Conventional milk pasteurization methods, operating at 72-75°C for 15-20 seconds, often create temperature gradients that can affect milk quality and energy efficiency. Ohmic heating, which generates heat through electrical resistance, achieves uniform temperature distribution throughout the fluid while requiring 30-40% less energy than plate heat exchangers.

The engineering challenge lies in maintaining precise voltage control and uniform electric field distribution while ensuring consistent product flow and preventing electrode fouling.

This page brings together solutions from recent research—including voltage-controlled bacterial reduction systems, optimized electrode geometries, turbulent flow mechanisms, and multi-stage thermal cycling approaches. These and other developments focus on improving pasteurization efficiency while preserving milk's nutritional and sensory qualities.

1. Probiotic Fermented Milk Production Using Ohmic Heating for Milk Pasteurization

INST FEDERAL DE EDUCACAO CIENCIA E TECNOLOGIA DO RIO DE JANEIRO, 2021

A process for making probiotic fermented milk using ohmic heating instead of conventional pasteurization. The process involves ohmic heating whole milk at 85-95°C for 2030 minutes at voltages of 4-12V/cm. After heating, a probiotic culture of Lactobacillus acidophilus is added and fermented at 37-45°C for 20-30 minutes. The milk is cooled, packaged, and refrigerated. Ohmic heating replaces conventional pasteurization to preserve the sensory and nutritional characteristics of the milk while meeting microbiological requirements.

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2. Ohmic Heating Process for Pasteurizing Infant Formula with Voltage-Controlled Bacterial Reduction

INST FEDERAL DE EDUCACAO CIENCIA E TECNOLOGIA DO RIO DE JANEIRO, 2021

Preparing pasteurized infant formula using ohmic heating to preserve aroma, bioactives, and nutrients compared to traditional pasteurization methods like UHT. The process involves resuspending powdered infant formula in filtered water and then treating it with ohmic heating at voltages of 8-24 V/cm for 10-15 seconds at temperatures around 72-75°C. This ohmic pasteurization technique allows for gentler, targeted killing of bacteria without denaturing sensitive proteins and components.

3. Process for Producing Minas Frescal Cheese Using Ohmic Heating of Milk

INST FEDERAL DE EDUCACAO CIENCIA E TECNOLOGIA DO RIO DE JANEIRO, 2021

A process for making Minas Frescal cheese using ohmic heating of the milk before cheese making. The ohmic heating step involves passing the milk through an electric field to heat it uniformly without temperature gradients. This preserves the aromatic compounds and nutrients better compared to conventional pasteurization. The ohmic heated milk is then used to make Minas Frescal cheese by adding rennet, lactic acid, calcium chloride, and salt. The cheese has improved microbiological safety and retains better sensory and nutritional qualities compared to conventionally pasteurized cheese.

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4. Device with Ring-Shaped Heating Element and Pear-Shaped Interior for Liquid Temperature Control

MUELLER JOSEF, 2020

A device for precise temperature control of liquids, particularly calf milk, that enables heating to target temperatures. The device features a ring-shaped heating element with an annular interior, where a rod with an immersion end is connected. The heating element's interior surface is designed to maximize heat transfer to the liquid through a pear-shaped configuration with a height-to-width ratio of 2.3. This optimized geometry enables efficient heat transfer between the heating element and the liquid, allowing precise temperature control of the milk.

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5. Method for Producing Sterilized Dairy Products via Controlled Joule Heating with Flow Path Transition from Transition to Turbulent Flow

MEIJI CO LTD, 2019

Method for producing high-quality sterilized dairy products through controlled Joule heating of milk-containing raw materials. The method involves adjusting the flow path characteristics of the raw material to achieve specific fluid dynamics, specifically transitioning from a transition flow to a turbulent flow. This enables precise control over heat transfer characteristics during Joule heating, allowing for optimized sterilization conditions while minimizing scorching and by-product formation. The method can be applied to a wide range of milk products, including dairy powders, concentrates, and beverages.

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6. High-Voltage Pulse Sterilizer with Series-Connected High-Voltage Units and Intermediate Electric Resistor

FRONTIER ENGINEERING CO LTD, 2018

High-voltage pulse sterilizer for food processing that enables continuous operation for extended periods without electrode surface seizure. The device employs a novel configuration where the high-voltage application units are connected in series, with an intermediate electric resistor between the electrodes and one output terminal. This configuration prevents electrode surface scaling and sparks by maintaining a turbulent flow of fluid food material between the units, while the resistor prevents excessive current flow. The device operates at high pulse frequencies (15 kHz) and uses AC power with sinusoidal waveforms. The configuration allows for continuous processing of food materials like milk, soy milk, and beverages without the need for frequent electrode replacement or surface cleaning.

7. Crescent-Shaped Heating Element with Dual Outward-Facing Sections and Integrated Flow Channel

HORIZONT GROUP GMBH, 2018

A heating element for a device for heating a liquid such as milk, featuring a crescent-shaped design that provides enhanced heat transfer efficiency. The heating element comprises two outwardly facing heating sections that form a crescent shape, with a common edge. This unique configuration enables the formation of a flow channel through the liquid, accelerating the heating process while minimizing resistance. The crescent shape also enables uniform heat distribution around the heating elements, ensuring consistent temperature distribution. The crescent-shaped design allows for efficient heat transfer while maintaining structural integrity, making it particularly suitable for devices that require precise temperature control.

8. Rotating Platform Milk Pasteurization System with Integrated Heating Wire and Cooling Box

YAN CHEN, Chen Yan, 2017

A milk pasteurization system heating device that provides uniform heating, simplified operation, and enhanced safety through a novel heating configuration. The device comprises a bottom plate, mounting table, heating device, heating wire, rotating electric machine, blade, turntable, hopper, cooling box, and collection box. The heating device is arranged on a rotating platform that features a rotating electric machine and a rotating blade. The heating wire is integrated into the blade, and the platform is equipped with a mounting table and a cooling box. The device's unique configuration enables consistent heating across the entire system while maintaining optimal operating conditions.

9. Method for Producing Nutritional Milk Composition with Retained Biological Agents and Reduced Bioburden through Sequential Filtration, Heat Treatment, and Component Recombination

MONTOYA ARMANDO, 2015

A method for obtaining a nutritional milk composition that retains beneficial biological agents and reduces bioburden while sterilizing whole milk. The method involves filtering whole milk, heat treating it, separating it into skim and fat portions, further processing the fat, mixing it with the skim, and adding a human milk composition. The human milk composition is obtained by filtering whole milk, heat treating it, separating it into skim and fat portions, further processing the fat, and mixing it with the skim. The human milk composition provides additional nutrients to supplement the nutritional value of the whole milk.

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