NEW SANITISING TECHNOLOGIES WITHOUT CHEMICALS. Dr. Marie Astrid Ottenhof Technical Director, Schreurs & Sons

Transcription

1 NEW SANITISING TECHNOLOGIES WITHOUT CHEMICALS Dr. Marie Astrid Ottenhof Technical Director, Schreurs & Sons 1

2 OBJECTIVES What made us look for an alternative? Reasons for selecting Electrolysed Oxidised Water (EOW) What were we thinking? How does EOW work? Advantages & disadvantages Another alternative without chemicals 2

3 SCHREURS & SONS 3 rd generation farming business, specialising in: Most of the produce is washed on the farm 3

4 CHLORINE DIOXIDE (ClO 2 ) This was used as a trial sanitiser for a triple wash bath system ClO 2 was a preformed gas Dispersed into solution Agitation used for washing produce can cause gas to come out of solution with OH&S consequences 4

5 ALTERNATIVE SANITATION SYSTEMS Dr Robert Premier (Global F.S. Pty Ltd) Evaluation of Vegetable Washing Chemicals (VG09086) June 2012 Compared efficacy of wide array of sanitising chemicals on leafy veg including: PAA Chlorine Chlorobromo Organics Gas based EOW 5

6 ALTERNATIVE SANITATION SYSTEMS Washing produce under running potable water can reduce the bacterial level by ~2 log Project measured sanitiser efficacy as % change in bacterial count vs water washed produce (control) 6

7 % CHANGE IN SPINACH TPC WATER VS SANITISER WASHING Individual Value Plot of percentage change from water Food = spinach Treatment Acetic acid 2% Acetic acid 4% A doxy san N14 100ppm A doxy san N14 40ppm Aussan 1% Aussan 2.5% C hlorine 100ppm Citrofresh 1% C itrofresh 2.5% Citrox 1% Citrox 2.5% Nylate 5ppm Proxitane 100ppm Proxitane 40ppm Summit 100ppm Summit 40ppm Tsunami 100ppm Tsunami 40ppm Unipolar 20ppm Unipolar 45ppm Unipolar 60ppm percentage change

8 AND THE WINNER IS EOW had superior efficacy Microbial perspective Product shelf life No chemical(s) to be added 8

9 HOW DOES EOW WORK? EOW is created by electrochemical disassociation of water and natural salts A cocktail of sanitiser molecules is generated, incl. HClO, OCl, Cl 2, H 2 O 2 and O 3 The concentration of sanitiser molecules is dependent on the current 9

10 EOW UNITS SUPPLIED BY UWT UWT = Unipolar Water Technologies Originally designed process to treat sewage and industrial effluents Technology has been validated in accordance with the Dept of Health VIC guidelines 2013 to inactivate at least 4 log bacteria and viruses EOW effective against array of human pathogens 10

11 EOW UNIT 12 cell unit footprint = ~ 1m x 3m 11

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13 START UP Fill recirculating wash bath with water and switch on pumps Add ~250g dissolved table salt to assist in electrolysis Hit START PLANT button 13

14 VARIABLES OF INTEREST Power supply (amps) required to start electrolysis Water flow (l/min) flow required through electrodes and bath Conductivity (µs/cm) indicative of salt concentration, target >1100µS/cm Chlorine level (ppm) only measurable sanitiser from chemical cocktail produced Chlorine Setpoint (ppm) dependant on HACCP plan 14

15 EXAMPLE OF DATA CAPTURED Date Time Maximum Minimum Minimum Maximum FLOW Rate CL2 EC AMPS 1/7/2017 5:39: /7/2017 5:44: /7/2017 5:49: /7/2017 5:54: /7/2017 5:59: /7/2017 6:04: /7/2017 6:09: /7/2017 6:14: /7/2017 6:19: /7/2017 6:24: /7/2017 6:29: /7/2017 6:34: /7/2017 6:39: /7/2017 6:44: /7/2017 6:49: /7/2017 6:54: /7/2017 6:59: /7/2017 7:04: /7/2017 7:09:

