Impact of plant essential oils on microbiological, organoleptic and quality markers of minimally processed vegetables
Date
2008-10-31Author
Gutierrez, Jorge
Bourke, Paula
Lonchamp, Julien
Barry-Ryan, Catherine
Metadata
Show full item recordCitation
Gutierrez, J., Bourke, P., Lonchamp, J. and Barry-Ryan, C. (2008) ‘Impact of plant essential oils on microbiological, organoleptic and quality markers of minimally processed vegetables’, Innovative Food Science & Emerging Technologies, 10(2), pp. 195-202.
Abstract
The objectives of this study were to evaluate the efficacy of plant essential oils (EOs) for control of the natural
spoilage microflora on ready-to-eat (RTE) lettuce and carrots whilst also considering their impact on
organoleptic properties. Initial decontamination effects achieved using EOs were comparable to that
observed with chlorine and solution containing oregano recorded a significantly lower initial TVC level than
the water treatment on carrots (pb0.05). No significant differences were found between the EO treatments
and chlorine considering gas composition, color, texture and water activity of samples. The sensory panel
found EO treatments acceptable for carrots throughout storage, while lettuce washed with the EO solutions
were rejected for overall appreciation by Day 7. Correlating microbial and sensory changes with volatile
emissions identified 12 volatile quality markers. Oregano might be a suitable decontamination alternative to
chlorine for RTE carrots, while the identification of volatile quality markers is a useful complement to sensory
and microbiological assessments in the monitoring of organoleptic property changes and shelf-life of fresh
vegetables.
Industrial relevance: There is industrial demand for natural alternatives to chlorine, which is commonly used
for decontamination of fresh produce but which has limitations with respect to antimicrobial efficacy and
possible formation of carcinogenic compounds in water. Plant essential oils have proven antimicrobial and
other bioactive properties, however their usefulness in foods can be mitigated by their high sensory impact.
This study examined the application of EOs for fresh produce decontamination addressing control of spoilage
microflora and improving shelf-life characteristics whilst also considering the impact on organoleptic
properties. The effectiveness of oregano as a decontamination treatment was comparable with that of
chlorine. Carrot discs treated with the EO regimes were acceptable in terms of sensory quality and
appreciation, therefore oregano could offer a natural alternative for the washing and preservation of fresh
produce. Combining EOs with other natural preservatives might minimize doses and reduce the impact on
organoleptic properties of fresh vegetables.