Food preservation includes food processing practices which prevent the growth of microorganisms, such as yeasts (although some methods work by introducing benign bacteria or fungi to the food), and slow the oxidation of fats that cause rancidity. Food preservation may also include processes that inhibit visual deterioration, such as the enzymatic browning reaction in apples after they are cut during food preparation. By preserving food, food waste can be reduced, which is an important way to decrease production costs and increase the efficiency of food systems, improve food security and nutrition and contribute towards environmental sustainability.For instance, it can reduce the environmental impact of food production.
Many processes designed to preserve food involve more than one food preservation method. Preserving fruit by turning it into jam, for example, involves boiling (to reduce the fruit's moisture content and to kill bacteria, etc.), sugaring (to prevent their re-growth) and sealing within an airtight jar (to prevent recontamination).
Different food preservation methods have different impacts on the quality of the food and food systems. Some traditional methods of preserving food have been shown to have a lower energy input and carbon footprint compared to modern methods.
Food Preservation by Drying - Premraja N.pptxPremraja N
This Presentation contains Information and knowledge about various drying methods for Food preservation for enhancing the shelf life of food by lowering the water activity.
various drying methods including, CONVECTIVE DRYING,AIR DRYING,FLUIDIZED BED DRYER,SPRAY DRYERS,
DIELECTRIC DRYING,
Ohmic heating, CABINET DRYER etc.
Sterilization refers to any process that removes, kills, or deactivates all forms of life (in particular referring to microorganisms such as fungi, bacteria, viruses, spores, unicellular eukaryotic organisms such as Plasmodium, etc.
Food preservation includes food processing practices which prevent the growth of microorganisms, such as yeasts (although some methods work by introducing benign bacteria or fungi to the food), and slow the oxidation of fats that cause rancidity. Food preservation may also include processes that inhibit visual deterioration, such as the enzymatic browning reaction in apples after they are cut during food preparation. By preserving food, food waste can be reduced, which is an important way to decrease production costs and increase the efficiency of food systems, improve food security and nutrition and contribute towards environmental sustainability.For instance, it can reduce the environmental impact of food production.
Many processes designed to preserve food involve more than one food preservation method. Preserving fruit by turning it into jam, for example, involves boiling (to reduce the fruit's moisture content and to kill bacteria, etc.), sugaring (to prevent their re-growth) and sealing within an airtight jar (to prevent recontamination).
Different food preservation methods have different impacts on the quality of the food and food systems. Some traditional methods of preserving food have been shown to have a lower energy input and carbon footprint compared to modern methods.
Food Preservation by Drying - Premraja N.pptxPremraja N
This Presentation contains Information and knowledge about various drying methods for Food preservation for enhancing the shelf life of food by lowering the water activity.
various drying methods including, CONVECTIVE DRYING,AIR DRYING,FLUIDIZED BED DRYER,SPRAY DRYERS,
DIELECTRIC DRYING,
Ohmic heating, CABINET DRYER etc.
Sterilization refers to any process that removes, kills, or deactivates all forms of life (in particular referring to microorganisms such as fungi, bacteria, viruses, spores, unicellular eukaryotic organisms such as Plasmodium, etc.
The PPT includes importance of grain drying, moisture content determination methods, equilibrium moisture content, different mode of heat transfer, types of different drying methods, different dryers etc. The presentation is best suitable for graduation level students.
Conventional food processing techniques Uma Bansal
its a presentation based on conventional food processing techniques and it contains drying methods also along with freeze drying and concentration and evaporation.
Food engineering operations are employed in food industries for production of good quality palatable and stable foods.Food engineering operations convert raw agricultural commodities into canned, frozen, dehydrated, formulated and otherwise modified forms of food.
Dehydration
food dehydration
preservation effect
controlling factors for dehydration
factors affecting dehydration
driers commonly used are
dehydration and nutritive value
disadvantage
drying and microbes
General Principles of Food Preservation:
a. Preservation using High temperature (12D concept), principle of canning
b. Low temperature
c. Drying
d. Food preservatives (organic acids & their salts, Sugar & salt)
e. Ionizing radiations
Drying is need because the high moisture grain will cause heat build up (Hot spot) from respiration of microorganisms, low thermal diffusivity of grain ,increased the mold growth, reduced starch and sugar content.
