WO2019240708A1

WO2019240708A1 - Method for processing liquid eggs by an ultrasound technique

Info

Publication number: WO2019240708A1
Application number: PCT/TR2019/050081
Authority: WO
Inventors: Muhammed YUCEER; Cengiz CANER; Riza TEMIZKAN
Original assignee: Canakkale Onsekiz Mart Universitesi Rektorlugu
Priority date: 2018-06-12
Filing date: 2019-02-09
Publication date: 2019-12-19
Also published as: TR201808369A2

Abstract

The invention is related to processing the liquid egg by ultrasound (sonication) technique. By said method, the foaming capacity of the liquid egg is increased and the shelf-life is prolonged.

Description

METHOD FOR PROCESSING LIQUID EGGS BY AN ULTRASOUND

TECHNIQUE

Technical Field The invention is related to a method developed for modifying a liquid egg by using an ultrasound technique.

Background of the Invention

Eggs, which are one of the fundamental foods of animal origin, have an important place in human health and the national economy. Eggs, which are important nutrients in terms of human nourishment and national economy, is a high nutrition food that can be easily accessible by the consumer and it can be easily prepared in various alternatives and consumed. The importance of the egg is because it contains almost all nutrients at a rich level.

Today, pasteurization technique is the only method that is used in preservation of the liquid eggs and there are studies for developing alternatives. Development and application of alternative methods gained speed due to the negative effects of the pasteurization on the functional properties, nutritional composition, aroma and structure of the liquid egg. The pasteurized liquid egg provides time savings in all applications where shelled eggs are used and no difference is observed in terms of taste and flavor. Liquid whole egg is used especially in bakery products, confectionery and ice cream industry production. The liquid egg also contributes to the functional properties of the food such as foaming, coagulation or emulsion in addition to the nutritional values.

Fecal coliform microorganisms having pathogen properties such as Salmonella and Escherichia coli which create a significant problem during processing of the liquid egg products must be completely removed from the system. Thus, it is essential to pasteurize/disinfect the egg products by any thermal or non-thermal method. For a suitable process design, functional and rheological properties must be measured and defined.

As the alternative to the traditionally used thermal pasteurization process, the alternative technologies that can be applied to extend the shelf-life of the liquid egg in refrigerator are ultra-pasteurization, aseptic packaging, ultrasound waves, UV, high impulse electrical field, high hydrostatic pressure and use of antimicrobial agents such as nisin. Besides, most of the studies mentioned above focus on the microbiologic point and the effects of these studies on the change of physico-chemical properties of the liquid egg have not been extensively investigated.

The non-traditional preservation techniques are developed to meet the environmental safety such as additives, low energy demand and consumer demands in terms of nutrition and sensory. In addition, in order to meet the consumer demand for fresh, more natural and healthier products, the interest to non-thermal preservation techniques is increased wherein the microorganisms and the enzymes are not inactivated.

In the food processing plants that use fresh eggs, the time spent for breaking the eggs, the waste from the shells of the eggs and the large space required to spare for storing the shelled egg create significant problems for the business. What is aimed in pasteurization of the egg is to kill the Salmonella. Depending on the pH difference and chemical composition in the egg white, whole egg and the egg yolk, the thermal resistance of the Salmonella differs. During pasteurization, by adjusting the pH in the egg white or the yolk, lower temperatures can be used. United States Department of Agriculture (USDA) requires that the pasteurization of the liquid egg must be performed in a critical temperature -time condition where egg protein coagulation can’t occur. For the egg white and the whole egg, minimum temperature and exposure times are 55.6 °C and 6.2 minutes and 60 °C and 3.5 minutes. Values below pH 7 damages the functional properties of the egg white while reducing the thermal resistance of the Salmonella. When the egg white is heat- treated, the first significant change is observed in the foaming ability. In egg white mixed with yolk, the foaming property changes with temperature. Moreover, the conalbumin present in the egg is the most heat-sensitive protein and loses its bioactive properties at 63 °C

Today, in order to prolong the shelf life and to protect the quality of the egg and its products, pasteurization is used. However, since heat-treatment damages the functional properties, nutritional composition, aroma and the structure of the egg, the studies towards developing and implementing methods that may be alternative to said method. Even though the thermal pasteurization represents the most up-to-date and best understood technique, it may affect the coagulation, foaming and emulsifying properties of the egg products. In order to improve these properties, the properties and shelf-life of the liquid egg products are investigated with various pasteurization techniques, ultrasonic wave treatment, high electrical field impulses, high hydrostatic pressure or aseptic packaging including ultra-pasteurization. Most of these techniques are thermal methods and they may bring significant changes on the structure of the liquid egg products, especially on the coagulation of the proteins and denaturation.

