Optimized high-acid pasteurization
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State of the art technology Optimized high-acid pasteurization MS/2013-11
description
Our research team started a project to look at why we are pasteurizing at 95 °C and holding the temperature for 15 seconds. Is it possible that our temperature is too high? Could we lower it and still have the same product quality with uncompromising food safety? Yes we can. Our team has proven that we can lower the energy cost by 20% by lowering the temperature. We can design our process more flexible than other beverage pasteurizers with uncompromising food safety. Want to know more? Download the whitepaper here: http://ow.ly/rQB44
Transcript of Optimized high-acid pasteurization
State of the art technologyOptimized high-acid pasteurization
MS/2013-11
Dramatically lowered energy cost made possible through technology research
► Uncompromising food safety► Lower energy cost by 20%
− Improved environmental performance
► World-leading in heat transfer technology− Research study− Patent
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80°C/15s
► New lower recommendation► Microbiology research study and lab test► PDC and customer field test
to verify result – proof► Pasteurization unit control
Progressing cutting-edge technology
Research study and customer site validation
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JNSD pH<4.2
► The traditional recommended heat treatment of JNSD is 95°C/15 s
► Primary pasteurization immediately after squeezing to deactivate enzymes and kill microorganisms− 95-98°C for 10-30 s
► A second pasteurization is usually performed prior to filling
− Recontamination during bulk storage of NFC juice
− Contamination while juice reconstituted from concentrate
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Microorganisms of concern
Hea
t res
ista
nce
95-98°C/10-30 s
95°/15s
Possibility to reduce heat treatment
► Possibility to reduce heat treatment of JNSD
► Growth study on bacterial spores’ possibility to grow at pH<4.2
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Target organism
Hea
t res
ista
nce
72°C/15s
95°/15s
?
YeastMouldsAcid-tolerant bacteriaPathogenic bacteria
Yeast ascospores
Bacterial sporesSpores of heat-resistant moulds
Result: No growth at pH<4.2
► Orange and apple juice► Adjustment of pH to 3.5, 3.8, 4.0, 4.2► Inoculation with spores or vegetative cells of selected bacteria
− Spores: B. lichenformis, P. polymyxa, Cl. pasteurianum, Cl. butyricum − Vegetative cells: B. megaterium, B. coagulans, P. macerans
► 5 replicates for each juice/pH/species► Incubated at room temperature for 3 weeks
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Growth test with bacterial spores at low pH
Conclusion: The tested bacterial spores are not an issue in juice with pH<4.2
Result: No growth in any of the juices at any of the pH levels
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Calculations confirmed. Target 9 log reductions
Results and theoretical log reductions
Test results:
Temperature / time Sterile packages
65°C/15 s 0%
72°C/15 s 100%
80°C/15 s 100%
Conclusions: the test results confirm the theoretical log reduction calculations
Theoretical log reductions based on D and z values:
Optimized high-acid pasteurization
Temp 1
D63= 1.6 minz=5.4°C
Put & de Jong 2
D60= 22 minz=6.5°C
Tetra Pak 3
D65= 19 sz= 5.5°C
95/15 131 800 2 755 225 000
80/15 222 13.57 421
77/15 62,0 4.69 120
72/15 7.39 0,8 14.79
65/15 0.38 0,07 0.791 Apple juice, pH 3.5, 2013 2 Buffer solution, pH 4.5, 19823 Orange juice, pH 3.8, DR8671, 1997
Tested at Valio, Finland, June 2013
► 4000 litres orange juice− pH 4.0, 11.3°Brix, initial load: 90 CFU/ml
► Processed at 78°C/22 s (=80°C/9.5 s)► Packed in Tetra Prisma® Aseptic (250 ml), 16 000 packages► Incubated at ambient temperature (20-23°C) for 3 weeks► Inspected for gas formation► 1043 packages streaked (10 μl) at OSA at Tetra Pak®, Lund
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Verification of commercial sterility
Conclusion: Commercial sterility achieved
Results: No gas formation in 16 000 packages; no growth detected from 1043 streaked packages
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Prerequisites
► Turbulent flow required► Content of Alicyclobacillus – negative in 10 g / 10 ml► Content of Byssochlamys – negative in 10 g / 10 ml
