University of California

Fruit Ripening & Ethylene Management

Spring 2021 Virtual Workshop


Who Should Attend

This workshop is intended for shippers, fruit handlers (wholesale and retail) and produce managers who are involved in handling and ripening fruits and fruit-vegetables. The workshop focuses on how to increase profits by reducing losses at the receiving end, and delivering ready-to-eat, delicious fruits and fruit-vegetables to the consumer.

Participating in this workshop is one way to earn credits towards completing the Produce Professional Certificate.


Format and Dates


Live Zoom Sessions Tuesdays and Thursdays 9-11:30am PDT, for 2 weeks starting April 13. In the week prior, participants will receive access to a set of pre-recorded presentations.

Study Week April 5; Live Sessions April 13 & 15
Study Week April 12; Live Sessions April 20 & 22

Sessions will be recorded if you are unable to participate at this time. They will be available for one week following the live session.

The interactive, virtual format will include pre-recorded video presentations, weekly live overview, highlights and Q&A sessions with instructors. Participants can submit questions during the study week and during the live sessions.

Price and Refund Policies


Full Registration: $600.00

Student and Developing Country Participant Registration: $200

If you feel you are eligible for this discount, please email Pam Devine at for more information.

The enrollment fee includes access to view pre-recorded videos of all topics and demonstrations, weekly live interactive Zoom meetings with instructors and PDF copies of all presentations.

If you are unable to pay by credit card, please contact Pam Devine at


For cancellation requests received via email on or before April 4, 2021: Reimbursement of registration fees paid less $50 USD administrative fee.

Registration substitution or transfers must be approved by class administrator and can be requested before April 4, 2021

In the unlikely event that this program is canceled or postponed due to insufficient enrollments or unforeseen circumstances, the Postharvest Technology Center will fully refund registration fees.

For inquiries, contact Pam Devine at


Topics included (2019)

  • Importance of ripening programs
  • Ripening fruit and fruit-vegetables
  • Ripening facilities & equipment
  • Fruit development-ripening
  • Maturity and quality relationships
  • Biology of ethylene production
  • Sensory quality attributes and measurement
  • Temperature management
  • Retail temperature storage conditions
  • Retail displays and handling
  • Demonstrations
  • Tools to control ripening and senescence
  • Ethylene inhibition and control
  • Designing/controlling a ripening program
  • Physiological disorders and other losses


  • Sensory
  • Quality measurements
  • Environmental equipment

Instructors (2019)

  • Mary Lu Arpaia, Subtropical Horticulturist, UCR
  • Jeff Brecht, Postharvest Physiologist, University of Florida
  • Christine Bruhn, Food Marketing Specialist Emerita, UCD
  • Marita Cantwell, Specialty and Fresh-cut Vegetable Specialist, UCD
  • Irwin Donis-Gonzalez, Postharvest Engineering Specialist, UCD
  • Dennis Kihlstadius, Postharvest Consultant, Produce Technical Services
  • Beth Mitcham, Postharvest Pomologist, UCD
  • Mikal Saltveit, Plant Physiologist, UCD
  • Jim Thompson, Postharvest Engineering LLC and UCD Emeritus
  • Florence Zakharov, Postharvest Sensory Specialist, UCD
  • And other industry and academic instructors

group photo 2019

Fruit Ripening Workshop Group Photo 2019


Mary Lu Arpaia, Ph.D.

Arpaia, Mary Lu
As an extension specialist for subtropical fruit, I have both an educational and research program dealing with citrus and avocado postharvest handling. There are two areas related to subtropical fruit postharvest handling in which I conduct research.

The first deals with the role of preharvest management on postharvest fruit quality. A clearer understanding of orchard management’s role is needed to develop strategies that optimize the postharvest life of subtropical fruits. I therefore collaborate in multi-disciplinary projects that examine the role of irrigation, fertilization, plant growth regulators and pest management on postharvest fruit quality.

I also conduct research that examines the response of subtropical fruit to the postharvest environment including temperature during handling and ethylene exposure.  As part of this research effort we have incorporated the use of sensory science procedures to study the impact of handling practices on eating quality.

For more information on technical content, please contact:

Mary Lu Arpaia Ph.D.
Title: CE Subtropical Horticulturist
Phone: (559) 646-6561

For more registration information, please contact:

Pam Devine
Title: Administrative Officer
Phone: 530-752-6941





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