S23 - Session O1 - The benefits and risks of short low oxygen treatment on the shelf-life of fast-melting 'Swelling' peach

Authors: Itay Maoz *, Akhilesh Yadav, Kamal Tyagi, Bettina Kochanek, Haya Friedman, Amnon Lichter

Fast melting peaches cultivars ( Prunus persica cv. Swelling) are subject to rapid softening, limiting their shelf life and marketing. Previously, short-term low oxygen stress was shown to slow down softening. Considering this treatment causes significant anaerobic stress, we re-evaluate its consequences to fruit flavor and determine the relations between its ripening stage and the effect of the treatment on its firmness. Peaches were measured after harvest for I AD n a nondestructive chlorophyll content index to study the treatments' effect on ripening. Peaches from two consecutive harvests were subjected to 20 h exposure to low oxygen ( < 1% O 2 ). Softening and ripening as measured by I AD were significantly delayed by the low oxygen treatment. The low oxygen stress treatment significantly reduced ethylene levels of the fruit of similar I AD values immediately after the treatment and 24 h later. Sensory evaluation carried out right after the low oxygen treatment showed a preference for the control fruit. After three days, fruit treated by low oxygen was preferred due to its higher firmness, a critical quality attribute in peaches. However, sensory evaluation of fruit with equal firmness showed preference to the control fruit due to the accumulation of off-flavor volatile compounds in the treated fruit. Nevertheless, a consumer acceptance panel demonstrated that the treated fruit had a high acceptance score almost a week after the control fruit was unavailable due to loss of acceptable firmness. We identified 55 volatile compounds differentiating between volatiles accumulating during the shelf life, i.e., ripening effect [gamma-decalactone] as compared to the volatiles accumulating due to the treatment, i.e., low oxygen stress effect [ethyl acetate]. We conclude that low oxygen treatments can extend the shelf life of fast meting peaches, but further research is required to tailor the optimal stress conditions to avoid the accumulation of detrimental off-flavors.