IMPACT OF ULTRASOUND ON PROCESS EFFICIENCY IN FOOD INDUSTRY · IMPACT OF ULTRASOUND ON PROCESS EFFICIENCY IN FOOD INDUSTRY Mladen Brnčić Faculty of Food Technology and Biotechnology

IMPACT OF ULTRASOUND ON PROCESS EFFICIENCY IN FOOD INDUSTRY

Mladen Brnčić

Faculty of Food Technology and Biotechnology

Zagreb

Croatia

TRENDS IN FOOD INDUSTRY – Koprivnica, Croatia, September 5th, 2014.



Sound waves at frequencies higher than the audible range (16 kHz)


Power ultrasound (20 -1000 kHz) can be used for IMPROVING PROCESSING EFFICIENCY

Enhancing drying

Enhancing extraction

Enhancing homogenisation

Defoaming

Enhancing emulsification

Viscosity modification

Enhancing oxidation processes


ULTRASOUND PROCESSING OF FOODS PHENOMENON OF CAVITATION The basis of ultrasound benefits

– LIQUIDS - Consequence of L-wave creation

leads to alternate cycles of expansion and rarefaction

Areas of pressure changes causes cavitation occurence during which bubbles are formed with higher surface area under expansion cycle

Cavitational bubble is growing and shrinking during dynamical phases equilibrium during phase within bubble and liquid outside

EXAMPLE - 24 kHz; Critical size of cavitational bubble is 170 µm and in that moment bubble is not able to absorb energy and IMPLODE


Ability of ultrasound to form cavitation depends on its properties: frequency, intensity, amplitude

Device properties and geometry: Maximal nominal output power, cycle adjustment,

diameter of sonotrodes (probes)

Treated material properties: Viscosity, particle size and particle size distribution,

surface tension, texture and composition

Surrounding conditions: Temperature, moisture, pressure

With very high frequencies ( >1 MHz) it is difficult to achieve cavitation effect and above 2,5 MHz – IMPOSSIBLE

ULTRASOUND PROCESSING OF FOODS


PHENOMENON OF CAVITATION

STABLE CAVITATIONS

TRANSIENT CAVITATIONS - WATER “COLD BOILING”


PHENOMENON OF CAVITATION TRANSIENT CAVITATIONS - “BOILING” (WITH IMPLOSION –

delivering of bubble energy within surrounding microenvironment )



Frequency vs. Intensity


Cavitational paradox LESS FREQUENCY WITHIN ULTRASONIC RANGE – MORE AGRESSIVE EFFECT


Hi intensity ultrasound (HIU) Applications in Food Technology:

EMULSIFYING

DRYING

EXTRACTION

HOMOGENIZATION

CRYSTALLIZATION

SPRAYING/COATING

FREEZING

CLEANING

INACTIVATION OF MICRORGANISMS

ENZYME ACTIVATION AND INHIBITION

DEFOAMING – AIR BORN

DEBLINDING – AIR BORN

CUTTING – AIR BORN



RESULTS – 3 DOCTORAL THESIS DEFENDED

SVEN KARLOVIĆ – US ASSISTED DRYING

TOMISLAV BOSILJKOV – US ASSISTED HOMOGENIZATION

MAJA DENT – US ASSISTED EXTRACTION

ULTRASOUND PROCESSING OF FOODS: Drying, homogenization and extraction in foods assisted by

ultrasound


ULTRASONICALLY AIDED DRYING

Food drying is one of the oldest, very simple, and very meaningful ways of preserving foods


• Microvawe dryer • Tunnel dryer (hand made)

• Experimental research – Doctoral thesis SVEN KARLOVIĆ - defended

• Apple slices – 3 x 2 x 0.5 cm respectively


• Hypotesis • Improved mass transfer • Enhanced textural properties • Shortening of drying procedure • Decreased costs • Lower energy consumption


ULTRASONICALLY AIDED DRYING Ultrasonic propagation could cause numerous series of alternative compressions and expansions, like pressing and releasing of a sponge (sponge effect).

The mechanical forces created are higher than surface tension which withold the moisture inside the capillaries of the fruit creating microscopic channels which may ease moisture removal.


