The Fresh Cut Fruit and Vegetable Industry (FFVI) is significantly different to Ready to Eat cooked foods, in that there is no opportunity with salads or fruit to carry out a thermal reduction step for control of microorganisms.
The past number of years has seen an increase in the consumption of fruit and vegetables, particularly in prepared salads, etc. Concurrently, there has been a larger number of foodborne disease outbreaks linked to fresh produce. This underlines the need of assuring produce safety and quality. Therefore, professional growers have established Good Agricultural Practice standards to minimise potential for contamination arising from seed onwards, and large-scale processors have put stringent disinfection protocols in place, whose role is to remove soil and associated microorganisms, reducing the risk of microbial foodborne disease and reduce spoilage by reducing contamination by pathogenic and non-pathogenic microorganisms.
Both pathogenic and non-pathogenic microorganisms have been shown to form intimate attachments and/or form biofilms on fruit and vegetable surfaces, as well as on food contact surfaces on processing equipment. Such interactions allow the microorganisms to effectively resist the antimicrobial activity of applied disinfectants and therefore provide a source of further contamination of produce. Cleaning the FFVI involves the removal of gross debris from generally large equipment.
Typically, low or medium pressure washdown systems are used for foam application and rinsing for the processing stages and then dry or semi dry cleaning for the packaging stages.
Chlorine Based Disinfectants
Chlorine-based disinfectants are most commonly used in the fresh cut fruit and vegetable industry. Benefits include their low cost, ease of use and numerous studies demonstrating the ability of chlorine to reduce microbial numbers by up to 2 logs. Nonetheless, there is a drive to minimise the use of chlorine in the industry due to environmental concerns, potential health implications of chlorine by-products and consumer reticence. Coupled with this is a need to reduce water consumption, whilst ensuring that the safety and quality of products is maintained.
Ozone has been proposed as a useful disinfectant solution in water. In principle, because it is a powerful oxidiser it should be effective as a disinfectant. However, it will be rapidly deactivated by any organic material it comes into contact with (for example food debris). Ozone leaves no residues to taint or contaminate food and passes only oxygen and water to the environment.
Peroxy acetic acid based disinfectant are effective against a wide spectrum of micro-organisms, including vegetative and sporing bacteria, moulds, spores, yeasts and viruses. They are suitable for a wide variety of vegetable, salad, and fruit washing operations, it is particularly suited to automated dosing systems. At typical use concentrations the biocidal efficacy of peroxy acetic acid based disinfectants (such as Crystal) is several orders of magnitude better than that of comparable concentrations of sodium hypochlorite. They are low foaming and can be used in soak and recirculation systems. Unlike hypochlorite based disinfectants, they do not cause pitting corrosion, and do not precipitate brown stains of iron and manganese, and are effective without the need to modify pH by the addition of organic acids. Peroxy acetic acid based disinfectants break down to form water and acetic acid; no chlorinated organic compounds are produced