Pre and post-harvest maturity evolution and storage potential of Packham's Triumph pears

Packham's Triumph pears (Pyrus communis L.) were evaluated from four weeks before harvest for maturity and ethylene production. Firmness and soluble solids showed the highest correlations (r = -0.97 y 0.98, respectively)with days after full bloom (DDPF). Ethylene production was low (< 0.07 mg kg-1) and was not correlated with DDPF. Fruit harvested with 7.8 (E1) and 7.0 kg (E2) were stored in conventional cold air (0°C) and two controlled atmosphere conditions (AC1: 2-2.5% O2 /1-1.5% CO2 and AC2: 1-1.3% O2/0.5-0.8% CO2), -1°C, for six months. Changes in maturity, and ethylene production were measured (monthly) and incidence of physiological disorders was assessed (after four and six months). Additionally, the ethylene production rate (TPE) was monitored for seven days at room temperature, after each storage period. Fruit from both harvests, stored under AC1 and AC2 were firmer, greener and had lower ethylene production than those of FC. There were no significant differences in ripening between AC1 and AC2. Ethylene accumulation was exponential and occurred earlier and with higher values in FC (900 mg kg-1 maximum at the 5th month), with respect to AC (146 and 230 mg kg-1 for E1 and E2 at the end of the storage period). At room temperature, the TPE of the three storage conditions increased from the second month, but the climacteric peak was observed only in FC. After six months, fruit from FC and from both harvests developed superficial scald (17% for E1 and 20% for E2)