Life Science Journal 2014;11(4)

Life Siene Journl 2014;11(4) http://www.lifesienesite.om Proution n Sensory, Texturl, Physiohemil Properties of Flvore Sprele Yogurt Ahmet Ayr, Esr Gürlin Skry University, Engineering Fulty, Foo Dep., Serivn, Skry, 54084, Turkey yr@skry.eu.tr Abstrt: In this stuy, yogurt ws initilly flvore with some fruits n herbs groups. The onsisteny of yogurt ws inrese by filtrtion n some stilizers in orer to give sprele struture. The yogurt smples were nlyze on ys 1, 10 n 20 uring storge t 4 C. Dry mtter, ph, wter holing pity, w n visosity ontent of yogurt smples hnge from 28.01% to 33.70%, 4.69 to 4.91, 88.44% to 96.10%, 0.856 to 0.960, 27.18P to 218.83P, respetively. Texture profile nlysis emonstrte tht the hrness, hesiveness, ohesiveness n frturility of yogurts signifintly showe ifferenes. Color hrteristis (L*, *, b*) re vrie oring to the kins of fruits n herbs use in yogurt. As result of the orgnolepti evlutions, herry e yogurt smple h the highest overll eptility. A men sore between five n six inite tht the smple prout ws like epte. Yogurt smples get sprele properties. Aoring to these results, yogurt n beome more ttrtive for hilren. It is lso thought this pplition will inrese yogurt onsumption n be n importnt improvement in people s nutrition with ifferent onsumption. [Ayr A, Gürlin E. Proution n Sensory, Texturl, Physiohemil Properties of Flvore Sprele Yogurt. Life Si J 2014;11(4):58-65]. (ISSN:1097-8135). http://www.lifesienesite.om. 6 Keywors: Spre yogurt; fruit; herbs; storge 1.Introution Yogurt s nutritionl profile hs similr omposition to the milk from whih it is me but will vry somewht if fruit, erel or other omponents re e. Yogurt is n exellent soure of protein, lium, phosphorus, Vitmin B 2, Vitmin B 1 n Vitmin B 12, n vlule soure of folte, niin, mgnesium n zin. The protein it provies is of high biologil vlue, n the vitmins n minerls foun in milk n iry foos inluing yogurt re bioville. Eting iry prouts, suh s yogurt, helps to improve the overll qulity of the iet n inreses the hnes of hieving nutritionl reommentions (Mkinley, 2005). Yogurts re lssifie in vrious wys oring to ft rtio, proution tehnique, rom, n the proeures fter inubtion. The yogurts re sol in the mrket in vrious wys oring to the lssifition metho. For exmple, remy yogurt (full ft), homogenize yogurt (ft n ifferent onstrution tehnique), light yogurt (nonft), fruit yogurt, filtrtion (bgs) yogurt n so on. Yogurt, proue in vrious regions of Turkey is very tritionl type n vriety of proeures n methos (eg, filtrtion, winter, Silivri, silifke, slt, rem, et.). Among these, preferre is the most proue yogurt torb or süzme type. Other bg or strine type prouts re mnufture in ifferent ountries for exmple, ln zeer (in Egypt), Bes (in Bulgri), skyr (in Ieln), lneh nbris or yogurt heese (in the Mile Est) n hkk n shrikhn (in Ini), Thn or Tn in Armeni n Ymer in Denmrk (Nergiz n Seçkin, 1998; Tmime n Robinson, 2007). The inrese in the per pit nnul onsumption of yogurt in the mjority of the ountries hs been ttribute to both the everinresing vilility of fruit or flvore yogurt, n to the iversity of presenttions of the prout. A vriety of ifferent flvoring ingreient (fruits, nturl flvors or syntheti flvors) re urrently e to yogurt. The types of flvoring mteril use in the yogurt inustry re fruits, fruits preserves, nne fruit, frozen fruits n misellneous fruit