Skip to content

CA Technology and Low Oxygen Research Update

Keywords: dynamic controlled atmosphere, low oxygen storage, Abate Fetel pears, internal browning, soft scald, 1-MCP integration, CO₂ scrubbing, nitrogen injection, AEROCLEAN, AMILON

Date: Tuesday, 5 November 2019
Location: Stellenbosch University
Presenter: Hubert Wieser (Isolcell Agronomist & Sales Manager)
Contact: +39 344 3483168 | hubert.wieser@Isolcell.com

Agenda

  1. What is this Isolcell brand?
  2. DCA-CF HarvestWatch™ – Dynamic Controlled Atmosphere using HarvestWatch Fluorescence Sensors
  3. Abate Fetel pear storage – a preliminary research update
  4. CO₂ Scrubber functional developments as consequence to the DCA-CF technology market introduction
  5. RQ STOREFRESH by Isolcell
  6. Latest Isolcell developments

1. The Isolcell DNA

  • Family owned company based in Bolzano, North Italy
  • Located in one of the world’s most specialized apple production areas
  • Over 60 years of experience in fruit & vegetable storage
  • Operating in more than 60 countries worldwide
  • Quality 100% made in Italy
  • High capacity to react with tailor-made solutions on customer request
  • World leader in the production of Controlled Atmosphere equipment for fresh fruit & vegetable storage

2. DCA-CF – HarvestWatch™

Dynamic Controlled Atmosphere using Chlorophyll Fluorescence Sensors

  • On the market since 2003
  • In 2019, more than 2300 commercial CA rooms worldwide (160 in RSA)
  • About 25 research institutes in 18 countries working with DCA-CF HarvestWatch

Principle in Short

  • Real-time communication with the fruits inside a storage room using special sensors
  • Measuring the chlorophyll fluorescence signal in the fruit peel
  • Below a specific oxygen level (ACP – anaerobic compensation point), the fluorescence signal clearly increases
  • Dynamically controls O₂ level, adapting it to the physiological fruit conditions

Advantages of Storing at the Lowest Possible O₂ Level (vs. Standard ULO)

For Apple Cultivars (Golden Delicious, Gala, Granny Smith, Red Delicious, Rosy Glow/Cripps Pink, Braeburn):

  • Reduction of rots and storage-related losses
  • Higher firmness and better freshness retention
  • Preservation of natural colour and organoleptic properties
  • Extended shelf-life after storage
  • Delaying of senescence scald or internal browning
  • Scald control without post-harvest use of chemicals
  • Control of internal browning (diffuse or radial)
  • Possibility of increased storage temperatures

For Pear Cultivars (Packhams, Forelle, Williams):

  • Preservation of natural colour
  • Better firmness control and freshness retention
  • Preservation of organoleptic properties (ripening on demand)
  • Reduction of rots and storage-related losses
  • Extended shelf-life after storage
  • Scald control without post-harvest use of chemicals (notably on Packhams)

Combining DCA-CF Storage with 1-MCP

  • Common practice in Italy for apple storage, especially for long shipping periods after storage
  • Adds 1-MCP benefits to DCA-CF storage behavior, but also its weaker features
  • If combining both technologies, discuss an adequate application protocol with the local 1-MCP representative
  • Recommended: First apply the 1-MCP protocol (step-wise cooling, possible RA periods), then follow the DCA-CF protocol (even if this postpones DCA-CF application)

Why DCA-CF?

Main benefits compared to other low O₂ storage systems:

  • SAFE and RELIABLE: ~2300 commercial rooms worldwide, strong research support
  • HarvestWatch Sensors are accurate and independent of other gas analyzing systems
  • Real-time communication with stored fruits is the safest method to keep lowest O₂ levels during storage
  • Possibility to increase the number of sensors for exact values from selected batches (avoiding generalized averages)
  • Not dangerous for operators (no need to take periodic samples from asphyxiation environments)

3. Abate Fetel Pear DCA-CF Storage – Preliminary Research Update

  • Abate Fetel general storage limits: Sensitive to common scald, soft scald, and internal browning
  • Sensitivities are strongly related to production practice, area, and yearly environmental factors

The Isolcell Approach

  • Trial in collaboration with Opera
  • 6 growers from 3 different pedo-climatic areas around Modena
  • 4th year of examination
  • 8 different air-tight tents inside a refrigerated storage room, with 8 different DCA-CF protocols

Main objective:
Find a solution for medium-term (6 months) Abate Fetel storage without any post-harvest chemical treatments

Preliminary Winning DCA-CF Protocol

  • Room filling at -0.5°C
  • Initial storage period in RA
  • Then O₂ pull-down until reaching fluorescence spike within 3 days
  • Final atmospheric levels: O₂ = ACP + 0.1%, CO₂ = 0.6%

Lessons from 3 Years

  • Initial delay of CA necessary to overcome soft scald
  • Do not exceed maximum time in CA (~100 days) to avoid forcing soft scald
  • Keep O₂ levels near ACP for optimal common scald control
  • Keep CO₂ constant at 0.6% to avoid internal disorders (IB, cavities)

4. CO₂ Scrubber Functional Developments (DCA-CF Market Introduction)

  • DCA-CF can be implemented in new and existing storage rooms (if air tightness is sufficient)
  • New generation of CO₂ scrubbers are necessary

New CO₂ Scrubber Functionalities

Automatic Cycle Adjustment

  • Real-time communication between CO₂ scrubber and analyzing system
  • Dynamic modification of scrubber operational parameters based on actual atmosphere levels
  • Optimizes scrubbing cycle, reduces energy consumption, and minimizes residual oxygen introduction during cycle changes

Cycle Ending Function

  • Ensures CO₂ scrubbing cycle ends in the room and switches to the next room only after activated carbon is fully regenerated
  • Prevents cross-contamination of air between rooms (important if different atmospheric levels or ethylene/pathogenic fungi contamination)

Turbo Regeneration (T.R.)

  • More powerful blower for enhanced regeneration of active carbon
  • Increases scrubber performance (up to 20%), reduces operation time and energy consumption, extends activated carbon life

Nitrogen Injection Function (N.I.F.)

  • Injects nitrogen into the regeneration tank at the end of the cycle (if necessary)
  • Requires a source of pressurized nitrogen

5. RQ STOREFRESH by Isolcell

Advantages of measuring RQ values in a separate container:

  • Overcomes technology issues: RQ measured in the room is critical (requires disabling CA actions for hours and only gives average values)
  • Overcomes mathematical issues: Small sensor errors can greatly affect RQ value
  • Overcomes safety issues: Disabling CA actions stresses the storage room

6. Latest Isolcell Developments

AEROCLEAN – The Air Ionizer from Isolcell

  • Controls and avoids appearance of moulds and fungal pathogens
  • Efficient in controlling harmful volatile substances and odours; also reduces ethylene
  • Deactivates microorganisms and air contamination with active oxygen (R.O.S. = Reactive Oxygen Species)

AMILON

  • Automatic determination of starch level (fruit ripening)
  • Eliminates human error
  • Works with the most popular starch scales worldwide

Closing

Highest Technology Made Simple

Thank you for your kind attention.

Hortgro Postharvest All White

Contact us

Tel: +27 (0)21 870 2900
Email: info@hortgro.co.za

258 Main Rd, Paarl, 7646
Back To Top
No results found...