Use of novel methods for improving the quality and safety of the food products is among the current topics and it is intensely researched and finds application areas. There is a need for novel, simple and inexpensive method to enable improvement of the quality of the egg and its products and to enable preservation of its freshness for a longer period of time. In response to these restrictions, ultrasound may be an alternative non-thermal method to obtain suitable reductions in pathogen populations for prolonging the shelf-life of these products. Production of the products such as egg and its products, where we have a say in the world production, presented for industrial consumption by using advanced technologies, increasing the variety and exporting potential of the tradable products and thus contributing to the regional and national economy are among the general objects of the project. The specific object of the invention is designed on improving the functional properties of the egg by using ultrasound technique. Detection of changes in the physical, chemical and functional quality of the egg depending on the application of ultrasound with different parameters is industrially essential for both preventing the economic loss while preserving the egg and for protecting the functional qualities.

Ultrasound is one of the non-thermal alternative processing techniques and means use of high energy ultrasound waves. Ultrasound may inactivate some enzymes and microorganisms quicker than the thermal applications. The advantages of the ultrasound application are minimizing the loss of aroma, high homogeneity and cavitation effect. Ultrasound has a mechanical quality and it has a sound that can be heard at very high frequency (18 kHz-500 MHz). While effects such as creation of vacuum spaces (cavitations) inside the cell, thinning of the cell wall, point temperature rises, micro vaporization and shock waves do not cause nutrition loss and negative sensory changes that occur in the traditional thermal applications, it enables inactivation of the microorganisms at lower temperatures and in shorter times.

The amplitude and application time of the used ultrasonic wave, the volume where the application is done, the composition of the food and the temperature impact the effectiveness of the ultrasound applications. If an ultrasound wave is directed to any material perpendicularly, the particles vibrate at the same direction with the force (pressure wave), if directed parallel then the particles are created perpendicular to the force (shear). The ultrasound frequency is an important parameter and determines the maximum bubble dimension. The size of the bubbles created at lower frequencies (for example 20 kHz) is large and they produce high energy when collapsed.^{2, 3}

Ultrasound waves have the property of propagation in solid, liquid and gas environments by compression and expansion and they have the property of creating cavitation. The ultrasound application used in the food industry is evaluated as low energy density (<l W/cm²; >100 kHz) and high energy density (10-1000 W/cm²; 20-100 kHz). Low density ultrasound applications are predominantly used in the non-destructive testing of the foods and classification systems used for specification of the egg quality are an example. High density ultrasound applications are utilized in the food industry for processing procedures. Extraction operations through enzyme or microbial inactivation are among these applications. Ultrasound application can be used by combining with many applications. Combination with heat is called thermoultrasonication, combination with pressure is called mano sonic ation or combination of heat and pressure with ultrasound is called monothermo sonic ation.^{2 2 5}

Inhibition effect of ultrasound application on the bacteria is explained by the cavitation mechanism. Cavitation is the implosion of the gas bubbles created after the micro bubbles in a liquid system grow to a significant size and reach a specific threshold value. The instantaneous temperature formed in this incident is approximately 5000 K and the pressure is reported as 500 MPa.

Ultrasound application has an inactivation effect against bacteria, mold and yeast, virus and bacterial spores. While the bacterial spores and the viruses are resistant to ultrasound, it was stated that gram positive bacteria are more sensitive than the gram-negative bacteria.^{6 8} Ultrasound application can be effectively used in inactivation of the microorganisms. When compared to pasteurization, the ultrasound has the advantages such as reducing loss of flavor, obtaining a more homogenous product and providing a substantial energy saving.^{6, 7}

In the Chinese patent document NO.CN106616513A of the known state of the art, the preparation method of an egg white with high foaming property is mentioned. The preparation method of an egg white with high foaming property comprises the steps of receiving the egg white as the raw material, adjusting the pH value to 6.5-8, performing ultrasound and microwave combined procedure on the egg white liquid and combining the processed egg white with the phosphorylated polysaccharide solution.⁹

In the United States patent document No.US20082064l0Al of the known state of the art, homogenous liquid egg products that can be prepared by subjecting all of the liquid egg material to a sufficient ultrasonic energy are mentioned. Also, methods for processing the liquid egg material with ultrasonic energy to prepare homogenized liquid egg products are described.¹⁰

In the United States patent document No.US6805244Bl of the known state of the art, a method developed for determination of quality related to ovulation, fertility or incubation vitality in bird’s eggs is mentioned. Ultrasound examination results are analyzed to obtain a finding related to the quality of the egg shell and this can be related to quality factors such as fertility, incubation or nestling viability.^

The number of applications performed by novel techniques on production of the commercial products and the number of the products on the market shelves increase every day. In production of the egg products, today commercial applications on alternative processing techniques and R&D studies gained a different dimension in the last 3-5 years and preserving the shelf life by protecting the functional properties of the product without using any preservative additives was adopted as a principle. For example, while the shelf life of the whole liquid eggs that can be produced by pasteurization technique reaches at most 2-3 months, storage times of 4-5 months was obtained by alternative techniques. A database valuable for the industry was created by performing physical and chemical analysis of the liquid eggs processed with ultrasound in the scope of this study. When all these studies are considered, there is a need for increasing the functional property and shelf life of the liquid egg. Objects of the Invention

The object of this invention is to embody a method that increases the shelf life and the functional properties of the liquid egg.