prouts. Results of reent stuies inite tht fruit ition levels ply signifint role in eptility of fruit e yogurt (Tmime n Robinson, 1988). Severl yogurt-bse prouts re mrkete with the ition of either fruit or vegetles rih in biotive foo ingreients or eible fibers lime to hve benefiil effets on humn helth (Deeth n Tmime, 1981). The flvorings n their osge re usully regulte oring to the regultions ientifie sy by eh ountry. The FAO/ WHO reommentions for fruit yogurt re fruit ontent between 5 n 15 %. In ition, fruit onten suggeste for fruit yogurt oring to Turkish Foo Coex (for fermente milk) ws 6% (Anonymous, 2001). If fruit n herb re e to it, yogurt is more nutritious n funtionl. The purpose of this stuy, fortifie with fruits n herbs, flvore yogurt is to proue for hilren n ults or gin sprele properties to it. The effet of these 58

Life Siene Journl 2014;11(4) http://www.lifesienesite.om itives on the physiohemil, olor n sensory hrteristis of sprele yogurt ws lso investigte uring storge. 2.Mteril n Metho The rw ow's milk for the proution of sprele yogurt ws obtine from Amenekşe iries, Skry, Turkey. The milk ontine 15.00% non-ft ry mtter, 7.70% ft, n 5.65% protein. The iity n ph of the milk were 6.80 SH, 6.65, respetively. Yogurt ultures (YO-MIXTMYOGURT CULTURES 499 with L. elbruekii subsp. bulgrius n Str. Thermophilus) were originlly obtine from İstnbul-Turkey istributor of Dniso (Deutshln GmbH Germny/Alemnh). Fruits n herbs e to yogurt, were obtine from lol mrkets ommerilly. Fruits were freeze-rie n groun using entrifugl mill with 0.12 numbere sieve. Sesme oil, flx see oil n blk umin oil nturlly proue by ol pressing hve supplie from ONEVA ompny- Istnbul. Skimme milk power ws obtine from Milkon Diry-Skry, Türkey. Yogurt proution: The quntities of fruits n herbs use in the proution of yogurt were etermine by preliminry tests. The proution flow hrt is given in Figure 1 for sprele flvore yogurt. Yogurts were proue from ows milk in 2 L stinless steel ontiners. All yogurts were supplemente with 5% non-ft milk power n 5% rem. The mixes were homogenize in stomher t 45 C (Tekmr 400, USA), hete t 90 C for 30 min, oole to 45 C, n then flvoring ingreients were e in Figure 1. Milks were then inoulte with 3 % yogurt strter ulture, septilly trnsferre into the plsti ups, n inubte t 42 C until the ph roppe to pproximtely 4.95. The yogurts were store t 5 C. Three replites of eh yogurt were me. Compositionl Anlysis: Yogurt smples store t 5 C were nlyze in 1, 10 n 20 ys. The using AND MX-50 moisture nlyzer for the etermintion of ry mtter n titrtion iity s lti i were rrie out oring to the stnr methos of AOAC (1995). The ph of smples ws mesure t 6 C using ph meter (Hnn Instruments ph Meter 211). Wter tivity ( w ) of the smples ws mesure using ommerilly ville w meter, mesuring system (Moel AQUALAB 3TE, Wshington). The wter holing pity (WHC) ws etermine by proeure pte from Guzmn-Gonzlez et l. (1999). Sensoril Evlution: A nine-point fil heoni sle in whih 1 = is-like extremely, 5 = neither like nor islike n 9 = like extremely ws use by eh prtiipnt for smple evlution. Approximtely 50 ml of eh smple ws presente in glss bowl n spre on bre with plsti spoon (Meilgr, 1999). Rw milk Anlysis n lening of the milk Crem + Stilizer The heting of milk (90 ºC e 10 min) Milk ooling (45 ºC) The ition of ulture (%3) + Milk power (%5) Inubtion (to ph 4.95 t 42 ºC) 3 % Strwberry 