Use of essential oils and biocontrol cultures for the improvement of shelf-life of fresh cut products

Siroli, Lorenzo (2014) Use of essential oils and biocontrol cultures for the improvement of shelf-life of fresh cut products, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Scienze e tecnologie agrarie, ambientali e alimentari, 26 Ciclo. DOI 10.6092/unibo/amsdottorato/6278.
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Abstract

The demand of minimally processed fruits and vegetables has increased in the last years. However, their intrinsic characteristics may favor the growth of pathogens and spoilage microbiota. The negative effects on human health reported for some traditional chemical sanitizers have justified the search for substitutes to guarantee food safety and quality. In this work we have evaluate the potential of some essential oils and their components to improve the safety and the shelf life of Lamb’s lettuce (Valerianella locusta) and apples (Golden delicious). Moreover, the effects of selected lactic acid bacteria alone or in combination with essential oils or their components, on the shelf-life and safety as well as organoleptic properties of minimally processed products, were evaluated. Since the lack of knowledge of microbial cell targets of essential oils represent one of the most important limit to the use of these molecules at industrial level, another aim of this thesis was the study of the action mechanisms of essential oils and their components. The results obtained showed the beneficial effects of the natural antimicrobials as well as the selected lactic acid bacteria on minimally processed fruit and vegetable safety and shelf-life, without detrimental effects on the quality parameters. The beneficial effects obtained by the use of the selected biocontrol agents were further increased combining them with selected natural antimicrobials. The natural antimicrobial employed induced noticeable modifications of membrane fatty acid profiles and volatile compounds produced by microbial cells during the growth. The modification of the expression in genes involved in fatty acid biosynthesis suggesting that the cytoplasmic membrane of microbial cells is one of the major cellular target of essential oils and their components. The comprehension of microbial stress response mechanisms can contribute to the scaling up of natural antimicrobials and bio-control agents at industrial level.

Abstract
Tipologia del documento
Tesi di dottorato
Autore
Siroli, Lorenzo
Supervisore
Co-supervisore
Dottorato di ricerca
Scuola di dottorato
Scienze agrarie
Ciclo
26
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
minimally processed products; essential oils; shelf-life; food safety; natural antimicrobials; biocontrol agents; mechanisms of action; pathogenic microorganisms; stress response
URN:NBN
DOI
10.6092/unibo/amsdottorato/6278
Data di discussione
30 Maggio 2014
URI

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