Process recommendation
Product Set point* / holding time
Juice, second pasteurization, pH<4.2 80°C / 15 s
Juice, first pasteurization, enzyme deactivation 95-98°C / 10-30 s
Nectar, pH<4.2 80°C / 15 s if turbulent flow
Still drinks, pH<4.2 80°C / 15 sJNSD pH 4.2-4.6 123°C / 15 sJNSD pH>4.6 138°C / 4 sJuice with pulp 80°C / 15 s
JNSD with particles Based on particle size
Pasteurization at lower temperature
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Same quality with unique control
► Pasteurization unit (PU) control− International patent pending on total heat load control− Each product has its own PU value and
by controlling this we secure the right pasteurization
Pasteurization at lower temperature
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Reduction of energy consumption and carbon footprint
Pasteurization at lower temperature
Tetra Therm® Aseptic DrinkProduct: Orange juice, 12°BrixCapacity: 10 000 l/h Production scenario: two shifts, 5 days/week, 50 weeks/yearProduction: 15 hours/day
Heat treatment process 95°C/15 s* 80°C/15 s* Difference
Heating load kW 182 153 -16%
Cooling load kW 70 40 -43%
Production cost per year kEUR/year 42 34 -17%
Production cost per 1000 litre EUR/1000 litre 1.11 0.92 -0.19 EUR/1000 litre
Carbon footprint kg CO2/1000 litre 7.1 6,0 -16%
* Reduced from PU value similar to 95°C/15 s to 80°C/15 s
Impact of process temperature and increased dT
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Process temperature 80°C or 95°C and dT 3-25° C
► Taste− Process temperature and increased dT
do not impact taste of orange juice made from concentrate
► Colour− Process temperature and increased dT
do not impact colour of orange juice made from concentrate
► Vitamin C− Process temperature and increased dT
do not impact Vitamin C degradation of orange juice made from concentrate
Impact of process temperature and increased dT
Taste
► External taste panel by IPSOS Marketing, Kristianstad, Sweden− 6 weeks storage at ambient temperature− 80°C/dT=3°C vs. 95°C/dT=25°C (extreme values)− 95°C/dT=5°C vs. 95°C/dT=12°C (reference process vs. increased dT)− 95°C/dT=5°C vs. 95°C/dT=25°C (reference process vs. further increased dT)
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Impact of process temperature and increased dT
BA
A
Conclusion: Process temperature (80-95°C) and increased dT do not impact taste of orange juice made from concentrate
Result: No significant difference in taste in any of the three tested pairs
3 months 7 monthsColour
► Visual appearance evaluated once a month► Photographed using DigiEye
(consistent light conditions) after 3 and 7 months
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Impact of process temperature and increased dT
Conclusion: Process temperature (80-95°C) and increased dT do not impact colour of orange juice made from concentrate
Results: The juice was overall darker after 7 months storage than after 3 months.
At each evaluation point no difference could be detected between the samples
Vitamin C reduction
► Vitamin C content was analyzed by HPLC at Eurofins after 3.5 and 6 months storage
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Impact of process temperature and increased dT
0 1 2 3 4 5 6 7300310320330340350360370380
Vitamin C content of orange juice during am-bient storage
80°C/dT=3°C80°C/dT=15°C95°C/dT=5°C95°C/dT=12°C95°C/dT=25°C
Storage time (months)
Vita
min
C c
onte
nt (m
g/l)
* Initial Vitamin C content measured on frozen raw material 3.5 months after processing
*
Conclusion: Process temperature (80-95°C) and increased dT do not impact
Vitamin C degradation of orange juice made from concentrate
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Results: Normal Vitamin C decrease due to OTR and anaerobic degradation
Conclusions
► Second pasteurization of orange juice with pH<4.2 can be reduced from 95°C/15 s to 80°C/15 s
► dT of orange juice can be increased from 5°C up to 25°C without impact on taste, colour or Vitamin C content
► Increased flexibility as more products can be run with the same configuration
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Dramatically lowered energy cost made possible through technology research
► Uncompromising food safety► Lower energy cost by 20%
− Improved environmental performance
► World leading in heat transfer technology− Research study− Patent