3 % Cherry 3% Blueberries 2 % Mint 3 % Pumpkin 5 % Blk rrot 5 % Sesme 2 % Thyme 5 % Cumin 5 % Linsee Filtering with loth (until rehes out 25% of ry mtter) Storge t 5 C Figure 1. The proution flow hrt for flvore sprele yogurt Visosity Anlysis: The visosity of yogurt smples fter 1, 10 n 20 y of storge t 5 C ws mesure using rottionl visometer (Fungil, ALPHA H, Spin) t the spee of 100 rpm t 30 seon with spinle 7 s P. Texture Anlysis: The smples were nlyze by texture profile nlyzer (Texture Anlyzer-CT3, Brookfiel Engineering Lortories, In.) using TA4/1000 probe. Texture Anlyzer Test Settings; MODE: Norml TRIGGER: 4.5g Trigger DISTANCE: 30mm SPEED: 1mm/s The following prmeters were quntifie n efine by Bourne (1982) s: springiness (the height tht the smple reovers uring the time tht elpses between the en of the first yle n the strt of the seon yle) n hesiveness (the negtive fore re for the first yle, representing the work neessry to pull the ompressing plunger wy from the smple). The first pek on the urve ws 59

Life Siene Journl 2014;11(4) http://www.lifesienesite.om onsiere to be mesure of frturility (ur tension). Hrness (mximum fore s the test ell penetrte 30 mm of penetrtion into the smple) ws lso quntifie s esribe by Mohme n Morris (1987). Color nlysis: A Hunter olorimeter (Hunter Lortories, Reston, VA, USA) ws use to etermine of Hunter L* (blk to white), * (green to re) n b* (blue to yellow) olor prmeters of yogurt smples. Sttistil nlysis: The t obtine from the physiohemil, rheologil, mirobiologil n sensory nlyses of the smples were sttistilly evlute by vrine nlysis n omprisons were me with Dunn s Multiple Rnge Test (Minit, 1991). 3.Results n Disussion Physiohemil Properties The physiohemil properties of yogurt smples re given in Tle 1. As n be seen from the tle, the physiohemil properties of the yogurt smples showe signifint ifferenes epening on itives (p<0.01). The mount of ry mtter in yogurts showe ifferenes oring to the mount n the nture of fruits n herbs use. The ry mtter in yogurt smples rnge from 28.01 % (mint e) to 33.70% (blk rrot e). This ifferene ws sttistilly signifint (p<0.01). The itives n hrteristis of their, the filtrtion is use of these ifferenes. In stuies on fruit or other itives e yogurt, hrterize in tht the e itives n fruits inrese ry mtter in yogurt (Öztürk n Akyüz, Ayr, Hshim, Rhmn et l., Yogurt smples isplye signifint ifferenes in the verge vlues of w (hnge from 0.856 in herry e to 0.960 in mint e). w of yogurt smples showe signifint reution uring storge (p<0.01) (Figure 2). w is iretly relte to the ry mtter. As n be seen from Tle 1, the verge lowest ph vlue ws in blueberry e yogurt with 4.69, while the highest ph vlue of 4.91 ws foun in sesme e yogurt. The overll ph vlues of yogurt smples were exmine, the verge etermine to be 4.95 in 1st y, 4.73 in 10th y n 4.76 in 20th ys. Reserhes hve shown tht fruits n other ingreients use in yogurt, ffet on ph n viility of ulture bteri. In the results of our stuy, s well s other reserhes hve foun tht the ph erese in yogurt uring the storge (Kilspthy et l., 2008). Aoring to our results, ph of yoghurt smples higher ws ue to the filtering proess n itives. Tle 1. The verge physiohemil properties of fruits n spies e sprele yogurts Aitive Cherry Strwber ry Blk rrot Blueberri es Pumpkin Linsee Sesme Cumin Mint Thyme Dry mtter (%) 32.11±0.6 18 b* 31.89±1.1 56 b 33.70±0.9 