SlideShare une entreprise Scribd logo
1  sur  19
HEAT TREATMENTS FOR MILK
Presented By:- Sourabh Kale
M. Tech. (Dairy Technology)
SMC, College of dairy science, AAU, Anand.
Content:-
Introduction
Commonly used heat treatments
 Thermization
 Stassanization
 Pasteurization
 Batch Sterilization
 UHT Treatment
 High Pasteurization (ESL)
Heat treatments for specific dairy products.
 After the introduction of pasteurization (Batch method -1885), heat
treatment of milk has attracted a huge amount of research attention.
 Any intentional heating above 50 ° C for a sufficient time such that
there is a reduction in the concentration of one or more microorganisms
is considered as heat treatment. (IDF Factsheet, 2018)
 Thus, the heat treatment concept covers an infinite number of
combinations of time and temperature.
 The treatments can be categorized into those used for milk for direct
consumption and those used for specific dairy products.
Introduction
Thermization
 Thermization is a generic description of a range of sub pasteurization
heat treatments (57 to 68°C for 15 s) that markedly reduce the number
of spoilage bacteria in milk with minimal heat damage.
 Thermization is a heat treatment applied to raw milk aimed at reducing
the number of organisms in milk and permitting longer storage of the
milk prior to further processing. The heating conditions are 62 to 65 °C
for 15 to 20 seconds. Thermized milk must be phosphatase
positive(CAC, 1999).
 Destruction of some non-spore forming pathogens and psychrotrophic
spoilage bacteria.
Stassanization
 Henri Stassano invented it in France.
 This method of pasteurization is carried out in a tubular heat
exchanger consisting of three concentric tubes.
 Passing milk between two water-heated pipes through the narrow
space of 0.6 to 0.8 mm.
 The milk is heated to about 74 ° c for 7 sec. and then promptly
cooled
Pasteurization
 According to FSSAI and Codex- Pasteurization, Pasteurized and similar
terms means a microbicidal heat treatment aimed at reducing the
number of any pathogenic micro-organisms in milk and liquid milk
products, if present, to a level at which they do not constitute a
significant health hazard.
 Pasteurization conditions shall be designed to effectively destroy the
organisms Mycobacterium tuberculosis and Coxiella burnettii.
 By LTLT or HTST and cooling it immediately to a temperature of 4 °C or
less.
 Phosphatase test should negative.
Pasteurisation Unit (PU)
 One PU results from heating at a temperature of 60 °C (140 °F) for 1
min. The equivalent. z-value is 10 °C (18 °F), which is high for
vegetative bacteria. Thus, the number of pasteurization units for a
heating temperature (T,°C) and heating time (t, min) is given by ;
 63 °C for 30 min would have a value of approximately 60 PU,
whereas HTST conditions (72 °C/15 s; originally 161 °F or 71.7
°C/15 s)would give only 3.96 PU (Wilbey, 1993).
 pasteurization destroys neither the spores nor the toxins secreted
in the milk by organisms that lived in it prior to its heat treatment.
Sterilization
 Referred to in-container batch wise heating process.
 According to FSSAI Sterilization when used in association with milk
or milk products, shall be taken to refer to the typical process of
heating milk or milk product in sealed containers continuously to at
least 115ºC for 15 minutes to ensure preservation at room
temperature for a period not less than thirty days from the date of
manufacture.
 Codex guidelines suggest using minimum temperature-time
conditions which achieve an Fo value of 3 min.
 The temperatures for sterilization are in the range 110 to 125°C in
