Heat Treatments Keep the Quality of Fresh-Cut ‘Pomona' Peach

Heat treatment could be an alternative to delay enzymatic browning and firmness losses for fresh cut peaches. Different heat times and processing degrees on fruit could change the effectiveness of the treatment. In addition, the quality of fresh cut peach fruit could be affected by the heat treatment. Short-term heat treatments on quality of fresh-cut ‘Pomona’ peach (non melting flesh) were applied during different steps of the processing. Intact fruit were immersed in heated water at 50 ºC for 6, 15, and 30 min before peeling and cutting. Other wedge peaches were inmersed for 30 sec in water at 50 ºC. Sequently around 250 g of cut fruit  were packed in polyethylene tray (0.5 L capacity) covered with a permeable plastic film. The cut fruit was stored at 5 ºC during 6 d. Changes in color (browning expressed as L* value), firmness, respiration rate, microbial growth (mesophilic aerobic and psychrotrophic bacteria) and appearance were measured. Treated fruit at 50 ºC for 6 min before processing showed the best appearance and lowest enzymatic browning after 6 d. However, small differences were observed in L* value and firmness during the cold storage. All treatments had mesophilic counts below the Chilean Legislation. Respiration rates were higher at the beginning and reduced during the storage for all treatments, but control fruit showed the highest rates. In summary, inmersion in water at 50 ºC would not affect the metabolic activity and overall quality of  non melting flesh peach, either whole fruit or fresh cut.

 Keywords: Minimally processed, postharvest, microbial quality, appearance, enzymatic browning.

 Acknowlegement: This study and the grant for Dr. Obando were supported by FONDEF (Chile) D07i1026 and Fondecyt 3100074, respectively.