43 30.37±0.4 14 31.74±1.1 03 b 29.32±0.9 67 29.21±1.2 39 29.35±0.9 67 28.01±0.6 97 E 28.54±1.2 29 e ph w Visosity (P) WHC (%) 4.70±0.135 4.71±0.150 4.91±0.115 4.69±0.199 4.77±0.125 4.85±0.105 b 4.91±0.112 4.88±0.082 4.85±0.067 b 4.86±0.063 b 0.856±0.0 86 0.923±0.0 41 b 0.933±0.0 28 b 0.908±0.0 48 0.931±0.0 29 b 0.948±0.0 15 0.954±0.0 14 0.959±0.0 14 0.960±0.0 14 0.954±0.0 17 27.18±8.927 i 82.37±18.74 6 b 218.83±36.1 86 46.75± 9.320 h 57.48± 3.585 f 52.17± 2.849 g 74.08± 5.363 62.05± 7.300 e 69.75± 2.803 59.73± 8.421 ef 92.77±3.5 06 b 96.00± 3.305 95.11±2.8 12 88.44±4.5 84 96.10± 2.197 91.73±2.3 44 90.93±2.0 34 94.36±2.7 03 92.06±4.5 6 b 92.13±2.4 34 b *Mens in the sme olumns of physiohemil properties n ftors with ifferent supersripts re signifintly ifferent (p<0.01) mong pplitions 100 Storge Time (Dy) 80 60 40 20 0 1 10 20 30,17 30,3 30,8 Dry mtter (%) 93,71 92,75 92,43b 81,05 79,72 64,36b 0,95 4,95 0,94 4,73b 0,9b 4,76b WHC (%) ph wvisosity (P) Dry mtter (%) ph w Visosity (P) WHC (%) Figure 2. The hnges in the physiohemil properties of yogurt smples Sprele fruit yogurt with blk rrot hs the highest visosity (218.8 P) n signifintly higher thn the visosity of other yogurt smples (p<0.01). In generl, substntil reution in visosity ourre uring the storge of yogurts smples (verge from 81.05 P to 64.36 P). The ry mtter of yogurt inreses with e itives, it lso helps to inrese the visosity of the yogurt. The visosity generlly vries epening on the mount of fruit in yogurt (Akin n Konr, 1999). In nother reserh, it ws foun tht petin in fruits e to yogurt ws swollen n use n inrese in onsisteny (Kmruzzmn et l., 2002). In vrious trils, visosity of yogurt h been foun to vry from 35 P to 360 P (Kmruzzmn et l., 2002; Ayr et l., 2005; Le et l., 2011). Visosity of flvore yogurt smples rnge from 27.18 P in herry e smple to 218.8 P in rrot e smple. The physiohemil hrteristis of yogurt, WHC in the first ple, re very ifferent 60

Life Siene Journl 2014;11(4) http://www.lifesienesite.om between fruits n herbs e yogurts smples. WHC of protein gel is n importnt prmeter in yogurt mnufturing. Low WHC, with 88.44% ws foun in blueberry e sprele yogurt, the highest ws foun in the pumpkin e yogurt s the 96.10%. The verge WHC of the smples erese uring the storge perio. In yogurt e 6% milk power, WHC ws etermine to be 90% (Remeuf et l., 2003). Yogurt whih ws e 3% milk power, WHC of 57.11%, while the ontrol smple ws 39.60% (Le et l., 2011). The results show tht the itives hve signifint impt on the WHC of yogurt. Color Properties Foo eptne n preferene re funtions of prout qulity. Often olor is the first sensory hrteristi pereive by the onsumer n olor tens to moify other pereptions suh s flvor n rom (Gri-Perez et l. 2005). Fruits n herbs e to the yogurt smples h strong effet on the olor properties. In the se of ll yogurt smples, the L* vlues were observe to be very high throughout the storge perio initing tht the prout retine the ppeling whiteness. The highest vlue of L* h been herry e yogurt smples with 95.73, etermine the lowest vlue of L* in the blk rrot e yogurt with 42.77. The blk rrot gve re olor to e yogurt. * vlue in this exmple were the highest (17.29). Blk Crrots ontin nthoynins, prt of the flvonoi fmily with ntioxint properties. Mint won more green olor to the yogurt (-1.35) (Tle 2). The pumpkin h the istintion of own yellow olor in yogurt, so b* vlue