CASE 1 – PROCESS TECHNOLOGIES AND FOOD INNOVATION
Food processing: the transformation of raw ingredients into products fit for human consumption.
Steps in food processing: separation – conversion – structure formation – stabilisation – packaging
SEPERATION TECHNNIQUES
• Centrifugation
o Separate components of different densities such as solids from liquids.
o When a sample is spun rapidly in a centrifuge, the centrifugal force causes denser
particles to move outward and settle at the bottom of the tube or centrifuge
chamber, while lighter particles remain suspended or collect at the top.
o Application: Removing fat form milk (skimmed milk) and clarification of wine
• Filtration
o The removal of solid particles from a fluid by passing through a filtering medium
o Application: concentration and purification of fruit juices, enzymes, fermentation
liquors and vegetable oils; concentration of wheat starch, egg white, milk, coffee,
syrups, matural extracts and flavours; clarification of wine and brew products;
dehydration of fruits and vegetables; and desalination of sea water.
o Reverse osmosis = applying a pressure higher than the osmotic pressure on the
solution side so that water molecules migrate from the solution side to pure water
and make the solution concentrated.
• Extraction
o A separation operation which applies a solvent to extract/separate a desired
component from a solid food
o Applications: tea, bioactive compounds form plants or orange flavour.
• Chromatography
o separation or identification of a mixture of components into individual components
by using finely divided adsorbent solid / (liquid) spread over a plate and liquid as a
mobile phase
o Application: removal toxic compound, purify bioactives, determine nutritional quality
(vitamins), detection of food spoilage and food additives.
MIXING: Blender: nutrients are exposed to air and blades break up nuts -> little fiber loss, little
vitamin loss; Juicer: sharp blades break down fiber an shred cells -> more fiber loss, almost no
vitamins left.
PRESERVATION TECHNIQUES
(= stop or slow down spoilage to prevent foodborne illness and extend shelf-life)
• High temperature treatment
o Blanching (Heat the food for a short time at 70-100 °C)
Briefly immersing food items in boiling water or steam, followed by rapid cooling in ice water.
-> FOODS: variety of fruits, vegetables, and some seafood
-> GOOD EFFECTS: enzyme inactivation, color retention, removal dirt and microbes, longer shelf-life.
-> BAD EFFECTS: softening texture, nutrient losses (water-soluble vitamins and phenolic antioxidants)
o Pasteurization (Heating the food to 63°C for 30 minutes)
,A process where packaged and unpacked foods are treated with mild heat. This heat kills or
deactivates harmful microorganisms and enzymes, extending the food's shelf life and reducing the
risk of disease. While pasteurization eliminates most bacteria, some bacterial spores may survive.
The acidity of the food determines the parameters (time and temperature) of the heat treatment as
well as the duration of shelf life. (acidic foods = pH <4,6 ; low acidic foods = pH >4,6)
-> FOODS: dairy products, fruit juices, alcoholic beverages, liquid eggs, soups and sauses. Used for
liquids, especially those with a high moisture content
-> GOOD EFFECTS: pathogen reduction, enzyme inactivation, preservation of nutritional quality
(compared to sterilization), minimal impact on flavor and texture, reduction of spoilage
microgragnisms, longer shelft-life.
-> BAD EFFECTS: losses of heat sensitive nutrients (vitamin C, antioxidants). Flavour change in
delicate foods (diary and fruit juices), requirement of refrigeration (maintain freshness and prevent
spoligae), does not eliminate all pathogens, energy consumption for process
o High Temperature Short Time (Heating for 15 sec at 72°C)
A pasteurization method used to pasteurize liquids such as milk and fruit juices. In this process, the
liquid is rapidly heated to a high temperature for a short period, then quickly cooled
-> Minimal impact on taste and texture, preservation of nutritional quality
o Sterilisation (Heating the food to 100 (110-121)°C)
Sterilization is the complete removal, killing, or deactivation of all forms of life, including
microorganisms and biological agents, from a surface, object, or fluid. It can be achieved using
methods like heat, chemicals, irradiation, high pressure, or filtration. Unlike pasteurization, which
only reduce microbial populations, sterilization eliminates all forms of life entirely.