Another object of this invention is to embody a method that comprises modifying the liquid egg by ultrasound technique.

Another object of this invention is to embody a method that increases the shelf life and foaming capacity of the liquid egg.

Detailed Description of the Invention

The invention is the method of modifying / processing the liquid egg in accordance with the technique and comprises the steps of, preparing the liquid egg,

application ultrasound technique to the prepared liquid egg, breaking the egg,

filtration of the obtained liquid egg (filtered and cooled between 0 and +4C),

subjecting the liquid egg to sonication by applying ultrasound at 150-375 W power and for 3-6 minutes.

First, the pasteurized liquid whole egg that is used as the raw material in the invention is procured from a local scale liquid egg producer in 20 kg packages and reached the department lab in cold chain (2-4 °C).

Ultrasound at desired power will be obtained by immersing the metallic probe of the ultrasound generator that is used to create acoustic cavitation into 1000 ml of water. Only a certain fraction of the ultrasound power generated by the device can be transferred to water. In order to detect the power transferred to the water, generally calorimetric methods are used, however the ultrasonic device that is used in the study has the property of instantly measuring the power passed to the liquid medium.

Liquid egg will be waited in a specially designed cabinet at 150 W and 375 W ultrasound power and for a certain time (3 and 6 minutes) and then will be conveyed to the protection environment.

In the developed method, pH measurements of the ultrasound -processed and not- processed liquid eggs were determined at 20 °C by using pH meter. Analyses were performed by using potentiometric pH meter by immersing pH probe to the liquid egg stirred for 1,5 minutes in a mixer. ^{7 12}· ¹³ In the ultrasound-processed and non-processed liquid egg, the measurements were first made with pure water to make zero calibration and then with refractometer at a sample temperature of 20±l °C and dry matter (Brix) was measured.¹⁴

In the ultrasound-processed and non-processed liquid egg, the measurements were performed by a calorimeter to measure L^*, a^*, b^* values.¹⁵ After the temperature of the enzyme -processed and non-processed 100 ml liquid egg was adjusted to 20±2 °C, the foam formed by 2 minutes of stirring in a mixer was taken into a 1000 ml measuring cylinder and the volume was recorded and then the calculations were performed. ¹⁴

Right after the volume of the formed foam was recorded, the measuring cylinder was turned upside down, rested in room temperature for one hour and the drainage was accumulated in a beaker. The drainage accumulated after one hour was placed into a 100 ml measuring cylinder and the volume was recorded (the stability of the foam was calculated by assessing the drainage created by resting the foam in room temperature for 60 minutes). ¹⁶

The method used to calculate the foam capacity (%) is given below 17 18

(foam volume)

Foam capacity (%) = 100 X (volume of initial liquid phase) Here, the foam volume represents the final volume of the foam formed after stirring and the volume of first liquid phase represents the volume of egg white before stirring in milliliter.¹²· ¹⁹

The foam stability is stated as percentage. The foam stability was calculated by observing the drainage which is the amount of liquid drained from the lamella of the foam structure.²⁰

The formula given below is used to define the foam stability of the whipped egg whited ⁷- ¹⁸

(volume of initial liquid phase)-(volume of drainage formed after 60 mins)

Foam stability (%) = 100 x

volume of initial liquid phase In this equation, the initial liquid phase is the volume of the egg before whipping in milliliters, the volume of the drainage is the volume of the drainage in milliliters accumulated after one hour in room temperature.²^

After liquid egg samples are placed into water activity containers, measurements were performed in water activity device.²² 100 ml liquid egg sample was stored in refrigerator in packages. By using gas analyzer in the air pocket of the package, shelf-life assessment was made through change of gas composition (%C0₂and %0₂). Gas content measurements were performed on the liquid egg white (LEW) stored in the refrigerator.

