Centre of Biotechnology and Fine Chemistry

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Publications

Continuous production of highly tuned silk/calcium-based composites: exploring new pathways for skin regeneration

Publication . Veiga, Anabela; Magalhaes, Rui; Duarte, Marta M.; Dias, Juliana R.; Alves, Nuno M.; Costa-Pinto, Ana Rita; Castro, Filipa; Rocha, Fernando; Oliveira, Ana L.

Calcium plays an important role in barrier function repair and skin homeostasis. In particular, calcium phosphates (CaPs) are well established materials for biomedical engineering due to their biocompatibility. To generate biomaterials with a more complete set of biological properties, previously discarded silk sericin (SS) has been recovered and used as a template to grow CaPs. Crucial characteristics for skin applications, such as antibacterial activity, can be further enhanced by doping CaPs with cerium (Ce) ions. The effectiveness of cell attachment and growth on the materials highly depends on their morphology, particle size distribution, and chemical composition. These characteristics can be tailored through the application of oscillatory flow technology, which provides precise mixing control of the reaction medium. Thus, in the present work, CaP/SS and CaP/SS/Ce particles were fabricated for the first time using a modular oscillatory flow plate reactor (MOFPR) in a continuous mode. Furthermore, the biological behavior of both these composites and of previously produced pure CaPs was assessed using human dermal fibroblasts (HDFs). It was demonstrated that both CaP based with plate-shaped nanoparticles and CaP-SS-based composites significantly improved cell viability and proliferation over time. The results obtained represent a first step towards the reinvention of CaPs for skin engineering.

2022Journal article

Open access

Chemical-based methodologies to extend the shelf life of fresh fish: a review

Publication . Amaral, Renata A.; Pinto, Carlos A.; Lima, Vasco; Tavares, Jéssica; Martins, Ana P.; Fidalgo, Liliana G.; Silva, Ana M.; Gil, Maria M.; Teixeira, Paula; Barbosa, Joana; Barba, Francisco J.; Saraiva, Jorge A.

Due to its characteristics, fresh fish is a highly perishable food with a very short shelf-life under refrigeration. Several methods have been introduced to slow down its deterioration, such as by means of oxygen depletion of the food package (vacuum packaging), or by changing the natural atmosphere that is in contact with the fresh fish (modified atmosphere packaging), or by the use of chemicals generally recognized as safe: such compounds can be directly applied (by dipping or spraying) or incorporated into packaging materials and slowly migrate to the product, exerting a hurdle effect against microbial development and lipid oxidation (active packaging). This review aims to cover the most recent advances in chemical-based approaches for fresh fish preservation, applied either singly or in combination. Vacuum packaging, modified atmosphere, and active packaging preservation methodologies are presented, along with the inclusion of chemical additives, such as organic acids and natural extracts, and their combination with icing systems. Advantages and disadvantages of these methodologies and their impact on fresh fish quality and shelf-life are discussed, reaching the conclusion that both are positively influenced overall. Indeed, the contribution of hemical-based strategies for fresh fish preservation is undeniable, and is expected to be a research topic of increasing interest in the future.

2021Journal article

Open access

Preliminary results on the effect of 1-naphthaleneacetic acid on restoring ‘Rocha’ pear ripening treated with 1-MCP

Publication . Dias, C.; Rodrigues, A.C.; Vasconcelos, M.W.; Ferrante, A.; Pintado, M.

Loss of ripening capacity is still a major problem associated with the use of 1-methylcyclopropene (1-MCP), despite its benefit in preserving climacteric fruit under long-term cold storage, specially, in controlled atmosphere. Several strategies have been tested to overcome this problem, namely the use of phytohormones (e.g., ethylene). In this study, ‘Rocha’ pear treated with 1-MCP was after storage exposed to a synthetic phytohormone, the auxin 1-naphthaleneacetic acid (1-NAA) at 2 mM, for 2 h. Before treatment, as well as 3, 6 and 24 h after treatment, the primary impact of 1-NAA on the expression of genes encoding ethylene receptor (PcETR2) and ethylene biosynthesis enzyme (PcACS4) was determined. The restoration of ripening capacity was assessed across shelf-life by measuring ethylene production and 1-aminocyclopropane-1-carboxyl acid oxidase (ACO) activity. Herein, the expression of PcACS4 significantly increased in pears treated with 1-NAA compared to pear treated only with 1-MCP. Additionally, the expression of PcETR2 was enhanced, revealing the potential of the 1-NAA treatment in inducing the production of new ethylene receptors. Time course physicochemical analysis revealed that fruit ripening was promoted by 1-NAA treatment, as judged by the higher ethylene production (ca. 50%) and ACO activity (ca. 15%) compared to treated only with 1-MCP. The application of the auxin indicated its potential in reactivating the ripening of ‘Rocha’ pear under the effect of 1-MCP.

2024-06-20Journal article

Restricted access

Relationship between minerals and physicochemical parameters with fruit quality in ‘Rocha’ pear orchards

Publication . Dias, Cindy; Ribeiro, Tânia; Rodrigues, Ana Cristina; Vasconcelos, Marta W.; Ferrante, António; Pintado, Manuela

At the same location, variability among orchards may be high, which is reflected in fruit quality, and it may be associated mainly with growers’ practices. This study aimed to identify physicochemical variability within pears (Pyrus communis L. cv 'Rocha') from three orchards from the same location and under the same climate conditions and correlate it with mineral composition.

2023-07-06Journal article

Open access