• Environmental aspects

• Clean technology • No moving parts • Shortening drying time • 40% of saved energy • Improved food Quality • Low noise • No waste material • No waste water



Apple sample before and after ultrasonic treatment



• Texture results

Elasticity

Work

Hardness



• Conclusions – SO FAR!!! • Ultrasonic pre-treatment of apple pieces before drying enables shorter time of drying • Increase of ultrasonic intensity additionally lead to more time shortening of drying • Removal of higher amounts of water from ultrasonically treated samples is enabled for the shorter duration of drying • Amplitude of 50% indicates as adequate with achieved results for ultrasonic pre-treatment of apple pieces – HARDNESS + • Under maximum of ultrasonic amplitude treatment and after drying of such pre-treated samples to large hardness of the samples occurred whereby those parameters of pre-treatment were not suitable • Improved elasticity – ELASTICITY - • More time for chewing – WORK +



ULTRASONICALLY AIDED HOMOGENISATION


Milk homogenisation

• Hypothesis

• Size reduce of fat globules • Improvesd homogenisation • Improved stability • Prolonged shelf life • Energy savings

• Material

• Cow, goat and soy milk • PhD thesis – Tomislav Bosiljkov (Cow milk)




METHOD 1

A – 30, 60, 90

t (5; 7.5; 10)

Cycle – 1

d – 10 mm

V – 400 mL

Im.depth – 3 cm

METHOD 2 A – 30, 60, 90 t (5; 7.5; 10) Cycle – 1 d – 7 mm V – 400 mL Im.depth – 3

cm


Descriptive

statistics

Mode Median Mean value

Variance Maximum

1.7 2.35 2.80 2.11 8.9


Inhomogenised milk


A = 90 %; t = 10 min; d (probe) = 7 mm A = 90 %; t = 10 min; d (probe) = 10 mm




A = 90 %; t = 10 min; d (probe) = 7 mm A = 90 %; t = 10 min; d (probe) = 10 mm






• CONCLUSIONS – Results were analyzed and compared

– The best results were obtained with treatment time of 10 min for both US devices

– Sonotrode diameter had significant influence due to dispersion of cavitaional “cloud” i.e. – intesities

– Decreased time of treatment with increase of US amplitude – increased intensities

– Less energy consumption compared with conventional homog.

– No moving parts – cheaper amortization

– More uniform particle size distribution of fat globules – prolonged shelf life

– Milk, Ketchup, Dressing, Juices, Sauces, Mayonaise

Milk homogenisation



ULTRASOUND ASSISTED EXTRACTION OF BIOACTIVE COMPOUNDS

Mechanical effect of US:

• Disruption of cell walls of the plant • Enable easier release of cell compounds • Better solvent admission to cell compounds • Improved mass transfer • Energy savings

• Material

• Sage • PhD thesis – Maja Dent


• PROCESS OPTIMIZATION

• Ultrasound

– Frequency

– Acoustic power

– Cycle

– Amplitude

• EXTRACTION

– Treatment time

– Temperature

– SOLVENT

– Particle size

– pH

• SOLVENT

– Selelective for targeted compounds

– Severe extraction capacity

– not be reactive with other plant compounds

– Inoffensive for the people and equipment

– Completely volatile

– Economical (low price)





Total phenols - SAGE

Conventional extraction - 60°C

Extraction time 30 min

Solvent 30% Ethanol 30% Acethone Water

TP (mg GAE/ g

dry sage)

62.78 54.96 51.7



Total phenols – Sage

ULTRASONIC EXTRACTION A-100% C-1

SOLVENT 30% Ethanol

Sonotrode 7 mm 22 mm

Extraction time

(min)

8 10 11 12 8 10 11 12

TP (mg GAE/ g

dry sage)

63.56 66.23 74.84 75.87 78.30 79.93 91.09 75.22



ULTRASONIC EXTRACTION A-100% C-1

SONOTRODE 22 mm

EXTRACTION T.

