文摘
Pressure ohmic thermal sterilization (POTS) involves ohmic heating of foods by applying an electric field under elevated pressure. Experiments were conducted using a custom made POTS apparatus using carrot as the model food. The samples were processed at a target temperature of 105聽掳C at 600聽MPa and treated for 0, 1, 3, and 5聽min by regulating the electric field (30聽V/cm). POTS treated carrot sample quality attributes were compared against those processed using ohmic heating (0.12聽MPa, 30聽V/cm, 105聽掳C) and pressure-assisted thermal processing (PATP; 600聽MPa, 0聽V/cm, 105聽掳C). Within the experimental conditions of the study, the thermal come-up time of the POTS, Ohmic and PATP were 1.45聽min, 3.58聽min and 6.84聽min respectively. PATP come-up time also included the pre-heating time (鈮?聽min). Results indicate the POTS samples had the least textural damage due to minimal thermal exposure. POTS samples had higher crunchiness index (CI) of 0.76 compared to PATP (CI聽=聽0.57) and ohmic heated (CI聽=聽0.62) carrots. All the technologies investigated had minimal impact on product color. This study demonstrates the potential to produce high quality shelf stable low-acid vegetable products using POTS.
