The volatilome response of fast-melting peaches to short low oxygen stress

Fast-melting peaches have a shelf life of only 3–4 d due to their rapid softening, and this poses a problem in marketing and consumer acceptability. A postharvest 22 h treatment at 20 °C of low oxygen (<1%) or 2 µl L−1 1-methylcyclopropene (1-MCP) was applied to delay softening. 1-MCP was ineffective, but the anaerobic stress delayed softening as expressed by texture measurements, ethylene levels, and chlorophyll index values. Taste panels showed a preference for untreated fruit of the same firmness as treated fruit, probably due to off-flavors volatiles evaporation. Nevertheless, consumer acceptance of treated fruit was high after 3 d at 20 °C and 4 d of cold storage, while control fruit was too soft to be sampled. Volatile compounds were analyzed on control and low oxygen-treated fruit following treatment and 48 h later. Forty-eight compounds were identified, and thirty-nine significantly differed among all four conditions. Eleven volatile compounds associated with anaerobic conditions increased in the low oxygen treatment after 72 h. However, the low oxygen treatment did not affect most ripening-related peach fruit volatiles, primarily lactones. It is hypothesized that these compounds diminished the perception of off-flavors associated with the anaerobic volatiles. This simple low oxygen treatment demonstrates promising results in delaying softening and extending the market life of fast-ripening peaches.