(min)

11

SOLVENT 30% ETHANOL 30% ACETHONE WATER

TP (mg GAE/ g dry

sage)

91.09 69.95 57.54

Conventional extraction - 60°C

Extraction time 30 min

Solvent 30% Ethanol 30% Acethone Water

TP (mg GAE/ g

dry sage)

62.78 54.96 51.7



Advantages of ultrasonic extraction v.s. classic extraction: INCREASED YIELD Enhanced extraction rate Extraction conducted under lower temperatures - enhance

extraction of heat sensitive components. Enhancement of extraction processes where solvents

cannot be used (juice concentrate processing) Potential opportunity for aqueous extraction or use of

alternative solvents by improving their performance Less creation and release of heat Ecologically more acceptable method – sustainable food

innovation Commercially viable and scaleable



Comparision and advantages over traditional food

processing

-

Shorter processing of foods - Low increase of temperature - Energy savings - Improved food quality - Decresed amount of emulsifiers - Increased yield - Improved texture and structure - Ecologically more acceptable method sustainable food innovation - No toxic waste

ULTRASOUND PROCESSING OF FOODS: Drying, homogenization and extraction in foods assisted by

ultrasound


DEFOAMING

ultrasound technology for use in the food and beverage industry

the foam issues present in the majority of beverage filling lines

easy to install, safe and cost-effective method of removing foam

by removing the need for chilling or slower line speeds there are productivity improvements

for carbonated soft drinks , non-carbonated juices, teas, dairy drinks, sparkling wine, carbonated alcoholic pre-mixes or beer

the solution can be applied all sizes of can, bottle and pouch containers on aseptic or hot fill lines.

it is not expensive to operate and it doesn’t affect the quality or taste of the product


SPRAY DRYING OF PROTEINS- reduction of viscosity

Ultrasound technology can modify the fluid dynamics of the protein concentrate stream feeding the spray dryer, allowing for higher concentration and percentage dry solids into the dryer.

It uses efficient, high-energy sound waves to deliver one or more of the following mechanisms:

Remove entrained air and oxygen bubbles Open up the compaction layers of the proteins Temporarily reduce viscosity Create a temporary change in the protein molecule alignment What are the benefits? In addition to reducing energy consumption, the ultrasound technology: increases output by 10% reduces overall fixed and variable cost reduces filling losses and waste treatment costs reduces chilling requirements reduces capital costs and increases profits provides payback in under one year


THE ULTRASOUNDS CLEANING PROCESS

designed specifically for each application to optimize performance and total cleanness.

different temperature, frequency and chemical combinations are used. Determination of the best process parameters for each problem (dirt, grease or coal dust adhered to the surface of the object)

Temperature: Temperature increases (80-90ºC) in liquids augment steam pressure

and facilitate the presence of bubbles (Cavitation). This results in increased cleaning power.

Frequency: It determines the size of the bubbles generated during Cavitation. High dirt levels require lower frequency levels, with higher power. High frequency levels are used for finishing operations or to clean delicate components (Optics).

Chemicals: Each application requires a certain chemical and concentration level based on factors such a working temperature, type of dirt, cleaning time and material.

Ultrasound waves optimize the effects of the cleaning agents, thus reducing the level of chemicals needed.

A suitable combination of the above named parameters significantly reduces cleaning time, which is the fourth parameter of the Ultrasounds Cleaning Process.


Ultrasounds cleaning systems are based on high-frequency sound waves transmitted through a cleaning liquid. The component to be cleaned is submerged into the cleaning liquid. The treatment lasts between 10 and 45 minutes and does not require the presence of any laborer.

The result is a micro-brushing effect on the objects. Since the air bubbles are smaller than 1µm, they get into any openings, regardless of their size. Therefore, ultrasound cleaning is the most suitable cleaning system for highly complex components of any material (alloys, steel, alluminium, copper, bronze, titanium, certain plastic types etc


SCALE UP SEMI

INDUSTRY (SMES)

INDUSTRIAL

LAB SCALE RESEARCH

LABORATORY FOR UNIT OPERATIONS R & D CENTRE FOR ULTRASOUND APPLICATIONS IN FOOD TECHNOLOGY &

BIOTECHNOLOGY




ACKNOWLEDGMENT

Dr. Nada Knežević

Dr. Davorka Gajari

Society of Chemists and Technologists of Koprivnica

Podravka Food Company

THANK YOU FOR YOUR ATTENTION



Mladen Brnčić Faculty of Food Technology and Biotechnology

Zagreb Croatia

[email protected]

mailto:[email protected]

Documents

IMPACT OF ULTRASOUND ON PROCESS EFFICIENCY IN FOOD INDUSTRY · IMPACT OF ULTRASOUND ON PROCESS EFFICIENCY IN FOOD INDUSTRY Mladen Brnčić Faculty of Food Technology and Biotechnology