Loading...
6 results
Search Results
Now showing 1 - 6 of 6
- Stability, kinetics, and application study of phycobiliprotein pigments extracted from red algae Gracilaria gracilisPublication . Pereira, Tatiana; Barroso, Sonia; Mendes, Susana; Gil, Maria M.Phycobiliprotein (PBP) pigments were extracted from red algae Gracilaria gracilis through maceration in phosphate buffer using previously optimized conditions. The stability of PBPs in the extracts was assessed by monitoring the extracts at different pHs and temperatures for 10 days. Since phycoerythrin (PE) is the main PBP present in G. gracilis, PE content was spectroscopically determined and used as a response factor. Kinetic modeling was used to describe PE degradation under different ranges of T and pH. The pigment extracts presented higher stability at pH 6.9 and −20 °C. PE was semipurified by precipitation with ammonium sulphate 65% followed by dialysis against water until a purity index of 0.7. The pigment was successfully applied as colorant in pancakes and yogurts with a pigment concentration of 0.15%. This study highlights the potential of PE pigments extracted from G. gracilis for applications in food products.
- Optimization of phycobiliprotein pigments extraction from red algae Gracilaria gracilis for substitution of synthetic food colorantsPublication . Pereira, Tatiana; Barroso, Sónia; Mendes, Susana; Amaral, Renata A.; Dias, Juliana R.; Baptista, Teresa; Saraiva, Jorge A.; Alves, Nuno; Gil, Maria M.The extraction of phycobiliprotein (PBP) pigments from red algae Gracilaria gracilis was optimized using maceration, ultrasound-assisted extraction (ultrasonic water bath and ultrasonic probe), high pressure-assisted extraction, and freeze-thaw. The experimental conditions, namely homogenization time (t1), buffer concentration (C), treatment time (t2), biomass: buffer ratio (R), and pressure (P), were optimized using Response Surface Methodology (RSM). The yield of phycoerythrin (PE) extracted, determined spectroscopically, was used as the response variable. Maceration was the most efficient extraction method yielding 3.6 mg PE/g biomass under the optimal conditions (t1 = t2 = 10 min; C = 0.1 M; R = 1:50). Scanning Electron Microscopy (SEM) analysis of the biomass before and after the cell disruption treatments revealed a more efficient cell wall rupture with maceration.
- Study of the seasonal variations of the fatty acid profiles of selected macroalgaePublication . Pereira, Tatiana; Horta, André; Barroso, Sonia; Mendes, Susana; Gil, Maria M.Due to the high consumption of fat-rich processed foods, efforts are being done to reduce their saturated fat (SFA) contents and replace it with polyunsaturated fatty acids (PUFA), creating a necessity to find alternative PUFA sources. Macroalgae, being a promising natural source of healthy food, may be such an alternative. The fatty acid (FA) profile of Fucus spiralis, Bifurcaria bifurcata, Ulva lactuca, and Saccorhiza polyschides were determined through direct transesterification and their seasonal variation was studied. F. spiralis showed the highest FA content overall, B. bifurcata presented the higher PUFA amounts, and U. lactuca and S. polyschides the higher SFA. The production of FA was shown to be influenced by the seasons. Spring and summer seemed to induce the FA production in F. spiralis and B. bifurcata while in U. lactuca the same was verified in winter. U. lactuca presented a !6/!3 ratio between 0.59 and 1.38 while B. bifurcata presented a ratio around 1.31. The study on the seasonal variations of the macroalgal FA profile can be helpful to understand the best season to yield FA of interest, such as ALA, EPA, and DHA. It may also provide valuable information on the best culturing conditions for the production of desired FAs.
- Valorization of the red seaweed Gracilaria gracilis through a biorefinery approachPublication . Martins, Alice; Pinto, Filipa R.; Barroso, Sónia; Pereira, Tatiana; Mouga, Teresa; Afonso, Clélia; Freitas, Marta V.; Pinteus, Susete; Pedrosa, Rui; Gil, Maria MThe interest in seaweeds as an abundant feedstock to obtain valuable and multitarget bioactive ingredients is continuously growing. In this work, we explore the potential of Gracilaria gracilis, an edible red seaweed cultivated worldwide for its commercial interest as a source of agar and other ingredients for cosmetic, pharmacological, food, and feed applications. G. gracilis growth conditions were optimized through vegetative propagation and sporulation while manipulating the physicochemical conditions to achieve a large biomass stock. Green extraction methodologies with ethanol and water were performed over the seaweed biomass. The bioactive potential of extracts was assessed through a set of in vitro assays concerning their cytotoxicity, antioxidant, and antimicrobial properties. Additionally, dried seaweed biomass was incorporated into pasta formulations to increase food's nutritional value. Pigments extracted from G. gracilis have also been incorporated into yogurt as a natural colorant, and their stability was evaluated. Both products were submitted to the appreciation of a semitrained sensorial panel aiming to achieve the best final formulation before reaching the market. Results support the versatility of G. gracilis whether it is applied as a whole biomass, extracts and/or pigments. Through implementing several optimized protocols, this work allows the development of products with the potential to profit the food, cosmetic, and aquaculture markets, promoting environmental sustainability and a blue circular economy. Moreover, and in line with a biorefinery approach, the residual seaweed biomass will be used as biostimulant for plant growth or converted to carbon materials to be used in water purification of the in-house aquaculture systems of MARE-Polytechnic of Leiria, Portugal.