Rheologic measurements were performed by a rheometer with 40 mm stainless steel plate/plate geometry measurement sensor at 1 mm interval. For each test, approximately 1,32 ml of liquid egg sample was placed on the rheometer plate. Amplitude scan test was performed by the help of a linear analysis software program before dynamic test (frequency scan) to detect the suitable stress value that resides in the linear region, to determine the linear region where the stress/strain ratio (modulus) stays constant (LVER) and the sinusoidal curves of the oscillation data in verification of the each data point’s linear viscoelastic distribution. Flow ramp scan test was performed at 25± 0,01 °C for 150 seconds starting from the low flow rate (0,01 l/s) to high flow rate (100 l/s). To use in the following analysis, in order to find the most suitable strain % value, deformation scan (oscillation amplitude) test was performed. Angular frequency was defined as 20 rad/s and the temperature was defined as 25 °C as the test parameters and the analysis was performed with strain % values varying from 0,01% to 100%.

The most suitable strain % in the linear region obtained at the end of this test was used in the following analysis and this procedure was repeated for each sample. Frequency scan (oscillation frequency) test was performed at 25 °C between a frequency of 0,01 and 10 Hz by using the most suitable strain % value found at the end of the previous analysis. ²³· ²⁴

Evaluation criteria and the obtained results are explained below. pH Results: pH value of the egg is an important indicator of the freshness and quality of the egg. The initial pH value (7,37±0,04) observed in the study increased with increasing ultrasound W power and the pH value of the eggs decreased during storage between the ultrasound-processed and non-processed liquid whole egg samples. Figure 1 shows the change in the pH value of the ultrasound-processed liquid whole egg. In accordance with this, it was determined that the increase was statistically different from the control group between 375 W (3 and 6 minutes of application) value and 150 W (3 and 6 minutes of application) ultrasound power applications, however similar in terms of application. In a study performed on egg white, ultrasound was reported as not causing oxidation on egg white -SH and disulfide groups and it was stated that there is no significant change at 65 °C and 81 °C which are the thermal transients. ¹ Moreover, in the study where the ultrasound was applied to egg albumin at 20 kHz and at 20% amplitude, it was stated that -SH content was not affected and surface hydrophobicity had increased.²⁵ Figure 1 shows the change in pH values of the ultrasound-processed liquid whole eggs during storage.

Water Soluble Dry Matter Results: The content of the solids in the whole egg varies with the ratio of white to yolk and with the chemical composition of the egg yolk and white. In the homogenized product, the contents may be required to be adjusted to produce the components characterized by certain total solid content values. The ratio of the white to yolk is related to the egg dimension which increases with the age of the chicken and the total solid content of the egg white and yolk may be affected by the breed of the chicken.^ The principle functional property of the egg white is its high foaming capacity. Besides, it is important to decrease the leakage and contamination of the egg yolk lipids to the egg white for the most suitable foaming capacity. Disintegration of the lipid and preserving the whole foaming capacity of the egg white are important. The water in the albumin may penetrate into the egg yolk. Weak and watery albumin causes changes in the water concentration of the egg yolk, the water-soluble dry matter (DMA) value increases during long storage times since the yolk of the albumin is mixed. Figure 2 shows the change in the dry matter values of the ultrasound -processed liquid whole egg.

In general, liquidation during storage causes the liquidity of the egg white to increase and damages the quality of the egg. However, rather than the whole egg, in the mixture egg that contains the mixture of yolk and white, the change in the dry matter does not directly indicate the quality parameter since it is independent between applications and it differs from the whole yolk and white situation.

Figure 2 shows the change in the dry matter values of the ultrasound-processed liquid whole egg.

Color Results of the Liquid Egg White: The visual impression of the egg color defines the acceptability of the egg and the egg containing products. Color L* Value: The change in the L* color values of the ultrasound-processed liquid whole egg is given in Figure 3. According to the obtained results, the transparency (being opaque) of the liquid egg changed by 375 W - 6 mins ultrasound application and the measurements of the L* brightness value following application was detected statistically significant.

When ultrasound-processed samples were compared to the control, while L* value stays in the 65 band, L* value increased during storage. After 5 weeks of storage, a general increase was detected in the brightness (L* value). L* values stayed between 66,61-66,86, however no statistically significant difference was achieved (P>0,05).

None of these differences were big enough to be practically meaningful. Despite the fact that these values are statistically significant, the effect of these values on the consumer will be minimal. Maillard reaction occurs as a result of the reaction of a small quantity of glucose with the amino acids in the egg white. The heat application and long-term storage may be problematic for egg white. When the aldehyde group of the glucose reacts with the amino group from the protein, it causes a Maillard type reaction and may hydrolyze free or linked polysaccharides and thus it becomes possible to form a simpler and more reactive aldose.

Similarly, in a study performed with egg white, Wang, et al. ²⁶ stated that the brightness value of the egg decreases with ultrasound application and this situation may be related to surface/wall effect of the riboflavin molecules on the protein macromolecules and by the effect of the ultrasound on the increase of protein surface hydrophobicity and the decrease on the sulfhydryl groups. Thus, it was stated that the ultrasound increased the solubility of the egg proteins.²⁷ The literature states that the brightness of the egg decreases with ultrasound application.²⁸

The change in other ultrasound applications were found to be similar.²⁹ Figure 3 shows the change in the L* color value of the ultrasound-processed liquid whole eggs.

