Year: 1994
Type: article
Abstract: Changes in flesh firmness of kiwifruit (Actinidia deliciosa) in response to fruit temperature were characterised for fruit removed from storage at 0°C at a range of levels of firmness generated by the normal softening associated with fruit ripening. Firmness was less after 24 h equilibration to 20°C ( f 2 ) than when measured immediately after removal from coolstorage (f 1 ) . Fruit regained firmness upon recooling to 0°C ( f 3 ) which, as a proportion of], occurred to greater extent in soft fruit than firmer fruit which were in the rapid phase of fruit softening. Thus, the firmness temperature coefficient (k ft , %/°C, a measure of the percentage change in firmness caused by a given temperature change) of kiwifruit was itself shown to be a function of flesh firmness. It is suggested this resulted from contributions from two processes: a direct, reversible, physical effect that was a linear function of temperature; and in the phase of rapid fruit softening, an irreversible, physiological loss of firmness associated with stimulated fruit ripening at elevated temperature. Fitted functions relating k fT to f 1 and f 2 were used to develop expressions which permit approximate calculation of f 2 given f 1 and vice versa. These expressions could be used to link more effectively research data obtained at 20°C with commercial assessments of fruit firmness made on fruit at 0°C e.g., by correcting estimates of time required for fruit to soften to commercially important firmness thresholds.
Authors: Peter B. Jeffery, Nigel H. Banks
Institution: Massey University
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W2120732961