is the higher in this exmple. In struture, its fruit pulp fetures golen-yellow to ornge olor epening up on the poly-phenoli pigments in it. The herry e yogurt hs been negtive in the b* vlue, whih mens tht it onsists of more bluish olor thn yogurt. The olor properties showe signifint hnges uring the storge of yogurt smples (Figure 3). * vlue, the vlue of folige or reness in yogurt smples erese uring the storge perio. Yogurt smples isplye n inrese in yellowness or blueness of the stte vlue of b*. In severl stuies, epening on the olors of the fruit n other itives e in yogurt, the olor properties (L*, *, b*) of yogurt smples hnge (Brtoo n Brie, 2005). It ws lso pointe out tht the olor properties of yogurt were influene by the ph (Gri-Perez et l., 2005). Sensoril Properties Sensory nlysis of flvore sprele yogurts ws rrie out by trine 10 people. The sensory properties of yogurt smples were given in Tle 3. The blueberry showe the gretest positive impt on the olor of yogurt with 7.809 point. The olor, strwberry e yogurt h the lowest sore with 6.380 points. The ogulum hrness of yogurt smples ffete epening on hrteristis of the itives e. The inrese ry mtter ws suppose to hrer struture in yogurt ogulum. The strwberry h the gretest positive impt on the smell of yogurt with 6.857 points. Despite the improvement of the texture n struture, blk rrot i not provie n importnt ontribution to the smell of yogurt. Some reserhers foun in their stuy on fruit e yogurts tht fruits signifintly inrese the sensory generlly eptility sores of yogurt smples, but reporte tht it i not inrese the oor (Öztürk n Akyüz, 1995; Ayr, 2002). Another reserh onute on fruit yogurt, strwberry lso ws showe tht the gretest positive impt on the smell of yogurt. It ws ientifie by other stuies onute on fruit yogurts, whih strwberry showe the gretest positive impt on the smell of yogurt (Hurşit n Temiz, 1999). Tle 2. The olor properties of fruits n spie e sprele yogurts Aitive L* * b* Cherry 95.731±1.123 ** 1.761±1.081-5.731±0.897 i Strwberry 74.146±1.880 1.553±0.476 6.341±0.294 f Blk rrot 42.773±2.311h 17.288±2.282-1.633±0.900 h Blueberries 58.883±1.444g 4.628±0.361 b -0.963±0.600 g Pumpkin 73.525±1.441 0.666± 0.292 e 13.255±1.025 Linsee 76.351±0.388b -.321±0.101gh 9.443±0.483 Sesme 76.500±0.594b -1.186±0.070g 7.191±0.245 e Cumin 76.541±0.506b -.240±0.095gh 7.230±0.277 e Mint 60.970± 2.781f -1.353±0.181h 11.068±1.811b Thyme 66.090±3.311e -0.261±0.202 f 10.013±1.461 - Greener thn stnr, + Reer thn stnr +b Yellower thn stnr, -b Bluer thn stnr **Mens in the sme olumns of olor properties n ftors with ifferent supersripts re signifintly ifferent (p<0.01) mong pplitions. 100 50 0 1 10 Storge 20 Time (Dy) 70,26b 69,05 71,15 2,336 1,991b 1,833 L* Figure 3. The hnges in the verge olor properties of yogurt smples uring storge Boy n texture sores erese uring storge. Yogurt proue by the ition of vrious types of fruits show signifint ifferene in the * 5,095 5,502b 6,267 b* L* * b* 61

