Biopreservation approaches to reduce Listeria monocytogenes in fresh vegetables. (February 2020)

• Record Type: Journal Article
• Authors: Ramos, Bárbara; Brandão, Teresa R.S.; Teixeira, Paula; Silva, Cristina L.M.
• Is Part Of: Food microbiology. Volume 85(2020)
• Publication Date: 2020-02
• Subjects: Biopreservation -- Listeria monocytogenes -- Fresh vegetables -- Protective culture -- Pediocin -- Pediococcus pentosaceus DT016; Food Microbiology -- Periodicals; Aliments -- Microbiologie -- Périodiques; Food -- Microbiology; Periodicals; Food -- Microbiology -- Periodicals; Food contamination -- Periodicals; 664.001579
• DOI: 10.1016/j.fm.2019.103282
• Languages: English
• ISSNs: 0740-0020

Abstract

Abstract: Two biopreservation approaches for fresh lettuce, rocket salad, parsley and spinach were studied. The potential of Pediococcus pentosaceus DT016, as a protective culture, to suppress Listeria monocytogenes in vegetables during storage was evaluated. The pathogen numbers in the vegetables inoculated with P. pentosaceus DT016 were significantly (p < 0.01) lower throughout the storage period and, at the last storage day, a minimum difference of 1.4 log CFU/g was reported when compared with the vegetables without the protective culture. Moreover, by using two levels of L. monocytogenes (about 6 and 4 log CFU/g), it was observed that the antagonist effect of P. pentosaceus was higher for the lower pathogen numbers. The second approach evaluated a pediocin DT016 solution to inactivate and control L. monocytogenes proliferation. The pathogen load was studied after washing with: water, chlorine and the pediocin solution and along storage at 4 °C. Comparing the various washing solutions, the vegetables washed with pediocin presented significantly (p < 0.01) lower pathogen numbers throughout storage, by a minimum of 3.2 and 2.7 log CFU/g, than in vegetables washed with water and chlorine, respectively. The proposed methodologies are promising alternatives to maintain the safety of fresh vegetables during extended storage at refrigeration temperature. Highlights: Vegetables are a suitable environment for protective culture grow. Pediococcus pentosaceus DT016 limited Listeria growth and load in fresh vegetables. Pediocin DT016 washing prevented the pathogen proliferation in vegetables. Listeria monocytogenes survived and grew in vegetables washed with water and chlorine.