Continuous Ohmic Sterilization for Pesto Production

Casalasco, a major Italian agricultural cooperative specializing in tomato processing, expanded its production scope into basil-based ingredients and pesto formulations. Located in Parma, Italy, the manufacturing facility benefits from direct proximity to regional basil farming regions. The expansion responded to farmer crop rotation requirements and rising global consumption of Mediterranean products. Maintaining consumer adoption required resolving critical processing hurdles: preserving the vibrant green color and delicate aroma of freshly harvested basil while ensuring microbiological stability across diverse recipe profiles.

Thermal Degradation Challenges in Basil Processing
Harvested basil degrades rapidly under extended thermal exposure. Conventional retorts or standard indirect heat exchangers expose food matrices to sustained elevated temperatures, causing non-enzymatic browning, structural collapse, and loss of volatile flavor compounds. Casalasco required a continuous processing system capable of processing fresh batches within hours of harvest, achieving commercial sterility without causing organoleptic damage or phase separation in oil-herb emulsions.

Rapid Ohmic Heating and Aseptic Packaging
To overcome thermal degradation, Casalasco integrated an industrial line engineered by JBT Marel combining continuous preparation tanks with dedicated ohmic sterilization and aseptic packaging equipment. The system relies on the Sterideal Ohmic sterilizer connected directly to an aseptic filler. Unlike conventional conductive heat transfer, ohmic technology passes alternating electrical current through the conductive food stream. Electrical resistance generates rapid, uniform volumetric heat throughout the liquid-particulate matrix.




This internal heat generation brings the pesto mass to targeted sterilization temperatures within seconds. Because heat transfer does not depend on slow conduction from hot tube walls, surface fouling and localized overheating are prevented. Immediate post-heating flash cooling curtails heat dwell time. The stabilized product transfers directly to an aseptic filler, packaging sterilized formulations into pre-sterilized barrier bags without environmental recontamination.

Operational Outcomes and Industrial Verification
Prior to commercial commissioning, engineering teams tested recipe rheology and thermal profiles at vendor pilot laboratories to optimize conductivity curves and flow rates. The validated parameters were transferred directly to the industrial facility in Parma.

The operational deployment enabled continuous sterilization of temperature-sensitive herb formulations without compromising color integrity or batch homogeneity. By pairing volumetric electrical heating with hermetic filling, the processing line delivers shelf-stable, food-safe semi-finished basil products that maintain fresh-picked organoleptic standards across diverse commercial specifications.

Edited by Evgeny Churilov, Induportals Media - Adapted by AI.

www.jbtmarel.com