Centre of Biological Engineering - University of Minho

Funder

Organizational Unit

Publications

Extraction of tomato by-products’ bioactive compounds using ohmic technology

Publication . Coelho, Marta; Pereira, Ricardo; Rodrigues, António S.; Teixeira, José A.; Pintado, Manuela E.

Tomato peels and seeds are the main by-products of the tomato industry and represent an interesting source of bioactive compounds (BC) including carotenoids, which can be then used as colorant to commercial aquaculture. The aim of the present work was to optimize the extraction of BC from tomato by-products using Ohmic heating (OH) technology. OH extraction experiments were done in the presence of moderate electric fields (MEF) of different intensity (i.e. 4, 6 and 11 V cm−1) to identify the presence of non-thermal effects on the extraction process and its influence on bioactive properties of the extracted compounds. Polyphenol extraction using OH was successfully optimized with the best extraction conditions being 70 °C for 15 min using 70% ethanol as a solvent, which exhibited rutin recovers of 77% higher than control samples. It allowed to recover up to 4.93 μg/gFW lycopene from tomato by-products without resorting to organic solvents. OH can be used as an environmental-friendly, fast and economic process to polyphenols recover from industrial tomato by-products. In addition, the use of different MEF during extraction shows to have a high potential to cause different levels of permeabilization and cell stress that can help to define a selective extraction process of valuable components from tomato by-products.

2019Journal article

Restricted access

Emergent food proteins – towards sustainability, health and innovation

Publication . Fasolin, L. H.; Pereira, R. N.; Pinheiro, A. C.; Martins, J. T.; Andrade, C. C. P.; Ramos, O. L.; Vicente, A. A.

There is an increasing demand for alternative and sustainable protein sources, such as vegetables, insects and microorganisms, that can meet the nutritional and sensory pleasantness needs of consumers. This emergent interest for novel protein sources, allied with “green” and cost-effective processing technologies, such as high hydrostatic pressure, ohmic heating and pulsed electric fields, can be used as strategies to improve the consumption of proteins from sustainable sources without compromising food security. In addition to their nutritional value, these novel proteins present several technological-functional properties that can be used to create various protein systems in different scales (i.e., macro, micro and nano scale), which can be tailored for a specific application in innovative food products. However, in order for these novel protein sources to be broadly used in future food products, their fate in the human gastrointestinal tract (e.g., digestion and bioavailability) must be assessed, as well as their safety for consumers must be clearly demonstrated. In particular, these proteins may become novel allergens triggering adverse reactions and, therefore, a comprehensive allergenicity risk assessment is needed. This review presents an overview of the most promising alternative protein sources, their application in the production of innovative food systems, as well as their potential effects on human health. In addition, new insights on sustainable processing strategies are given.

2019Journal article

Open access

Bioactive extracts from brewer's spent grain

Publication . Bonifácio-Lopes, Teresa; Boas, Ana Vilas; Coscueta, Ezequiel R.; Costa, Eduardo M.; Silva, Sara; Campos, Débora; Teixeira, José A.; Pintado, Manuela

In this study antioxidant-rich extracts from brewer’s spent grain (BSG) extracted with solid-to-liquid extraction using different solvents water and ethanol and their mixtures at two ratios (80% ethanol:water (v/v) and 60% ethanol:water (v/v)) were characterized. Nutritional composition was evaluated for the extracts and for the solid residues obtained after extraction. Additionally, the extracts were analyzed for the total phenolic content and individual phenolic compounds and related biological properties including antioxidant capacity (ABTS; ORAC and DNA protection), antihypertensive capacity, antibacterial activity and antibiofilm capacity. Safety was also demonstrated through genotoxicity and cytotoxicity tests. The results obtained showed that while all the extracts exhibited high antioxidant capacity (except ethanolic extract), the highest values were obtained for the 60% ethanol:water extract. The identification of phenolic compounds using HPLC showed that catechin and vanillin were the main compounds identified with the highest concentration being obtained for 60% ethanol:water extraction. In the biological activity assays water and hydroethanolic extracts showed to be multifunctional (antioxidant and antihypertensive capacity, antibacterial and antibiofilm activity), the 80% ethanol:water presented better results in some assays. All were non-genotoxic, but the cytotoxicity was dependent on the extract concentration, with complete safe application for all up to 1 mg/mL. Therefore, this study shows the potential of a viable green solvent based and a low cost extraction recovery method of bioactive compounds from brewer’s spent grain.

2020Journal article

Restricted access