Effects of the rate of heating on apple and pear fruit quality

There is evidence that the rate of heating to meet quarantine security impacts fruit quality as well as insect mortality, Linear heating rates of 4, 6, 8, 10, and 12C/h to treatment temperatures of 44 and 46C were used to treat 8 cultivars of apples ('Delicious', 'Golden Delicious', 'Granny Smith', 'Fuji', 'Gala', 'Jonagold', 'Braeburn', and 'Cameo') and two cultivars of winter pear ('d'Anjou' and 'Bosc'). Fruit were stored ripened, and tested for various quality parameters. Scald was controlled firmness was higher in heat treated fruit, ripening was delayed but uniform in pears, decay organisms were suppressed, red fruit became redder and green fruit remained green, the Brix-acid ratio (SS/TA) was either unchanged ('Granny Smith') or increased. Physiological disorders such as bitter pit were exacerbated by the heat treatment, requiring culling after treatment to avoid storage of fruit so affected.