Life Siene Journl 2014;11(4) http://www.lifesienesite.om sensory spets, n builing long-term storge hs been reporte tht sores erese (Trkçi n Küçüköner, 2003). The spoon (Sesme: 7.428 point) n the mouth onsisteny (Cumin: 7.476 point) sores in ol-presse vegetle oil e yogurt smples were the highest. The onsisteny of yogurt smples ws versely ffete uring storge. The fruits e to flvore yogurt, signifintly etermines the tste (Deeth n Tmime, 1981). Aoring to other flvoring gents, strwberry more inrese the tste n rom of yogurt. The tste n rom sore of yogurt e of thyme ws below of 5.00. In generl, tste n rom sores, the first y of storge of yogurt smples ws the highest n the lowest ws the tenth y. It hs been ientifie in vrious stuies tht fruit n other flvorings substnes e to yogurts ffet flvor n rom hrteristis of yogurt. This effet is more positive (Hshim, 2001; Luthmeil et l., 2004). Depening to the mterils, fruit flvor in yogurts ws felt. 9 points out of full, fruity tste points of yogurt smples, the highest n the lowest ws 7.238 in blueberries e, 5.190 in sesme e, respetively. Yogurts reeive the highest sores fruity rom t the beginning of storge. The sweetness shows the egree of onentrtion of sugr in foo. Out of 9 points, the highest sore of the sweetness of with 6.619 point ws the pumpkin e yogurt smple. Yogurt supplemente with the thyme got the lowest sore with 4.142 point. The sweetness of yogurt smples i not show signifint hnge uring storge. The ii feture points of yogurt smples rnge from 5.476 n 4.000 point (Tle 3). The iity ws the highest t the en of the storge. So, the iity property of yogurt smples inrese uring the storge perio. Aitive Color Smell Blueberr ies Blk rrot Cherry Strwber ry Pumpkin Mint Thyme Linsee Cumin Sesme 7.809±1.030 * 7.047±1.532 6.809±1.249 6.380±1.465 7.285±1.230 7.047±1.687 6.523±1.600 b 6.761±1.578 7.666±1.110 7.190±1.600 Tle 3. Sensoril properties of fruit n spies e sprele yogurts 6.190±1.631 5.523±1.123 b 6.523±1.470 6.857±1.458 6.714±1.230 5.857±1.851 4.761±1.410 5.714±1.792 6.714±1.383 6.285±1.101 Clot hrness 5.571±1.20 7 6.523±1.28 9 5.476±1.07 7 b 5.380±1.11 6 b 5.523±1.20 9 b 6.380±1.39 5 6±1.140 5.904±1.64 0 5.666±1.55 9 6.238±1.44 5 Texture n struture 6.904±1.4 10 5.952±1. 65 6.476±1.4 35 6.428±1.3 98 6.761±1.3 00 6.619±1.3 95 6.285±1.7 92 6.571±1.6 90 6.857±1.2 36 6.714±1.1 46 Consisten y with spoon 6.904±1.4 10 7.142±1.4 92 6.761±1.4 10 7.000±1.3 03 6.714±1.3 83 7.285±1.2 70 6.857±1.1 52 6.857±1.4 58 7.380±1.2 44 7.428±0.6 76 The tste n rom 6.095±1.894 5.095±1.480 5.952±1.532 6.761±1.044 6.714±1.383 5.190±1.661 b 3.952±1.071 5.238±1.997 b 6.428±1.660 6.047±1.430 Fruitiness 7.238±1.81 3 6.666±1.77 0 6.238±1.33 8 6.428±1.28 7 6.571±1.20 7 7.190±1.86 0 5.904±2.64 3 5.904±2.46 7 6.285±2.12 4 5.190±1.96 5 b Sweetness 6.000±1.26 4 5.380±1.11 6b 6.285±1.45 4 6.428±1.16 4 6.619±1.32 1 4.476±0.92 8 4.142±1.01 4 5.047±1.90 9 4.523±0.81 3 4.619±0.97 3 *Mens in the sme olumns of sensory properties n ftors with ifferent supersripts re signifintly ifferent (p<0.01) mong pplitions. Aii tste 4.666±1.90 6 4.238±.047 4.952±1.68 7 4.000±2.12 1b 4.238±1.78 6 5.190±1.60 0 4.857±1.23 6 5.476±1.53 6 4.809±1.12 3 5.000±1.26 4 Overll eptilit y 6.619±1.203 5.142±1.152 7.142±1.424 6.571±1.207 6.476±1.364 5.142± 1.711 3.285±1.707 5.333±2.287 b 6.142±2.007 5.380±1.883 b The sores of overll eptility properties of yogurt smples rnge from 3.285 in thyme e smple to 7.142 in herry e smple. The hrteristis of the generl eptility showe signifint ifferenes between yogurt smples (p<0.01). Fruit e yogurt smples isplye signifint reution in the overll eptility uring storge, i not use signifint hnge in herb e smples. Sensory eptility of yogurt is ffete by milk use for proution, the ulture, itives n proution tehniques (Ayr et l., 2005). Texturl