ID: 2259

• Title:
  Pulsed Electric Fields in Winemaking: Yield Extraction Optimization
  
  Authors:
  

  Aguiar-Macedo, Mafalda - EnergyPulse Systems, EPS, Lisbon, Portugal
  Redondo, Luis Manuel - Pulsed Power Advanced Applications Group, Lisbon School of Engineering, GIAAPP/ISEL, Lisbon, Portugal
  Teotónio Pereira, Marcos - EnergyPulse Systems, EPS, Lisbon, Portugal
  Silva, Carlos - Carlos Silva Vinhos, Unip. Lda. Viseu, Portugal.

  
  
  Abstract:
  Guarantying food production sustainability has been an increasing concern amongst consumers, producers, and organizations. Thus, the emergence of new technologies with the potential to reduce and/or supplant the use of production factors and increase the efficiency of pre-established methodologies. Recently, the application of Pulsed Electric Fields (PEF) has been indicated as a prospective contributor to the achievement of this objectives, especially when considering its nonthermal aspect, mainly due to its potential contribution to energy efficiency, waste reduction and decrease of food additives’ input; directly and indirectly contributing not only to environmental but also to a better economical sustainability. This can potentially be achieved thanks to the ability of PEF to induce electroporation of the membranes of the cells, thus leading to the main premisses of this technology in the Food Industry: a) mass transfer optimization and b) microbial inactivation.
  
  Thus, one of the largest promises of PEF Tech consists of the optimization of the juice yield obtained from food matrixes, such as fruits and vegetables, without comprising quality of the final product. While there are several published papers other food products, such as apple, citrus, tomato, red fruits and olive oil, to name a few, evidence of this effect on wine grapes is still quite scarce. Adding to the fact that most of these studies were performed at laboratory scale, it was realized that there was a need of contributions towards this particular effect on the Wine Industry.
  
  With this objective in mind, two wine grape varieties were subjected to two independent assays. The chosen varieties were Arinto, a Portuguese white grape, vinified in 2022, with the main objective of increasing cuvée yield, and Tinta Roriz (Tempranillo), in 2021, where the main objective of the study consisted of the possible reduction of maceration time; in this case both Saigneé and Press must volumes were assessed. Trial design consisted in the existence of a control batch and a PEF treated batch (Arinto: 1kV/cm; 2kJ/Kg, n=3; Tinta Roriz: 2kV/cm;2-2.8kJ/Kg, n=2). Oenological parameters were assessed to determine if the application of PEF influenced the quality of the must and final product. The results obtained were promising. Arinto presented an increase in cuvée yield of 5.47%. Significant differences were found in terms of Total Phenols and Colour Intensity. Using %Ye as a browning indicator, it might be indicated that control presented an higher susceptibility to oxidation. 3 months after vinification, PEF treated Arinto demonstrated lower turbidity and could achieve a faster natural tartaric stability. Regarding Tinta Roriz, a 6.95% increase of total yield was achieved. Saigneé yield was 13% higher on PEF treated batches, and obviously followed by a reduction of the press obtained yield extraction. PEF presented a higher positive impact in terms of oenological characteristics when applied in grapes with lower sanitary conditions.
  
  
  
  Keywords:
  Pulsed Electric Fields, Winemaking, Yield Optimization
  
  Refs:
  
  
  Topic 1:
  10. Food safety and food preservation
  
  Topic 2:
  11. Agricultural crops and farming