Food Preservation | 5 Food Preservation Methods You Should Know | Techno Food
Summary
TLDRThis video delves into the fascinating world of food preservation, a critical technique to extend the shelf life of food while maintaining its nutritional and sensory qualities. It explores the causes of food spoilage, emphasizing the significance of preservation in enhancing food safety and reducing waste. The video outlines various preservation methods, including drying, canning, fermentation, chilling, and freezing, each with its unique process and benefits. It also touches on the importance of selecting the right preservation technique based on the food's properties. The informative content is aimed at consumers and those interested in food science and technology.
Takeaways
- 🍽️ Food preservation is crucial to prevent spoilage, maintain food quality, and extend shelf life.
- 📉 Food spoilage can occur due to physical, chemical, or microbial reactions, leading to a decrease in edibility and nutritional value.
- 🌡️ Food preservation methods aim to inhibit or kill spoilage and pathogenic microorganisms, and slow down chemical reactions.
- 🔥 Drying is an ancient preservation method that works by reducing moisture content, thus preventing microbial growth.
- 🌞 Sun drying is a natural method of drying food using solar energy, which is beneficial in areas with abundant sunlight.
- 🏭 Artificial drying methods like tray drying, spray drying, and freeze drying are controlled processes that use mechanical or electrical equipment.
- 🥫 Canning involves sterilizing food and sealing it in containers to create an anaerobic environment that inhibits microbial growth.
- 🍶 Fermentation uses specific microorganisms to change food properties and produce metabolites that can inhibit spoilage.
- 🧊 Chilling or refrigeration slows down microbial activity and chemical reactions, extending the shelf life of perishable foods.
- ❄️ Freezing immobilizes water in food, reducing available free water for microorganisms and preserving food for longer periods.
Q & A
What is food preservation?
-Food preservation is defined as the processes or techniques used to prevent food spoilage, maintain desired properties, and prolong the shelf life of food for as long as possible while retaining its original nutritional value and sensory properties.
Why does food spoilage occur?
-Food spoilage occurs due to physical, chemical, or microbial reactions that reduce the edibility of food, making it unfit for human consumption, and also reduce its nutritional value and sensory attributes like color, texture, and flavor.
What are the benefits of food preservation?
-Food preservation helps to increase the shelf life of food, overcome inappropriate planning of agriculture, reduce wastage during peak harvesting periods, ensure food quality and safety, and improve nutritional and functional properties. It also increases profit margins and consumer acceptability through value addition.
How do drying methods preserve food?
-Drying methods preserve food by removing moisture through evaporation, which reduces the water activity to a level that inhibits the growth of spoilage and pathogenic microorganisms, thus preventing food spoilage.
What are the different types of drying methods mentioned in the script?
-The script mentions natural drying methods like sun drying and artificial drying methods such as tray drying, tunnel drying, roller or drum drying, spray drying, fluidized bed drying, vacuum drying, and freeze drying.
What is canning and how does it preserve food?
-Canning, also known as in-container sterilization, is a method where food is sterilized and hermetically sealed in containers. It preserves food by applying heat to destroy microorganisms, removing air to create an anaerobic environment, and sealing to prevent recontamination.
What are the key steps in the canning process?
-The key steps in the canning process include selecting raw materials, preliminary operations, blanching, filling, exhausting air, sealing, sterilizing, and finally cooling, labeling, and storage.
How does fermentation contribute to food preservation?
-Fermentation uses specific microorganisms to change the sensory and functional properties of food, producing metabolites that are lethal or inhibitory to spoilage and pathogenic microorganisms, thus preserving the food.
What are some common examples of fermented foods?
-Common examples of fermented foods include wine, beer, sake, cider, yogurt, cheese, buttermilk, and soy sauces.
How do chilling and freezing differ in food preservation?
-Chilling, or refrigeration, stores food below 8 Celsius but above freezing, slowing down chemical and microbial reactions without killing all microorganisms. Freezing stores food at temperatures below minus 18 Celsius, immobilizing water as ice to reduce free water available for microbial growth, thus preserving food for longer periods.
What are the ideal conditions for sun drying according to the script?
-The ideal conditions for sun drying are dry, hot, and breezy days with a minimum temperature of 86 Fahrenheit (30 Celsius) and humidity below 60 percent.