Vietnam Mushroom Market Growth, Demand and Challenges of the Key Industry Pla...IMARC Group
The Vietnam mushroom market size is projected to exhibit a growth rate (CAGR) of 6.52% during 2024-2032.
More Info:- https://www.imarcgroup.com/vietnam-mushroom-market
The PPT includes importance of grain drying, moisture content determination methods, equilibrium moisture content, different mode of heat transfer, types of different drying methods, different dryers etc. The presentation is best suitable for graduation level students.
Conventional food processing techniques Uma Bansal
its a presentation based on conventional food processing techniques and it contains drying methods also along with freeze drying and concentration and evaporation.
Food engineering operations are employed in food industries for production of good quality palatable and stable foods.Food engineering operations convert raw agricultural commodities into canned, frozen, dehydrated, formulated and otherwise modified forms of food.
Dehydration
food dehydration
preservation effect
controlling factors for dehydration
factors affecting dehydration
driers commonly used are
dehydration and nutritive value
disadvantage
drying and microbes
General Principles of Food Preservation:
a. Preservation using High temperature (12D concept), principle of canning
b. Low temperature
c. Drying
d. Food preservatives (organic acids & their salts, Sugar & salt)
e. Ionizing radiations
Drying is need because the high moisture grain will cause heat build up (Hot spot) from respiration of microorganisms, low thermal diffusivity of grain ,increased the mold growth, reduced starch and sugar content.
Similar to FT- Analysis of Food Constituents.pptx (20)
Vietnam Mushroom Market Growth, Demand and Challenges of the Key Industry Pla...IMARC Group
The Vietnam mushroom market size is projected to exhibit a growth rate (CAGR) of 6.52% during 2024-2032.
More Info:- https://www.imarcgroup.com/vietnam-mushroom-market
Roti Bank Hyderabad: A Beacon of Hope and NourishmentRoti Bank
One of the top cities of India, Hyderabad is the capital of Telangana and home to some of the biggest companies. But the other aspect of the city is a huge chunk of population that is even deprived of the food and shelter. There are many people in Hyderabad that are not having access to
Ang Chong Yi Navigating Singaporean Flavors: A Journey from Cultural Heritage...Ang Chong Yi
In the heart of Singapore, where tradition meets modernity, He embarks on a culinary adventure that transcends borders. His mission? Ang Chong Yi Exploring the Cultural Heritage and Identity in Singaporean Cuisine. To explore the rich tapestry of flavours that define Singaporean cuisine while embracing innovative plant-based approaches. Join us as we follow his footsteps through bustling markets, hidden hawker stalls, and vibrant street corners.
Hamdard Laboratories (India), is a Unani pharmaceutical company in India (following the independence of India from Britain, "Hamdard" Unani branches were established in Bangladesh (erstwhile East Pakistan) and Pakistan). It was established in 1906 by Hakeem Hafiz Abdul Majeed in Delhi, and became
a waqf (non-profitable trust) in 1948. It is associated with Hamdard Foundation, a charitable educational trust.
Hamdard' is a compound word derived from Persian, which combines the words 'hum' (used in the sense of 'companion') and 'dard' (meaning 'pain'). 'Hamdard' thus means 'a companion in pain' and 'sympathizer in suffering'.
The goals of Hamdard were lofty; easing the suffering of the sick with healing herbs. With a simple tenet that no one has ever become poor by giving, Hakeem Abdul Majeed let the whole world find compassion in him.
They had always maintained that working in old, traditional ways would not be entirely fruitful. A broader outlook was essential for a continued and meaningful existence. their effective team at Hamdard helped the system gain its pride of place and thus they made an entry into an expansive world of discovery and research.