Color a* Value: The change in the a* color value of the ultrasound-processed liquid whole eggs is shown in Figure 4. According to Hutchings ³⁰, a* and b* measurement coordinates are the values most sensitive to the structural changes in the food matrix. In many foods subjected to thermal treatment, the proteins may denaturate and thus semi-transparency and/or opacity may develop.²·⁵- ³¹

Thermal coagulation of the egg proteins explains the main color changes occurring in the processed liquid egg samples. According to the obtained results, a* color value changed by processing the liquid egg with ultrasound and the color parameter decreased during storage time in all application groups and in the control sample.

Figure 4 shows the change in the a* color value of the ultrasound-processed liquid whole eggs. In the study, red/green (a* values) showed a statistically significant difference (P>0,05) by decreasing from 5,8-5, 1 interval to 1,88-1,90.

Yellow/blue (b* values) between 35,83-35,06 and showed a significant difference after storage 34,67-24,45 (P>0,05).

Color b* Value: The change in the b* color value of the ultrasound-processed liquid whole eggs is shown in Figure 5. According to the obtained results, b* color values decreased by processing the liquid egg with ultrasound.

Figure 5 shows the change in the b* color value of the ultrasound-processed liquid whole eggs.

Water Activity (a_w) Results: water activity plays a critical role in the microbial growth. Microbial life and growth depend on various factors such as pH and oxygen. Most bacterial development is hindered below a_w 0,85. The a_w value of the egg is approximately 0,96 and this provides an ideal environment for microbial growth.

In the study of the invention, the a_w value of the control is 0,956 and the a_w value of the ultrasound application is 0,953, thus no significant difference was formed. This may be assessed as the indication of change in the egg water loss due to the over-heating of the ultrasound system used in the said study. Accordingly, a partial reduction in the water activity values was recorded with increasing ultrasound application intensity and treatment time. Thus, with increasing ultrasound application intensity and treatment time, a reduction in the water activity values was recorded during storage. In this study, the a_w value of the control is 0,915 and the a_w value of the ultrasound application is between 0,933 and 0,937 and there is a significant difference. The results of the experiment is in compliance with the literature studies.²⁹ Liquid Egg White Foaming Capacity Results: The foam is the colloidal systems where the small air bubbles are dispersed in the aqueous and continuous phase.²²

When the whole egg is whipped, the air bubble is trapped in the albumin and the foam is formed. The egg white has excellent foaming properties. These properties are defined by rapid adsorbability on the air-liquid interface during whipping or foaming and by the ability of forming a cohesive viscoelastic film through inter- molecular interactions.²²

The amphibious molecules are required to form and stabilize the air bubbles in the liquid phase. These molecules can be used as several protein-active foaming agents and stabilizers. Egg white proteins are mostly globular proteins and it is expected that increasing surface hydrophobicity and flexibility by partial unfolding of the proteins to make them better surfactants (e.g. foam forming materials) and to improve their foaming properties. Structural modification of the egg albumin proteins can be obtained by partial unfolding of the proteins. The protein molecules behave like hydrophilic and hydrophobic groups. Hydrophilic groups are regulated towards water phase and the hydrophobic groups are regulated towards air phase. During bloating, it comes to the solution to create air bubbles, the hydrophobic regions facilitate the adsorption on the interface and partial unfolding (surface denaturation) follows in a while.

This change in the molecular configuration causes the resolution or precipitation of some proteins accumulated on the liquid-air interface. The continuous reduction in the surface tension facilitates formation of new interfaces and more bubbles and this enables combining around the partially unfolded molecules and then around the bubbles required for the stability of the foam to create a stabilizing film. ²¹

Molecular flexibility plays a role in the protein foaming ability that is related to reducing the interface tension. Changing the pH value of a protein medium leads to unfolding of the proteins. The egg acidity that is represented as pH value has a strong impact on the volume, capacity and stability of the egg foam. The foam is defined as a colloidal dispersion where the gaseous phase is dispersed in the liquid or solid phase. The egg white with different foaming properties can be used for different food applications and the used unfolding and re-folding can be adjusted by controlling the pH value. It is observed that the foaming stability of the whole liquid egg changes between 470-500 and it is affected by the applied ultrasound and the application time as can be seen in Figure 6.

