Ultrasound or Sonication Technology in Food Processing-2-30.pdf

food related to ultrasonification

1. Introduction
•Ultrasoundwavesaresimilartosoundwavesbut,havinga
frequencyabove16kHz,cannotbedetectedbythehuman
ear.
•Ultrasoundreferstosoundwaves,mechanicalvibrations,
whichpropagatethroughsolids,liquidsandgaseswitha
frequencygreaterthantheupperlimitofhumanhearing.
•Useofultrasoundinfoodprocessingincludesextraction,
drying, crystallization,filtration,defoaming,
homogenizationandalsouseofultrasoundaspreservation
technique.
•Theprincipleaimofthistechnologyistoreducethe
processingtime,saveenergy,improvetheshelflifeand
qualityoffoodproducts.

2. 7Figure 1. Frequency ranges ofultrasound

3. Figure 2. Frequency ranges ofsound

4. History
•ThediscoveryofultrasoundcamewithPiereCuriein
1880.
•Inthe1960s,Ultrasoundtechnologywaswell
establishedandusedforcleaninginsteelandplastic
industries.
•Foodindustry:Late1960stocharacterizethefoods
suchasmeat,fatsandoils,milk,bread,fruit,and
saucesbasedonparticlesize,distributionand
composition.

5. •Ultrasoundwhenpropagatedthroughabiologicalstructureinducescompressions
andrarefactionsoftheparticlesandahighamountofenergyisimparted.
Figure 3. Propagation of ultrasound wave

6. •Soundwavescanpropagateparallelorperpendiculartothe
directionoftravelthroughamaterial.Sincethe
propagationofsoundwavesisnormallyassociatedwitha
liquidmedium.
•Parallel waves are known as longitudinalwaves.
•Perpendicular waves are also known as shearwaves.
•Longitudinalwavesarecapableoftraveling
insolids,liquids,orgases.And
haveshortwavelengthswith
respecttothetransducer
dimensions,producingsharply
definedbeams andhigh
velocities.
Figure 4. longitudinalwave

7. •ShearwavesTheparticlemotionisperpendiculartothe
directionofwavepropagationandliquidsandgasesdonot
supportstressshearundernormalconditions,shearwavescan
onlypropagatethroughsolids.
•Thevelocityofshearwaveisrelativelylowcomparedto
longitudinalwaves.
Figure 5. shearwave

8. Principle
Atsufficientlyhighpower,therarefactionexceedstheattractiveforcesbetween
moleculesinaliquidphase,whichsubsequentlyleadstotheformationofcavitation
bubbles.
Principle

9. Ultrasoundgeneration
•Ultrasonic wave producing system contains the generator, transducer
and the applicationsystem.
•Generator: It produces mechanicalenergy.
•Transducer: It converts mechanical energy into the sound energy at
ultrasonicfrequencies.
There are 3 types ofTransducer
1)Fluid-driven
2)Magnetostrictive
3)Piezoelectric

10. 1)Fluid-driven Transducer: The fluid-driven transducer produces vibration at
ultrasonic frequencies by forcing liquid to thin metal blade which can be
used for mixing and homogenisationsystems.
2)MagnetostrictiveTransducer:Themagnetostrictive
transducerismadefromakindofferromagneticmaterials
suchasironornickel.Thefrequencyoftheoscillatorcan
beadjustedbychangingthecapacitanceofthecondenserC.
•Amagnetostrictiongeneratorproducesultrasonic
wavesofcomparativelylowfrequency.upto200kHz.
Figure 6.fluid-driven
Figure 7.MagnetostrictiveTransducer

11. •PiezoelectricTransducer:
•Somenaturallypiezoelectricoccurring
materialsincludeBerlinite,
canesugar,quartz,Rochellesalt,
topaz,tourmaline,andbone.
•man-madepiezoelectricmaterialsincludes
bariumtitanateandleadzirconatetitanate.
•PiezoelectricTransducerproducesultrasonic
wavesmorethan300kHz.
•In application system a coupler device is used to transfer ultrasonic vibrations to
thesample.
•probesystem
•ultrasonicbath
Figure 8. PiezoelectricTransducer:

12. •Probesystem:
•Ultrasonicbath: Figure 9. probesystem
Figure 10. ultrasonicbath

13. Typesof Ultra sonication Treatment
Figure 11. Ultrasonic bath

14. Figure 12. Ultrasonic probe

15. •Uses of Ultrasound in FoodProcessing
✓Filtration anddrying
✓Freezing
✓Mixing andhomogenization
✓Defoaming
✓Crystallization of fats, sugarsetc
✓Cutting
✓Degassing

16. Ultrasound in foodpreservation
•Microbial inactivation mechanism: By cavitationphenomena.
✓During the cavitation process it changes the pressure and temperature cause
break-down of cell walls, disruption and thinning of cell membranes and DNA
will bedamage.
✓Cavitation can be divided into twotypes
1)TransientCavitation:
The bubblesoscillate in airregular
fashion and finallyimplode.
This produces high local temperatures
and pressures that woulddisintegrate
biological cells and denatureenzymes.
Figure 13. transientCavitation

17. 2) StableCavitation:
•The bubbles that oscillate in a regular fashion
for many acousticcycles.
•The inactivation effect of ultrasound has also been attributed to the generation of
intracellular cavitation and these mechanical shocks can disrupt cellular structural
and functional components up to the point of celllysis.
Figure 14. stableCavitation
Figure 15. Mechanism of ultrasound-induced celldamage

18. •Methods of Ultrasound:
a)Ultrasonication(US):
•it is the application of ultrasound at lowtemperature.
•it requires long treatment time to inactivate stable enzymes and microorganisms which may
cause high energyrequirement.
b) Thermosonication(TS):
•It is a combined method of ultrasound and heat. The product is subjected to ultrasoundand
moderate heat simultaneously. This method produces a greater effect on inactivation of
microorganisms than heatalone.
c) Manosonication (MS):
•It is a combined method in which ultrasound and pressure are appliedtogether.
•Manosonication provides to inactivate enzymes andmicroorganisms.
d) Manothermosonication (MTS):
•It is a combined method of heat, ultrasound andpressure.
•MTS treatments inactivate several enzymes at lower temperatures and/or in a shorter time than
thermal treatments at the sametemperatures

19. Table 1.Effects of ultrasound in combination with heat and
pressure
Inactivationby Vegetativecells Spores Enzymes
Ultrasound alone(US) + - -
US and heat(MT) + + -
US and heat andpressure
(MTS)
+ + +

20. •MicroorganismInactivation
•Different kinds of microorganisms have different membranestructure.
•Gram-positive bacteria have a thicker cell wall and also Gram-negative bacteria
have a thinner cell wall.
•Factors affecting the effectiveness of microbial inactivationare.
➢Amplitude of ultrasoundwaves.
➢Exposure or contacttime.
➢Volume of foodprocessed.
➢Treatmenttemperature.
•The inactivation of Listeria monocytegenes by high-power ultrasonic waves (20
kHz) at ambient temperature and pressure has been found to be low with decimal
reduction values in 4.3min.
•By combining sub lethal temperatures and higher pressures of 200kPa the decimal
reduction value will be over 1.5 min to 1.0min.

21. •SporeInactivation
•Microbial spores are resistant to extreme conditions such as high temperatures and
pressures, high and low pH and mechanicalshocks.
•The endospores of Bacillus and Clostridium species are very resistant to extreme
conditions.
•Manosonication treatment at 500kPa for 12min inactivated over 99% of the spores.
Increasingthe amplitude ofultrasonic vibrationofthe transducer.Theincreasingthe
level ofinactivation.
•For example 20 kHz probe at 300 kPa, 12 min sonication at 90µmamplitude
inactivated 75% of thespores.
•By raising the amplitude to 150µm resulted in 99.5% sporeinactivation.
•Finally increasing the thermal temperature of the treatment resulted in greater rates of
inactivation certainly at 300kPa compared to thermal treatmentalone.