combination with appropriate holding times such as 121°C for 3
minutes or 115°C for 13 minutes.
 Turbidity test should be negative.
 12 log reduction of Cl. Botulinum is essential.
UHT treatment
 UHT treatment referred to high-temperature/short-time heat treatment
aimed at producing a commercially sterile product which can be
stored at room temperature.
 According to FSSAI, UHT refers to the process of heating milk or milk
product to at least 135ºC for one second or more in a continuous
flow and then packing under aseptic condition in hermetically sealed
containers to ensure preservation at room temperature for a period of
not less than fifteen days from the date of manufacture.
 The total heat treatment is equivalent, in terms of its effectiveness
against heat-resistant bacterial spores, to a minimum Fo value of 3
min.
 The main requirement is to reduce spores of Cl . Botulinum.
 Reduction of B. stearothermophilus to minimum 2 log is
considered to be good .
 Turbidity test is positive.
 UHT-treated milk and cream are packaged aseptically into
sterilized, hermetically sealed containers.
High Pasteurization
 It is a continuous heat treatment between HTST pasteurization and UHT
sterilization, and is used to produce extended shelf life (ESL) milk.
 An exact, generally accepted definition of the term ESL milk with regard
to shelf life does not yet exist.
 EU legislation (EU, 1992) states that pasteurized milk, which shows a
negative reaction to the peroxidase test, must be labelled ‘high
temperature pasteurized milk’.
 Treatment is carried out at 120 - 135°C for 1-4 sec
 The combination of microfiltration(average pore size of 1.4 μm) and
pasteurization has proved to be a very efficient way to produce ESL
milk (Hoffmann et al., 1996).
 Commercial ESL milk has a shelf life varying from 30 to 90 days at
4°C.
 Low original bacterial count in the raw milk is recommended. A
microbial count of 100,000 cfu should not be exceeded
(TeGiffel et al., 2005).
Comparison
(Ozer and Akdemir - Evrendilek, 2014)
Innovative steam injection(ISI)
 To overcome problems which are inherently present in UHT milk and to reduce the
appreciable amount of denaturation of whey proteins, the Innovative Steam Injection (ISI) is
introduced.
 very short heating is combined with very high temperatures: less than 0.1 s at 150–200°C
 The heating is directly followed by flash cooling in a vacuum vessel.
 The process costs of the ISI technology are some 10% higher than the prevailing UHT
process.
Comparison of ISI with
conventional Heat treatments
Technology Time(s) Temperature
(°C)
Denaturati
on of whey
proteins
(%)
Log reduction B.
stearothermophilus
spores
Pasteurizatio
n
15-1 72-80 4-8 0
Indirect UHT 20-5 130-145 75-90 6
Direct UHT 6-2 142-150 60-85 6
ISI 0.1 160-180 25 6
Tamime (2009)
Heat treatments for specific
dairy products
72–120°C 15
sec to 30min
Heating
before
concentratio
n
Reduction of
microbial
load, inactivate
enzymes
Stabilizing the proteins
or controlled
denaturation of
proteins
70–95°C
(outlet) and
180–230°C
(inlet) Few
seconds
Heating of
milk
concentrate
in a spray
dryer
Reduced water
activity, reduced
chances of
microbial
survival
Drying, Product can be
stored at room
temperature for more
than a year
Scalding at
40°C
Scalding of
cheese curd
Felicitates
growth of
starters
Sufficient to expel whey
Whey separation, final
product moisture
control and cheese
body
80°C 30 min or
90°C for 10
min
Heat
treatment of
milk for
yoghurt
Reduction of
bacteriophages,
microbes etc.
Improve viscosity and
texture of yoghurt in
addition to reduction
in
microbial load
THANK YOU

