Application and Effects of Ohmic-Vacuum Combination Heating on the Quality Factors of Tomato Paste

Abstract

Ohmic-vacuum combination heating is a common method used in the food industry as a concentration process. In the present study, an OH-VC combination heating system was developed for producing tomato paste at temperatures of 70, 80, and 90 °C and pressure of 0.3, 0.5, and 0.7 bar and electric field of 1.82, 2.73, and 3.64 V/cm using a central composite design. The effects of heating conditions on the quality and sensory evaluation of tomato paste were also evaluated. Each combination of temperature, pressure, and the electric field was quantified for specific energy consumption, energy efficiency, and productivity. A decrease of 35.08% in the amount of acid ascorbic and lycopene content 19.01%, using conventional heating compared to ohmic-vacuum heating under optimized conditions, was attained. The results also highlighted an increase in the amount of HMF (69.79%) and PME (24.33%) using conventional heating compared to ohmic-vacuum heating under optimized conditions. Ascorbic acid, lycopene, titratable acidity, productivity, energy efficiency was higher than conventional heating; on the other hand, HMF, PME, pH, SEC were lower than conventional heating at the applied OH-VC process. No significant effects between OH-VC and conventional heating on the TSS were observed. In addition, OH-VC heating was highly efficient in the inhibition of bacterial growth. Further, a minor effect on the sensory properties of tomato paste with OH-VC heating compared to the conventional treatment. The obtained results indicate a strong potential for an OH-VC combination heating system as a rapid-heating, high-efficiency alternative for saving electrical energy consumption and preserving nutritional value.

Eugenol and Aloe vera blended natural wax-based coating for preserving postharvest quality of Kaji lemon (Citrus jambhiri)

“…The ascorbic acid content in the juice samples was evaluated using iodine titration method as described by Alkanan, Altemimi, Al-Hilphy, Cacciola, & Ibrahim, 2021 ( Alkanan et al, 2021 ). Briefly, 25 mL of juice samples (of control or treated lemon) instantly after homogenization was mixed with 35 mL of starch-sulphuric acid solution and it was titrated against previously standardized 0.1 M iodine solution.…”

Rheological properties of thermally or non‐thermally treated juice/nectar/puree: A review

“…The disruption of the chain reaction of PME and PG by thermal or non‐thermal treatments can prevent the loss in the viscosity of juices, and there was a significant difference between the PME activities of mango juices treated by using different technologies (sonication, thermosonication, ohmic heating, and conventional heating) (Abedelmaksoud et al, 2022). Moreover, the combination of the electric field with temperature or pressure may significantly impact the PME activity of food (Alkanan et al, 2021).…”

Editorial Overview on Emerging Thermal Food Processing Technologies

“…Ohmic heating, as one of the most interesting emerging thermal processing technologies, was explored in one of the accepted papers in this Special Issue, entitled “Application and Effects of Ohmic-Vacuum Combination Heating on the Quality Factors of Tomato Paste” [ 2 ]. These researchers combined ohmic heating and vacuum to concentrate the tomato paste at various processing conditions.…”