Non-Thermal Food Processing

Abstract Food is the necessity of all the creatures on earth but the human body cannot digest many raw foods. The processing and preservation of food is done for long storage and convenience. Processing involves drying, dehydration, heating, cooking, solutes addition, concentration and freezing. Somehow all the processing affects the texture, nutrition and sensory characteristics of the food. The heating depletes the nutrition of the food. The impact on protein and texture is reported. The state of food is changed in drying and dehydration. Though drying is one of the best ways to preserve food for the longest time, the impact is great on the food structure and nutrition. Consequences of thermal processing and increase in health concern from consumer fetched the researchers concern towards the novel processing where the preservation can be done without affecting the food quality. Several new food processing and preservation technologies have been investigated by the researchers which have expected potential to inactivate micro-organisms named as non-thermal processing technologies.

- Preeti Birwal

Pulsed Electric Field

Pulsed electric field (PEF) is a novel emergent technology which was first reported in the early 90s. High voltage pulses are utilized with voltages up to 20-80 kV/cm for a very short duration i.e. 10-100 μs. The exposure of bacterial cells to high voltage leads to irreversible permeation in the cell wall due to decrease in resistance and increase in conduction. This is called electroporation. The permeability leads to swelling of the cell and helps in degrading the microbes. Many reports have been reported on the application of PEF. Recently processing of liquid, semi-liquid and to some extent solids, have been reported for juices, yoghurt, cheese, soups, egg, water treatment, potato, purees. Also an application on drying enhancement, modification of enzymes, improvement in extraction are reported by a large number of groups. A tremendous application can be forecasted in liquid commodities like milk. Milk is a complete food and milk treated with PEF, definitely preserves all the nutrients required for the growth of children.

High Pressure Processing