Title
Organic acids produced by lactic acid bacteria (Leuconostoc sp.) contribute to sensorial quality loss in modified-atmosphere-packed fresh-cut iceberg lettuce
Author
Paillart, M.J.M.
van der Vossen, J.M.B.M.
Lommen, E.
Levin, E.
Otma, E.C.
Snels, J.C.M.A.
Woltering, E.J.
Contributor
Cantwell, M.I. (editor)
Publication year
2016
Abstract
The shelf-life of fresh-cut lettuce packed in a modified atmosphere (MA) is determined by its "overall visual quality" (OVQ), being a measure of its general appearance based on colour and shape criteria. In addition to the OVQ, the development of off-flavour and acid off-smell reduces consumer acceptance of such products. Concomitant with these changes in organoleptic properties, there is a rapidly developing microbial population inside the MA package (MAP), dominated by lactic acid bacteria. We studied the bacterial population dynamics of active MAP freshcut lettuce as well as the effect of metabolites produced by the bacteria (lactic acid and acetic acid) on lettuce quality aspects. Within 3 days of packaging, the oxygen concentration in the package was reduced to near zero, and this resulted in the selective advantage of lactic acid bacteria, in particular Leuconostoc and Lactococcus species. Leuconostoc, when cultivated on lettuce-enriched artificial medium, was found to produce both acetic and lactic acids. Low concentrations of acetic and lactic acids were found in MAP lettuce after 5 days of storage at 7°C. Freshly prepared fresh-cut product treated with comparably small amounts of acetic and lactic acids showed severe quality loss. This was reflected by rapid browning, yellowing and loss of texture. The experiments demonstrate that, under anaerobic conditions, organic acids are produced by lactic acid bacteria, affecting both off-flavour production and sensorial quality in fresh-cut lettuce. © 2016, International Society for Horticultural Science. All rights reserved.
Subject
Life
MSB - Microbiology and Systems Biology
ELSS - Earth, Life and Social Sciences
Biomedical Innovation
Biology
Healthy Living
Acetic acid
Fresh-cut
Lactic acid
Lettuce
Leuconostoc
Overall visual quality
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DOI
https://doi.org/10.17660/actahortic.2016.1141.36
TNO identifier
575664
ISBN
9789462611290
ISSN
0567-7572
Source
Acta Horticulturae, 1141, 289-296
Document type
conference paper