Salmonella enterica Control in Stick Carrots Through Incorporation of Coriander Seeds Essential Oil in Sustainable Washing Treatments

Marika Pellegrini,Chiara Rossi,Clemencia Chaves-López,Dario De Medici,Claudio Lo Sterzo,Francesca Maggio,Sara Palmieri,Annalisa Serio,Antonella Ricci,Antonello Paparella

doi:10.3389/fsufs.2020.00014

Marika Pellegrini, Chiara Rossi + Show 8 more

Open Access

https://doi.org/10.3389/fsufs.2020.00014

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Abstract

Chemical disinfectants represent one of the commonly used practice in minimal processed vegetables food-chain. However, the scarce safety and sustainability of these agents force food industry to move toward more sustainable “green washing solutions”. Among the latter, while the application of plant derivates for the control of several pathogens is already well-known, specific information on the potential anti-Salmonella activity of Coriandrum sativum seeds derivates are still limited and were therefore investigated in this study. In detail, Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) of different coriander seed derivates (i.e. essential oil, hydrosol and ethanolic extract) were determined by broth dilution against six Salmonella enterica strains isolated from fresh and minimally processed fruits and vegetables. Only the essential oil (EO) was effective in vitro with strain-dependent results. In addition, when mixed in co-culture, the strains were more sensitive to the essential oil treatment. Chemical investigations allowed to define (s)-(+)-linalool as major compound, and to underline interesting phenolic content with correlated antioxidant capacity. A cocktail of three strains of different serovars was selected and employed for a preliminary in situ trial on stick carrots. The obtained results allowed to establish that the application of coriander seed EO at concentrations of 5 µL mL-1 was able to reduce and contain the growth of the Salmonella cocktail up to 24 hours at 10°C. Good sensory evaluation results were obtained by applying this EO concentration as washing treatment, especially in terms of color parameter. Further studies should be undertaken to emphasize the upstream activity, improving the formulation or exploiting a combined effect with other sanitizers or treatments (e.g. physical treatments). The present study contributes to the knowledge on coriander derivates activity against Salmonella spp. and on the potential application as sustainable washing treatment in removing this pathogen from fresh cut carrots.

Highlights

Processed vegetables (MPV) are defined as fresh, raw vegetables processed to supply ready-to-eat or ready-to-use foods (Nguyen-the and Carlin, 1994)
The C.sativum seeds extracts were tested for their antimicrobial activity against six S. enterica strains of different serovars, previously isolated from vegetables, and belonging to the most recently isolated Salmonella serotypes in Italy in this kind of products (Rossi et al, 2019)
The color preserving activity should be ascribed to phenolic compounds and to their related antioxidant capacity. These antioxidants, are well-known compounds utilized to prevent, retard or delay oxidative reaction and increase color stability (Mandal and Mandal, 2015). This is the first report on anti-Salmonella activity of C. sativum seeds essential oil on carrots

Summary

Introduction

Processed vegetables (MPV) are defined as fresh, raw vegetables processed to supply ready-to-eat or ready-to-use foods (Nguyen-the and Carlin, 1994) These products can harbor a variety of spoilage microorganisms and a particular concern is related to the potential presence of cold-tolerant pathogens such as Listeria monocytogenes, Escherichia coli, Bacillus cereus, Aeromonas hydrophila, Yersinia enterocolitica, and Salmonella spp. Salmonella spp. represent a significant public health concern, being responsible of several foodborne outbreaks (Cai et al, 2016; Rossi et al, 2019) This food-borne pathogen, usually linked to poultry meat and products, is found in a wide variety of fruits and vegetables (Pui et al, 2011) such as carrots (Daucus carota) (Gutiérrez-Alcántara et al, 2016; Liu et al, 2019) and fresh unpasteurized carrot juice (Torres-Vitela et al, 2013). Food industry should move away from these chemical disinfectants, the implementation of washing steps with effective “green washing solutions” is of great importance (Gil et al, 2009)

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