Outlines
🍽️ Introduction to Food Preservation
This paragraph introduces the topic of food preservation, explaining the concept of food spoilage and its causes, such as physical, chemical, or microbial reactions. It emphasizes the importance of food preservation in maintaining food quality, safety, and nutritional value. The paragraph outlines the purpose of food preservation, which is to increase the shelf life of food while retaining its original properties. It also highlights the benefits of food preservation, including reducing waste, ensuring food quality and safety, and improving nutritional value. The classification of food preservation methods is briefly touched upon, mentioning inhibition, inactivation, and avoiding recontamination as the main categories.
🌞 The Art of Drying Food
The second paragraph delves into the oldest method of food preservation: drying. It describes how drying works by removing moisture from food, which inhibits the growth of spoilage and pathogenic microorganisms. The process reduces water activity to a level that prevents microbial growth. Two types of drying methods are discussed: natural drying, which uses solar energy, and artificial drying, which employs mechanical or electrical equipment under controlled conditions. The paragraph also mentions the ideal conditions for sun drying and lists various artificial drying techniques, such as tray drying, tunnel drying, and freeze drying, emphasizing the need to choose the appropriate method based on the food's characteristics and preservation goals.
🥫 Canning: Container Sterilization
Paragraph three explains the canning process, another method of food preservation. It outlines the steps involved in canning, starting from selecting raw materials to sterilizing and sealing the food in containers. The process includes preliminary operations like grading, sorting, and cleaning, followed by blanching to inactivate enzymes and reduce microbial load. The paragraph also discusses the importance of filling,排气, sealing, and sterilizing the food in containers. The canning process is effective because it applies heat to destroy microorganisms, removes air to create an anaerobic environment that inhibits aerobic microbes, and seals containers to prevent recontamination, thus preserving the food and preventing spoilage.
🍶 Fermentation: A Flavorful Preservation Method
The fourth paragraph introduces fermentation as a food preservation method that uses specific microorganisms to change the sensory and functional properties of food, making it more desirable to consumers. It explains how fermentation works by having key microorganisms produce metabolites that are lethal or inhibitory to spoilage and pathogenic microorganisms, thus preserving the food. The paragraph provides examples of fermented foods, such as wine, beer, yogurt, and sauerkraut, and mentions the types of microorganisms used in fermentation, including yeast and lactic acid bacteria. It highlights the benefits of fermentation, such as being relatively inexpensive and accessible, especially for developing countries and rural communities.
🧊 Chilling and Freezing: Temperature-Based Preservation
The final paragraph discusses chilling and freezing as methods of food preservation. Chilling involves storing food below 8°C to slow down chemical and microbial reactions, prolonging the shelf life of fresh and processed food. Freezing, on the other hand, involves storing food at temperatures below -18°C, which immobilizes water in food as ice, reducing free water available for microbial growth and chemical degradation. The paragraph explains that freezing can preserve food for months or even years if properly packaged. It also mentions that these methods are used to preserve a variety of foods, including fruits, vegetables, meat, and more.
Mindmap
Keywords
💡Food Preservation
💡Food Spoilage
💡Shelf Life
💡Drying
💡Canning
💡Fermentation
💡Chilling
💡Freezing
💡Water Activity
💡Microbial Reactions
💡Sensory Properties
Highlights
Introduction to the concept of food preservation and its significance in food technology.
Definition of food spoilage and its impact on edibility, nutritional value, and sensory attributes of food.
The importance of food preservation in maintaining food quality, safety, and extending shelf life.
Classification of food preservation methods into inhibition, inactivation, and avoidance of recontamination.
Drying as an ancient method of food preservation through moisture removal.
Mechanisms of food preservation by drying, including reduction of water activity to inhibit microbial growth.
Different drying methods: natural sun drying and various artificial methods like tray drying and freeze drying.
Canning as a preservation method involving sterilization and hermetic sealing of food in containers.
Steps in the canning process, including selection, blanching, filling, sealing, and sterilization.
How canning achieves preservation through heat application, air removal, and vacuum seal creation.
Fermentation as a preservation method using microorganisms to change food properties and inhibit spoilage.
Examples of fermented foods and the specific microorganisms involved in their production.
Chilling and freezing as short-term and long-term preservation methods, respectively, through temperature control.
The role of chilling in slowing down chemical and microbial reactions without completely killing microorganisms.
Freezing's effectiveness in preserving food for extended periods by immobilizing water and reducing water activity.
Summary of the video's key points on food preservation methods and their practical applications.