Contenu connexe

Tendances

condensed milk processing
condensed milk processing condensed milk processing
condensed milk processing Muhammad waqas
 
traditional dairy products
traditional dairy productstraditional dairy products
traditional dairy productsRobinVarghese51
 
cleaning and sanitation of milk plant.pptx
cleaning and sanitation of milk plant.pptxcleaning and sanitation of milk plant.pptx
cleaning and sanitation of milk plant.pptxSaranuTeja1
 
Milk microbiology (standards)
Milk microbiology (standards)Milk microbiology (standards)
Milk microbiology (standards)munniradhika
 
Evaporated milk
Evaporated milkEvaporated milk
Evaporated milkAsma Bano
 
Milk, Physical Properties and milk fat
Milk, Physical Properties and milk fatMilk, Physical Properties and milk fat
Milk, Physical Properties and milk fatArab Khan
 
Contamination spoilage and preservation of milk and milk products
Contamination spoilage and preservation of  milk and milk productsContamination spoilage and preservation of  milk and milk products
Contamination spoilage and preservation of milk and milk productsDr Madhuri Kaushish Lily
 
Novel non thermal preservation technologies
Novel non thermal preservation technologiesNovel non thermal preservation technologies
Novel non thermal preservation technologiesRavi Kant Agrawal
 
CHEMISTRY OF MILK ENZYMES AND THEIR SIGNIFICANCE
CHEMISTRY OF MILK ENZYMES AND THEIR SIGNIFICANCECHEMISTRY OF MILK ENZYMES AND THEIR SIGNIFICANCE
CHEMISTRY OF MILK ENZYMES AND THEIR SIGNIFICANCEARCHANA MADPATHI
 
RECOMBINED SWEETENED MILK
RECOMBINED SWEETENED MILKRECOMBINED SWEETENED MILK
RECOMBINED SWEETENED MILKChethanN23
 
Dairy product technoloy
Dairy product technoloyDairy product technoloy
Dairy product technoloyAarti Nimesh
 
Physico chemical properties of milk
Physico chemical properties of milkPhysico chemical properties of milk
Physico chemical properties of milkDr. Ashish Saini
 
Determination of specific gravity
Determination of specific gravityDetermination of specific gravity
Determination of specific gravityhawbash mhedin
 

Tendances (20)

condensed milk processing
condensed milk processing condensed milk processing
condensed milk processing
 
traditional dairy products
traditional dairy productstraditional dairy products
traditional dairy products
 
Instantization of Milk
Instantization of Milk Instantization of Milk
Instantization of Milk
 
Special types of milk
Special types of milkSpecial types of milk
Special types of milk
 
cleaning and sanitation of milk plant.pptx
cleaning and sanitation of milk plant.pptxcleaning and sanitation of milk plant.pptx
cleaning and sanitation of milk plant.pptx
 
Milk microbiology (standards)
Milk microbiology (standards)Milk microbiology (standards)
Milk microbiology (standards)
 
Evaporated milk
Evaporated milkEvaporated milk
Evaporated milk
 
Milk, Physical Properties and milk fat
Milk, Physical Properties and milk fatMilk, Physical Properties and milk fat
Milk, Physical Properties and milk fat
 
Contamination spoilage and preservation of milk and milk products
Contamination spoilage and preservation of  milk and milk productsContamination spoilage and preservation of  milk and milk products
Contamination spoilage and preservation of milk and milk products
 
Novel non thermal preservation technologies
Novel non thermal preservation technologiesNovel non thermal preservation technologies
Novel non thermal preservation technologies
 
Condensed milk
Condensed milkCondensed milk
Condensed milk
 
CHEMISTRY OF MILK ENZYMES AND THEIR SIGNIFICANCE
CHEMISTRY OF MILK ENZYMES AND THEIR SIGNIFICANCECHEMISTRY OF MILK ENZYMES AND THEIR SIGNIFICANCE
CHEMISTRY OF MILK ENZYMES AND THEIR SIGNIFICANCE
 
RECOMBINED SWEETENED MILK
RECOMBINED SWEETENED MILKRECOMBINED SWEETENED MILK
RECOMBINED SWEETENED MILK
 
Dairy product technoloy
Dairy product technoloyDairy product technoloy
Dairy product technoloy
 
Physico chemical properties of milk
Physico chemical properties of milkPhysico chemical properties of milk
Physico chemical properties of milk
 
Milk introduction
Milk  introductionMilk  introduction
Milk introduction
 
Concentrated milks technology and faults
Concentrated milks technology and faultsConcentrated milks technology and faults
Concentrated milks technology and faults
 
Hurdle technology
Hurdle technology Hurdle technology
Hurdle technology
 
Khoa - Anas Shaikh - 13FET1006
Khoa - Anas Shaikh - 13FET1006Khoa - Anas Shaikh - 13FET1006
Khoa - Anas Shaikh - 13FET1006
 