-> FOODS: canned foods (vegetables, fruits, meats, seafood, ready to eat meals), UHT milk and dairy
products.
-> GOOD EFFECTS: effectively kills microorganisms, longer shelf-life, preserves vitamins and minerals,
no refrigerated storage necessary, preserves flavour and texture.
-> BAD EFFECTS: packaging limitations (must whitstand high temperatures and pressure), loss of
freshness (color, aroma and taste), must be packaged in closed container immediately afterwards,
difficult heath penetration for for viscous foods.
o UltraHeat treatment (Heating the food for 1–8 sec at 135–154°C)
heating the food for two to five seconds to a temperature greater than 140 °C to kill bacterial
endospores.
-> FOODS: primarily used for the preservation of liquids, particularly dairy products and plant-based
beverages
-> GOOD EFFECTS: short processing time, long shelf-life without refrigeration, safer, cheaper
packaging, keeping quality.
-> BAD EFFECTS: Taste/flavour and colour is different than pasteurized milk (lipid oxidation), 20% less
folate (B-vitamins), loss of Vitamin C and thiamine. Can alter the taste, texture, and appearance of
food products, very expensive.
o Microwaving
,Microwave processing in food involves heating through the interaction of electromagnetic radiation.
This process causes polar molecules, particularly water molecules, to rotate and align with the
electric field created by the microwaves. As a result, friction occurs between the molecules,
generating heat and increasing the temperature of the food. The rapid alignment of water molecules
with the high-frequency microwaves causes them to rub against each other, further contributing to
the internal heating of the food.
-> FOODS: Ideal for food containing water. NO: large cuts of meats because of uneven heating, baked
goods because of texture or browning, fried foods can become soggy because of moisture creating
steam, certain dairy products like cheese can become rubbery or oily, raw eggs in shells can explode
due to buildup of steam)
-> GOOD EFFECTS: Nutrient retention is high, can help preserve texture (vegetables).
-> BAD EFFECTS: non-uniform temperature distribution. This can result in hot and cold spots in foods.
Shape of food can effect heat in certain part, not suitable for all packaging (aluminium).
Principle of heat treatment
the use of heat to eliminate or reduce
harmful microorganisms, enzymes, and
other spoilage agents in food while
preserving its quality and safety
D value = decimal reduction time, the time
taken for 1 log cycle/1 decimal
reduction
Decimal reduction = A reduction from 105
to 104
The start concentration of microorganisms
is essential for the settings
• Low temperature preservation
o Refrigeration (temperature between 0 °C and 8 °C)
o Freezing (below freezing point, usually between -18 °C and -35 °C)
It is usually used for fresh food to slow down microbial growth
-> FOODS: are used on almost all foods - meats, fruits, vegetables, beverages, etc
-> GOOD EFFECTS: extends shelf-life, slows down activity of enzymes and microbial growth. Slow
down the formation of brown pigments (melanin). maintain the freshness of fruits and vegetables,
delaying their natural decay processes.
-> BAD EFFECTS: Texture and flavour can be affected (crystallisation) changed texture after
defrosting. Vitamin C content can decline (temperature and UV-light). Vitamin losses (B and C).
Protein denaturation (bioavailability and digestibility change), ice crystals disrupt cellular structure
leading to availability of water soluble nutrients (vitamins and minerals).
Crystallization occurs when water molecules present in the food freeze and form ice crystals. These
ice crystals can grow larger over time (freezing), especially if the food is not properly stored, leading
, to changes in texture and flavour. => degradation of pectin’s (cell walls). High pressure freezing or
dehydrofreezing prevents damage. After defrosting(thawing), browning process can be enhanced
• Control of water activity
o Air draying
involves exposing the material to air at ambient temperature and humidity levels. The moisture in
the material evaporates gradually over time, leaving behind the dried product.
