The document discusses the process of waxing fruits. It describes how waxing improves the appearance and shelf life of fruits by creating a protective coating. It covers the benefits of waxing, different types of waxes used, common waxing methods, and how wax acts to reduce moisture loss from fruits. Examples are given of how wax coatings are applied and their advantages for apples and citrus fruits.
3. Introduction
Fruits benefited by waxing
Advantages vs disadvantages of waxing
Types of waxes
Waxing methods
How wax acts
Wax coating on apples
Wax coating on citrus
Conclusion
References
Contents
4. Fruit waxing is the process of covering fruits. Natural wax is removed
first, usually by washing. Waxing materials may be either natural or
petroleum-based.
Waxes are often mixed with water or other wetting agents to ensure
they are applied thinly and evenly to the outer surface of the product.
External appearance is an important attribute of overall fruit and
quality
Various types of waxes and edible surface coatings may be applied to
fruits to improve the cosmetic features (shine, color) of the product.
Waxing is recommended only for good quality products because it
does not improve the quality of inferior ones
Introduction
6. Artificial Appearance
Added Cost
Surface Burn
Wax Whiting (Chalking
Off-flavor development
Disadvantages
It improves the appearance of produce
Reduce Moisture Loss
Less Economic Loss
Reduced Postharvest Decay
It prevents damage and disease;
Replace natural wax
Increase the freshness
Decrease the rate of transpiration
Longer Postharvest Life
Less Susceptibility to Chilling Injury
Advantages
Advantages vs disadvantages of waxing
8. Liquid Paraffin wax method
o In this method fruits and vegetables are dipped
in hot paraffin.
o Some times resins are added.
o The main disadvantage of this method is too
much of coating material is used.
Slab wax method/roller brushing method
o In this case the wax is pressed against rapidly
revolving brushes.
o But the efficiency is very less
Waxing methods
9. 3. Spray method:
Spraying of melted wax on the fruit, which is subsequently brushed mechanically until a
film of desired thickness is obtained. The wax is dissolved in a suitable solvent. This
depends on,
The pressure employed
Volume of wax used
Wax temperature
Distance of fruit from the spray
Number of spray nozzles.
4. Dipping or cold wax method:
Fruits and vegetables are washed and then without being dried are dipped into a wax
emulsion of proper concentration. They are dried before packing. Purified wax is odour
less, tasteless and nontoxic and it can be heat- sealed.
10.
11. All fruits and vegetables are covered naturally in a
cuticle that is a barrier to moisture loss.
However, some water vapors can move through the
pores, cuticle and micro-cracks in the cuticle.
During the process of waxing, a tightly adhering thin
firm of the coating substance is applied to the surface of
the fruit.
The wax coating blocks the pores in the cuticle, which
significantly reduces the amount of water vapor loss.
How wax acts ?
12. o Coating of apples is carried out by applying a thin layer
of wax on the surface.
o The coating process can be carried out by either
dipping, brushing or spraying with wax.
o This coating is normally referred to as edible coating.
o An edible coating is a thin layer that is applied on the
surface of a fruit or vegetables which is consumed
together with the fruit.
o An apple with a good waxy coating will store better
than one with a partial waxy coating or no waxy coating
at all
o The waxes applied on apples can either be animal wax,
vegetable wax or mineral and synthetic wax.
o The most common wax used on apples is a vegetable
wax called carnauba wax or shellac
o .
o .
Wax coating on Apples
13. Advantages
o apples can apply wax to improve appearance and increase visual freshness
o The main reasons are either for preservation, aesthetic (appearance) or the
obvious one of replacing the natural wax.
o The apples are waxed to reduce loss of water hence ameliorating weight
loss.
o Preventing the loss of water in apples also helps to maintain firmness and
juiciness.
o The distributors and sellers of apples can apply wax to improve appearance
and increase visual freshness
o Disadvantages
o Waxing apples can have some negative effects on the apple fruit.
o One of the effect is anaerobic respiration that can occur in the fruits
since the wax may act as oxygen barrier.
o The wax can be used to disguise the quality of apples.
o Waxed apples may look glossy, sleek, shiny, firm and appealing , but
they could be soggy and lacking the desirable crispy texture.
14. Citrus fruits are the juiciest among all other fruits. So the
waxing coating process is widely used on Citrus fruits.
After production of Citrus, Cultivators, Wholesalers,
Dealers and sellers adopt the use of Waxes for waxing
coating of Citrus.
Wax is applied on citrus by dipping. Paraffin based
coatings are used to control weight loss while resin water
solution containing shellac, alkali resins and emulsifiers
used for longer shelf life and better shine.
Wax Coating for Citrus has the following advantages:
o Reduces Weight Loss
o Maintains Freshness and Firmness
o Reduces spoilage during transportation and storage
o Enhances original texture and color of the fruit
Wax coating on Citrus
15. Coating improves product appearance, color, crispness, flavor, nutritive value,
juiciness, texture.
Continuous Mechanization is not available for various coating operations.
Safety of food product should be maintained in the coating operations.
Many of the coating materials are high in cost and some of the coating operations are
also higher cost. This leads to increase the cost of operation of coating. So, we have to
reduce the cost of coatings
Coatings can extend shelf-life and make product available thought-out the season by
• Delay the ripening processes
• Delay the color changes
• Reduce the weight loss
• Maintain the texture
• Reduce the decay
Conclusion