Determination of specific gravity
Determination of specific gravityDetermination of specific gravity
Determination of specific gravity
 

Similaire à Heat treatments for raw milk

Drinking Milk Technology.pptx
Drinking Milk Technology.pptxDrinking Milk Technology.pptx
Drinking Milk Technology.pptxTrcMai51
 
Food preservation by thermal processing
Food preservation by thermal processingFood preservation by thermal processing
Food preservation by thermal processingImtiaz Uddin
 
Principles-Methods-of-Pasteurization (1).pptx
Principles-Methods-of-Pasteurization (1).pptxPrinciples-Methods-of-Pasteurization (1).pptx
Principles-Methods-of-Pasteurization (1).pptxSantoshBhandiwad1
 
Pasteurisation of food product
Pasteurisation of food productPasteurisation of food product
Pasteurisation of food productRekha Kumari
 
Pasteurization by sajib reza
Pasteurization by sajib rezaPasteurization by sajib reza
Pasteurization by sajib rezaSajib Reza
 
THERMAL AND MICROWAVE HEATING .pdf
THERMAL AND MICROWAVE  HEATING .pdfTHERMAL AND MICROWAVE  HEATING .pdf
THERMAL AND MICROWAVE HEATING .pdfvtae7
 
Pasteurization- Nimisha Kaikkolante
Pasteurization- Nimisha KaikkolantePasteurization- Nimisha Kaikkolante
Pasteurization- Nimisha KaikkolanteNimisha Kaikkolante
 
Pasteurization of various food products
Pasteurization of various food productsPasteurization of various food products
Pasteurization of various food productsSumit Bansal
 
Heat sterilization of canned food vahid 1
Heat sterilization of canned food  vahid 1Heat sterilization of canned food  vahid 1
Heat sterilization of canned food vahid 1ABDUL VAHID M
 
nikhil sharma 190080830014.pptx
nikhil sharma  190080830014.pptxnikhil sharma  190080830014.pptx
nikhil sharma 190080830014.pptxNehaYadav489508
 
Milk & milk products (alfahad farwa)
Milk &  milk products (alfahad farwa)Milk &  milk products (alfahad farwa)
Milk & milk products (alfahad farwa)AlfahadFarwa
 
Shelf life enhancement of milk products.
Shelf life enhancement of milk products.Shelf life enhancement of milk products.
Shelf life enhancement of milk products.Gail Barnes
 

Similaire à Heat treatments for raw milk (20)

Milk pasteurization
Milk pasteurizationMilk pasteurization
Milk pasteurization
 
Drinking Milk Technology.pptx
Drinking Milk Technology.pptxDrinking Milk Technology.pptx
Drinking Milk Technology.pptx
 
PASTEURISATION
PASTEURISATIONPASTEURISATION
PASTEURISATION
 
Food preservation by thermal processing
Food preservation by thermal processingFood preservation by thermal processing
Food preservation by thermal processing
 
Principles-Methods-of-Pasteurization (1).pptx
Principles-Methods-of-Pasteurization (1).pptxPrinciples-Methods-of-Pasteurization (1).pptx
Principles-Methods-of-Pasteurization (1).pptx
 
Pasteurisation of food product
Pasteurisation of food productPasteurisation of food product
Pasteurisation of food product
 
Pasteurization
PasteurizationPasteurization
Pasteurization
 
Pasteurization
PasteurizationPasteurization
Pasteurization
 
Pasteurization by sajib reza
Pasteurization by sajib rezaPasteurization by sajib reza
Pasteurization by sajib reza
 
THERMAL AND MICROWAVE HEATING .pdf
THERMAL AND MICROWAVE  HEATING .pdfTHERMAL AND MICROWAVE  HEATING .pdf
THERMAL AND MICROWAVE HEATING .pdf
 
Pasteurization- Nimisha Kaikkolante
Pasteurization- Nimisha KaikkolantePasteurization- Nimisha Kaikkolante
Pasteurization- Nimisha Kaikkolante
 
