a ratio of 12.5% (m/m), with the assistance of ultrasounds. The supplemented oil was characterized in terms of its total phenolic content (TPC), which was determined using the Folin-Ciocalteu method, and its antioxidant capacity, which was evaluated using both the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay and the ferric reduction antioxidant power (FRAP) assay. Also, the color of the oil and the oxidation products (K232 and K270) were analyzed. Supplementing the oil with fig tree leaves resulted in a higher antioxidant capacity compared to the control, as demonstrated by the DPPH assay (5128 ± 466 vs. 1106 ± 407 µM Trolox eq/kg oil), as well as lower levels of primary and secondary oxidation products. The results suggest that fig tree leaves can be a valuable source of antioxidant compounds with the capacity to improve the nutritional value and oxidative stability of sunflower oil under frying temperatures.
- Influence of Codium tomentosum Extract in the Properties of Alginate and Chitosan Edible FilmsPublication . Augusto, Ana; Dias, Juliana R.; Campos, Maria J.; Alves, Nuno; Pedrosa, Rui; Silva, SusanaThe growing search for natural alternatives to synthetic food packaging materials and additives has increased, and seaweed extracts’ bioactivity has made them suitable candidates for incorporation in novel edible films. This study aims to investigate the effect of Codium tomentosum seaweed extract (SE) incorporation in alginate and chitosan edible films. Alginate- and chitosan-based films with and without the incorporation of 0.5% SE were characterized according to their physical, optical, mechanical, and thermal properties. Seaweed extract incorporation in chitosan films resulted in an increase of film solubility (50%), elasticity (18%), and decrease of puncture strength (27%) and energy at break (39%). In alginate films, the extract incorporation significantly decreased film solubility (6%), water vapour permeability (46%), and elasticity (24%), and had no effect on thermal properties. Depending on the type of application, the addition of SE in edible films can bring advantages for food conservation.
- Chemical characterization of fungal chitosan for industrial applicationsPublication . Cruz, Pedro; Vaz, Daniela C.; Ruben, Rui B.; Avelelas, Francisco; Silva, Susana; Campos, Maria