Raw Processing

Enzyme Deactivation and Juice Refining

For tomatoes, many fruits and vegetables, the first processing steps involve deactivation of the natural enzymes to inhibit quality degradation, followed by refining to a puree or fine juice. Ing. A. Rossi offers various technologies to accomplish these processes.

Enzyme Deactivation

Enzyme Deactivation is accomplished by rapidly heating the raw product to a specific temperature. This process is sometimes referred to as Hot or Cold Break, referencing the fact that heat literally breaks the molecular structure of the target enzymes. The particular temperature is determined based on the desired characteristics of the finished product, such as color or viscosity. For example, tomato destined for use as consumer tomato juice will be subjected to temperatures in the range of 150 F to 160 F (Cold Break) which results in a bright red color and low but palate pleasing viscosity. For tomato paste where high viscosity is most desirable, temperatures or 195F or higher (Hot Break) are employed.

Ing. A. Rossi offers a selection of equipment, specifically designed to deliver the right process for your product. For Hot Break, both Horizontal and Vertical Forced Circulation systems are available. These units function by continuously recirculating a volume of the product through a heat exchanger at the target temperature, while simultaneously introducing cold, raw product, and extracting hot product to the next process step. Given the significant volume of hot product contained in the system, the incoming raw product is heated very rapidly for optimum viscosity.

For Cold Break applications with Tomato, Fruit, and Vegetables, Ing. A. Rossi offers a range of Tubular Heat Exchangers for uniform treatment, precise temperature control and minimal thermal degradation.

The New METIS Enzyme Deactivation System

METIS Energy Efficient Hot and Cold Break

The newest innovation from Ing. A. Rossi is the patented METIS Enzyme Deactivation System. Designed specifically to be the most energy efficient system on the market, METIS is configured to utilize existing waste heat sources, such as hot condensate, to reduce or fully replace live steam. METIS is fully customizable to plant conditions, and can consist of up to 3 separate heating zones:

Tube in Tube Pre Heater using hot condensate.
Tube in Shell Intermediate Heater using Low Temperature Vapor that would typically be sent to condenser.
Tube in Shell Final Heater Loop with Recirculation Pump using steam turbine exhaust vapor.

Whether you require Hot or Cold Break treatment of your product, METIS is the ideal solution for energy efficient operation.

Turbo Refiner and Cold Extraction

Ing. A. Rossi EUREKA line of Turbo Finishers

Following the Enzyme Deactivation step, the product must be refined to the desired finish, with any remaining seeds, skins, or foreign material removed. To accomplish this, Ing. A. Rossi has developed the EUREKA line of Turbo Finishers. These units consist of a housing which contains a screen and an internal, high speed rotor to force the product through the screen with the maximum yield possible, while removing and discharging the seeds and other objectionable material. Key to the superior design of the EUREKA is the use of straight, radial paddles without any curvature or pitch. This design ensures the highest degree of centrifugal force is applied to the product for optimum yield, and minimal energy consumption. In addition, the conical screen and rotor configuration allows easy clearance adjustment with a handwheel during operation to fine tune the finished product characteristics. EUREKA is available is single or dual body configurations, and is capable of Cold Extraction using low temperature product and inert gas (or steam) blanket for exclusion of oxygen, resulting in fresh-like color and flavor of the finished product.