This document discusses food dehydration and drying. It begins by introducing dehydration as a method of food preservation that removes moisture from food to inhibit bacterial growth. It then discusses the basics of the dehydration process using heat, dry air, and air movement. Next, it covers fundamental processes of heat and mass transfer during drying. Several methods of food drying are presented including open sun drying, dehydrators, and freeze-drying. Packaging methods for dehydrated foods like vacuum packaging and modified atmosphere packaging are also outlined. The document concludes by looking at effects of drying on food quality and future trends in dehydrated food packaging and production.

1. Overview of
Presentation
Definition
Concept
Method
Packaging Requirement
Selection
Different Food Products
Effect on Food Quality
Future Trends

2. INTRODUCTION
• Drying is one of the oldest methods of fruits and
vegetables preservation
• Dehydration is the process of removal of moisture from
the food products
• Removal of moisture stops the growth of bacteria, yeasts
& molds that normally spoil food
• Slows down but doesn’t completely inactivate enzymes
• Dehydrated foods are ideal for backpacking, hiking, and
camping

3. Basics of food dehydration
• Heat — hot enough to force out moisture (140°F),
but not hot enough to cook the food;
• Dry air — to absorb the released moisture;
• Air movement — to carry the moisture away.

4. Fundamental Process
HEAT TRANSFER- Transfer of heat through
latent heat of evaporation released by food
product
MASS TRANSFER- Moisture diffusion within
the product and evaporation from the surface

5. METHODS OF FOOD DRYING
1. Open sun drying
– Water is usually removed by evaporation
2. A solar or electric food dehydrator
– it can greatly speed the drying process and ensure more consistent results
3. Freeze-drying
– food is first frozen and then the water is removed by sublimation

6. Open Sun Drying practices
Traditional practice of grain drying
• Spread crop on the ground
• exposing it to the effects of sun, wind and rain
– the sun supplies source of heat to evaporate moisture from the grain
– the velocity of the wind to remove the evaporated moisture
Possible only in areas where, in average year, the weather allows food
to be dried immediately after harvest

8. REFERENCES
• http://ecoursesonline.iasri.res.in/mod/page/view.php?id=881
• https://pubs.ext.vt.edu/348/348-597/348-597.html
• https://www.process-heating.com/articles/86586-the-drying-
curve-part-1
• http://www.emergencyfoodstorage.co.uk/pages/Freeze-Dried-
Food.html

9. METHOD OF DEYDRATED FOOD
PACKAGING
• Content:
• Vacuum packaging
• Shrink packaging
• MAP
• Canning
• Stand up pouch
This Photo by Unknown Author is licensed under CC BY-ND

10. METHOD OF DEYDRATED FOOD
PACKAGING
• Vacuum Packaging
It is a method of packaging that
removes air from the package
prior to sealing.
Placing the dehydrate food
product in a plastic film package,
removing air from inside, and
sealing the package.
It is also commonly used to store
dry foods over a long period of
time, such as cereals, nuts,
cured meats dry fish,& dry fruits
etc.
This Photo by Unknown Author is licensed under CC BY-SA-NC

11. • It is the practice of
modifying the composition
of the internal atmosphere
of a package in order to
improve the shelf life of dry
food product.
• The modification process
generally lowers the
amount of oxygen(O2) in
the space of the package.
Oxygen can be replaced
with nitrogen (N2), a
comparatively inert gas,
or carbon dioxide (CO2).
Modified Atmosphere Packaging

12. • Shrink film is sometimes used to have
a tight fit to the contents. The intent of
vacuum packing is usually to remove
oxygen from the container to extend
the shelf life of dry foods.
• shrink packaging commonly known as
shrink wrapping. Shrink wrapping is
done in following four
stages:
• wrapping (sleeve wrapping or over-
wrapping)
• sealing (necessary only for over-
wrapping)
• shrinking (with application of hot air),
and
• Cooling
Shrink Packaging

13. Canning
• It is a method of preserving
food in which the food
product are dried and sealed
in an airtight container.
• Canning provides a shelf
life typically ranging from
one to five years.
Standup Pouches
• We using stand up pouches
and zipper pouches with
great shelf life for food
products like namkeen, dry
fruits, sweets etc.
• All the pouches can be
provided printed and non-
printed. It is one of the most
successful packaging mode
which is always in demand

14. PACKAGING REQUIRMENT
Packaging and package labeling have several objective are:-
• Physical protection - The food enclosed in the package
may require protection from, among , shock, vibration,
compression, temperature, bacteria, etc.
• Barrier protection - A barrier from oxygen, water vapor,
dust, etc., is often required. Modified atmospheres or
controlled atmospheres are also maintained in some
food package.
• Containment - Small items are typically grouped
together in one package to allow efficient handling such
as dry fish , meat ,dry fruits etc. need containment.

