Application of a preservative on a fresh product
Fresh products have a limited shelf life. Keeping their native quality while extending the sell-by date is a challenge. Recent advances offer a sensible solution with regards to the consumer trend towards natural products.
The range of fresh products forwarded to the consumer is wide and expanding: diced fruits mixes, salads, sliced meat, prepared meals, bakery … Alterations may come from physical (staling), chemical (oxydation), enzymatic (oxydation) or microbial causes.
Solutions have been developed: minimal processing, hygienic production conditions, packaging, modified atmosphere and ultimately the application of a surface substance mix …
The range of ingredients matches the diversity of food products:
Chemical organic or inorganic preservatives: BHA, BHT, sorbates, acetic acid, alcohol, nitrites… They are usually incorporated in the food product itself e.g. processed meat
Microbial cultures e.g. lactic bacteria, yeast… They have the ability to grow and occupy “space” thus limiting the growth of other bacteria while not being harmful
Bacteriophages are viruses that have the ability to destroy the bacterial population
The choice of the ingredient depends on the product sensitivity to a specific alteration which is the most limiting the shelf life. The application of an ingredient is used in combination of other preservation techniques e.g. modified atmosphere packaging to create a hurdle effect against alteration.
How does it work?
It is a continuous operation in the industry.
After coating, the product must be air-tight packed to prevent the alteration and loss of the preservative itself. After coating, the product needs to be stored in a stove at regulated temperature and moisture during 12 – 24 hours to finalize the crystallization.
Forming of the packaging e.g. thermoformed plastic tray
Filling of the tray with the food product(s)
Application of the preservative
Closing of the tray
To achieve an even disribution, spraying the preservative is the preferred solution.
The spraying system must be positionned on top of the trays between filling and closing.
How do you measure your success?
Key quality features
The evaluation regards as much the product as the packaging
The targeted sell-by date is checked by test
The application of a preservative does not affect the product itself
The application does not affect the package : smear, condensation, sealing zone
Key quality parameters
The process displays critical factors to control
Choice of the preservative as a function of the product and sheld-life
Accurate dosage and application. Homogenous distribution
Hygiene of the system and operation. Safety and health hazards issues for some preservatives: alcohol, microbial cultures