Logo do repositório

ISEL - Engenharia Electrotécnica

URI permanente desta comunidade:

http://hdl.handle.net/10400.21/221

Navegar

Percorrer ISEL - Engenharia Electrotécnica por autor "Aguiar-Macedo, Mafalda"

A mostrar 1 - 2 de 2
  • PEF priming of seeds for microgreen production: a comparative study
    Publication . Aguiar-Macedo, Mafalda; Dulyanska, Yuliya; Guiné, Raquel P. F.; Costa, Daniela V. T. A.; Redondo, Luis
    Seed priming with Pulsed Electric Fields (PEF) is a promising strategy to enhance early plant development and crop quality. This study evaluated PEF priming effects on Beetroot (Beta vulgaris L.), Arugula (Eruca vesicaria), and Basil (Ocimum basilicum L.) microgreens by assessing the effects of three distinct monopolar PEF protocols (PEFA: 2 kV/cm; PEFB: 3 kV/cm; PEFC: 4 kV/cm). PEFB and PEFC treatments significantly influenced imbibition. Germination Indexes (DGI, CGI, and SVI) were positively and significantly affected, with radicle length increasing up to 33% and DGI improving from 40 to 66 on the 1st day (Beetroot, PEFC). Chlorophylls and the Total Carotenoid concentration increased in Basil but decreased in Beetroot and Arugula. Fat and Protein increased in Beetroot (Fat: +41%; Protein: +34%) and Arugula (Fat: +91%; Protein: +11%) treated with PEFC. PEFB led to an increase in Starch in all species. Crude Fibre and Neutral Detergent Fibre decreased amongst all species. Methionine rose by 100% in Beetroot treated with PEFC. Sensory analysis showed slight increases in Sweet (Beetroot) and Aroma Intensity (Basil and Arugula), although these changes were not statistically significant. Species-specific responses to different PEF protocols were observed: optimal protocols seem to be PEFC for Beetroot, PEFB for Arugula, and PEFA/B for Basil.
    2025-11-25Artigo científico Acesso aberto Ver mais
  • Pilot scale continuous pulsed electric fields treatments for vinification and stabilization of Arinto and Moscatel graúdo (Vitis vinifera L.) white grape varieties: effects on sensory and physico-chemical quality of wines
    Publication . Silva, Filipa V.M.; Borgo, Riccardo; Guanziroli, Andrea; Ricardo-da-Silva, Jorge M.; Aguiar-Macedo, Mafalda; Redondo, Luis
    Pulsed electric field (PEF) processing of white grapes (Arinto, Moscatel Graúdo also known as Moscatel de Setúbal) before pressing for must extraction (1.2 and 1.6 kV/cm) and before bottling for finished wine physical stabilization (10 kV/cm) was implemented in a pilot-scale winery to produce about 540 L of wine for each variety. PEF was applied at these two different stages of wine production, and its effects on the sensory and physico-chemical quality of the wines were investigated. The sensory triangle tests revealed no significant change in both wine varieties’ colour, odour, and taste with PEF extraction and PEF stabilization treatments. However, for colour coordinates assessed with a spectrophotometer, a significant increase in CIE b* colour coordinate was registered for PEF extracted Arinto and Moscatel wine samples, showing a development of a more intense yellow colour. Concerning physico-chemical quality parameters, the PEF extraction increased both wine varieties’ turbidity and pH, although total acidity was not affected. The total phenols also increased in Arinto with extraction. The second PEF treatment applied for wine stabilization did not affect any of the quality parameters, except total phenols, which decreased in Moscatel wine. The results encourage the application of PEF in the wineries at different stages of vinification of white wine grape varieties.
    2024-01-08Artigo científico Acesso aberto Ver mais