The relative foam capacity values in the control and the ultrasound-processed liquid egg samples are given in Figure 6. Accordingly, with increasing ultrasound application intensity and treatment time, an increase was recorded at 150 W and a partial reduction was recorded at 375 W in the relative foaming capacity values. 150 W ultrasound application was found to increase the foaming capacity in a positive manner. When increased to 375 W, the foaming capacity was observed to decrease depending basically on the physical denaturation of the proteins. (Figure

6)

It was observed that 150 W ultrasound and application time caused a significant increase in the foaming power. Molecular flexibility plays a role in the protein foaming ability that is related to reducing the interface tension. Since high ultrasound (375 W) causes decomposition of the random spiral type proteins that decrease the interface tension of the sequential structure of the protein molecules, it also causes a reduction in the foaming capacity. When applied at different dosage and durations, ultrasound can cause agglomeration and disintegration and this can affect the foam capacity.

According to the results of the study, the change in the relative foaming capacity values of the ultrasound-processed liquid whole egg is given and it was recorded that relative foam forming values increased with increasing ultrasound day and duration, this situation shows the effectiveness of the ultrasound on preserving and improving the functional properties of the liquid whole egg.

Liquid Egg White Foam Stability Results: Foaming stability significantly increased depending on the time and applied power depending on the conformational changes of the egg white protein that increases its surface hydrophobicity.

Foam stability is related to the surface viscosity. Thus, it was observed that the aggregates formed on the air-water interface create a surface gel network and this may be responsible from the stability of the ultrasound -processed egg white. Egg white (basically a protein colloid solution) can expand up to 6 or 8 times of its volume and can form stable foams when in whipped state. Egg foam can be included into various foods and used in many recipes ⁴ In Figure 8, it is seen that the foaming stability of the whole liquid egg changes between 90-93. It is seen that it is affected by the applied ultrasound and the application time. Relative foam stability values of the control and the ultrasound- processed liquid egg samples are given in Figure 7. Accordingly, it was observed that it caused a partial reduction in the relative foaming capacity values with the ultrasound application intensity and the application time. When the protein solution is over-whipped, it causes a smaller bubble concentration that causes a less stable foam. This instability is caused by the over-dissolving of the proteins in the air- albumin interface depending on the reduction in the whipping elasticity ⁵ Figure 7 shows the changes in the foaming stability values of the ultrasound- processed liquid whole egg.

In-Package Gas Concentration: In the study of the invention, the changes in the 0₂ values of the ultrasound-processed liquid whole egg is given in Figure 8 and the in-package 0₂ level decreased statistically significant with increasing storage time. However, this reduction is found to be similar in the application and control group especially at the end of the storage. (p>0,05)

Figure 8 shows the changes in the 0₂ values of the ultrasound-processed liquid whole egg.

In said study, the change in the C0₂ values of the ultrasound -processed liquid whole eggs is given in Figure 10 and the C0₂ level in the packaging increased statistically significant with increasing storage time. The difference in said increase between the application and control groups was found to be significant during and at the end of the storage. (p<0,05)

When considered that C0₂ values decrease with increasing ultrasound power and time and the relation between storage and shelf-life is taken into consideration, it was observed that the shelf-life of the egg increased with increasing ultrasound W and treatment time. This situation was also verified by the change in the pH values. Figure 9 shows the change in the C0₂ values of the ultrasound-processed liquid whole eggs.

Rheologic Behavior of the Liquid Whole Egg: The viscoelastic properties of the liquid whole egg were identified by performing dynamic sweeping test in the linear viscoelastic region. In this context, the elastic and viscous modulus was observed to change with frequency.

The graphics that define the viscoelastic properties of the ultrasound-processed and non-processed liquid whole eggs were shown in the related figures.

Figure 10 shows the change of viscosity values of the ultrasound-processed / non- processed liquid whole egg samples with shear velocity.

Figure 11 shows the change of viscoelastic behaviors of the ultrasound-processed / non-processed liquid whole egg samples.

Figure 12 shows the change of viscoelastic behaviors of the ultrasound-processed / non-processed liquid whole egg samples with frequency. It was observed that shear velocity and viscosity change (fluidity curve) is proportional and viscosity has increased with increasing ultrasound power and times in accordance with the Newton laws (Figure 10).

In said study, it was identified that elastic modulus (G’) has increased and viscous modulus (G”) has decreased with increasing frequency. In all non-ultrasound- processed liquid whole egg samples, (G’) was determined to be higher than (G”). Specifically, liquid egg samples that show viscoelastic behavior was observed to exhibit a liquid -like structure. (Figure 11)

The change of viscoelastic behaviors of the ultrasound -processed (non-processed liquid whole egg samples with frequency was given. It was identified that G” and G’ intersects on a certain frequency and the system exhibits a solid-like behavior characteristic at this frequency value (G’ > G”). Moreover, it was observed that the liquid whole egg samples treated with 150 W - 3 minutes and 375 W - 3 minutes significantly changed G” and G” values when compared to other samples. When the samples are examined, a liquid-like (G” > G’) character was identified at low angular frequency values and an elastic/solid-like (G’ > G”) structural behavior was identified with increasing frequency values. (Figure 12)