Hamdard Laboratories was founded in 1906 in Delhi by Hakeem Hafiz Abdul Majeed and Ansarullah Tabani, a Unani practitioner. The name Hamdard means "companion in suffering" in Urdu language.(itself borrowed from Persian) Hakim Hafiz Abdul Majeed was born in Pilibhit City UP, India in 1883 to Sheikh Rahim Bakhsh. He is said to have learnt the complete Quran Sharif by heart. He also studied the origin of Urdu and Persian languages. Subsequently, he acquired the highest degree in the unani system of medicine.
Hakim Hafiz Abdul Majeed got in touch with Hakim Zamal Khan, who had a keen interest in herbs and was famous for identifying medicinal plants. Having consulted with his wife, Abdul Majeed set up a herbal shop at Hauz Qazi in Delhi in 1906 and started to produce herbal medicine there. In 1920 the small herbal shop turned into a full-fledged production house.
Hamdard Foundation was created in 1964 to disburse the profits of the company to promote the interests of the society. All the profits of the company go to the foundation.
After Abdul Majeed's death, his son Hakeem Abdul Hameed took over the administration of Hamdard Laboratories at the age of fourteen.
Even with humble beginnings, the goals of Hamdard were lofty; easing the suffering of the sick with healing herbs. With a simple tenet that no one has ever become poor by giving, Hakeem Abdul Majeed let the whole world find compassion in him. Unfortunately, he passed away quite early but his wife, Rabia Begum, with the support of her son, Hakeem Abdul Hameed, not only kept the institution in existence but also expanded it. As he grew up, Hakeem Abdul Hameed took on all responsibilities. After helping with his younger brother's upbringing and education, he included him in running the institution. Both brothers Hakeem Abdul Hameed and Hakim Mohammed
3. It is important for a number of different
reasons:
Legal and Labeling Requirements
Economic
Microbial Stability
Food Quality
Food Processing Operations.
4. Moisture content of a food material is defined
through the following equation:
% Moisture = (mw/msample)* 100
Where mw - mass of water; msample - mass of
sample
5.
6. 1. Drying Methods
◦ Oven drying methods
2. Distillation method
◦ Dean and Stark Method
3. Chemical Methods
◦ Karl Fisher
◦ Gas production
4. Physical Methods
7. Principle:
Measuring the mass of water in a known mass
of sample.
Measuring the mass of a food before and after
water is removed by evaporation
% moisture = (Minitial – Mdried) × 100
Minitial
8. MINITIAL and MDRIED are mass of the sample before
and after drying, respectively.
Basic principle of this technique is that water has a
lower boiling point than other major components
within foods
e.g., lipids, proteins, carbohydrates and minerals.
9. Total solids, is reported as a measure of the
moisture content.
It is the amount of material remaining after all
water has been evaporated
% Total Solids = (Mdried) × 100
(Minitial)
Thus, %Total solids = (100 - %Moisture)
10. You have the following gravimetric results:
weight of dried pan and glass disc = 1.04 g,
weight of pan and liquid sample = 4.63 g,
weight of the pan and dried sample =1.73 g.
Calculate the percent moisture and the percent solids
of the sample.
11. % moisture = (4.63-1.04) – (1.73-1.04) x 100
(4.63 - 1.04)
= 3.59 – 0.69 x 100
3.59
= 80.78 %
% solids = 0.69 x 100 or (100 – 80.78)
3.59
= 19.22 %
12. Weighed samples are placed in an oven for a specified
time and temperature and they are dried until they reach
constant mass.
◦ 1. Convection ovens.
◦ Disadv: Greatest temperature variations - because hot air
slowly circulated with out the aid of fan, air movement is
obstructed further by pans placed in the oven
13. Samples with high carbohydrates or volatile
materials should not be dried in a
convection or forced draft oven.
2. Forced Draft Oven
The least temperature difference across interior (< 1oC).
Air is circulated by a fan that forces air movement
throughout the oven cavity
14. 3. Vacuum oven.
Weighed samples are placed under reduced pressure (25 –
100 mm Hg) in a vacuum oven for a specified time and
temperature and their dried mass is determined.
Boiling point of water is reduced when placed under vacuum.
