NOVEL TECHNIQUES OF FOOD PROCESSING
SUBMITTED BY:AAKRITI
GFT/115201
Electro-heating, High voltage electrical discharge
HPP, High intensity light, Ultrasound MAP, Active packaging Jet impactation Gamma radiation, X-rays LASERS and MASERS Microfiltration Cryogenic thermal shock Immobilized enzymes Ozone Nitrous oxide
LIST OF NOVEL MINIMAL PROCESSING TECHNOLOGIES
Classification
THERMAL Ohmic heating Microwave heating Radiofrequency
heating Infrared heating Inductive heating
NON-THERMAL High pressure
processing Pulsed electrified field Ultrasound High intensity light Pulsed X-rays Gamma radiation MAP Membrane technology
Short electric pulses (20-80kV, microseconds) Alternative of thermal pasteurization Used for liquid and semi-liquid food products Microbial inactivation:- Electroporation Factors affecting:- electric field strength,
treatment time, cell size, growth phase Products with no air bubbles, low electrical
conductivity and easily pumpable Stored: refrigeration Components:- Pulse generator, treatment
chamber, control & data acquisition
PULSED ELECTRIFIED FIELD
Sound waves, frequency >16 kHz Principle:- Intracellular cavitations Types:- high frequency low energy, low frequency high energy,
power ultrasound Requirements:- a liquid medium, source of high energy vibration Applications:- a) Physical-freezing, degassing, crystallization,
extraction, filtration, drying, homogenization/emulsification, extrusion, cleaning
b) Chemical- oxidative ageing, enzymatic activity, bacteriocidal, effluent treatment, living cell
Microbial destruction Designs- Ultrasonic bath, probe system, reaction vessel, liquid
whistle, resonating type
ULTRASONICATION
Isostatic principle Food subjected to high hydrostatic pressure
(100-800MPa for 1 sec to 30 min) Instantaneous and uniform Independent of food size, shape,
composition 3ºC rise in temp per 100MPa Inactivation depends on temp C. botulinum spores (500-700MPa, 90-
100ºC) Order of resistance:- Spores>gram +ve >gram -ve
HIGH PRESSURE PROCESSING
Effects of high hydrostatic pressure:- a) Cell enveloped related effect b) Pressure induced cellular changes c) Biochemical aspect d) Genetic mechanism △V=2.3 R T [Log Kp1-Log Kp0]/[P1-P0] Applications:- enzyme inactivation, gel
formation, protein denaturation, tenderization of meat, tempering of chocolate
Components:- pressure vessel, pressure generating system, temp controller
ITU (915±13MHz and 2450±50MHz) Similar to visible light Non ionizing radiation Depends on:-size, shape, dielectric constant Penetration depth is inversely proportional to
frequency Penetration depth- dielectric constant & the loss
factor of food. Lower the loss factor, greater the penetration Mechanism:- ionic polarization, dipole rotation Mechanism of microbial destruction Components:- power supply, magnetron, wave
guide, stirrer, oven capacity
MICROWAVE HEATING
Electrical energy is dissipated into heat Also called electrical resistance heating, Joule
heating, or electro-heating. Volumetric heating
△P=△U2/△Ω=σE2△A△Z=σE2△V Liquid foods, soups, fruit slices in syrups,
sauces, heat sensitive liquids, proteinaceous foods
Every 120ºC rise in temp causes 2-3 times fall in resistance
Rapid heating 1ºC/sec
OHMIC HEATING
)U( = Q 2
An evolving field Better potential Equipment cost (though coming down) still
is a major limiting step Process documentation, verification
procedures need to be worked out for government approval to assure safety (adequate processing)
CONCLUSION
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