As a result, in the study in which the effects of the application conditions (Watt power and application time) on the functional and physicochemical properties of the ultrasound-processed liquid egg was investigated; it was determined that 150 W ultrasound application is quite effective in increasing the foaming capacity and the quality criteria of the egg. Moreover, it was identified that relative foam forming values was increased with increasing ultrasound day and time, this situation shows the effectiveness of the ultrasound in preserving and improving the functional properties of the whole liquid egg. Within the context of the study, it was identified that elastic modulus (G’) increases and viscous modulus (G”) decreases with increasing frequency. In the non-ultrasound-processed liquid whole egg samples, it was identified that G” is higher than G”. Specifically, it was observed that the liquid whole egg samples exhibiting viscoelastic behavior showed a liquid-like structure and 150 W - 3 minutes and 375 W - 3 minutes processed liquid whole egg samples significantly changed the G” and G” values when compared to other samples. When the samples were examined, a liquid-like (G” > G’) character was identified at low angular frequency values and an elastic/solid-like (G’ > G”) structural behavior was identified at increasing frequency values.

In the scope of said study, the aimed success criterion of increasing the relative foam forming value of the egg was achieved and at the same time the importance of combined in-package gas concentration and pH parameters in establishing the shelf-life towards increasing the shelf-life of the egg was shown. REFERENCES

1. Arzeni, C.; Perez, O. E.; Pilosof, M. R., Aggregation and gelation properties of egg ehite proteins as affected by high intensity ultrasound. In 11th International Congress on Engineering and Food, Athens, Greece, 2011; s 1-6. 2. Chemat, F.; Huma, Z.; Khan, M. K., Applications of ultrasound in food technology: Processing, preservation and extraction. Ultrasonics Sonochem. 2011, 18, 813-35.

3. Dolatowski, Z.; Stadnik, J.; Stasiak, D., Applications of Ultrasound in Food Technology. Acta Sci. Pol. Technol. Aliment. 2007, 6, 89-99. 4. Aygun, A.; Sert, D., Effects of ultrasonic treatment on eggshell microbial activity, hatchability, tibia mineral content, and chick performance in Japanese quail (Coturnix coturnix japonica) eggs. Poult. Sci. 2012, 91, 732-8.

5. Baysal, T.; Demirdoven, A., Ultrasound in Food Technology. In Handbook on Applications of Ultrasound: Sonochemistry for Sustainability, Chen, D., Ed. CRC Press Inc.: USA, 2012.

6. Mason, T. J.; Paniwnyk, L.; Lorimer, J. P., The uses of ultrasound in food technology. Ultrasonics sonochemistry 1996, 3, 253-260.

7. Piyasena, P.; Mohareb, E.; McKellar, R. C., Inactivation of microbes using ultrasound: a review. Int. J. of Food Microbiol. 2003, 87, 207-216. 8. Adewuyi, Y. G., Sonochemistry-environmental science and engineering applications. Ind. Eng. Chem. Res. 2001, 40, 4681-4715.

9.4¾HiiK;

Preparation Method of Egg White Liquid with High Foaming Property. 2017.

10. Efstathiou, J. D.; Patist, A.; Prochnow, R. R. Liquid Egg Material. 2008. 11. Toelken, L. T. Ultrasound Quality Inspection of Avian Eggs. 2004.

12. Patrignani, F.; Vannini, L.; Sado Kamdem, S. L.; Hernando, L; Marco-Moles, R.; Guerzoni, M. E.; Lanciotti, R., High pressure homogenization vs heat treatment: Safety and functional properties of liquid whole egg. Food

microbiology 2013, 36, 63-69.

13. Ragni, L.; Berardinelli, A.; Cevoli, C.; Sirri, F., Admittance Measurements to Assess the Total Solids and Fat Contents in Fiquid Whole Egg Products. J. of Food Eng. 2011, 107, 179-185.

14. Caner, C.; Yuceer, M., Maintaining functional properties of shell eggs by ultrasound treatment. Journal of the science of food and agriculture 2015, 95,

2880-91.

15. Caner, C.; Yuceer, M., Efficacy of various protein-based coating on enhancing the shelf life of fresh eggs during storage. Poultry science 2015, 94, 1665-77.

16. Min, B. R.; Nam, K. C.; Lee, E. J.; Ko, G. Y.; Trampel, D. W.; Ahn, D. U., Effect of irradiating shell eggs on quality attributes and functional properties of yolk and white. Poultry science 2005, 84, 1791-1796.

