Waxing the Right Way

Daniel CooperFresh

An article about citrus waxing was recently published by Citrus Australia. The article, written by John Golding, a research horticulturist with the New South Wales Department of Primary Industries, is summarized here.


Waxing citrus can help maintain quality and enhance the fruit’s appearance. However, using the wrong type of wax or applying an excessively thick layer can overly restrict gas exchange between the fruit’s skin and the air. This lowers the oxygen levels and increases the level of carbon dioxide within the fruit, triggering the accumulation of fermentation off-flavors. These off-flavors can make the fruit taste stale. Therefore, the selection and use of wax is critical.


Fruit growing in an orchard has a natural wax that protects its skin from damage and water loss. When the fruit is harvested, then handled and cleaned in the packhouse, this natural wax layer is damaged or removed. It is essential to replace this wax with another natural food-grade wax in the packhouse to maintain the quality of the fresh citrus through the supply chain.

Wax on fresh citrus helps reduce water loss, improves appearance, increases freshness, protects the fruit’s surface, slows down the development of some rind disorders and reduces waste. Reduction in water loss from the fruit is most important; it is critical to maintaining fruit firmness and quality.

Wax provides a barrier to water loss and slows the evapotranspiration of the water from the fruit. In addition, the wax barrier reduces air permeability of the peel, thus creating a unique environment to extend shelf life.

Wax also gives fruit a strong, shiny appearance that appeals to many consumers.


The main wax formulations used on citrus are carnauba and shellac-based waxes, or a combination of both.

Carnauba is a natural wax extracted from the leaves of the carnauba palm. It is widely used as a component in citrus waxes due to its attractive shine. However, it has relatively poor control of water loss and is relatively permeable to gas exchange.

Shellac-based waxes impart high shine and help to maintain moisture within the fruit and reduce shrinkage. However, they are more susceptible to the development of off-flavors than carnauba-based wax coatings.

Packers should test which wax is best for their operations.

Morpholine is sometimes used as an emulsifier in some waxes, but some importing countries, including the European Union, have banned its use.


Wax needs to be applied to the fruit’s surface evenly, at a low pressure. It should not be diluted with water.

Fruit should be damp prior to application. Wax is normally sprayed or dripped onto pieces of fruit while they are being rotated on a bed of brushes. The revolving brushes help to spread the wax evenly over the fruit’s surface.

In some instances, the wax formulation may be used as a carrier of postharvest fungicides and inhibitors of senescence.

Source: Citrus Australia

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