16 WHEN GRAPHED CHLORINE CONCENTRATION (PPM) 5:39:49 5:59:49 5:49:49 6:09:49 6:19:49 6:29:49 6:39:49 6:49:49 6:59:49 7:09:49 7:19:49 7:29:49 7:39:49 7:49:49 7:59:49 8:09:49 8:19:49 8:29:49 8:39:49 8:49:49 8:59:49 9:09:49 9:19:49 CURRENT (AMPS) Minimum CL2 Maximum AMPS TIME

17 WHILST THE SYSTEM IS RUNNING Conduct 3 chlorine test strip checks across production day Start Middle End Staff monitor screen regularly Warning light comes on when out of spec Chlorine probes calibrated every 4months 17

18 SHUT DOWN Before dumping water, start backwash: This cleans electrodes by reverse electrolysis 18

19 ADVANTAGES OF EOW No chemicals are needed (except table salt to assist electrolysis) Countries across the globe are beginning to ban chlorine based sanitisers Any chemical formed reverts back to the same chemical prior to electrolysis in due time 19

20 ADVANTAGES OF EOW Can be used for direct food applications without rinsing More effective clean versus conventional sanitisers The system automatically records the chlorine level at a pre determined frequency Date Time Maximum Minimum Minimum Maximum FLOW Rate CL2 EC AMPS 1/7/2017 6:04: /7/2017 6:09: /7/2017 6:14: /7/2017 6:19:

21 ADVANTAGES OF EOW Is automated and continuously produces certain amount of sanitisers Shelf life of sensitive produce such as baby leaf appears to be better (quality and age) compared to other sanitisers 21

22 ADVANTAGES OF EOW It is cost efficient to run and operate Low power consumption kWh/kL Runs at ambient temperature and pressure Cleaning is automated reverse electrolysis and no chemicals Short cleaning cycles minimise down time 22

23 DISADVANTAGES Initial cost If wash water needs changing, the changeover can take ~30 45min Solution: have a tank with electrolysed oxidised water ready to go to assist start up dosing 23

24 ANOTHER ALTERNATIVE WITHOUT CHEMICALS COLD PLASMA MORE ELECTRICITY INDUCED SANITATION 24

25 COLD PLASMA New, non thermal food processing technology Application of electric current to air or a gas Reactive gases produced have antimicrobial activity Has been used on meats, poultry, fruits and vegetables

26 COLD PLASMA USES Proposed for decontamination of fruits & veg... without changes to sensory attributes Growing demand for fresh produce Challenge to food industry to supply safe food with minimal processing

27 HOW BEST TO DESCRIBE COLD PLASMA? Fourth state of matter Commonly used method to generate and sustain a low temperature plasma = apply electric field to a neutral gas Mishra et al. (2016) Cold Plasma: Emerging as the New Standard in Food Safety, Research Inventy: International Journal of Engineering and Science, Vol. 6, Issue 2

28 HOW DOES IT HAPPEN? When gas is passed through electrodes, electrons are stripped off the gas and combine with other gases to form sanitising compounds Mishra et al. (2016) Cold Plasma: Emerging as the New Standard in Food Safety, Research Inventy: International Journal of Engineering and Science, Vol. 6, Issue 2

29 WHAT DOES IT LOOK LIKE? Atmospheric plasmas containing high levels of bactericidal molecules (> 100 ppm ozone, nitric oxides, peroxides, etc.) are generated Done with minimal power under roomtemperature conditions in seconds to minutes

30 WHAT DOES IT LOOK LIKE? Little or no product heating, increases <5 C Generate bactericidal molecules in situ efficiently solely from air

31 Have teamed up to study cold plasma in the horticultural industry including vegetables Contact Project Leader Dr Sukhvinder Pal at the NSW DPI

32 THANK YOU Dr ROBERT PREMIER GLOBAL F.S. Pty Ltd UNIPOLAR WATER TECHNOLOGIES 32

33 QUESTIONS? 33

34 REFERENCE MATERIAL ELECTROLYSED OXIDISED WATER: Premier, R. (2012) Evaluation of Vegetable Washing Chemicals (VG09086) COLD PLASMA: Mishra, R. et al. (2016) Cold Plasma: Emerging as the New Standard in Food Safety, Research Inventy: International Journal of Engineering and Science, Vol. 6, Issue