Ultrasonics Sonochemistry xxx (2014) xxx–xxx

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Ultrasonics Sonochemistry

journal homepage: www.elsevier .com/locate /u l tson

Applications of sonochemistry in Russian food processing industry

http://dx.doi.org/10.1016/j.ultsonch.2014.03.0151350-4177/� 2014 Published by Elsevier B.V.

⇑ Corresponding author. Tel.: +7 9513118930.E-mail address: okrasulya@mail.ru (O. Krasulya).

Please cite this article in press as: O. Krasulya et al., Applications of sonochemistry in Russian food processing industry, Ultrason. Sonochem. (2014)dx.doi.org/10.1016/j.ultsonch.2014.03.015

Olga Krasulya a,⇑, Sergey Shestakov a, Vladimir Bogush a, Irina Potoroko b, Pavel Cherepanov c,Boris Krasulya d

a Moscow State University of Technology and Management, Moscow, Russiab Federal State Funded Educational Institution of Higher Professional Education, ‘‘South Ural State University’’ Sub-division: Quality Expertise of Consumer Products,Chelyabinsk, Russiac Physical Chemistry II, University of Bayreuth, Universitaetsstrasse 30, Bayreuth, Germanyd M.V. Lomonosov Moscow State University, Moscow, Russia

a r t i c l e i n f o a b s t r a c t

Article history:Received 3 December 2013Received in revised form 12 March 2014Accepted 16 March 2014Available online xxxx

Keywords:Food sonochemistryCavitationCavitation reactorsMechanism of binding water

In food industry, conventional methodologies such as grinding, mixing, and heat treatment are used forfood processing and preservation. These processes have been well studied for many centuries and used inthe conversion of raw food materials to consumable food products. This report is dedicated to the appli-cation of a cost-efficient method of energy transfer caused by acoustic cavitation effects in food process-ing, overall, having significant impacts on the development of relatively new area of food processing suchas food sonochemistry.

� 2014 Published by Elsevier B.V.

1. Introduction

Modern food industry requires large quantities of water to beused for food processing [1]. Quality of water in terms of purity,hardness, or dissolving ability might significantly affect the proper-ties of the final products available to consumers. Thus, in rapidlygrowing production of foods that have to be stored in dried form(powdered milk for example) or the ones which have to be slated(ground meat), development of low-cost, energy-efficient waterpretreatment technology is quite crucial. Amount of dairy drinksprepared from powdered milk has grown significantly over lastdecades and transformed into a big part of modern dairy industry.Reconstitution of powdered milk is among the leaders of waterconsumption. One of the prospective solutions for energy savingand enhancement of final product quality is application of ultra-sound in food processing industry. Food sonochemistry [2] is rela-tively new scientific area which has gained a lot of interest amongresearchers in the recent years [3]. It has been already shown thatultrasound can be potentially applied in the dairy industry [4,5].Possibility of ultrasound implementing in meat and dairy food pro-cessing technology is based on the idea that at low frequencies(20 kHz) cavitation effect [6,7] reveals itself not as much in

formation of free radicals but mainly in changing self organizationof water molecules [8].

Here we report on how ultrasound pretreatment of water canbe implemented into food processing industry [9]. We built twosonochemical reactors [10,11]: one of the reactors was used forground meat processing, namely at the stage of brine (NaCl solu-tion) preparation, the other one was used for preparation of a milkdrink for school meals from powdered milk. Water which was pro-cessed in these reactors was evaluated in terms of physical andbacteriological properties to assure safety. Quality of the final meatproducts treated with US modified brine was assessed with respectto water and valuable nutrition compounds loss upon heat treat-ment [12], while milk drinks prepared with US treated waterunderwent microbial growth [13] studies to evaluate the shelf life.It is important to note that both reactors underwent ‘‘Federal Ser-vice for Supervision of Consumer Rights and Human Welfare’’ and‘‘State Standards of Russia’’ inspections and were permitted forfood processing use.

2. Experimental section

Meat samples were prepared from ground meat (50% beef, 50%pork) of regular as well as PSE (pale soft exudative) and DFD (darkfirm and dry) quality. Amount of brine in meat samples was ad-justed to the value of 3.85 g per 100 g. Brine treatment was carriedat ambient temperature for 30 min. Water holding capacity was

, http://

Hydrogen-bonded network

Surface of the expanding cavita on bubble

Free water molecules

(a)

(b) Binding water

molecules

Amino acidparts of proteinsAmino acid

parts of proteins

Fig. 1. Schematic representation of hydrogen-bonded network destruction due tocavitation effect of ultrasound (a) and released free water molecules incorporationinto proteins (b).

