AROMA VOLATILES OF SMARTFRESH^SM TREATED 'HAYWARD' AND 'HORT16A' KIWIFRUIT

SmartFresh^SM (Agrofresh Inc.) is a commercial formulation of 1-methylcyclopropene that blocks ethylene action in plant material and retards softening in kiwifruit. SmartFresh^SM treated kiwifruit soften to eating ripe, but it has been suggested that treatment may reduce volatiles that affect fruit acceptability. The effect of SmartFresh^SM on 'Hayward' and 'Hort16A' kiwifruit volatiles was examined using fruit from four orchards. Fruit were SmartFresh^SM treated commercially after harvest and assessed for volatiles twice during storage (11 and 24 weeks at 0°C for 'Hayward'; 9 and 13 weeks at 1.5°C for 'Hort16A') and twice during shelf life at 20°C (after 1 day and when at 0.6 – 0.8 kgf (5.9 – 7.8 N) for 'Hayward'; after 1 and 4 days for 'Hort16A'). Overall, the amounts and profile of volatiles produced by SmartFresh^SM treated fruit were similar to those of untreated fruit. Total volatile data are presented to illustrate the main effects of SmartFresh^SM, storage and orchard differences. 'Hayward' kiwifruit from four orchards differed in their capacity to produce volatiles, 15–28 μg/g total volatiles after 11 weeks of storage, declining to 9–12 μg/g after 24 weeks of storage. After 11 weeks of storage, the longer the time for SmartFresh^SM treated 'Hayward' kiwifruit to reach 0.6–0.8 kgf firmness, compared with untreated fruit, the lower the volatile production. However, after 24 weeks of storage, there was little difference between SmartFresh^SM treated and untreated fruit at 0.6–0.8 kgf, as volatile production capacity had declined naturally in storage and the prolonged shelf life of SmartFresh^SM treated fruit made no difference. Results for 'Hort16A' were similar to those for 'Hayward', although there was no decline with storage, and volatile production remained at a relatively low level throughout storage. It is concluded that the volatile production and profile of SmartFresh^SM treated kiwifruit is likely to be within the range of production and profiles found in untreated fruit. SmartFresh^SM treatment does not result in any unpleasant odours in kiwifruit.