Food Preservation | 5 Food Preservation Methods You Should Know | Techno Food

Summary

This 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

00:00

🍽️ 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.

05:00

🌞 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.

10:01

🥫 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.

15:03

🍶 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.

20:05

🧊 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.

Keywords

💡Food Preservation

Food preservation refers to the various processes and techniques used to extend the shelf life of food while maintaining its desired properties. In the video, it is highlighted as a crucial method to prevent food spoilage and maintain the nutritional value and sensory attributes of food. Examples from the script include drying, canning, and fermentation, all of which are traditional methods to preserve food for longer periods.

💡Food Spoilage

Food spoilage is the process where food undergoes deterioration due to physical, chemical, or microbial reactions, making it unfit for human consumption. The video script mentions spoiled milk and rotten eggs as examples of food spoilage, illustrating how it affects the edibility and sensory qualities of food.

💡Shelf Life

Shelf life denotes the period during which food remains safe, retains its intended quality, and is suitable for consumption. The video emphasizes the importance of food preservation in increasing the shelf life of foods, which is a key goal of preservation techniques to ensure food safety and quality over time.

💡Drying

Drying is an ancient food preservation method that involves the removal of moisture from food to inhibit the growth of spoilage and pathogenic microorganisms. The video describes both natural and artificial drying methods, such as sun drying and mechanical dehydrators, which are used to reduce water activity and prevent food spoilage.

💡Canning

Canning, also known as in-container sterilization, is a preservation method where food is sterilized and sealed in airtight containers. The video explains that this process involves steps like blanching, filling, sealing, and sterilization in retorts, which ultimately kills microorganisms and prevents recontamination, thus preserving the food.

💡Fermentation

Fermentation is a food preservation technique that uses specific microorganisms to alter the sensory and functional properties of food, producing desirable flavors and textures. The video mentions that fermentation is a cost-effective method that can be done with basic equipment, making it suitable for developing countries and rural communities. Examples include the production of wine, beer, and yogurt.

💡Chilling

Chilling, or refrigeration, is a short-term preservation method where food is stored at temperatures above freezing but below 8°C. The video explains that chilling slows down chemical and microbial reactions without completely killing all microorganisms, thus prolonging the shelf life of perishable foods like fruits, vegetables, and dairy products.

💡Freezing

Freezing is a preservation method that involves storing food at temperatures below -18°C to maintain a frozen state. The video describes how freezing immobilizes water in food, reducing free water available for microbial growth and chemical degradation, thus preserving food for months or even years with proper packaging.

💡Water Activity

Water activity is a measure of the availability of water in a food product for microbial growth and chemical reactions. The video explains that reducing water activity through methods like drying and freezing is crucial for food preservation as it inhibits the growth of spoilage and pathogenic microorganisms.

💡Microbial Reactions

Microbial reactions refer to the biochemical processes caused by microorganisms that can lead to food spoilage. The video script discusses how food preservation methods aim to control or prevent microbial reactions to maintain food quality and safety.

💡Sensory Properties

Sensory properties are the characteristics of food that are perceived by the senses, such as taste, smell, color, and texture. The video highlights the importance of preserving these properties through food preservation techniques to maintain the consumer's pleasurable food experience.

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

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it will really be helpful to me to bring

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again thank you for watching and we'll

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