Transcripts
hello everyone you all are welcome to
this channel in this video we are going
to talk about a very interesting topic
in food technology which is called food
preservation
at the end of the video you will be able
to have a better idea about what is
meant by food preservation importance of
food preservation and common food
preservation methods that you can
utilize to preserve your food for a
longer period of time
okay let's begin with the definition of
food preservation before we move into
the definition have you heard of the
term called food spoilage
the idea is that all food that we are
consuming May undergo a different level
of deterioration because of different
reasons
the reason for this food spoilage can be
physical chemical or microbial reaction
as a result of that it will reduce the
edibility of food and make them unfit
for human consumption
as well as it will reduce the
nutritional value and sensory attributes
like color texture and flavor of food
for instance think about spoiled milk
which smells bad and having sour taste
also you may experience unpleasant odor
in rotten eggs
not only that food spoilage will lead to
change in the appearance of food
for example rotten apples you may see
some bruised spots on the surface of the
fruit as well as you may see mold grow
on the bread when it gets spoiled
furthermore you can observe slimy
textures on spoiled fish and meat
so in order to keep the quality and
safety of food for a long time we need
to preserve them
we can Define food preservation as
processes or techniques used to prevent
food spoilage maintain their desired
properties and prolong shelf life for as
long as possible
the ultimate objective of food
preservation is to increase the shelf
life of foods while retaining their
original nutritional value and sensory
properties
that means just enhancing the shelf life
of food is not enough
we have to retain the original quality
of the product through this preservation
process our next question is why do we
need to preserve food what are the
importance of the food preservation
process here are some benefits of the
food preservation process as you already
know food preservation helps to increase
the shelf life of food and enhance their
organoleptic properties
also it will help to overcome
inappropriate planning of Agriculture
further we can reduce the wastage of
food during Peak harvesting periods by
using food preservation methods
not only that we can ensure food quality
and safety but also improve nutritional
and functional properties of food by
preserving them
in addition to that we can increase the
profit margin and consumer acceptability
through value addition
you know as consumers we mostly like to
enjoy a wide variety of food items and
get pleasurable experiences
isn't it so through preserving we can
experience variation in diet
let's see how we can classify food
preservation methods food preservation
methods can be broadly classified as
inhibition inactivation and avoid
recontamination
food preservation methods that slow down
or inhibit the growth of spoilage and
pathogenic microorganisms and other
chemical deterioration include drying
freezing fermentation
acidification concentration
refrigeration-like methods
methods that directly inactivate or kill
bacteria molds yeasts and enzymes
include pasteurization
sterilization cooking and irradiation
like methods
methods that avoid recontamination of
the product before and after the
processing include aseptic processing
hygienic storage packaging hygienic
processing and more
even though there are numerous food
preservation methods we should think
about properties of food that need to
preserve before selecting one
the thing is one property may be
important for one product but
detrimental for others
for example a consumer expects apple
juice to be clear whereas orange juice
could be cloudy as the next part of this
video we are going to talk about common
food preservation techniques that are
widely used in the world
we can also use those methods to
preserve our Foods most of the methods I
am going to teach you today are
conventional food preservation methods
I will bring you another video about
novel food preservation techniques
applied in the food processing industry
well Shall We Begin with our very first
method of food preservation which is
called drying
drying is considered one of the oldest
methods of food preservation drying
involves removing moisture from the food
through the evaporation process it is a
combination of heat and mass transfer
processes do you know how to preserve
food by drying mechanism in this method
what we are doing is we reduce the
moisture content of foods up to the
desired level which inhibits the growth
of food spoilage and pathogenic
microorganisms
that means drying reduces the free water
available for microbial growth and other
chemical and enzymatic degradation
processes
so in drying food preservation is
achieved through the reduction of water
activity of the food to the level which
prevent the food spoilage by pathogenic
and spoilage microorganisms
most of the bacteria get inactivated at
Water activity below 0.9 whereas most
yeast and molds are inhibited in water
activity below 0.8 and 0.7 accordingly
drying methods can be categorized as
natural drying methods or artificial
drying methods
in natural drying methods we are
removing moisture present in food by
using solar energy
in case of artificial drying methods we
dehydrate the food by efficient removal
of moisture by using mechanical or
electrical equipment under controlled
conditions like temperature airflow and
time
let's see how we can preserve our food
by natural Sun drying method
Sun drying refers to the process of
removing excess water from food by
exposing them to sunlight
