Effects of Gaseous Ozone on Microbiological Quality of Andean Blackberries (Rubus glaucus Benth).

Sandra Horvitz,Paloma Vírseda,Mirari Arancibia,Cristina Arroqui,Erika Chonata

doi:10.3390/foods10092039

Sandra Horvitz, Paloma Vírseda + Show 3 more

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https://doi.org/10.3390/foods10092039

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Abstract

Andean blackberries are highly perishable due to their susceptibility to water loss, softening, mechanical injuries, and postharvest diseases. In this study, the antimicrobial efficacy of gaseous ozone against spoilage (mesophiles, psychrotrophs, and yeasts and molds) and pathogenic (E. coli, S. enterica, and B. cinerea) microorganisms was evaluated during 10 days of storage at 6 ± 1 °C. Respiration rate and mass loss were also determined. Ozone was applied prior to storage at 0.4, 0.5, 0.6, and 0.7 ppm, for 3 min. The best results were observed with the higher ozone dose, with initial maximum reductions of ~0.5, 1.09, and 0.46 log units for E. coli, S. enterica, and B. cinerea, respectively. For the native microflora, maximum reductions of 1.85, 1.89, and 2.24 log units were achieved on day 1 for the mesophiles, psychrotrophs, and yeasts and molds, respectively, and this effect was maintained throughout storage. In addition, the lower respiration rate and mass loss of the blackberries ozonated at 0.7 ppm indicate that this treatment did not induce physiological damage to the fruit. Gaseous O3 could be effective in maintaining the postharvest quality of blackberries throughout refrigerated storage but higher doses could be advisable to enhance its antimicrobial activity.

Highlights

Andean blackberries (Rubus glaucus Benth) are mostly cultivated in temperate and cold climates in South America and are usually consumed processed as pulp, jams, juices, and desserts [1]
The contamination of berries with pathogens can result in foodborne illness outbreaks and microorganisms such as Escherichia coli or Salmonella are of great concern for fruit growers and processors
The respiration rate of the blackberries ranged between 11.30 ± 0.26

Summary

Introduction

Andean blackberries (Rubus glaucus Benth) are mostly cultivated in temperate and cold climates in South America and are usually consumed processed as pulp, jams, juices, and desserts [1]. The interest in blackberries as fresh fruit has increased in the last years driven by the consumer’s interest in berries as sources of bioactive compounds and health benefits [2]. As non-climacteric fruit, blackberries must be harvested at full maturity when they have the best organoleptic and nutritional quality. At this stage, they are more susceptible to mechanical injuries and microbial attacks, which impair their commercial quality and shorten the postharvest shelf-life [3,4]. The contamination of berries with pathogens can result in foodborne illness outbreaks and microorganisms such as Escherichia coli or Salmonella are of great concern for fruit growers and processors

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