Interesting presentation by Tatiana Koutchma presented in Process Expo 2017, describing AseptoRay's technology and it's advantages over HPP in cold pressed juice processing.

1. Challenges and Solutions of Quality Validation
of Commercial UV Preservation Process
for Premium Cold Pressed Juices
Tatiana Koutchma, PhD

2. Learning Objectives
• Learn about non-thermal preservation technologies and understand why UV light
is an effective and economical preservation solution for cold pressed juices and
beverages
• Learn about new studies of UV light treatment of premium cold pressed juices
and beverages in commercial scale and understand critical issues with their
production and shelf-life
• Learn about new commercial UV equipment, understand critical parameters of
juice products and process that affect microbial efficacy and learn about key
results during pilot and commercial scale up of the validation process
•
•

3. Presentation Outline
1. Background Information
• Why cold-pressed?
• Challenges related to cold-pressed
juices
• Current pasteurization techniques
(Thermal vs. HPP)
• Ultraviolet-C light treatment
2. UV-C Treatment of Commercial
Juice
• Treatment parameters
• Impact on micro, nutritional,
quality, enzymatic, & sensory
parameters
3. Juice Stability & Appearance
• Spoilage enzymes
• Pressing temperature & juice pH
• Conclusion
4. Effect of product nutrients on
efficacy of microbial inactivation
• Vitamin C
• Antioxidants
5. Future Work
Conclusions
3

4. 4
1. Background Information

5. Why Cold-Pressed?
• Majority of store bought juice is from concentrate or purees and thermally pasteurized
• Cold-pressed leaves enzymes and other nutritional content intact
• Perceived health benefits of cold-pressed juice
• Popularity has increased rapidly since 2013 and is expected to continue to grow
• Industry valuation of ~3.4 billion
5
Background Information

6. Cold-Pressed Juice - Challenges
• Short shelf life (4-5 days)
• Cannot be resold, distributed, or sold wholesale
• Product appearance
(ex. separation)
• 5-log reduction of pathogens
required for approval from
US. FDA juice HACCP or Health Canada
• Non-thermal solution required
• Current solution = High Pressure Processing (HPP)
6
Background Information

7. High Pressure Processing (HPP)
7
Background Information
Advantages Drawbacks
• Non-thermal process (minimal effect on nutrients)
• High initial investment + maintenance costs + size
requirements
• Can be used for liquids and solids • Specific packaging requirements
• Effective regardless of medium • Batch process (limited batch size)

8. Background Information
8
Ultraviolet-C (UV-C) Treatment
• UV-C: 200 – 280 nm
• UV-C is germicidal against bacteria,
viruses, protozoa, yeasts, molds, algae
• Causes mutations in nucleic acid that
prevent replication
• Low Pressure Mercury (LPM) lamps emit
at 254 nm; close to optimal for inactivation
• Commonly used to disinfect water and
surfaces
Koutchma, T.; et al., Comprehensive Reviews in Food Science and Food Safety 2016, 15, 844-867.

9. +UV-C
9
Supplementary Information
• Formation of pyrimidine dimers
between thymine or cytosine on
same DNA strand prevent replication
• Inability to replicate = inability to infect
• Other cell functions still intact; repair is possible
• Sufficiently high dose required to ensure irreparable damage
Germicidal Effect of UV-C Light

10. Background Information
Current Commercial Juice Processors:
•First approved in 2001 – Currently one in Canada, two in U.S.
•Generally low impact on nutrients & juice qualities
•Much less expensive than HPP; lower maintenance costs than thermal pasteurization
Challenges:
•Limited understanding of effects
•Dependent on UV-C transmittance (UVT) and composition
•Difficult to cross-compare results; no standards for reporting data
•No established validation practices, UV dose, measurement, control
10
Ultraviolet-C (UV-C) Treatment

11. Establishment of optimal UV dose
• 5 log reduction of most resistant pathogenic organisms
• E.coli, Listeria, Salmonella
• Reduction of natural microflora, yeasts, molds and spoilage organisms
• Effects on enzymes (after treatment, packaging and storage)
• Shelf-life achieved (15 or 30 days)
• Microbiological
• Chemical
• UV dose effects on quality (color), nutrients (vitamins antioixidants)
• UV does effects on sensory and appearance

12. Validation of UV preservation process
• Microbial validation
• To achieve a specific 5 log reduction of the indicator organism consistently in time in
the pilot/commercial scale operation
• To determine the most UV resistant pathogen of concern for specific product
• To determine the surrogate organism
• To establish Design Reduction Equivalent Dose (RED)
• To establish critical process and product parameters
• Quality validation
• Equipment validation

