ID: 2170

• Title:
  Pulsed electric field technology for apple puree preservation: Escherichia Coli inactivation, quality and financial viability assessment
  
  Authors:
  

  Pino-Hernández, Enrique - INOV.LINEA/TAGUSVALLEY – Science and Technology Park, 2200-062, Abrantes, Portugal
  Valério, Paula - INOV.POINT / TAGUSVALLEY – Science and Technology Park, 2200-062, Abrantes, Portugal
  Rego, Duarte -  EnergyPulse Systems, Est Paco Lumiar Polo Tecnológico Lt3, 1600-546 Lisbon, Portugal
  Redondo, Luis - EnergyPulse Systems, Est Paco Lumiar Polo Tecnológico Lt3, 1600-546 Lisbon
  Alves, Marco - INOV.LINEA/TAGUSVALLEY – Science and Technology Park, 2200-062, Abrantes, Portugal

  
  
  Abstract:
  Non-thermal treatments as alternative processes to complement or replace the conventional thermal techniques for retaining the fresh-like qualities of products by efficiently inactivating bacteria are interesting to the industry. Pulsed electric field (PEF) technology, based on pulsed power technology, is the application of an electric field to foods for a short time, to inactivate by electroporation harmful bacteria in food. Besides the application in preservation processing, PEF technology can also increase industrial competitiveness by replacing or complementing conventional techniques to improve product’s function, drying and freezing, extractability, and recovery of bioactive compounds by increasing cell permeability. However, before fully implementing PEF technology in an industrial environment, a model that supports investment decisions is an extremely important factor that needs to be taken into account for a successful transfer. The objective of this study was to evaluate the inactivation of Escherichia coli WDCM00013 (ATCC 25922, ielab, a surrogate for the pathogenic E. coli O157:H7) in Reineta Parda apple puree treated by PEF and to present a model that supports investment decisions taken by Portuguese agri-food companies on using PEF equipment to apple puree processing with pasteurization replacement. This study was carried out on an industrial environment at INOV.LINEA/TAGUSVALLEY. Apples were obtained from an industrial producer (Cooperfrutas) of Alcobaça, Portugal. Apple puree was processed by PEF (7, 10, and 12.5 kV/cm, 70 – 115 A, 44 – 604 kJ/kg, 2.5-45 s, with bipolar pulses, 8 μs per pulse) and by thermal pasteurization (TP, 72 °C for 15 seg). Untreated apple puree was also used as a control group. Before and immediately after all treatments, sensorial attributes and physicochemical characteristics such as colour, total soluble solids, and pH of puree were evaluated. Moreover, over the storage period (30 days under refrigerated storage 5 °C) the native microbial and inoculated E. coli loads were also evaluated. Moreover, financial viability assessment was developed using 2021 data (CAE 10320) considering 20 Portuguese companies. The results showed that PEF treatment at 10 kV/cm, 115 A, 604 kJ/kg, 70 bipolar pulses of 8 µs, and 57.2°C was the most successful due to possible synergistic effects of mild heat, resulting in more than 5 log CFU/g of E. coli inactivation, meeting FDA requirements to achieve the pasteurization status. PEF treatment was equivalent to TP in terms of E. coli inactivation. Thus, the current study demonstrates how these equivalent treatments differ from each other in terms of their effect on product safety and quality characteristics during refrigerated storage. PEF and TP reduced natural microbiota below 1 log CFU/g ensuring the stability of the product for at least 30 days. Untreated and treated samples exhibited pH, acidity, °Brix and colour changes, which were dependent on the processing conditions. Sensory analysis indicated that PEF samples had better’s appearance and texture attributes than the TP-treated samples. Regarding to financial viability, the initial PEF investment (max 15 kV/cm) becomes advantageous in the short run regarding the Portuguese companies targeted on this study. The estimated additional cost of using PEF for apple puree was 6.97 USD per kg of product. With an initial investment on equipment around 115000 USD, the payback time occurs within 4 years. The breakeven point for the 1st year of project is reached after 163,500 kg of product are sold or when revenue reaches 1,04 M USD. Utility and labor costs were estimated to be around 266,330 USD /year and 130,65 USD /year, respectively. In conclusion, PEF is a sustainable technology that can replace thermal pasteurization, in equivalent conditions, with the advantage of retaining sensorial attributes of the product.
  
  Keywords:
  non-thermal technology, microbial stability, food industry, innovation process
  
  Refs:
  
  
  Topic 1:
  10. Food safety and food preservation
  
  Topic 2:
  0.