Table 1Bacteriological properties of regular and US treated water.

Sample Absoluteviscosity, cP

Viability index ofmicroorganisms

2 h after US processing for 5 min 0.971 ± 0.008 0.6301 day after US processing for 5 min 0.987 ± 0.004 0.849Control (not treated water) 1.019 ± 0.007 1.760

Fig. 2. Sonochemical reactor for brine preparation. 1 – stainless steel platform, 2 – houscoolant, 7 – coolant pump, 8 – ultrasonic generator, 9 – brine pump, 10 – brine outlet a

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evaluated as following: weighed test tubes with meat sampleswere placed in water bath and kept for 20 min at 98 �C, upon cool-ing to ambient temperature released moisture drops were col-lected with filter paper and test tubes were re-weighed. Allchemicals for brine preparation were purchased from ABASTOLand were the highest grade available. Only drinking (bottled) waterwas used for the experiments. Ultrasound treatment of water wascarried at operating frequency of 20 kHz. pH measurements wereperformed on pH-213 (Hanna Instruments, Germany). Standardviscometer (A&G, Japan) was used to measure absolute viscosity.Chemical content of alcoholic extracts was determined on TraceDSQ gas chromatograph mass spectrometer (Finnigan, USA). Via-bility index of microorganisms was evaluated on Biotox-7equipped with biosensor Ecolum (Russia). Microbial growth in pre-pared milk samples was studied on Infusoria Tetrahymena Pyrifor-mis with use of BioLaT-2 (Russia).

3. Results and discussion

We suggest that pulses of pressure occurring due to oscillatingcavitation bubble growth shift water self-organization equilibrium(H2O)n = n(H2O) to the right, thus, destroying three-dimensionalhydrogen-bonded network (Fig. 1a). Released in such a way so-called ‘‘free molecules’’ of water have higher possibility to betrapped by proteins present, for example, in meat or powderedmilk (Fig. 1b).

3.1. US treatment of water for ground meat brining

At the initial stage we evaluated bacteriological properties ofwater treated with ultrasound [14] that was later used in meatbrining process. Analysis showed decrease in microorganism via-bility index compared to water which was not treated with US. Itwas also found that even after 24 h after US treatment viability in-dex value was still much lower than the one for control sample.The actual values are presented in Table 1. In addition, we alsomeasured absolute viscosity of US treated water and observedthe same tendency (Table 1), which might indirectly indicate theformation of water molecules that were not incorporated intohydrogen-bonded network. All parameters for brine processingreactor (Fig. 2) such as ultrasound intensity, frequency, and flowrate based on dissolving ability of US treated water were previ-ously optimized and reported elsewhere [10]. It is also important

ing, 3 – cavitation reactor, 4 – electroacoustic transducer, 5 – radiator, 6 – tank fornd 11 – water inlet, 12 – electric starter, 13 – control key.

ry in Russian food processing industry, Ultrason. Sonochem. (2014), http://

Table 2Chemical content of alcoholic extracts of ground meat samples prepared with USmodified brine and regular.

Compound Content (mg/kg)

US treated samples Control

1,3- Methyl n-pentadecanoate 1.6 Not detectedMethyl isostearate 1.2 Not detectedEthylhexyl adipate 10.6 Not detectedPalmitic acid 1.0 Not detectedLinoleic acid 12 Not detectedCreatinine 32 Not detectedCyclohexylpiperidine 4.0 Not detected

O. Krasulya et al. / Ultrasonics Sonochemistry xxx (2014) xxx–xxx 3

to note that technological conditions were set up in the way thatfinal meat product would not contain more than 10% of brine byvolume. At the next stage, all brined meat samples were subjectto heat treatment followed by valuable compounds content evalu-ation and water trapping ability of proteins. Table 2 summarizesthe results on chemical content of alcoholic extracts of brinedmeat. All listed in the table chemical compounds normally definethe taste and flavor of the final product. Alcoholic extracts of con-trol samples (meatballs treated with regular water based brine) did

Fig. 3. Measured pH values for initial minced meat samples of PSE – j, NOR – , and DFD– j, NOR – and DFD – h), which were treated with sonochemically processed brine

Please cite this article in press as: O. Krasulya et al., Applications of sonochemistdx.doi.org/10.1016/j.ultsonch.2014.03.015

not show presence of any compounds listed in the table after ther-mal treatment. The opposite results were observed when brine wasprepared with use of US treated water – all valuable compoundsdid not decompose upon thermal treatment. We believe that ab-sence of hydrogen-bond network in US treated water allowed itsmolecules to form dense hydration shells of compounds presentin meat preventing the last ones from participating in chemicalreactions. Thus, it can be clearly seen that preliminary US treat-ment of water for brine preparation leads to significantly increasedthermal resistivity of chemical compounds present in processedmeat.

