Severity of scuffing injury of ‘Zesy002’ kiwifruit as influenced by maturity

ABSTRACT

Kiwifruit (Actinidia chinensis var. chinensis ‘Zesy002’) have a relatively long harvest season, where fruit will change in maturity and hence attributes. Harvest may be followed by a long postharvest storage period. Scuffing is the discolouration of kiwifruit skin in response to an injury. This injury is observed throughout the supply chain to some extent and thus, it is of interest to identify possible reasons that predispose kiwifruit to skin discolouration. In this work, maturity, as influenced by harvest date and estimated by firmness and total soluble solids, was investigated as a potential descriptor of scuffing susceptibility. ‘Zesy002’ kiwifruit were sampled from 11 orchards in New Zealand on three occasions (ISO weeks 12, 18 and 20) during the 2020 harvest season. Upon arrival to the lab, 24 fruit from each grower were non-destructively assessed prior to a deliberately controlled scuffing treatment and subsequently stored for 2 weeks at 0°C, to allow symptom development. Of the at-harvest maturity indicators, firmness was found to be the strongest indicator of scuffing susceptibility and severity of the damage. Further work is required to understand the physical or physiological reasons that cause softer fruit to be more susceptible to scuffing.

KEYWORDS:

• Actinidia chinensis
• vibration injury
• abrasion
• friction
• firmness

Acknowledgements

The authors would like to thank Zespri for the Master’s scholarship of the lead author and providing the fruit used within the study. Plant and Food Research are acknowledged for the design and provision of the ‘Scuffometer’ utilised in this study. Anthony Pangborn (Agriculture Risk Management Ltd) is thanked for assisting in liaising with growers and sourcing fruit. Sue Nicholson is thanked for the training and management of the postharvest lab space utilised in this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Zespri International (FP21004).