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High pressure processing in food ppt
High Pressure Processing (HPP) involves subjecting foods to high pressures between 300-800 MPa for short periods of time to pasteurize foods without affecting their sensory qualities or significantly reducing their shelf life. HPP inactivates microorganisms and enzymes through changes to cellular structures and biochemical reactions. Properly applied HPP can reduce pathogens like Listeria and Salmonella by over 6 log while maintaining food quality and functional properties.
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High pressure processing in food ppt
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- 2. High Pressure Processing(HPP) What? –Subjecting foods to 300- 800MPa for 1-30 min at or around room temp. Why? – Cold pasteurization –- Inactivation of micro- organisms and enzymes, -No adverse sensory changes, -2-3 times extension in shelf life, ->6 log reduction in Listeria, Salmonella, E-coli (Source: www.relayresearch.ie).
- 4. High Pressure Processing(HPP) History • HPP has been recognized by scientist to kill bacteria as early as the 1890’s. Effects of HHP on organisms • Viable bacteria on water samples collected from 5100 m depth ( 50 MPa) . Certes, 1883 • Reduction of spoilage organism by HHP (Hite 1899)-1st time in food • From Milk and meat products to fruits and vegetables ( Hite et.al,1914) • Peaches and pears treated at 400 MPa for 30 min at room temperature – good after 5 years of storage • European, Japanese and US food Industries are investing on HPP research
- 5. High Pressure Processing(HPP) • Non thermal in nature • Inactivates the vegetative microorganisms, spores and enzymes • Increase in shelf life of foods • Denatures proteins and polysaccharides • Interesting application in the area of food texturization • Development of novel foods of superior nutritional and sensory quality • Higher safety • Increased ambient shelf life
- 6. Will HPP damagethe food product? • During HPP, pressure is uniformly applied around and throughout the food product • Grape is squeezed from all sides simultaneously, it will not be crushed. • By squeezing the bottle, you pressurize the water inside as well as the grape. Yet the grape is not damaged, • Foods processed by high pressure will not be damaged by the applied pressure. Isostatic ,uniform pressure ,no shear stress
- 7. High Pressure Processing(HPP) Principle Iso-static Principle • Application of pressure is instantaneous and uniform through out the sample Le Chateliers’s Principle • Any chemical reaction associated with a decrease in total molar volume will be accelerated by pressure • In combination with mild heat, reaction rates also may increase according to Arrhenius law.
- 8. • Electrostriction • Pressureleads to ionisation-water molecules arrange compactly around the electric charge leading to destruction of m.o • Compression energy • The compression energy contained in the pressure vessel is approximated as 2/5CPV0 • Adiabatic heating • There is no net heat heat transfer between the system and sorrounding
- 9. High Pressure Processing(HPP) • What functional properties does HPP impart to food products? • High pressure treatment is expected to be less detrimental than conventional processes to low molecular weight food compounds such as flavouring agents, pigments, vitamins, etc., as covalent bondings are not affected by pressure • Heat-sensitive, antimutagenic and therefore health- promoting substances in fruit and vegetables are also largely retained.
- 10. High Pressure Processing(HPP) • What functional properties does HPP impart to food products?
- 12. High Pressure Processing(HPP) Pressure effects on microorganisms Mechanism of action • Number of changes to the morphology, biochemical reactions, genetic mechanisms, cell membrane and wall of microorganisms. Cellular morphology • Intracellular gas vacuoles can collapse at 0.6 MPa • Cell wall damage and sub cellular structure altered in yeasts above 200 Mpa • Lethal effects of HHP – mechanism involved –ionization and precipitation of protein complexes Spores has proven pressure resistance • Spore proteins are protected against the ionization precipitation by dipicolinic acid (Timson and Short 1965) • Highly viscous glassy state within the core of a spore contribute to resistance and dormancy (Gould 1986)
- 14. HPP batch equipment ModelCIP 42260,ABB Autoclave Systems, Columbus,OH,USA).
- 15. HPP - Sugarcaneand pine apple juice Research at McGill, Canada • Research at McGill,canada • Pressure – 100- 400 MPa • Holding time 15-45 min • Storage studies
- 16. HPP – Sugarcaneand Pine apple juice • Pressure – 100- 400 MPa • Holding time 15-45 min • Storage studies • Microbial reduction of 4 log cycle at 400 MPa and 45 min time • Pressure reduced the Polyphenoloxidase activity • Bromelin activity increased up to 100 MPa stabilized from 100-300 and increased after 300MPA