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Vegetable & Fruit WashingFresh fruit, vegetables and salad are delicate foods in many respects. On the one hand from the taste, on the other hand from the microbiological point of view. Since lettuce comes directly from the field, is not thermally pre-treated, and does not undergo much other processing, washing is of great importance. Ideally, this not only removes dirt, but also reduces germs such as mould spores, which are responsible for premature spoilage of harvested plant foods.
While lettuce and vegetables were traditionally sold directly after harvesting without further treatment, the trend towards convenience food is producing more processed, ready-to-eat vegetables and lettuce. In other words, vegetables and lettuce are washed, peeled if necessary, chopped and packed in tubular bags.
Vegetables are often frozen and thus preserved. Vegetables such as diced brunoise or chopped onions do not contain as much water as lettuce, which makes them much more resistant to spoilage pathogens.
Lettuce, on the other hand, is quite susceptible to germs, and since lettuce is not heated before consumption, reducing the initial germ count is desirable not only for extended shelf life but also for increased food safety.
A standard procedure for freeing lettuce or vegetables from soil, dust or other adhering dirt is often to wash the crops. In addition to cleaning by washing the vegetables or lettuce, this should also result in a general reduction of germs and thus ideally improve the shelf life of the cut lettuce in the tubular bag.
Unfortunately, the washing water in which the lettuce is dipped often leads to contamination, as germs are evenly distributed on the lettuce. The mechanism is the same for vegetable washing water.
UV lamps, ozonisers and/or filters can reduce germs in the wash water in certain areas, but they cannot prevent high concentrations of germs from forming in the water.
By adding Sanosil Super 25 to the wash water (provided that local laws allow the addition of hydrogen peroxide as an oxidising agent to reduce oxidisable organic material in the water), a reduction in germs and thus a longer shelf life of the lettuce can be achieved. With cut lettuce and 50 – 100 ppm Super 25 the additional shelf life is 2-4 days depending on the initial germ count.
The addition is very simple with the help of a dosing pump directly into the lettuce washing water. A dosage of 50 -100 ml of Sanosil Super 25 is usually selected per m3 of water. The Sanosil Super 25 content can be easily monitored with Sanopstrips 200.
Important: Any existing UV disinfection systems complement the effect of Sanosil Super 25 and can be operated in parallel. In the case of severe contamination, this is even explicitly recommended.
In order to reduce losses, e.g. of citrus fruits due to rotting and especially moulds, in practice an immersion bath with effective, but from a health and environmental point of view questionable chemicals such as naphtalene acetic acid (NAA) or cloramizole is often used.
However, these products are strongly suspected of being carcinogenic and polluting the environment. The use of Sanosil Super 25 provides an alternative to these products with a much more environmentally friendly profile. A brief immersion in a Sanosil Super 25 solution, or spraying if necessary, greatly reduces the number of mould spores and rotting bacteria on surfaces.
In an increasingly competitive world, reducing crop postharvest loss is an important agronomic goal. Of the highly perishable fruits such as tomatoes, apricots and peaches, up to 39% of harvested fruits spoil due to crop secondary damage before they reach the market.
Sprout reduction with products that decompose to water and oxygen with virtually no residues can therefore be an important contribution to avoiding food waste in the production of fruit and salad without exchanging one evil for another.
During storage and transport, fruit and vegetables are constantly at risk of being attacked by moulds such as Rhizopus, Penicillium, Mucor and others, making them inedible.
Careful hygiene with regard to transport containers, processing and sorting tables, transport trolleys and refrigerated / storage rooms can therefore significantly reduce the loss rate.
Regular cleaning and disinfection of surfaces as well as, if necessary, intervention with fogged Sanosil disinfectant to reduce moulds and spores in the air are effective and proven methods.