17. Chang, Y. L; Chen, T. C.; Lee, G. h.; Chang, K. s., Rheological, surface and colorbvietric properties of egg albumen gel affected by pH. International Journal of Food Properties 1999, 2, 101-111. 18. Janssen, H. J. L., Methods of Determination of the Quality of Chicken Egg

White. Voedingsm Technology 1971, 2, 11-13.

19. Macherey, L. N.; Conforti, F. D.; Eigel III, W.; O’Keefe, S. F., Use of mucor miehei lipase to improve functional properties of yolk -contaminated egg whites. Journal of food science 2011, 76, C651-C655. 20. Kuropatwa, M.; Tolkach, A.; Kulozik, U., Impact of pH on the interactions between whey and egg white proteins as assessed by the foamability of their mixtures. Food Hydrocol. 2009, 23, 2174-2181.

21. Lomakina, K.; Mikova, K., A study of the factors affecting the foaming properties of egg white - a review. Czech J. of Food Sci. 2006, 24, 110-118.

22. Cervenka, L.; Brozkova, L; Vytrasova, J., Effects of the principal ingredients of biscuits upon water activity. Journal of Food and Nutrition Research 2006, 45, 39-43.

23. Spencer, J. E.; Scanlon, M. G.; Page, J. H., Drainage and Coarsening Effects on the Time-Dependent Rheology of Whole Egg and Egg White Foams and

Batters.

24. Ahmed, J.; Ramaswamy, H. S.; Alli, L; Ngadi, M., Effect of high pressure on rheological characteristics of liquid egg. LWT - Food Science and Technology 2003, 36, 517-524. 25. Arzeni, C.; Perez, O. E.; Pilosof, A. M. R., Functionality of egg white proteins as affected by high intensity ultrasound. Food Hydro. 2012, 29, 308-316.

26. Wang, Y.; Zhang, M.; Adhikari, B.; Mujumdar, A. S.; Zhou, B., The application of ultrasound pretreatment and pulse-spouted bed microwave freeze drying to produce desalted duck egg white powders. Drying Technology 2013, 31, 1826-1836.

27. Stefanovic, A. B.; Jovanovic, J. R.; Dojcinovic, M. B.; Levic, S. M.; Nedovic, V. A.; Bugarski, B. M.; Knezevic-Jugovic, Z. D., Effect of the controlled high- intensity ultrasound on improving functionality and structural changes of egg white proteins. Food and Bioprocess Technology 2017, 10, 1224-1239. 28. Sert, D.; Aygun, A.; Torlak, E.; Mercan, E., Effect of ultrasonic treatment on reduction of Esherichia coli ATCC 25922 and egg quality parameters in experimentally contaminated hens' shell eggs. J. of the Sci. of Food andAgric: 2013, 93, 2973-2978.

29. Sert, D.; Aygun, A.; Demir, M. K., Effects of ultrasonic treatment and storage temperature on egg quality. Poult. Sci. 2011, 90, 869-75. 30. Hutchings, J. B., Food color and appearance. 2.nd Edition ed.; Gaithersburg:

Aspen Publishers: 1999.

31. Stadelman, W. J., Quality identification of shell eggs. In Egg Science and Technology, Stadelman, W. J.; Cotterill, J., Eds. The Haworth Press Inc. 4th ed. Westport, Conn.: AVI. Publishing.: New York., 1995; pp 39-66. 32. Damodaran, S.; Paraf, A., Food Proteins and Their Application. Marcel

Dekker, Inc., New York.: 1997; p 180.

33. Mine, Y., Recent advances in the understanding of egg white protein functionality. Trends in Food Sci. & Techn. 1995, 6, 225-232.

34. Damodaran, S., Amino acids, peptides, and proteins. In Fennema's Food Chemistry, Fourth Edition ed.; Damodaran, S.; Fennema, O.; Parkin, K.; Decker, E.; Sikorski, Z.; McClements, D.; Brecht, J.; Schwartz, S.; Swaisgood, H.; Ho, C., Eds. Boca Raton: CRC Press.: London, UK, 2007; pp 269-281.

35. Johnson, T. M.; Zabik, M. E., Ultrastmctural examination of egg albumen protein foams. Journal of food science 1981, 46, 1237-1240.

Claims

1. The invention is a processing method suitable to modifying /technique of a liquid egg (yolk, whole and white), comprising the steps of; breaking the shelled egg,

- filtration of the obtained liquid egg (yolk, whole and white),

preparing the liquid egg (yolk, whole and white),

applying the ultrasound technique to the prepared liquid egg, characterized by comprising the step of; subjecting the liquid egg to sonication by applying ultrasound at 150-375 W power.

2. A method according to Claim 1, characterized by applying ultrasound to the liquid egg for 3-6 minutes.

3. A method according to Claims 1 or 2, characterized by cooling the liquid egg to 0-4 °C after filtration.