Fermentation products and succinate content in two apple cultivars with different tolerances to carbon dioxide.
Watkins, C. B., Fernandez-Trujillo, J. P. and Nock, J. F.
ISHS Acta Horticulturae 553: 273-274.
2001
บทคัดย่อ
Differences in metabolism of apple cultivars under elevated CO2 conditions either with or without diphenylamine (DPA) pretreatment were studied. Apple cultivars Cortland and Law Rome fruits were either untreated or immersed in DPA (No Scald DPA) at rates of 1000 and 2000 ppm, respectively, prior to cooling overnight. Untreated and treated fruits were then exposed to 45 kPa CO2 for 0, 3, 6, 9 or 12 days. Additional fruit replicates, untreated or treated with DPA were air-stored and sampled on 0, 6 and 12 days. When treated with 45 kPa CO2, Cortland had a high incidence of external CO2 injury but incidence of internal CO2 injury was low. In contrast, incidences of external and internal CO2 injury in Law Rome were low and high, respectively. DPA reduced external CO2 injury greatly and to a lesser extent, internal CO2 injury. Fermentation products increased in peel and flesh of both cultivars with increasing exposure to CO2. However, acetaldehyde concentrations were about 10 times higher in peel and flesh of Law Rome than Cortland apples. Ethanol concentrations in the flesh were similar in both cultivars, but were about twice as high in Cortland as in Law Rome peel. Neither acetaldehyde nor ethanol concentrations were affected consistently by DPA treatment. Succinate accumulation occurred only in CO2-treated fruit and was greater in peel than in flesh tissue, and overall, slightly lower in Law Rome than in Cortland. No effect of DPA on succinate was detected.