Kiwifruit size influences softening rate during storage

Abstract

Large (~101 g), medium (~93 g) and small (~81 g) Hayward kiwifruits were stored in either ethylene-free air or in a controlled atmosphere (CA) of 5% carbon dioxide (CO2) and 2% oxygen (O2) at 32°F for 18 weeks. Under both storage conditions, large fruits had a slower rate of softening than smaller fruits. Air-stored kiwifruits softened approximately 2.6 times faster than CA-stored fruits. Under air conditions, large, medium and small kiwifruits reached 5.0 lbf (the minimum pounds firmness required for packaging with minimal bruising) by 12, 10 and 8 weeks, respectively, while those stored under CA conditions softened to 5.0 lbf by 49, 30 and 20 weeks. Understanding the relationship between fruit size and the rate of softening under air and CA conditions will help cold storage managers safely monitor kiwifruit softening during bin storage.