the main aim of sun drying is to prolong
the shelf life of food
since ancient times people have used Sun
drying methods to preserve their Foods
the interesting fact is Sun is a free
source of energy and most of the
developing countries who are struggling
to access fossil fuels can get benefits
out of sun drying
the most traditional method of sun
drying is the open sun drying method
next let's see how we can perform open
sun drying first food products to be
dried are spread on the ground or
concrete or wooden floors as a thin
layer
then they are exposed to direct contact
with sunlight to remove excess moisture
from food with the action of wind
this drying process continues for
several days until achieving the
required level of drying
do you know what are the ideal
conditions for sun drying dry hot Breezy
days are best for sun drying also we
need a minimum temperature of 86
Fahrenheit or 30 Celsius and humidity
below 60 percent to facilitate a better
drying process in the sun drying method
take care to prevent product
contamination by dust dirt insects or
any other contaminants
Sun drying method is used to dry fruits
vegetables fish and more
our next question is what are the
artificial ways of drying we can use to
preserve our food
some of the methods can be simply
mentioned for your understanding they
include tray drying method tunnel drying
roller or drum drying spray drying
fluidized bed drying vacuum drying
freeze drying method and many more
even though there are numerous drying
methods we should select the most
appropriate drying method based on the
nature of the food commodity the desired
nature of the finished goods economic
and operational conditions
for your understanding tray dryers are
mainly used to dry fruits like apples
apricot banana and vegetables
spray dryers are used to dehydrate foods
that can be atomized including liquid
foods low viscosity purees and pastes
furthermore roller or drum dryers can
dry liquid foods pastes purees and
mashes
if you want to dry products that contain
heat sensitive components like vitamins
microbial cultures antioxidants like
carotenoids ascorbic acid plant phenol
and antibiotics you can use freeze
drying method let's move on to our
second method of preservation it is
called canning this method is also
termed as in container sterilization in
this method what we are doing is we
sterilize the food product and
hermetically sealed in containers to
preserve them
do you know what are the basic steps in
Canning process okay now let's see what
the typical stages of canning process
initially we should select appropriate
raw materials to do the canning process
here are the key points the material we
select should be in required quality and
quantity
also they should withstand the heat
treatment process once we receive the
materials into our processing area we
should follow up preliminary operations
like grading sorting cleaning peeling
and cutting based on the nature of the
material we are going to preserve
as a Next Step you can go through a
blanching process depending on the
material
it is a mild heat treatment where we're
heating our food to a predetermined
temperature
this process helps to inactivate enzymes
that are responsible for enzymatic
Browning processes
it also helps to reduce microbial load
and Aid in packaging after that you can
go through filling step here you should
fill the products in sterilized
containers or jars here boiled syrup
brine juice or sauces are added over the
food in containers
it will Aid in better heat transfer and
preservation when filling we need to
take care of the accuracy of filling and
headspace
we need to keep space in between packed
food and container lids
as the next step we should exhaust the
air before move into the sealing process
it will help to avoid excessive
development of pressure during heat
treatment
after that products with containers can
move for sealing operations here we
hermetically seal the product the next
step is sterilizing the products for
this purpose large pressure vessels
called retorts are used on an industrial
scale which can be operated in batchwise
or continuous way
on a small scale we can use either
pressure canner or boiling water canner
depending on the food we need to
preserve
for instance if we're going to preserve
high acid containing foods like fruits
we can use boiling water canners which
heat the food up to 100 Celsius
in this case the organic acids that are
naturally present in fruits will inhibit
the growth of botulinum bacteria While
most bacteria yeast molds are killed due
to heat
in order to preserve low acid containing
food like meat seafood and vegetables we
can use pressure canners which can
provide temperature required to kill
botulism bacteria
the final steps are cooling the products
labeling them in storage do you know how
we can achieve food preservation by
canning process
basically it's due to the application of
heat removal of air and creation of
vacuum seal
you already know that in Canning we heat
the products to a higher temperature
this heat will destroy the food spoilage
and pathogenic microorganisms not only
that it will destroy the enzymes and
inhibit the enzyme's activity
in the case of canned foods the most
prominent microbes that easily
contaminate the product are called
clostridium botulinum
they can grow well inside low acid foods
and anaerobic conditions the idea is
that they can produce hazardous toxins
called botulinum toxins under a low
oxygen environment
these botulinum bacteria not only spoil
the food but also can cause severe
foodborne illnesses
so in Canning we have to ensure our
canning process will kill all the
botulism bacteria and their spores
in order to kill those hazardous
microbes we need to apply much higher