13. • Approached by company with novel UV-C processor
• Second of it’s kind in Canada (CiderSure 3500, NY)
• No studies exist for UV-C treated green juices
Objectives:
• Test feasibility of UV-C commercial unit designed for low UVT food liquids
• Quality validation - explore effect of UV treatment on attributes of green blend juice
• Explore juice nutrients affecting bacterial inactivation
13
UV-C Treatment of Commercial Juice
Industrial-Scale UV-C Processor

14. Quality Validation of UV Process
• Indigenous microbial populations
• Natural aerobic micro-flora, yeasts,
molds, spoilage organisms
• Indigenous enzyme activities
• Shelf-life studies
• Physical attributes
• pH, Brix, color, viscosity
• Chemical attributes
• Sugar profile, acid profile, minerals, and
titratable acidity
• Furan
• Nutritional content
• ascorbic acid, folic acid, and beta-
carotene, polyphenols, anti-oxidants
• Organoleptic properties
• aroma profile, flavor profile
• Product appearance
• Stability/separation, browning
• Packaging validation

15. UV-C Processor Treatment Parameters
Treatments
100 % energy 30% energy
(4.39 kJ L-1) (1.32 kJ L-1)
15
UV-C Treatment of Commercial Juice
UV-C Processor Specifications
Lamp Type: Low Pressure Mercury (LPM)
# of Lamps 20
Flow Rate 1000 L h-1
Residence Time 27 s
# of Passes 1

16. Commercial UV-C unit 6 Lamps 20 Lamps
Single lamp (W) 320 320
# of lamps 6 20
Total input power (W) 1920 6400
TubeUV transparency(1=100%...0=0%) 0.6 0.6
UV-C factor (%) 32.8 32.8
Total UV-C output (W) 369 1,229
Flow rate (m3 s-1) 0.00028 0.00028
Total energy per volume (J m -3) 4,114,286 13,714,286
UV-C energy per volume (J m -3) 1,316,571 4,389,286
UV-C energy input per pass (kJ L-1) 1.32 4.39
Incident UV-C fluence (mJ cm-2) 255 617
*Absorbed fluence per pass (mJ cm-2) 18.9 61.3
UV-C Processor – Energy and Dose
16

17. Microbiological Results
• Higher reduction in aciduric count, mold & yeast from 100% energy input
• Both treatments equally effective on coliforms
17
UV-C Treatment of Commercial Juice

18. N/A
Quality Parameters
• Little to no change in quality parameters
• Minor increase in absorption coefficient
• Slight change in colour; however undetectable by eye
18
UV-C Treatment of Commercial Juice
Caminiti, I.M. et al., Food and Bioprocess Technology 2010, 5, 680-686.
Pala, Ç.U.; Toklucu, A.K., Journal of Food Composition and Analysis 2011, 24, 790-795.
Pala, Ç.U.; Toklucu, A.K., Food and Bioprocess Technology 2012, 6, 719-725.
Zhang, C. et al., Food Chemistry 2011, 126, 254-260.

19. Nutritional Results
• No vitamin C detected; method was validated w/ orange juice
• Reported only ~5 mg/100 g juice in commercial product
• No significant change (p > .05) in all other parameters
19
UV-C Treatment of Commercial Juice
N/A
Koutchma, T.; et al., Comprehensive Reviews in Food Science and Food Safety 2016, 15, 844-867.

20. Enzymatic Results
20
UV-C Treatment of Commercial Juice
• Minor increase in PPO for 30 % energy treatment (p < .05)
• No other significant change observed
Koutchma, T.; et al., Comprehensive Reviews in Food Science and Food Safety 2016, 15, 844-867.

21. Sensory Results – Triangle Test
• Panelists served three samples – two controls & one treated
• # of incorrect responses prove insignificance
• Panel found no difference between samples
21
UV-C Treatment of Commercial Juice
Roessler, E.B.; Pangborn, R.M.; Sidel, J.L.; Stone, H., Journal of Food Science 1978, 43, 940-943.

22. Conclusion – Part 1
• Reduction in natural micro-flora for both treatments
• 30 % energy UV treatment no objection from Health Canada
• Aside from colour, no significant change in quality, nutritional,
enzymatic, or sensory parameters
• UV-C treatment could replace HPP
• Juice stability & appearance still an issue
22

23. Spoilage Enzymes
23
Juice Stability and Appearance
PME (Sedimentation)
PPO (Browning)
POD (Browning)

24. Enzymes – Pressing Kale & Romaine
• Needed new way to press juice to test individual
components
• Explored effect of using different pressing process &
pressing temperatures (Cold vs. Room Temp.)
24
Juice Stability and Appearance
Kale Romaine
Shredding Speed 2500 RPM 2500 RPM
Shredding Time 25 s 15 s
Pressing Speed Slow Slow
Juice Temp (R.T.) 21.5°C 21.5°C
Juice Temp (Walk-in Fridge) 5°C 5°C
Yield (~3.5 kg produce) ~1.5 L ~1.5 L