A number of advantages over conventional oven drying
techniques.
i. If sample is heated at same temperature, drying can be
carried out much quicker.
ii. Alternatively, lower temperatures can be used to remove
the moisture (e.g. 70oC instead of 100 oC),
iii. Degradation of heat labile substances can be reduced.
16. 2. Clumping and surface crust formation.
Some samples form clumps / a semi-
permeable surface crust during drying.
Loss of moisture is restricted by clumps or
crust.
To avoid, samples are mixed with dried sand.
17. 3. Water type.
Easy removal of water depends on its
interaction with other components present.
Free water is most easily removed.
More severe conditions required to evaporate
chemically or physically bound water.
18. 4. Decomposition of other food components.
Decomposition of heat-sensitive components.
Eg. Decomposition of carbohydrates
C6H12O6 6C + 6H2O
Water released by this reaction lead to an overestimation
of true moisture content.
Many chemical reactions occur at elevated temperatures
lead to water absorption. e.g., sucrose hydrolysis
(sucrose + H2O fructose + glucose)
lead to an underestimation of true moisture content.
19. 5. Volatilization of other food components.
For foods that have significant amounts of volatile
components (e.g. spices and herbs) must use
alternative methods e.g., distillation, chemical or
physical methods.
20. 1. Organic compounds:
◦ Carbohydrates
◦ Lipids
◦ Proteins
◦ Nucleic acids
◦ Vitamins
◦ Organic acids
2. Inorganic Compounds:
- Minerals
“Ash content” - total amount of minerals present
within a food.
21. Ash - inorganic residue remaining after water and
organic matter removed by heating in the presence
of oxidizing agents.
Principle: Minerals are not destroyed by heating,
and they have low volatility compared to other
food components.
22. Main types Ashing: dry ashing, wet ashing, plasma
ashing
Method chosen depends on the reason for carrying
out analysis, type of food analyzed and equipment
available
24. Before ash analysis, samples high in moisture are
dried to prevent spattering.
High fat samples are defatted by solvent extraction
Avoid contamination of samples by minerals in
grinders, glassware or crucibles etc.
25. Use a high temperature muffle furnace (To between 500
and 600oC).
Water and other volatile materials are vaporized and
organic substances are burned in the presence of O2 in
air to CO2, H2O and N2.
Most minerals are converted to oxides, sulfates,
phosphates, chlorides or silicates.
26. Some minerals are volatile and may be partially lost,
e.g., iron, lead and mercury.
For such minerals - use an alternative ashing method
that uses lower temperatures.
27. Food sample is weighed before and after ashing to
determine the concentration of ash present.
The ash content can be expressed on either a dry or
wet basis:
28. The following data was obtained on a sample of hamburger:
sample wt, 2.034 g ; wt after drying, 1.0781 g; and wt of ash,
0.0233 g.
What is the percentage ash on a) a wet weight basis and b)
dry-weight basis?
Wet Basis Ash % = (0.0233 / 2.034) *100
= 1.15 %
Dry Basis Ash % = (0.0233 / 1.0781) * 100
= 2.16 %
29. Different types of crucible - quartz, Pyrex,
porcelain, steel and platinum.
Selection depends on sample being analyzed and
furnace temperature used.
Most widely used - porcelain (relatively
inexpensive, resistant to high temperatures
(< 1200oC) and easy to clean).
31. Advantages: Safe, few reagents are required, many
samples can be analyzed simultaneously, not labor
intensive, and ash can be analyzed for specific
mineral content.
Disadvantages: Long time required (12-24 hours),
muffle furnaces are quite costly to run due to
electrical costs, loss of volatile minerals at high
temperatures, e.g., Cu, Fe, Pb, Hg, Ni, Zn.
32. Topic: Analysis of crude fat content (by Soxhlet
extraction method) and crude protein content (by
kjeldhal method) of foods.
Sample preparation techniques
Equipment and method
Calculation
Advantages and disadvantages of technique
Reference: Chapter 18, Nielsen, S.S. (Ed.) Food Analysis
– Food Science Texts Series (4th ed.) Springer 2003