Effects of stepwise cooling and oxygen level on quality of apple (Malus domestica ‘Summerred’) stored under controlled atmosphere

Abstract

The major part of Norwegian apples is marketed within 3-4 months after harvest. ‘Summerred’ is a popular medium early cultivar in Norway, however, it is known to soften quickly during storage and marketing. Storing apples in low temperature and low oxygen atmosphere will slow down the ripening and the fruit will keep green and firm. Delayed cooling has been reported to reduce susceptibility to develop physiological disorders like scald. The experiment included different strategies in delaying cooling (5 days at 7°C) and allowing the apples to reach 1 kPa oxygen storage after an intermediate period (5 days) at 3 kPa oxygen. The main focus was on changes in firmness, degreening, scald and fruit rots. The apples were stored for 3, 6 or 9 weeks in 1 or 4°C and analyzed for standard fruit quality factors (color, firmness, IAD-index, starch, soluble solids content and titratable acidity) as the samples were removed from low temperature and low oxygen storage and after a week at 20°C in regular atmosphere (shelf life). Physiological disorders and fruit rots were registered. In these experiments the fruit quality changes were greater (poorer quality) in apples kept at 7°C for 5 days before storage at 1 or 4°C compared to apples stored immediately at low temperature. The intermediate storage in 3 kPa oxygen tended to make the apples keep firmer during storage. The stepwise reduction in oxygen content reduced the negative effect of delayed cooling. Delayed cooling slowed the starch degradation. The incidences of soft scald and fruit rots were low, and the effects of delayed cooling and/or delayed low oxygen storage were weak.

Keywords

Delayed cooling; Delayed oxygen reduction; Firmness; Ground color; IAD-index; Starch degradation

Published in

Acta Horticulturae
2020, volume: 1275, pages: 377-381
Title: Proceedings of the International Symposium on Strategies and Technologies to Maintain Quality and Reduce Postharvest Losses : XXX International Horticultural Congress: Bridging the World Through Horticulture : Istanbul, Turkey, August 12-16, 2018
Publisher: International Society for Horticultural Science

Conference

XXX International Horticultural Congress IHC2018: International Symposium on Strategies and Technologies to Maintain Quality and Reduce Postharvest Losses, Istanbul, Turkey, August 12-16, 2018

SLU Authors

• Tahir, Ibrahim

  • Department of Plant Breeding, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Horticulture

Publication identifier

• DOI: https://doi.org/10.17660/ActaHortic.2020.1275.52
• ISBN: 978-94-62612-73-0

Permanent link to this page (URI)

https://res.slu.se/id/publ/129856