Title: Hot Water Treatment of Postharvest Mei Fruit to Delay Ripening
Abstract:Mei ( Prunus mume `Daqinghe') fruit were immersed in 20 °C (control), 47 °C (HWT 47 ), 50 °C (HWT 50 ), or 53°C (HWT 53 ) water for 3 min after harvest, then stored at 20 °C. Firmness, peel color, chl...Mei ( Prunus mume `Daqinghe') fruit were immersed in 20 °C (control), 47 °C (HWT 47 ), 50 °C (HWT 50 ), or 53°C (HWT 53 ) water for 3 min after harvest, then stored at 20 °C. Firmness, peel color, chlorophyll, chlorophyllase activity, soluble solids content (SSC), titratable acidity (TA), respiration, ethylene production, and pectinmethylesterase (PME) and polygalacturonase (PG) activity were monitored to determine the effects of hot water treatment in delaying fruit ripening. Control fruit displayed a typical climacteric pattern of respiration and ethylene production. Peak CO 2 production and ethylene production were observed 6 days after harvest. Fruit softening was accompanied by decreases in hue angle, chlorophyll content, SSC, and TA and increases in chlorophyllase and PME and PG activity. Hot water treatment delayed the onset of the climacteric peaks of CO 2 and ethylene production. The delays were associated with delays in fruit softening, consistent with lags in the rise of PME and PG activity; delays in yellowing and chlorophyll breakdown, consistent with lags in the rise of chlorophyllase activity; and delays in loss of SSC and TA. The shelf life of fruit increased by 6 days, or 60%, with HWT 47 , and by 8 days, or 80%, with HWT 50 or HWT 53 .Read More