What is ohmic heating procedure?

Ohmic heating (also referred to as Joule heating) is defined as a process wherein (primarily alternating) electric currents are passed through foods or other materials with the primary purpose of heating them. Heating occurs in the form of internal energy generation within the material.

What is pulsed electric field extraction?

Pulsed electric field (PEF) processing is an efficient non-thermal food processing technique using short, high voltage pulses. These pulses induce poration of plant, animal and microbial cells, leading to cell disintegration and microbial inactivation.

What causes ohmic heating?

Ohmic heating (joule heating, resistance heating, or electroconductive heating) generates heat by passage of electrical current through food which resists the flow of electricity. However, ohmic heating is limited by viscosity, electrical conductivity, and fouling deposits.

What are some applications of ohmic heating due circuit resistance?

Ohmic heating presents a wide range of potential applications including pasteurization, sterilization, aseptic processing, cooking, thawing, blanching, evaporation, extraction, fermentation, and in the military field or long-duration space missions.

Which mode of electric heating is used for food processing?

The application of infrared radiation to food processing has gained momentum due to its inherent advantages over the conventional heating systems. Infrared heating has been applied in drying, baking, roasting, blanching, pasteurization, and sterilization of food products.

What is the principle of dielectric heating?

In dielectric heating the energy of high-frequency electromagnetic field is being transferred to thermal energy. It happens due to the effect of alternating electromagnetic field to the polar molecules of the material.

What is hurdle effect?

Hurdle technology involves the combination of a number of milder preservation factors to achieve an enhanced level of product quality, safety, and stability. In food preservation, the combined effect of preservative factors must be taken into account, which is illustrated by the hurdle effect.

What is cold plasma in food processing?

Cold plasma is a novel nonthermal food processing technology that uses energetic, reactive gases to inactivate contaminating microbes on meats, poultry, fruits, and vegetables. A wide array of cold plasma systems that operate at atmospheric pressures or in low pressure treatment chambers are under development.

How is heat generated by electric current?

Electric currents generate heat as they pass through resistive elements of a circuit. The higher the resistance of a conductor, the more heat will be generated as current passes through it. Thus, generation of heat by electric current as it passes through a conductor is an inevitable consequence.

What is Joule’s Law of electric heating?

Joule’s law of heating states that, when a current ‘i ‘ passes through a conductor of resistance ‘r’ for time ‘t’ then the heat developed in the conductor is equal to the product of the square of the current, the resistance and time.

How is Ohmic heating differ from microwave?

Ohmic heating is more efficient than microwave heating because nearly all of the energy enters the food as heat. Another important difference is that microwave and radio frequency heating have a finite depth of penetration into a food whereas ohmic heating has no such limitation.

What is the purpose of heating in food processing?

The basic purpose for the thermal processing of foods is to reduce or destroy microbial activity, reduce or destroy enzyme activity and to produce physical or chemical changes to make the food meet a certain quality standard. e.g. gelatenization of starch & denaturation of proteins to produce edible food.