Textural degradation, drying and rehydration behaviour of ohmically treated pineapple cubes. (May 2021) - Kumar, Amardeep
Abstract: The present research aimed to study the effect of Ohmic heating (OH) treatment on textural degradation and as a pretreatment step prior to drying freshly cut pineapple ( Anana comosus ) cubes. The fresh samples were heated up to 90 °C with electric field strength (EFS: 25, 30, 35 V/cm) for a time duration (60, 90, 120, 150, 180 s), and the textural degradation and color changes were studied. The OH treated samples were dried in a tray drier at 70 °C with an airflow of 0.1 m 3 /s and the rehydration of these dehydrated samples was carried out at room temperature (25 ± 1 °C) for 7 h in distilled water. It was found that the maximum textural degradation occurred with the treatment time 90 and 120 s for the respective EFS. The effective moisture diffusivity during drying of the OH treated samples was found to be in the range of 1.91 × 10 −8 to 2.30 × 10 −8 m 2 /s. Non-significant differences of % mass gain and rehydration ratio were observed to increase treatment time at p > 0.05. Based on the current study, OH heating can be used as an alternative to conventional blanching of fruits and vegetables prior to drying and storing. Graphical abstract: Image 1 Highlights: Effect of EFS on textural damage, drying and rehydration of pineapple were studied. Maximum textural disintegration index was found after 90 s treatment at all EFS. Pineapple cubes treated at 35 V/cm EFS showed a higher drying rate at 70 °C temperature. Diffusivity for drying and rehydration was affected by EFS and treatment time. QV, 5 for drying and rehydration of pineapple cubes were changed with the change in EFS.