Use of olive leaf extract (OLE) to inhibit the growth of Campylobacter spp. in an active packaging for fresh chicken preservation
: development of the packaging and overview of the literature

  • Ismael Chahed el Ouazzani (Student)

Student thesis: Master's Thesis

Abstract

This work is composed of a bibliographic survey and an experimental part. The bibliographic part consists of a study on the epidemiological situation of Campylobacter spp. in Europe, advances in research on natural solutions for the conservation of chicken, studies aimed at reducing contamination by Campylobacter spp., the use of olive leaf extract (OLE) for the conservation of food, and other new alternatives for food preservation. The experimental part consists of a laboratory study on the effectiveness of OLE against Campylobacter spp. and its application in an active packaging for the conservation of chicken. The epidemiological situation related to Campylobacter infections in the EU is not homogeneous between countries and its related to the consumption of foods contaminated with these bacteria. Some seasonality has also been observed for infections. In recent years many studies have been carried out to develop new natural solutions for the conservation of chicken, due to the need to increase the shelf life of food. In these studies, new natural plants have been found as well as very effective minerals to lengthen the shelf life of food. OLE is a by-product of the olive industry that is widely used in phytotherapy, but in recent years it has been shown that it has a potential to increase the shelf life of food mainly due to its antioxidant and antibacterial effects. In microbiological studies it has been demonstrated its effectiveness against Campylobacter spp., however, there are no studies in the literature that have the objective of reducing or eliminating Campylobacter spp. in chicken with the use of OLE. For this reason, OLE was chosen to carry out an experimental study. In the experimental work, results from in vitro and in situ tests were in agreement. OLE has been effective as a growth inhibitor at the optimal growth conditions of Campylobacter spp., that is, at 41.5 oC and in microaerophilia. Nevertheless, once samples were removed from contact with OLE growth was observed, this means that the extract has not killed all the bacteria. The experimental design was not able to prove the efficacy of OLE in reducing the viable cell count at low temperatures.
Date of Award14 Jul 2021
Original languageEnglish
Awarding Institution
  • Universidade Católica Portuguesa
SupervisorMaria de Fátima Poças (Supervisor) & Paula Teixeira (Supervisor)

Keywords

  • Olive leaf extract
  • Chicken
  • Poultry
  • Natural extracts
  • Food safety
  • Campylobacteriosis
  • Active packaging
  • Oleuropein
  • Hydroxytyrosol

Designation

  • Mestrado em Engenharia Alimentar

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