temperature conditions
for instance at 121 Celsius it will
destroy the clostridium botulinum and
their spores within a short time
in the case of canning high acid foods
botulinum can destroy due to high
acidity
since this canning process helps to
destroy clostridium botulinum in earlier
it's called as botulism cook
also the air removal process creates
some kind of anaerobic condition
this will inhibit the growth of aerobic
microbes since it reduces the amount of
oxygen in containers it will prevent
deterioration of food due to oxidation
reaction
for instance it will prevent the
creation of rancid odors and flavors due
to lipid oxidation
further when containers are hermetically
sealed they are impermeable to liquid
gas and microorganisms
this will prevent the recontamination of
the product thereby it preserves the
food by preventing the food spoilage for
example canned fish products have a
longer shelf life approximately two
years or more compared to Fresh Fish
which types of foods can we preserve by
using a canning process
we can preserve fruits vegetables meat
Fish seafood legumes like Foods by using
this method the next preservation method
we are going to discuss today is called
fermentation
in the fermentation process what we are
doing is we are using specific
microorganisms to change the sensory
properties like odor flavor and
functional properties of the food
the end product we are producing through
this fermentation as desirable to
Consumers
compared to other food preservation
methods this method is relatively
inexpensive and can be done by using
basic equipment
so developing countries and Rural
communities with limited facilities can
get benefits out of this method
do you know how can we achieve
preservation through this process here
what happens is the key microorganisms
who involve in food fermentation process
will improve their own competitiveness
by changing the environment
that means they produce different
metabolites during food fermentation
those produced metabolites will become
lethal or inhibitory to other spoilage
and pathogenic microorganisms
thereby it will preserve the food for
your understanding in the production of
alcoholic beverages like wine and beer
we are using yeast as our key
microorganisms who involve in
fermentation process
during this process yeast produces
metabolites called alcohol even though
this produced alcohol is favorable for
yeast it will unfavorable and lethal for
other spoilage microbes
this will inhibit the growth of
contaminating microflora and inactivate
them finally it will preserve our food
by preventing food spoilage let's see
what are the common examples of
fermented foods the most common
fermented foods include wine beer sake
cider yogurt cheese buttermilk soy
sauces and many more
each of these fermented foods are
produced by using key ingredients with
the presence of specific microorganisms
for example by fermenting grapes using
yeast the end product we produced are
called wine while barley are used to
produce beer with the presence of yeast
furthermore cider is the product we get
by fermentation of apple with yeast
also we can produce yogurt cheese and
buttermilk like products by fermenting
milk with the action of the lactic acid
bacteria
in addition to that fermentation of
cabbage with the presence of lactic acid
bacteria will produce sauerkraut
I think now you have some idea about
what happens in the fermentation process
now let's summarize who are the key
microorganisms that can be used in
fermentation
these include yeast lactic acid bacteria
acetic acid bacteria molds like
aspergillus or as a well shall we move
on to our next methods of food
preservation
it is chilling and freezing when
chilling or what we call Refrigeration
we store food below 8 Celsius and
temperatures above freezing
that means in chilling we maintain
temperature in between -1 Celsius and 8
Celsius
chilling is considered an effective
short-term preservation method the idea
is in chilling we cannot completely kill
all the microorganisms Instead This
method helps to slow down the chemical
and microbial reactions rate of food
thereby it helps to prolong the shelf
life of fresh and processed food
chilling can be used to preserve fruits
vegetables fresh fish meat dairy
products fruit juices baked foods and
more
basically under Cool Storage perishable
foods can be stored for days or weeks
based on the food
when it comes to freezing foods are
stored at temperatures that maintain
them in Frozen conditions
we need temperatures of minus 18 Celsius
or below in order to maintain good
Frozen storage
in freezing what happens is that water
available inside the food will
immobilize to ice
as a result of that it will reduce the
free water available inside the food for
the microorganisms and other chemical
degradation process
so freezing will preserve the foods due
to reduction of water activity and low
temperature conditions
generally Frozen storage May preserve
food for months or even years if
properly packaged
use it to preserve fruits vegetables
meat and other food stuff I think up to
now you may have some idea about what is
meant by food preservation what is meant
by food spoilage importance of food
preservation methods how to classify
food preservation methods and common
food preservation methods that we can
use to preserve our Foods including
drying canning fermentation chilling and
freezing hope you all enjoy the today
video and you may learn something out of
it
so if you're willing to see more videos
related to food science and technology
please like the video and subscribe to
this channel
it will really be helpful to me to bring
this kind of videos
again thank you for watching and we'll
meet with another video
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