Fruit dry matter concentration: a new quality metric for apples

In the fresh apple market fruit must be crisp and juicy to attract buyers to purchase again. However, recent studies have shown that consumer acceptability could be further enhanced by improving taste. This study evaluates the use of fruit dry matter concentration (DMC) as a new fruit quality metric for apple.

Fruit samples collected at harvest, in the two main fruit growing regions of New Zealand, showed a variation in mean fruit DMC from 130 to 156 g kg(-1) with 'Royal Gala' and with 'Scifresh' from 152 to 176 g kg(-1). Individual fruit DMC showed a larger range, from 108 to 189 g kg(-1) with 'Royal Gala' and from 125 to 201 g kg(-1) with 'Scifresh'. Fruit DMC proved a more reliable predictor of total soluble solids after 12 weeks of air storage at 0.5 °C than TSS at harvest for both 'Royal Gala' and 'Scifresh'. Fruit DMC was also positively related to flesh firmness, although this relationship was not as strong as that seen with soluble solids and was more dependent on cultivar. Consumer studies showed that consumer preference was positively related to fruit DMC of 'Royal Gala' apples.

Fruit DMC can therefore be measured before or at harvest, and be used to predict the sensory potential for the fruit after storage.