22. Table 2. Experiences using ultrasound in foodpreservation

23. •Enzymeinactivation
•Thestudyofenzymeinactivationbyultrasoundhasreceivedlessattentionthan
microbialinactivation.
•Ultrasoundcreatescontinuousvibrationandproducestablecavitationbubbles
whichcollapseduetotheextremelocalincreaseinpressure(1000P)and
temperature(5000K).
•Duetohighpressureandtemperaturethesecondaryandtertiarystructurewill
breakdown.Andalsolossofmanyenzymes.
•ApplicationofMTStreatmentstomodelenzymesrelevanttothefoodindustryin
modelbuffersystemsprovedtobemuchmoreefficientthanheattreatmentfor
inactivatingtheseenzymes,especiallythosewhicharemorethermallylabile
(lipoxygenaseandpolyphenoloxidase).

24. Table3.Inactivationofenzymesbyusingheat,pressureandultrasoundtreatments
Enzyme Medium TreatmentEffect onactivity
Pectinmethylesterae
(PME) and
Polygalacturanase
(PG)
Phosphatebuffer20 kHz, 52°C-
86°C, 12 -45
kg/cm2, 0 -104μm
PME; D62.5°C = 45 min decreased to 0.85 minby
MTS
PGI; D86°C = 20.6 min decreased to 0.24min
byMTS
PGII; D52.5°C = 38.4 decreased to 1.46 min byMTS
Glucose-6phosphate
dehydrogenase
Distilledwater
(pH =5.6)
27 kHz, 60W/cm2,
36°C -47°C880
kHz and 1W/cm2,
36°C -47°C
Caused higher inactivation as compared to thermal
treatment, dependent on enzyme concentration,higher
activation energy at lowerfrequency.
Orange juice
pectinmethylesterase
Citrate bufferand
orangejuice
20 kHz, 33°Cand
72°C,200kPa,
117μm
MTS increased the inactivation by 25 times incitrate
buffer and >400 times in orangejuice.
PME and (PG)of
tomatopaste
Tomatopure
(5.5%solid)
20 kHz,200kPa,
70°C, 117μm
100% inactivation of PME, 62% inactivation ofPG.

25. •Effect of ultrasound on foodquality
•Effects of Ultrasound on DairyProducts
i.Serum proteins are lactalbumin and lactoglobulin are denatured more
extensively when ultrasound is combined with heat than with these two
treatments performedseparately.
ii.Similar results were obtained in fat globule homogenization when
applying continuousmanothermosonication.
iii.This also results in a slight change in milkcolour.

26. •Effect of ultrasound onjuices
i.vitamin C retention of orange juice after ultrasonic treatment is
higher when it is compared to thermalprocessing.
ii.The effects of ultrasound and temperature on vitamin C content of
tomato extract. It was found that there is no significant effect of
ultrasound whereas heat treatment significantly reduces vitamin C
content of tomatoextract.
iii.MTS treatments of pure pectin solutions yielded molecules with
lower apparent viscosities due to a sizereduction.

27. •Conclusion
•Ultrasoundisconsideredtobeanemergingtechnologyinthefood
industry.Ithasadvantagesofminimizingflavorloss,increasing
homogeneity,savingenergy,highproductivity,enhancedquality,
reducedchemicalandphysicalhazards,andisenvironmentally
friendly.
•Whenitisappliedwithpressureandtemperatureitsefficiency
increasesandcontrolnutritionalloss.
•Ultrasoundisagoodalternativemethodforthefoodpreservationand
alsonoadverseeffectonhumanhealth.

28. References
•SongulSahinErcanandCigdemsoysal.(2013)Useofultrasoundin
foodpreservation.NaturalScience,(5),5-13.
•FaridChemat,Zill-e-Huma,MuhammedKamranKhan.(2011)
Applicationsofultrasoundinfoodtechnology:Processing,
preservationandextraction.UltrasonicsSonochemistry,(18),813–
835.
•EmergingTechnologiesforFoodProcessing.EdtedbyDa-WenSun.
323-351.