APPLICATION

Preserving fruits with a wax coating

Fruits engaged on a long journey are best protected with a thin organic film.

Updated Jun 03, 2022 - 10 min Read

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

5

2.

Emulsion spraying

5

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.