Browsing by Author "Teixeira, Raquel"
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- Flow-based method for total protein content monitoring in by-products hydrolysatesPublication . Teixeira, Raquel; Ribas, Tânia C. F.; Almeida, André; Pintado, Manuela; Rangel, A. O. S. S.For this purpose, the conventional and reliable Biuret method was used. This method was chosen for its ease of preparation and the use of reagents with associated low toxicity. The flow-based approach consisted of a double injection of the sample and reagent in a continuous stream, resulting in the reduction of the reagent consumption. For the development of the flow injection analysis (FIA) system, essential parameters, including reagent concentration, flow rate and reactor length, were optimized. The method was validated across various matrices, addressing potential interferences, and demonstrated repeatability and reproducibility. This optimized protocol offers a robust, efficient tool for the food industry, enhancing quality control and nutritional assessments.
- Optimized flow-based protein content monitoring in by-products hydrolysates with two merge zones integrationPublication . Teixeira, Raquel; Ribas, Tânia C. F.; Almeida, André; Pintado, Manuela; Rangel, António O. S. S.In the past few years, the interest in protein hydrolysates has been growing exponentially due to their nutritional and functional benefits for both human food and animal feed. In this context, total protein content is a key parameter for characterizing by-products, monitoring the hydrolysis processes, and the hydrolysates. This study aims to develop an accurate and expeditious, revisiting a merging zones flow-based spectrophotometric method for total protein quantification in food samples and hydrolysates. For this purpose, the conventional and reliable Biuret method was used. This method was chosen for its ease of preparation and the use of reagents with associated low toxicity. The flow-based approach consisted of a double injection of the sample and reagent, using a commutator, in a continuous stream, resulting in the reduction of the reagent consumption. For the development of the flow injection analysis (FIA) system, essential parameters, including reagent concentration, flow rate and reactor length, were optimized. The method was validated across various matrices, addressing potential interferences, and demonstrated repeatability and reproducibility. This optimized protocol offers a robust, efficient tool for the food industry, enhancing quality control and nutritional assessments.
- Processing slime from snail (Helix aspersa maxima): a preliminary study on the effect on microbial loadPublication . Teixeira, Raquel; Barbosa, Joana; Albano, Helena; Maciel, Cláudia; Silva, Joana; Saraiva, Jorge A.; Castro, Sónia M.; Teixeira, PaulaSlime from earth snails (Helix aspersa maxima) is a sub-product often used in the cosmetic industry. Due to its origin, a decontamination process ought to be considered. After exposure to UV radiation, no significant (P > 0.05) reduction of the initial microbial load of slime was observed, while treated at 60 °C, a decrease of 4.0 log CFU∙mL-1 was obtained (when compared to non-treated slime). A similar reduction was attained for pressurized (500 MPa) slime. The sequential combination of temperature and pressure treatment had a similar effect (P > 0.05) on the microbial load when compared to 400 MPa (30 min), but the reduction was higher when compared to the less intense treatments (60 °C, 15 min; 400 MPa, 15 min). Overall, the results suggest that pressure ( 400 MPa) is a promising technology for processing snail slime, which can have positive effects on its microbial load, for further use in the cosmetic industry
- Revisiting merging zones in a flow-based approach for the total protein content monitoring in hydrolysatesPublication . Teixeira, Raquel; Ribas, Tânia C. F.; Almeida, André; Pintado, Manuela; Rangel, António O. S. S.In the past few years, the interest in protein hydrolysates has been growing exponentially due to their nutritional and functional benefits for both human food and animal feed. In this context, total protein content is a key parameter for characterizing by-products, monitoring the hydrolysis processes, and hydrolysates. This study aims to develop an expeditious, revisiting a merging zones flow-based spectrophotometric method for total protein quantification in hydrolysates (Fig.1). For this purpose, the conventional and reliable Biuret method was used. The flow-based approach consisted of a double injection of the sample and reagent, using a injector commutator, in a continuous stream, resulting in the reduction of the reagent consumption. For the development of the flow injection analysis (FIA) system, essential parameters, including reagent concentration, flow rate and reactor length, were optimized. The method was validated across various matrices, addressing potential interferences, and demonstrated repeatability and reproducibility. This optimized protocol offers a robust, efficient tool for the food industry, enhancing quality control and nutritional assessments.