- Food texture design by 3D printing: a reviewPublication . Pereira, Tatiana; Barroso, Sónia; Gil, Maria M.An important factor in consumers’ acceptability, beyond visual appearance and taste, is food texture. The elderly and people with dysphagia are more likely to present malnourishment due to visually and texturally unappealing food. Three-dimensional Printing is an additive manufacturing technology that can aid the food industry in developing novel and more complex food products and has the potential to produce tailored foods for specific needs. As a technology that builds food products layer by layer, 3D Printing can present a new methodology to design realistic food textures by the precise placement of texturing elements in the food, printing of multi-material products, and design of complex internal structures. This paper intends to review the existing work on 3D food printing and discuss the recent developments concerning food texture design. Advantages and limitations of 3D Printing in the food industry, the material-based printability and model-based texture, and the future trends in 3D Printing, including numerical simulations, incorporation of cooking technology to the printing, and 4D modifications are discussed. Key challenges for the mainstream adoption of 3D Printing are also elaborated on.
- Gracilaria gracilis as a novel source of food colorants: extraction optimization of phycobiliprotein pigmentsPublication . Pereira, Tatiana Filipa Martins; Silva, Maria Manuel Gil de Figueiredo Leitão e; Mendes, Susana Luísa da Custódia Machado; Baptista, Teresa Maria CoelhoOs corantes alimentares sintéticos têm sido utilizados na indústria alimentar durante séculos, mas hoje em dia com a mudança das tendências de consumo, existe uma grande procura por alternativas naturais com capacidade de substituir esses corantes. As ficobiliproteinas (PBPs) são proteínas solúveis em água presentes maioritariamente nas algas vermelhas e cianobactérias, com grande potencial económico nas indústrias farmacêuticas, biomédicas, alimentares e cosméticas. Estas proteínas podem ser classificadas em três grupos principais, baseados no seu comportamento de absorção: Ficoeritrinas (PE), Ficocianinas (PC) e Aloficocianinas (APC) com máximos de absorção entre os 540-570, 610-620 e 650-655 nm, respetivamente. Este trabalho tem como objetivo principal otimizar as condições de extração das PEs a partir da alga vermelha Gracilaria gracilis, presente na costa portuguesa que contém PBPs, principalmente PEs, como pigmentos acessórios, sendo uma alga principalmente utilizada como alimento e fonte de agar. Adicionalmente, foi estudado o efeito do pH e da temperatura na estabilidade dos extratos aquosos, bem como a sua aplicação em produtos alimentares. Foram estudadas cinco metodologias distintas, com elevado potencial em termos económicos e ambientais: maceração com almofariz, banho de ultrassons, sonicador, congelamento/descongelamento e altas pressões. As condições experimentais, tais como a concentração do tampão fosfato (C), o rácio solvente/biomassa (R), o tempo de homogeneização (t1), o tempo de extração (t2) e a pressão (P) foram otimizadas utilizando a Metodologia de Superfície de Resposta (RSM). Esta permitiu delinear modelos sustentados nas variáveis independentes e explicar a variabilidade que ocorre nos parâmetros considerados significativos (rendimento). A maceração foi o método de extração mais eficiente (condições ótimas t1 = t2 = 10 min; C = 0,1 M; R = 1:50) atingindo valores de 3,583 ± 0,033 mg de PE/g de alga rendimentos 55-65 % superiores aos outros métodos testados. Quanto às condições, a variável t2 foi a que exerceu maior influência no rendimento obtido, enquanto o aumento de C resultou em menores rendimentos. t1 foi a avariável que menos efeito teve no resultado. Relativamente à estabilidade, foi monitorizado o efeito de diferentes temperaturas de armazenamento (-20, 4, temperatura ambiente (~19) e 40 ºC) e pH (4, 6,9 e 8) na concentração de PE durante 10 dias. Os resultados demonstram maior estabilidade a -20 ºC e pH 6,9. Como caso de estudo, o extrato purificado (pigmento) foi incorporado em panquecas (0,15 %) e iogurtes (0,12 %) como corante rosa. As PEs foram precipitadas com sulfato de amónio (65 %) e purificadas por diálise, permitindo a utilização em alimentos. Durante o processo de cozimento das panquecas, foi observada uma ligeira perda de cor, enquanto nos iogurtes a cor manteve-se praticamente inalterada durante mais de dois meses, sugerindo uma melhor aptidão deste tipo de produto para a coloração com PEs. Com este trabalho foi possível concluir que a Gracilaria gracilis tem potencial enquanto fonte de pigmentos para aplicações alimentares, especialmente para utilização em produtos que não necessitem de elevadas temperaturas no processo de produção.