INTERACTION OF HOT-WATER TREATMENTS AND CONTROLLED-ATMOSPHERE STORAGEON QUALITY OF FUYU PERSIMMONS

A matrix of 80 hot water treatment (HWT) temperatures/durations and co ntrolled atmosphere (CA) storage regimes were tested for effects on re spiratory activity, ethanol (EtOH) and acetaldehyde accumulation (AA), and storage quality of 'Fuyu' persimmon. Fruit were hot water treated at 47 degrees C for 45, 60, 90, or 120; min, 50 degrees C for 30, 45, 55, or 60 min; 52 degrees C for 20, 30, 40, or 50 min; 54 degrees C f or 15, 20, 25, or 30 min; and as a control treatment, 20 degrees C in air. After treatment, fruit were stored in air, 5% CO2: 2% O-2: 10% CO 2: 2%, or 100% N-2 for 6 weeks at 0 degrees C. Fruit quality was asses sed after a 5 day shelf-life at 20 degrees C. Respiration (CO2 product ion) was measured on fruit held at 20 degrees C following HWT. After s torage, C2H4, CO2, EtOH and AA production were measured on selected tr eatments at 0, 1, 3, and 5 days at 20 degrees C. Hot water treatment a lone, or in combination with CA, ameliorated chilling injury (CI). Ext ernal browning symptoms developed on fruit in some treatments upon rem oval from storage, severity of symptoms being positively correlated wi th increasing HWT duration, and most severe in the CA treatments, espe cially the 100% N-2 CA. CO2 production increased after HWT and then de creased (within 24 h), but remained at a higher level than the non-hea ted control. Following storage, CO2 production rates of fruit from all treatments were relatively similar by the end of the 5 days at 20 deg rees C. EtOH and AA production were the greatest in the 100% N-2 treat ment. Fruit under the longer HWT durations had lower CO2 and C2H4 prod uction after storage and accumulated more EtOH and AA during the 5 day shelf life. These were also the treatments resulting in the lowest le vels of CI. Possible mechanisms of HWT and CA alleviation of CI in 'Fu yu' persimmon are discussed. (C) 1997 Elsevier Science B.V.