Er. Anchal Jaiswal, Ph. D. Scholar (Agricultural Processing & Food Engineering)
S V College of Agricultural Engineering and Technology & Research Station
Faculty of Agricultural Engineering, IGKV, Raipur (C.G.)

  • High-pressure processing (HPP) is a “non-thermal” food preservation technique that inactivates harmful pathogens and vegetative spoilage microorganisms by using pressure rather than heat to effect pasteurization. It is also known as high pressure processing ,ultra- high pressure, pascalization, hyperbaric pressure.

  • It uses pressure of 100MPa to >1,000 MPa for short period. The microbiological shelf-life and food quality can be substantially extended by inactivating microorganism and bacteria responsible for food spoilage.
  • Pressure treatment can be used to process both liquid and high-moisture-content solid foods.
  • HPP provides a means for retaining food quality while avoiding the need for excessive thermal treatments or chemical preservation.
  • The temperature of homogenous food will increase uniformly due to compression. An increase in food temperature above room temperature and to a lesser extent a decrease below room temperature increases the inactivation rate of microorganisms during HPP treatment.
  • This “clean” technology offers an effective and safe method of modifying protein structure, enzyme inactivation, and formation of chemical compounds.
  • India’s first company to launch extended shelf-life, ready-to-eat curries, and meals using non-thermal cold pasteurization through its proprietary cooking process aided by HPP (High-Pressure Processing) technology.

Process Principle of HPP

1. Isostatic Processing
The food product is compressed by uniform pressure from every direction and then returns to its original shape when the pressure is released process time is independent of sample size and shape, assuming uniform thermal distribution within the sample.

Fig – Principle of isostatic processing



2. Le Chatelier principle
Any reaction, conformational change is accompanied by a decrease in volume will be favoured at high pressure . Reactions involving an increase in volume will be inhibited. Accordingly, pressure shifts the system to that of lowest volume.

HPP Operation process



HPP Application on Food and Effect on Food Product and Quality

The extent of microbial inactivation depends on a number of interacting factors-
  • Type and number of microorganisms-
  • Most bacteria are capable of growth at pressures around 20–30 MPa
  • Barophiles- grow at pressures higher than 40–50 MPa
  • Baroduric or barotolerant- pressures 200 MPa
  • Magnitude and duration of High-pressure treatment
  • Temperature
  • Composition of the food
References
  • J. C. Cheftel, High-pressure, microbial inactivation and food preservation, Food Sci. Technol. Int. 1:75 (1995).
  • Gould G.W. and Sale A.J.H. (1970) J. Gen. Microbiol., 60, 335-346.
  • Howson, G. (2009). High pressure processing for food safety, extended shelf life and all-natural. Avure Technologies, USA.
  • Balny C. and Masson P. (1993) Food Rev. Int., 9(4), 611- 628.
  • Frakas D. and Hoover D. (2000) J. Food Sci., 65, 47-64.