The powerpoint presentation gives a brief information about the ultrasound processing and its utilization in food processing and preservation.

1. ULTRASOUND PROCESSING
Presented by:
Siddharth Vishwakarma
Roll no. : 17AG63R08
Agricultural and Food Engineering Department
Indian Institute of Technology, Kharagpur

2. Outline
1. Introduction
2. Ultrasound principle
3. Physical effect : acoustic cavitation
4. Working
5. Methods of Ultrasound application
6. Applications in food processing
7. Application in Food Preservation
8. Reference
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3. 1. Introduction
 Modern food industry is always on the way looking for innovative technologies which
can produce
 high-quality and safe products,
 enhance the processing efficiency,
 and reduce the energy consumption.
 Power ultrasound is considered to be an emerging and promising technology for food
processing industry.
 Ultrasound makes use of physical and chemical phenomena that are fundamentally
different compared with those applied in conventional processing or preservation
techniques.
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4. 2. Ultrasound principle
 Physical effect
 Chemical effect
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5. 3. Physical effect : acoustic cavitation
 Acoustic cavitation
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6. 4. Working
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7. 5. Methods of Ultrasound application
 Direct application to the product.
 Coupling with the device.
 Submergence in an ultrasonic bath.
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8. 6. Applications in Food Processing
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9. 6.1 Filtration
 Conventional filtration have problem of clogging of solids in filter
membrane.
 Ultrasound prevent solid deposition by using acoustic cavitation.
 Ultrasonically filtration use vibration as a principle.
 Ultrasound do not affect the intrinsic permeability of membrane.

10. 6.2 Defoaming
 Foam is historically controlled by mechanical breaker, lowering
packaging temperature and the use of chemical anti-foams. (many
drawbacks)
 High intensity ultrasound waves break the foam by acoustic
pressure, radiation pressure, bubble resonance or streaming and
liquid film cavitation
 Effectively used in controlling the excess foams produce during
canning and bottling lines of beverages.
 Two parameters are important viz. acoustic energy and treatment
time.

11. 6.3 Degassing
 Degassing is the removal of dissolved gases from the liquid.
 Mechanical agitators and boiling has some drawbacks.
 Ultrasound processing can easily deaerate the liquid by bring bubbles to
the surface and finally burst with a small temperature change.
 Used to degas carbonated beverages such as beer before bottling.
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12. 6.5 Demoulding
 Industrial cooking of food leads to the adhesion of the product to the
cooking vessel and it is difficult to remove.
 Moulds are fabricated with the coating of silicon or PTFE but these
have shorter self life and are also expensive.
 Ultrasound can effectively use for demoulding by coupling the
source of ultrasound with mould.
 It also ensure no residual material left in the cooking vessel.
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13. 6.6 Cutting
 Ultrasonic food cutting equipment provide a new way to cut or slice a
variety of food products that minimizes product waste.
 Ultrasound food cutting uses a knife slide blade attached through a shaft
to the ultrasonic source.
 Ultrasound food cutting has advantage of hygienic cutting.
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14. Cutting difference in cutting slices of a bakery product
cut with and without ultrasound.
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15. 6.7 Freezing and Crystallization
 The problems related to conventional freezing is non-uniform crystal development,
destruction of food material structure and loss in sensory food quality.
 Sonication is thought to enhance both the nucleation rate and rate of crystal growth in a
saturated or super cooled medium.
 With the influence of ultrasound, conventional cooling will be much faster.
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16. 6.8 Thawing
 Thawing using conventional method by generating heat is a fast process
but there is always chance of loss of flavour, colour, etc.
 Utilization of acoustic energy, thawing under the relaxation frequency
range is faster than the thawing using conductive heating only.
 Acoustic thawing shorten the thawing time which result in the reduction
of drip loss and improve product quality.
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17. 6.9 Drying
 Traditional method of drying takes longer time to eliminate the interior
moisture content and increase temperature cause change in colour, taste,
nutritional value of food.
 Ultrasound field + hot gas stream = fast drying.
 Ultrasonic osmotic dehydration technology uses lower temperature thus
saved colour, flavour and nutritional value of the food.
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18. 6.10 Emulsification
 Acoustic emulsification has particle in sub-micro range.
 Emulsions are more stable.
 No use surfactant to stabilize the emulsion.
 Energy used by acoustic waves is less than the conventional method.
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19. 7.0 Application in Food Preservation
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20. 7.1 Introduction
 High-intensity ultrasonic waves can rupture cells and denature enzymes, and even
low-intensity ultrasound is able to modify the metabolism of cells.
 In combination with heat, ultra-sonication can accelerate the rate of sterilization of
foods, thus lessening both the duration and intensity of thermal treatment and the
resultant damage.
 The advantages of ultrasound over heat sterilization includes the minimizing of
flavour loss, greater homogeneity and significant energy savings.
 The mechanism of microbial killing is mainly due to the thinning of cell membranes,
localized heating and production of free radicals.
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21. 7.2 Principle
 High temperature and shear stress can rupture the cell membrane.
 In transient cavitation the growth and collapse of bubble are violent which led to
violent jet of liquid causes rupture of cell wall.
 In stable cavitation, low amplitude and high frequency waves causes only
oscillation of bubbles and induce micro-streaming in liquid which causes stress in
microorganism.
 Intercellular cavitation can disrupt cellular structure and functional components up
to the point of cell lysis.
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22. 7.3 Working
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23. 7.4 Factors affect the microbial inactivation
 Amplitude of ultrasound waves.
 Frequency of ultrasound waves.
 Exposure or contact time.
 Volume of food processed.
 Treatment temperature.
 Type, shape or diameter of the micro-organisms.
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24. 7.5 Can ultrasound alone effective to inactivate micro-
organism?
 Manosonication: combination of ultrasound and pressure (MS).
 Thermosonication: combination of ultrasound and heat (TS).
 Manothermosonication: combination of ultrasound, pressure and
heat (MTS).
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25. 7.6 Effect on Saccaromyces cerevisiae
 Treatment of yeast in water at 45 C.
 Using ultrasound treatment alone.
 At a power of 5 KW, the ultrasound waves didn’t increase the sensitivity of
Saccaromyces cerevisiae cell to heat.
 At a power of 180 KW sensitizing action due to ultrasound is visible but not so
much.
 At a power of 100 KW, the sensitivity of cell to heat increase drastically.
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26. 7.7 Values of decimal reduction time for the various
treatments of Saccharomyces cerevisiae
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Treatment D (50 C) D (55 c)
control 16 min 4.3 min
Pact= 50 KW 16 min 4.3 min
Pact = 100 KW 9 min 1.6 min
Pact = 150 KW 15 min 2.4 min

27. 7.8 Effect of ultrasound with temperature change
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28. 8.0 References
 A. Scotto, Device for demoulding industrial food products, Fr. Pat. FR 2
604 063, 1988.
 Feng Hao, Barbosa-Cánovas Gustavo V., and Weiss Jochen, Ultrasound
Technologies for Food and Bioprocessing,(2010), 321-340
 Chemat Farid , Zill-e-Huma, and Kamran Khan Muhammed, Journal of
Applications of ultrasound in food technology: Processing, preservation
and extraction.(2010)
 Abbas Shabbar ,Hayat Khizar ,Karangwa Eric,Bashari Mohanad and
Zhang Xiaoming, Journal of An Overview of Ultrasound-Assisted Food-
Grade Nanoemulsions.(2013) 3/17/2018
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29. Thank you