Pasteurization of various food products
Pasteurization of various food productsPasteurization of various food products
Pasteurization of various food products
 
thermal processing of food
thermal processing of food thermal processing of food
thermal processing of food
 
fsm 9 presentation.pdf
fsm 9 presentation.pdffsm 9 presentation.pdf
fsm 9 presentation.pdf
 
Heat sterilization of canned food vahid 1
Heat sterilization of canned food  vahid 1Heat sterilization of canned food  vahid 1
Heat sterilization of canned food vahid 1
 
nikhil sharma 190080830014.pptx
nikhil sharma  190080830014.pptxnikhil sharma  190080830014.pptx
nikhil sharma 190080830014.pptx
 
Dairy Pasteurization Process
Dairy Pasteurization Process Dairy Pasteurization Process
Dairy Pasteurization Process
 
Milk & milk products (alfahad farwa)
Milk &  milk products (alfahad farwa)Milk &  milk products (alfahad farwa)
Milk & milk products (alfahad farwa)
 
Shelf life enhancement of milk products.
Shelf life enhancement of milk products.Shelf life enhancement of milk products.
Shelf life enhancement of milk products.
 
Feather meal for fish feed
Feather meal for fish feedFeather meal for fish feed
Feather meal for fish feed
 

Dernier

Beet Kvass The Probiotic-Rich, Fermented Tonic from Eastern Europe
Beet Kvass The Probiotic-Rich, Fermented Tonic from Eastern EuropeBeet Kvass The Probiotic-Rich, Fermented Tonic from Eastern Europe
Beet Kvass The Probiotic-Rich, Fermented Tonic from Eastern EuropeGarden Goddess, LLC
 
Reclaiming Pure Traditions Plants Enrichen Our Farms and Food.pdf
Reclaiming Pure Traditions Plants Enrichen Our Farms and Food.pdfReclaiming Pure Traditions Plants Enrichen Our Farms and Food.pdf
Reclaiming Pure Traditions Plants Enrichen Our Farms and Food.pdfStephen Gleave
 
Empowering Communities: Food Donation NGO Making a Difference
Empowering Communities: Food Donation NGO Making a DifferenceEmpowering Communities: Food Donation NGO Making a Difference
Empowering Communities: Food Donation NGO Making a DifferenceLovely Foundation
 
Food Supplement Directive No. 333-2020.pdf
Food Supplement Directive No. 333-2020.pdfFood Supplement Directive No. 333-2020.pdf
Food Supplement Directive No. 333-2020.pdfMohamed Miyir
 
HOTMEN TAJUR BOGOR JAWA BARAT INDONESIAA
HOTMEN TAJUR BOGOR JAWA BARAT INDONESIAAHOTMEN TAJUR BOGOR JAWA BARAT INDONESIAA
HOTMEN TAJUR BOGOR JAWA BARAT INDONESIAAPermataAnnisa3
 
Explore The flavors Of Indian cuisine In Budapest : Indian Palate
Explore The flavors Of Indian cuisine In Budapest : Indian PalateExplore The flavors Of Indian cuisine In Budapest : Indian Palate
Explore The flavors Of Indian cuisine In Budapest : Indian PalateIndian Palate
 

Dernier (6)

Beet Kvass The Probiotic-Rich, Fermented Tonic from Eastern Europe
Beet Kvass The Probiotic-Rich, Fermented Tonic from Eastern EuropeBeet Kvass The Probiotic-Rich, Fermented Tonic from Eastern Europe
Beet Kvass The Probiotic-Rich, Fermented Tonic from Eastern Europe
 
Reclaiming Pure Traditions Plants Enrichen Our Farms and Food.pdf
Reclaiming Pure Traditions Plants Enrichen Our Farms and Food.pdfReclaiming Pure Traditions Plants Enrichen Our Farms and Food.pdf
Reclaiming Pure Traditions Plants Enrichen Our Farms and Food.pdf
 