-> FOODS: fruits, vegetables, herbs
o Freeze drying
Freeze-drying is a way of dehydrating frozen food via a process that transforms ice into vapor(damp),
also known as sublimation. It involves freezing the material at very low temperatures (-40°C to -50°C)
and then subjecting it to a vacuum environment. Under reduced pressure, the frozen water in the
material sublimates directly from solid to vapor, bypassing the liquid phase. This results in a dried
product with minimal damage to its structure and properties.
-> FOODS: fruits, vegetables, meats, dairy, instant coffees - food high in aroma’s, delicate
-> GOOD EFFECTS: removes moisture from the food, extending its shelf life without significantly
affecting its taste, texture, or nutritional content. No damage due to freezing water. No refrigeration
required. nutritional value is almost completely maintained
-> BAD EFFECTS: slow process (24+hours), dry texture, not possible for all foods, airtight containers
are required, cost.
While both air drying and freeze drying are methods used to remove moisture from materials, freeze
drying offers several advantages, including better preservation of quality and shorter processing
times. However, it is also more complex and expensive compared to air drying.
o Spray drying
Spray drying is a process used to turn liquids into powders by breaking them down into tiny droplets
and then drying them out. The technique takes a liquid, semi-liquid, or soft surface product and turns
it into a powder. In many instances, the solid will be transformed back into a liquid by adding another
liquid.
-> FOODS: Dairy products, instant coffee, tea
extract, fruit and vegetable juice,
supplements, infant formula
-> GOOD EFFECTS: preserves the flavour,
aroma, and color of the food. Minimize
bacteria, fast process, cost effective
-> BAD EFFECT: Variations in particle shape
and size distribution, high temperature, fast
drying rates that don’t allow encapsulation of
some bioactives, only for foods with low
viscosity.
o Agitated thin film drying
Food processing: the transformation of raw ingredients into products fit for human consumption.
Steps in food processing: separation – conversion – structure formation – stabilisation – packaging
SEPERATION TECHNNIQUES
• Centrifugation
o Separate components of different densities such as solids from liquids.
o When a sample is spun rapidly in a centrifuge, the centrifugal force causes denser
particles to move outward and settle at the bottom of the tube or centrifuge
chamber, while lighter particles remain suspended or collect at the top.
o Application: Removing fat form milk (skimmed milk) and clarification of wine
• Filtration
o The removal of solid particles from a fluid by passing through a filtering medium
o Application: concentration and purification of fruit juices, enzymes, fermentation
liquors and vegetable oils; concentration of wheat starch, egg white, milk, coffee,
syrups, matural extracts and flavours; clarification of wine and brew products;
dehydration of fruits and vegetables; and desalination of sea water.
o Reverse osmosis = applying a pressure higher than the osmotic pressure on the
solution side so that water molecules migrate from the solution side to pure water
and make the solution concentrated.
• Extraction
o A separation operation which applies a solvent to extract/separate a desired
component from a solid food
o Applications: tea, bioactive compounds form plants or orange flavour.
• Chromatography
o separation or identification of a mixture of components into individual components
by using finely divided adsorbent solid / (liquid) spread over a plate and liquid as a
mobile phase
o Application: removal toxic compound, purify bioactives, determine nutritional quality
(vitamins), detection of food spoilage and food additives.
MIXING: Blender: nutrients are exposed to air and blades break up nuts -> little fiber loss, little
vitamin loss; Juicer: sharp blades break down fiber an shred cells -> more fiber loss, almost no
vitamins left.
PRESERVATION TECHNIQUES
(= stop or slow down spoilage to prevent foodborne illness and extend shelf-life)
• High temperature treatment
o Blanching (Heat the food for a short time at 70-100 °C)
Briefly immersing food items in boiling water or steam, followed by rapid cooling in ice water.