15. • Information transmission and marketing -
Packages and labels communicate how to use,
transport, recycle, or dispose of the package or
product. And also we can print the nutrition
value of food product.
• Convenience - Packages can have features
which add convenience in distribution,
handling, stacking, display, sale, opening,
reclosing, use, and reuse.
• Easy to handle- Single-serving packaging has a
precise amount of contents to control usage.
Bulk commodities can be divided into
packages that are a more suitable size for

16. References
https://en.wikipedia.org/w/index.php?search=f
ood+packaging+method&title=Special:Search&g
o=Go
http://ecoursesonline.iasri.res.in/course/view.p
hp?id=28
http://www.paraspack.com/blog/want-to-know-
about-spout-pouches-packaging/
https://www.britannica.com/topic/canning-
food-processing

17. Different type of dried Food Products
• Powdered Milk
• Instant Noodles like Maggie
• Dried Coffee powder
• Oat Meals
• Instant Soup
• Tamarind Powder
• Dehydrated Vegetable Flakes
• Dehydrated Garlic Powder
• Dehydrated Apples and Bananas

18. • Desiccated Coconut Powder
• Dehydrated Potato Cubes
• Dried nut –
• Like Almonds, Fig , Date , Cashews etc

19. Selection Criteria
Machine Performance:-
Over the years dehydrated food manufacturers has developed from
handpacking lines to high speed fully automatic system.. These
properties include frictional characteristics, stiffness, crush resistance,
seal ability, ease of opening, ease of separation, good cutting and folding
characteristic. Friction control ensures that the packaging feeds readily
onto the filling line but is not slippery as to cause handling difficulties.
Printability:-
The materials must have an appropriate surface to enable the print
results requested to be obtainable. This require control of surface
smoothness, gloss, absorbency, wettability and resistance to
appropriate ink medium.

20. Storage And Transport Performance:-
Packaging must perform good in storage and transport. This
requires good crush resistance, resistance to variable moisture
content, no embrittlement at the low temperature experienced by
frozen foods, sufficient barrier properties to prevent staining and
dehydration of contents, and sufficient scuff resistance to avoid
deterioration of surface appearance of printed matter.
Heating Performance:-
Often the packaging is required to withstand the reheating or
cooking process experienced in preparation of food by purchaser.
This could expose the material to temperature in excess of 200
Celsius for as long as 30-40 min, although when food have high
moisture content the temperature rarely exceeds 105 Celsius.

21. Environmental Impact:-
When selecting packaging it is essential to take the environmental
implications of packaging into account. During manufacturing of
packaging, factors to be considered will be effluents (liquid waste),
emissions or waste products, any unacceptable by-product from the
process. In application, it is necessary to consider the usage of
renewable and/or non-renewable energy resources ,the presence of
facilities to collect, separate and decontaminate any packaging
waste and convert it into an economically viable waste.

22. Effects on Food Quality
1. Cell/ tissue shrinkage
2. Case hardening
3. Chemical changes

23. Cell/ tissue shrinkage
Food materials do not have perfect elasticity
and water is not removed evenly throughout
food as it is dried and causes shrinkage.

24. Case hardening
• Due to high surface temperature and unbalanced
drying, dry skin will form and causes case hardening .
• Rapid drying- compounds (such as sugar) form a
hard, impermeable “case” around the food piece .
• Common in high sugar products .

25. Chemical changes
• Enzymatic browning of products due to poor
blanching.
• Denaturation of proteins due to aggregation of
polysaccharides.
• Caramelization of sugars due to excess heat.
• Loss of volatile flavor constituents.
• Partial loss of some essential nutrients like Vit C.

26. Future Trends
• Future Market Insights predicts a 4.8% growth rate of the
global market for dehydrated vegetables over the coming
decade.
• Packaged dehydrated foods halt or slow down the growth of
microorganisms and have long shelf life increase the demand
for packaged dehydrated foods.
• This technique is less expensive when compared with other
dehydration technologies.
• This technique is considered to be safe as the products are
not treated with additives and preservatives.
• The popularity of dehydration with the help of ovens is
increasing among the urban end-users.

27. • The convenience and economic benefits of the drying-at-home
technique reduce the demand for packaged dehydrated foods.
• Certain producers of dehydrated vegetables use infra-red drying
technology to dehydrate vegetables without any loss of nutrients
• One of the producers of organic fruits and vegetables operating
in the global market has recently launched their line of
dehydrated vegetables and fruits in powder form.

28. REFERENCES
• https://www.slideshare.net/RAGHAVENDRAHI
REHAL/principles-and-methods-of-
preservation-by-drying?from_action=save
• https://www.businesswire.com/news/home/2
0180322005529/en/Global-Packaged-
Dehydrated-Food-Market---Trends
• https://www.prnewswire.com/news-
releases/global-packaged-dehydrated-food-
market-2018-2022-300642257.html

29. THANK YOU