APPLICATION
Preserving fruits with a wax coating
Fruits engaged on a long journey are best protected with a thin organic film.
BASE
Core products
The fruits with smooth surfaces are prone to mould growth: apples, citrus, and mangoes.
RECIPE
Ingredients
The coating ingredient is generally an emulsion:
- Water
- Wax
- Surfactant to lower the surface tension
- An additional substance with antioxidant properties.
PROCESS
How does it work?
Upstream
The fruits are cleaned of dust, which may hinder the coating process, and washed.
Process
The whole fruit surface must be in contact with the emulsion. Partial tipping and tumbling enhance the dispersion.
Downstream
- The fruits are drained from the excess of the emulsion and partially dried by air blowing.
1.
Fruit positioning
on a single layer
2.
Emulsion spraying
3.
Blowing with air knife
(emulsion removal)
PROCESS
Coating system
The coating system includes dipping in a batch, overhead curtaining, and spraying.
PROCESS
Coating system
Typically, the fruits are continuously run in a conveyor.
PRODUCT EVALUATION
How do you measure your success?
Key quality features
The fruit should display its freshness.
Homogeneity
Even the coating of the fruit, the layer holds onto the surface.
Integrity
No damaged surface, no dent.
Key quality parameters
The process is relatively straightforward and consists mainly of flow management: fruit and emulsion.
Composition
The rheology of the emulsion adapts to the surface type.
Productivity
Given the enormous volume of the fruits themselves and the quantity to process, the design of the handling system is essential.
Recycling
As a large volume of emulsion is recovered, it needs filtering to be reused.
How to tackle a project?
Do you want to develop or improve the coating of a food product? Or do you have a problem that we can solve with a coating application?
First, write the brief, and define the purpose of the coating: aspect, texture, taste, flavour, preservation, and functionality.
Core product
What is the core centre to coat? Composition, size, shape, texture, moisture, bulk density.
Ingredients
Are they specific ingredients to apply, or are you looking for the right ingredients?
How does it work?
Upstream
Where does the core product come from? How is it shaped?
Coating process
Is there an existing process, or are you seeking a technical solution?
Downstream
A finishing step is probably required to stabilize and give its characteristics to the coated product.
Step 1
Upstream
Forming process
Step 2
Emulsion spraying
Step 3
Downstream
Finishing process
Coating system
The challenge is to reproduce at a larger scale what has been done manually in the kitchen or at the bench scale. What operating principle to choose: band, pan, tumbler with dipping, dribbling, dispersing, spraying.
Coating system
If existing, what are the coating system characteristics? Type, capacity, making. Any picture, documentation, or reference of it? Where to source it?
How do you measure your success?
Key quality features
The fruit should display its freshness.
Homogeneity
Even the coating of the fruit, the layer holds onto the surface.
Integrity
No damaged surface, no dent.
Key quality parameters
The process is relatively straightforward and consists mainly of flow management: fruit and emulsion.
Composition
The rheology of the emulsion adapts to the surface type.
Productivity
Given the enormous volume of the fruits themselves and the quantity to process, the design of the handling system is essential.
Recycling
As a large volume of emulsion is recovered, it needs filtering to be reused.