In order to estimate water binding ability of proteins in groundmeat, we used method of mass loss suggested by A. Fisher (Univer-sity of Hohenheim, Germany). Shortly, this method relies on theconcept which distinguishes between two different types of watermolecules present in biomass – strongly bounded (incorporatedinto proteins) and ‘‘free’’ easily removable. Thus, heating the bio-mass at atmospheric pressure to nearly water boiling point forces‘‘free’’ water molecules to transfer into the vapor state due toestablishing thermodynamic equilibrium. Monitoring the sampleweight loss makes it possible to estimate amount of water thatwas not incorporated into proteins. In the present work, we inves-tigated meat samples of different quality, namely, PSE (pale soft

– h quality (a). The difference of thermal losses between minced meat samples (PSEand without (b).

ry in Russian food processing industry, Ultrason. Sonochem. (2014), http://

a b

Fig. 4. Solubility of powdered whey in regular (a) and sonochemically treated water(b).

Fig. 6. Development of microflora in dairy beverages obtained by sonochemicalprocessing with an amplitude of sound pressure in the reactor of 2.5 bar andacoustic energy: 1 – 0 kJ, 2 – 30 kJ, 3 – 60 kJ, 4 – 90 kJ.

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exudative) meat with lower pH values, DFD (dark firm and dry)high level pH meat, and NOR (normal) meat. All measured pH val-ues for 30 samples of each type of meat are presented in Fig. 3a.After pH measurements all meat samples were split in two parts– one part was mixed with brine prepared using US treated waterand other part was mixed with regular brine. Upon water lossexperiments we revealed that samples of meat containing US mod-ified brine lost less water compared to control ones. Fig. 3b repre-sents the difference in thermal loss of water by both US modifiedand control samples. Based on the detailed evaluation of samples’pH and difference of thermal loss data we were able to derive thefollowing equation which allows correlating amount of sonicatedwater incorporated into protein with meat pH:

m ¼ �0:0175 � 1:45pHp lgðsÞ

where p – amount of proteins (%) and s – mincer plate hole diameter(mm).

Thus, US modification of water for brine preparation positivelyinfluences ability of proteins to incorporate water molecules andprevents their loss upon thermal treatment.

3.2. US treatment of water for powdered milk recovery

Biochemists believe that chemically pure protein undergoinghydration reaction can theoretically bind up to 40% of water byweight. Increasing dissolving ability of water by the action of

Fig. 5. Sonochemical reactor for water treatment used in powdered milk reconstitutionsonochemical reactor, 4 – ultrasonic generators. The arrows show water direction flow.

Please cite this article in press as: O. Krasulya et al., Applications of sonochemistdx.doi.org/10.1016/j.ultsonch.2014.03.015

cavitation can effectively compensate natural water which wasartificially removed for the purpose of prolonged storage of milkin the dried form. Fig. 4 shows how US treatment can improve dis-solving ability of water. Equal amounts of dry milk whey wereadded to regular water (Fig. 4a) and to the water which was preli-minary sonicated (Fig. 4b). It can be clearly seen that US treatmentof water significantly enhances whey dissolving. Thus, taking intoaccount increased dissolving ability and improved bacteriologicalproperties of sonicated water we established the sonochemicaltechnology of dairy drinks production for school meals from pow-dered milk and whey with the following chemical composition: fat– 2.8%, protein – 3.5%, lactose – 7.8%. The sonochemical reactor forwater pretreatment is shown in Fig. 5. Previously, it has been al-ready shown that sonochemical treatment of water and attributedto it epithermal energy transfer is much more efficient than thethermal treatment [7]. Beneficial properties of US allow eliminat-ing one of the energy and time consuming steps in milk productionwhich is called pasteurization, when liquid has to be heated to atleast 70 �C to slow the microbial growth in the final product. Werevealed that cavitation effects on water caused by acoustic wave

process. 1 – Rotary cavitational disintegrator (Estonia), 2 – pump, 3 – composite