Empowering Communities: Food Donation NGO Making a Difference
Empowering Communities: Food Donation NGO Making a DifferenceEmpowering Communities: Food Donation NGO Making a Difference
Empowering Communities: Food Donation NGO Making a Difference
 
Food Supplement Directive No. 333-2020.pdf
Food Supplement Directive No. 333-2020.pdfFood Supplement Directive No. 333-2020.pdf
Food Supplement Directive No. 333-2020.pdf
 
HOTMEN TAJUR BOGOR JAWA BARAT INDONESIAA
HOTMEN TAJUR BOGOR JAWA BARAT INDONESIAAHOTMEN TAJUR BOGOR JAWA BARAT INDONESIAA
HOTMEN TAJUR BOGOR JAWA BARAT INDONESIAA
 
Explore The flavors Of Indian cuisine In Budapest : Indian Palate
Explore The flavors Of Indian cuisine In Budapest : Indian PalateExplore The flavors Of Indian cuisine In Budapest : Indian Palate
Explore The flavors Of Indian cuisine In Budapest : Indian Palate
 

Heat treatments for raw milk

  • 1. HEAT TREATMENTS FOR MILK Presented By:- Sourabh Kale M. Tech. (Dairy Technology) SMC, College of dairy science, AAU, Anand.
  • 2. Content:- Introduction Commonly used heat treatments  Thermization  Stassanization  Pasteurization  Batch Sterilization  UHT Treatment  High Pasteurization (ESL) Heat treatments for specific dairy products.
  • 3.  After the introduction of pasteurization (Batch method -1885), heat treatment of milk has attracted a huge amount of research attention.  Any intentional heating above 50 ° C for a sufficient time such that there is a reduction in the concentration of one or more microorganisms is considered as heat treatment. (IDF Factsheet, 2018)  Thus, the heat treatment concept covers an infinite number of combinations of time and temperature.  The treatments can be categorized into those used for milk for direct consumption and those used for specific dairy products. Introduction
  • 4. Thermization  Thermization is a generic description of a range of sub pasteurization heat treatments (57 to 68°C for 15 s) that markedly reduce the number of spoilage bacteria in milk with minimal heat damage.  Thermization is a heat treatment applied to raw milk aimed at reducing the number of organisms in milk and permitting longer storage of the milk prior to further processing. The heating conditions are 62 to 65 °C for 15 to 20 seconds. Thermized milk must be phosphatase positive(CAC, 1999).  Destruction of some non-spore forming pathogens and psychrotrophic spoilage bacteria.
  • 5. Stassanization  Henri Stassano invented it in France.  This method of pasteurization is carried out in a tubular heat exchanger consisting of three concentric tubes.  Passing milk between two water-heated pipes through the narrow space of 0.6 to 0.8 mm.  The milk is heated to about 74 ° c for 7 sec. and then promptly cooled
  • 6. Pasteurization  According to FSSAI and Codex- Pasteurization, Pasteurized and similar terms means a microbicidal heat treatment aimed at reducing the number of any pathogenic micro-organisms in milk and liquid milk products, if present, to a level at which they do not constitute a significant health hazard.  Pasteurization conditions shall be designed to effectively destroy the organisms Mycobacterium tuberculosis and Coxiella burnettii.  By LTLT or HTST and cooling it immediately to a temperature of 4 °C or less.  Phosphatase test should negative.
  • 7. Pasteurisation Unit (PU)  One PU results from heating at a temperature of 60 °C (140 °F) for 1 min. The equivalent. z-value is 10 °C (18 °F), which is high for vegetative bacteria. Thus, the number of pasteurization units for a heating temperature (T,°C) and heating time (t, min) is given by ;  63 °C for 30 min would have a value of approximately 60 PU, whereas HTST conditions (72 °C/15 s; originally 161 °F or 71.7 °C/15 s)would give only 3.96 PU (Wilbey, 1993).  pasteurization destroys neither the spores nor the toxins secreted in the milk by organisms that lived in it prior to its heat treatment.