25. Enzymes - Pressing Temperature
• Increase in enzyme activity with countertop press
• No statistically significant (p > .05) difference between temperatures
25
Juice Stability and Appearance
PME PPO POD

26. Colourimeter Metrics
ΔE :
Not noticeable = 0 - 0.5
Slightly noticeable = 0.5 - 1.5
Noticeable =1.5 - 3.0
Well noticeable = 3.0 - 6.0
Greatly noticeable = 6.0 - 12.0
26
Quality parameters Untreated
6 Lamps
(1.32 kJ L-1 )
20 Lamps
(4.39 kJ L-1 )
°Brix (%) 6.8 6.8 6.8
pH 3.39 3.39 3.39
Viscosity (mPa·s) 1.6 ± 0.1 1.77 ± 0.08 1.82 ± 0.05
Titratable acidity (%) 0.50 ± 0.00 0.49 ± 0.00 0.50 ± 0.00
α254nm (cm-1) 22.47 - 23.64
ΔL - -0.8 ± 0.2 -0.7 ± 0.1
Δa - -1.4 ± 0.2 -0.6 ± 0.2
Δb - -1.3 ± 0.4 -1.8 ± 0.3
ΔE - -1.5 ± 0.4 -1.7 ± 0.3
1
Supplementary Information

27. Appearance - Pressing Temperature
4-Day Storage Period
• Higher temp leads to enhanced browning & sedimentation
• Most pronounced in kale samples
27
Juice Stability and Appearance

28. Effect of Juice pH
• Browning decreases at lower pH
• Kale browning > romaine
• Rate of sedimentation increases as pH is lowered
• Balance between browning and rate of sedimentation
28
Juice Stability and Appearance

29. Effect of Juice pH
• Enzymatic browning decrease expected (lower PPO & POD activity)
29
Juice Stability and Appearance
PODPPO
Mizobutsi, G.P. et al., Scientia Agricola 2010, 67, 213-217.

30. PME
Effect of Juice pH
• Rate of sedimentation increases, but PME should be less active
30
Juice Stability and Appearance
Unal, M.U.; Sener, A., Journal of food science and technology 2015, 52, 1194-1199

31. Conclusion – Part 2
• Kale: PME and POD activity; Romaine: PPO activity
• Pressing temp. & juice pH affect juice stability
• Keeping produce & juice cold seems to help stability
• Low pH helps to reduce browning; but sedimentation occurs more quickly
• Not strictly due to enzymatic activity
31

32. Part 3. Juice Antioxidants and Bacterial survival
4.9
5.2 5.2
5.4
1.7
0.3
5.0
4.5
0.0
6.4
6.2
1.3
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
70% UV 50% UV 30% UV 20% UV 10% UV 5% UV
Log(CFU/ml)
Log reduction of E.coli in juices
Turbid Orange
Juice
Tropical juice
Clear Apple juice

33. Added Vitamin C In Grape Juice
0.7
6
4.7
7.2
0.9
5.9
4.5
7.2
0
1
2
3
4
5
6
7
8
9
4162771390
Log
reduction
Ascorbic acid, ppm
Reduction of microbial count in grape juice
ATC Yeasts

34. Phenolic compounds in juice models

35. Conclusion – Part 3
• The addition of common antioxidants such as Lycopen, Gallic acid,
beta carotene and antioxidants in black tea didn’t effect the
effectiveness of UV exposure to reduce total aerobic and yeasts
counts
• The addition of ascorbic acid in model juice increased juice
absorption coefficients and decreased inactivation of aerobic bacteria
and yeasts
• Possibility of adverse influence of nutrients in fresh juices on UV
efficiency should be further explored

36. 4. Future Work
36

37. Future Work
• Try to reduce cloud loss & browning
• Alter treatment parameters
• Further examine the effect of pH & pressing temperature
• Study chlorophyll levels in treated vs. untreated juice
• Investigate other vegetable juices
• Influence of lemon juice and vitamin C on UV-C effectiveness
• Effect of produce freshness
• Effect of antioxidants and vitamins
37

38. Acknowledgements
AAFC, GRDC
• Vladimir Popović, MSc
Coop students
• Michael Biancaniello
• Jake Pierscianowski
• Andrew Green
University of Guelph
• Dr. Keith Warriner
• Fan Wu
Special Thanks
• AseptoRay, Israel
• Goodnature, NY, USA
• Green House, Toronto, ON