-> FOODS: variety of fruits, vegetables, and some seafood
-> GOOD EFFECTS: enzyme inactivation, color retention, removal dirt and microbes, longer shelf-life.
-> BAD EFFECTS: softening texture, nutrient losses (water-soluble vitamins and phenolic antioxidants)
o Pasteurization (Heating the food to 63°C for 30 minutes)
,A process where packaged and unpacked foods are treated with mild heat. This heat kills or
deactivates harmful microorganisms and enzymes, extending the food's shelf life and reducing the
risk of disease. While pasteurization eliminates most bacteria, some bacterial spores may survive.
The acidity of the food determines the parameters (time and temperature) of the heat treatment as
well as the duration of shelf life. (acidic foods = pH <4,6 ; low acidic foods = pH >4,6)
-> FOODS: dairy products, fruit juices, alcoholic beverages, liquid eggs, soups and sauses. Used for
liquids, especially those with a high moisture content
-> GOOD EFFECTS: pathogen reduction, enzyme inactivation, preservation of nutritional quality
(compared to sterilization), minimal impact on flavor and texture, reduction of spoilage
microgragnisms, longer shelft-life.
-> BAD EFFECTS: losses of heat sensitive nutrients (vitamin C, antioxidants). Flavour change in
delicate foods (diary and fruit juices), requirement of refrigeration (maintain freshness and prevent
spoligae), does not eliminate all pathogens, energy consumption for process
o High Temperature Short Time (Heating for 15 sec at 72°C)
A pasteurization method used to pasteurize liquids such as milk and fruit juices. In this process, the
liquid is rapidly heated to a high temperature for a short period, then quickly cooled
-> Minimal impact on taste and texture, preservation of nutritional quality
o Sterilisation (Heating the food to 100 (110-121)°C)
Sterilization is the complete removal, killing, or deactivation of all forms of life, including
microorganisms and biological agents, from a surface, object, or fluid. It can be achieved using
methods like heat, chemicals, irradiation, high pressure, or filtration. Unlike pasteurization, which
only reduce microbial populations, sterilization eliminates all forms of life entirely.
-> FOODS: canned foods (vegetables, fruits, meats, seafood, ready to eat meals), UHT milk and dairy
products.
-> GOOD EFFECTS: effectively kills microorganisms, longer shelf-life, preserves vitamins and minerals,
no refrigerated storage necessary, preserves flavour and texture.
-> BAD EFFECTS: packaging limitations (must whitstand high temperatures and pressure), loss of
freshness (color, aroma and taste), must be packaged in closed container immediately afterwards,
difficult heath penetration for for viscous foods.
o UltraHeat treatment (Heating the food for 1–8 sec at 135–154°C)
heating the food for two to five seconds to a temperature greater than 140 °C to kill bacterial
endospores.
-> FOODS: primarily used for the preservation of liquids, particularly dairy products and plant-based
beverages
-> GOOD EFFECTS: short processing time, long shelf-life without refrigeration, safer, cheaper
packaging, keeping quality.
-> BAD EFFECTS: Taste/flavour and colour is different than pasteurized milk (lipid oxidation), 20% less
folate (B-vitamins), loss of Vitamin C and thiamine. Can alter the taste, texture, and appearance of
food products, very expensive.
o Microwaving
,Microwave processing in food involves heating through the interaction of electromagnetic radiation.
This process causes polar molecules, particularly water molecules, to rotate and align with the
electric field created by the microwaves. As a result, friction occurs between the molecules,
generating heat and increasing the temperature of the food. The rapid alignment of water molecules
with the high-frequency microwaves causes them to rub against each other, further contributing to
the internal heating of the food.