  • 8. Sterilization  Referred to in-container batch wise heating process.  According to FSSAI Sterilization when used in association with milk or milk products, shall be taken to refer to the typical process of heating milk or milk product in sealed containers continuously to at least 115ºC for 15 minutes to ensure preservation at room temperature for a period not less than thirty days from the date of manufacture.  Codex guidelines suggest using minimum temperature-time conditions which achieve an Fo value of 3 min.
  • 9.  The temperatures for sterilization are in the range 110 to 125°C in combination with appropriate holding times such as 121°C for 3 minutes or 115°C for 13 minutes.  Turbidity test should be negative.  12 log reduction of Cl. Botulinum is essential.
  • 10. UHT treatment  UHT treatment referred to high-temperature/short-time heat treatment aimed at producing a commercially sterile product which can be stored at room temperature.  According to FSSAI, UHT refers to the process of heating milk or milk product to at least 135ºC for one second or more in a continuous flow and then packing under aseptic condition in hermetically sealed containers to ensure preservation at room temperature for a period of not less than fifteen days from the date of manufacture.
  • 11.  The total heat treatment is equivalent, in terms of its effectiveness against heat-resistant bacterial spores, to a minimum Fo value of 3 min.  The main requirement is to reduce spores of Cl . Botulinum.  Reduction of B. stearothermophilus to minimum 2 log is considered to be good .  Turbidity test is positive.  UHT-treated milk and cream are packaged aseptically into sterilized, hermetically sealed containers.
  • 12. High Pasteurization  It is a continuous heat treatment between HTST pasteurization and UHT sterilization, and is used to produce extended shelf life (ESL) milk.  An exact, generally accepted definition of the term ESL milk with regard to shelf life does not yet exist.  EU legislation (EU, 1992) states that pasteurized milk, which shows a negative reaction to the peroxidase test, must be labelled ‘high temperature pasteurized milk’.
  • 13.  Treatment is carried out at 120 - 135°C for 1-4 sec  The combination of microfiltration(average pore size of 1.4 μm) and pasteurization has proved to be a very efficient way to produce ESL milk (Hoffmann et al., 1996).  Commercial ESL milk has a shelf life varying from 30 to 90 days at 4°C.  Low original bacterial count in the raw milk is recommended. A microbial count of 100,000 cfu should not be exceeded (TeGiffel et al., 2005).
  • 14. Comparison (Ozer and Akdemir - Evrendilek, 2014)
  • 15. Innovative steam injection(ISI)  To overcome problems which are inherently present in UHT milk and to reduce the appreciable amount of denaturation of whey proteins, the Innovative Steam Injection (ISI) is introduced.  very short heating is combined with very high temperatures: less than 0.1 s at 150–200°C  The heating is directly followed by flash cooling in a vacuum vessel.  The process costs of the ISI technology are some 10% higher than the prevailing UHT process.
  • 16. Comparison of ISI with conventional Heat treatments Technology Time(s) Temperature (°C) Denaturati on of whey proteins (%) Log reduction B. stearothermophilus spores Pasteurizatio n 15-1 72-80 4-8 0 Indirect UHT 20-5 130-145 75-90 6 Direct UHT 6-2 142-150 60-85 6 ISI 0.1 160-180 25 6 Tamime (2009)
  • 17. Heat treatments for specific dairy products 72–120°C 15 sec to 30min Heating before concentratio n Reduction of microbial load, inactivate enzymes Stabilizing the proteins or controlled denaturation of proteins 70–95°C (outlet) and 180–230°C (inlet) Few seconds Heating of milk concentrate in a spray dryer Reduced water activity, reduced chances of microbial survival Drying, Product can be stored at room temperature for more than a year
  • 18. Scalding at 40°C Scalding of cheese curd Felicitates growth of starters Sufficient to expel whey Whey separation, final product moisture control and cheese body 80°C 30 min or 90°C for 10 min Heat treatment of milk for yoghurt Reduction of bacteriophages, microbes etc. Improve viscosity and texture of yoghurt in addition to reduction in microbial load