ry in Russian food processing industry, Ultrason. Sonochem. (2014), http://

O. Krasulya et al. / Ultrasonics Sonochemistry xxx (2014) xxx–xxx 5

could also influence the microbial growth. Fig. 6 shows the totalmicrobial content of the milk samples which were prepared by dis-solving of powdered milk in regular and sonicated in different re-gimes (variable acoustic energy) water. Clearly, US treatment ofwater used for milk drink preparation significantly slows the bac-terial growth, which gives the possibility to store the product for alonger time without reducing its quality. Therefore, optimization ofthe duration of water US treatment makes it possible to control thequality and the shelf life of the final product, as well as opens theopportunity to use sonochemistry on industrial level.

4. Conclusion

Here we reported on the effect of ultrasound for water pretreat-ment. We showed that US treatment of water is changing its dis-solving ability, due to destruction of water hydrogen-bondednetwork. Free molecules of water have higher affinity to the milkor meat proteins, thus enhancing their thermoresistivity. In addi-tion, thermoresistivity of biologically valuable compounds andcompounds responsible for flavor and taste quality of the producthas also increased. Importantly, bacteriological properties of soni-cated water has significantly improved, leading to much slowerbacterial growth, which as it was found can be controlled by dura-tion of US water treatment at fixed intensity. Overall, we showedthat the sonochemical reactors reported here used for ultrasoundwater pretreatment can be successfully implemented in foodindustry and have positive effect on quality of processed with itground meat and powdered milk as well as extend shelf life ofthe final product.

Please cite this article in press as: O. Krasulya et al., Applications of sonochemistdx.doi.org/10.1016/j.ultsonch.2014.03.015

References

[1] M.R. Kasaai, Use of water properties in food technology: a global view, Int. J.Food Prop. 17 (2014) 1034–1054.

[2] J. Chandrapala, C. Oliyer, S. Kentish, M. Ashokkumar, Ultrasonics in foodprocessing, Ultrason. Sonochem. 19 (2012) 975–983.

[3] M. Ashokkumar, R. Rink, S. Shestakov, Hydrodynamic cavitation – analternative to ultrasonic food processing, Electron. J. Tech. Acoust. 9 (2011).Available from:<http://www.ejta.org>.

[4] T. Leong, P. Juliano, L. Johansson, R. Mawson, S. McArthur, R. Manasseh,Temperature effects on the ultrasonic separation of fat from naturalwhole milk, Ultrason. Sonochem. (2014). http:// dx.doi.org/10.1016/j.ultsonch.2014.02.003.

[5] A.E. Torkamani, P. Juliano, S. Ajlouni, T.K. Singh, Impact of ultrasoundtreatment on lipid oxidation of Cheddar cheese whey, Ultrason. Sonochem.21 (2014) 951–957.

[6] M. Ashokkumar, O. Krasulya, S. Shestakov, R. Rink, A new look at cavitation andthe applications of its liquid-phase effects in the processing of food and fuel,Appl. Phys. Res. 4 (2012) 19–29.

[7] S. Shestakov, O. Krasulya, J. Artemova, N. Tikhomirova, Ultrasonic watertreatment, Dairy Indus. 5 (2011) 39–42.

[8] K.B. Jinesh, J.W.M. Frenken, Experimental evidence for ice formation at roomtemperature, Phys. Rev. Lett. 101 (2008) 036101.

[9] S. Shestakov, O. Krasulya, Research and experience of sonochemical technologyin the food industry, Electron. J. Tech. Acoust. 10 (2011). Availablefrom:<http://www.ejta.org>.

[10] S. Shestakov, O. Krasulya, V. Bogush, Sonochemical treatment of brine, RUPatent 2402909, Russia, 2010.

[11] S. Shestakov, O. Krasulya, V. Bogush, Sonochemical treatment of watersolutions for biopolymer hydration, RU Patent 2422198, 2011.

[12] Method for increase of thermoresistibility of biologically active components offood and drug raw materials of vegetable and animal origin, RU Patent2444201, Russia, 2012.

[13] P. Piyasena, E. Mohareb, R.C. McKellar, Inactivation of microbes usingultrasound: a review, Int. J. Food Microbiol. 87 (2003) 207–216.

[14] S. Shestakov, Food Sonochemistry: Concept, Theoretical Aspects and PracticalApplications, Lambert Academic Publisher, Saarbrueken, 2012.

ry in Russian food processing industry, Ultrason. Sonochem. (2014), http://