-> FOODS: Ideal for food containing water. NO: large cuts of meats because of uneven heating, baked
goods because of texture or browning, fried foods can become soggy because of moisture creating
steam, certain dairy products like cheese can become rubbery or oily, raw eggs in shells can explode
due to buildup of steam)
-> GOOD EFFECTS: Nutrient retention is high, can help preserve texture (vegetables).
-> BAD EFFECTS: non-uniform temperature distribution. This can result in hot and cold spots in foods.
Shape of food can effect heat in certain part, not suitable for all packaging (aluminium).
Principle of heat treatment
the use of heat to eliminate or reduce
harmful microorganisms, enzymes, and
other spoilage agents in food while
preserving its quality and safety
D value = decimal reduction time, the time
taken for 1 log cycle/1 decimal
reduction
Decimal reduction = A reduction from 105
to 104
The start concentration of microorganisms
is essential for the settings
• Low temperature preservation
o Refrigeration (temperature between 0 °C and 8 °C)
o Freezing (below freezing point, usually between -18 °C and -35 °C)
It is usually used for fresh food to slow down microbial growth
-> FOODS: are used on almost all foods - meats, fruits, vegetables, beverages, etc
-> GOOD EFFECTS: extends shelf-life, slows down activity of enzymes and microbial growth. Slow
down the formation of brown pigments (melanin). maintain the freshness of fruits and vegetables,
delaying their natural decay processes.
-> BAD EFFECTS: Texture and flavour can be affected (crystallisation) changed texture after
defrosting. Vitamin C content can decline (temperature and UV-light). Vitamin losses (B and C).
Protein denaturation (bioavailability and digestibility change), ice crystals disrupt cellular structure
leading to availability of water soluble nutrients (vitamins and minerals).
Crystallization occurs when water molecules present in the food freeze and form ice crystals. These
ice crystals can grow larger over time (freezing), especially if the food is not properly stored, leading
, to changes in texture and flavour. => degradation of pectin’s (cell walls). High pressure freezing or
dehydrofreezing prevents damage. After defrosting(thawing), browning process can be enhanced
• Control of water activity
o Air draying
involves exposing the material to air at ambient temperature and humidity levels. The moisture in
the material evaporates gradually over time, leaving behind the dried product.
-> FOODS: fruits, vegetables, herbs
o Freeze drying
Freeze-drying is a way of dehydrating frozen food via a process that transforms ice into vapor(damp),
also known as sublimation. It involves freezing the material at very low temperatures (-40°C to -50°C)
and then subjecting it to a vacuum environment. Under reduced pressure, the frozen water in the
material sublimates directly from solid to vapor, bypassing the liquid phase. This results in a dried
product with minimal damage to its structure and properties.
-> FOODS: fruits, vegetables, meats, dairy, instant coffees - food high in aroma’s, delicate
-> GOOD EFFECTS: removes moisture from the food, extending its shelf life without significantly
affecting its taste, texture, or nutritional content. No damage due to freezing water. No refrigeration
required. nutritional value is almost completely maintained
-> BAD EFFECTS: slow process (24+hours), dry texture, not possible for all foods, airtight containers
are required, cost.
While both air drying and freeze drying are methods used to remove moisture from materials, freeze
drying offers several advantages, including better preservation of quality and shorter processing
times. However, it is also more complex and expensive compared to air drying.
o Spray drying
Spray drying is a process used to turn liquids into powders by breaking them down into tiny droplets
and then drying them out. The technique takes a liquid, semi-liquid, or soft surface product and turns
it into a powder. In many instances, the solid will be transformed back into a liquid by adding another
liquid.
-> FOODS: Dairy products, instant coffee, tea
extract, fruit and vegetable juice,
supplements, infant formula
-> GOOD EFFECTS: preserves the flavour,
aroma, and color of the food. Minimize
bacteria, fast process, cost effective
-> BAD EFFECT: Variations in particle shape
and size distribution, high temperature, fast
drying rates that don’t allow encapsulation of
some bioactives, only for foods with low
viscosity.
o Agitated thin film drying
