Look deep into nature, and then you will understand everything better.
This is a statement of Albert Einstein. He was and is still right. When you understand nature, you will understand what is happening with and in certain postharvest process’.
The sooner you understand you work with living material, the better.
Nature never ever breaks her own laws, not yesterday, today, or tomorrow.
To understand this matter and statement fully, one must understand that fresh horticultural commodities are unique packages of water!
In fact, freshness is water, and freshness sells!
Water loss is one of the main causes of deterioration that reduces the marketability of fresh fruits, vegetables, and flowers.
Profitability in fresh fruit, vegetable, and flower sales depends on the ability to deliver as much of this water as possible to consumers in good condition.
The effects of water loss are devastating. Many fruits, vegetables, and flowers become shriveled after losing only a small percentage of their original weight due to water loss.
Severe desiccation results in considerable losses, e.g., wilted leafy vegetables may require excessive trimming to make them marketable, and grapes may shatter loose from clusters if their stems are severely dried.
Seriously shriveled fruits, vegetables, and flowers are unmarketable and must be discarded.
Water loss represents saleable weight loss and reduced profits.
The factors that affect water loss are Relative humidity (RH), the temperature of the product and its surrounding atmosphere, well documented, and air velocity. (Another often forgotten area)
And all affect the amount of water lost from fresh fruits, vegetables, and flowers. Water loss from warm products to warm air is particularly serious under windy conditions or during transport in an open vehicle.
Maintaining high relative humidity is sometimes difficult because refrigeration removes moisture.
Professional and controlled humidification should be used in pre-coolers and storages…
And please, stop believing the myth that your cold rooms are designed to maintain high humidity…
Measure your starting RH in the beginning of the process and start thinking.
Cheap and nasty solutions like keeping the floor wet is helpful but is also messy and may harbor disease organisms on old produce on the floor. And that is the least you want, and you only must refer to what happened in Europe in 2011, to fully understand that you don’t really need these kinds of things to happen.
Also, something to remember is that molds grow the best above 4°C and above 60% humidity.
So, if your process’ flow asks to precool at 17–22°C at 95% RH, pay due diligence in keeping your walls and floors always clean!
Therefore, frequent sanitizing procedures should be employed, such as cleansing frequently and rinsing with a weak solution of chlorine bleach. Commodities that can tolerate direct contact with water can be sprinkled to promote high relative humidity.
But in most cases, direct water must be always avoided.
Excepted for photographers that want to take nice pictures.
Bottom line, you can research all you want, the subject is well documented by many researchers worldwide, hence the huge reference lists that are available on request.
Once you understand nature, it is easy. It is fun to see that by respecting nature and its laws, you really get perfect results every time in maintaining shelf life.
Talk to the right people that proved their metal by implementing the right methods at the right time, because they understand mother nature.