Properties Texturl hrteristis of yogurts hve been efine by hrness, hesiveness, ohesiveness, frturility n springiness (Megenis et l., 2006). The texturl properties of yogurts were lso nlyze uring storge t 5 C n the results showe signifint ifferenes (p<0.01) throughout the shelflife perio, being not similr t 1 n 20 ys for eh type of yogurt. The texture profile ws ifferent oring to the tretment, storge n fruits or herbs types use. The results of texturl nlysis re shown in Figure 4-7. The ition of fruit or herbs to milk use to inrese in yogurt prmeters suh s frturility, hrness n hesiveness (p<0.01). The frturility power h the highest in rrot e yogurt n the lowest in strwberry e yogurt. The frturility i not show ny signifint hnge uring storge (Figure 4). As the probe returns to its strting position, the negtive lo vlues on the grph result from 62

Life Siene Journl 2014;11(4) http://www.lifesienesite.om bk extrusion. This gives n inition of the hesiveness/ohesiveness n resistne of the smple. The mximum negtive fore on the grph inites smple hesive fore; the more negtive the vlue, the more stiky the smple. The higher the vlue, the more energy require to brek the pro be/smple ontt s the probe withrws from the smple. Crrot e yogurt is more hesive thn other yogurt smples. The hesive properties of yogurt smples showe vritions uring storge (Figure 5). Figure 4. The hnges in the frturility properties of yogurt smples uring storge n ws n importnt ftor governing the stility of the prouts. This resulte in the goo mouth-feel, improve the texture hrteristis n the stility of yogurts uring storge. Hrness n hesiveness of yogurts obtine with the 2% ot-mltoextrin ition inrese uring refrigerte storge for 21 ys (Domgł et l., 2005). Similr results were obtine uring storge of probioti torb yogurt (Ksenks, 2010). Cohesiveness inites struturl integrity n is often isusse in terms of the bon strength; hesiveness inites herene of yogurt; wheres springiness reflets the struturl integrity of yogurt. Greter ohesiveness n springiness my be relte to stronger gel strutures, initing greter struturl integrity; perhps ue to inrese hrge groups on the mino i groups- funtion of whey protein enturtion (Megenis et l., 2006). The springiness (mm) vlues re reporte in Figure 6. The intertion of tretment x time ws signifint (p<0.01). The highest flexibility vlue ws etermine in rrot e yogurt. Springiness hs inrese in the yogurt smples prepre with rrot between the 1st n 10th ys, t the en of 20th y, erese ws observe. Figure 6. The hnges in the springiness properties of yogurt smples uring storge Figure 5. The hnges in the hesive fore properties of yogurt smples uring storge Ahesive fore hs inrese in the yogurt smples prepre with rrot between the 1st n 10th ys, t the en of the experiment, uring the 20th y, erese ws observe. Similr remrks were reporte by Rwson n Mrhl (1997) n Ktsiri et l. (2002) who reporte n inrese in hesiveness of ewe s yogurt uring storge. Hrness n hesiveness of ontrol yogurt inrese systemtilly from 39.77 g to 45.89 g fter 21 ys of refrigerte storge. The similr effet ws observe in the se of yogurts obtine with ition of 1% of resistnt strh. The hesiveness h positive effet on the thikness of the yogurts, As with other properties of texture, the mximum hrness vlue ws etermine in rrot e yogurt smple. Hrness properties inrese in the yogurt smples prepre with rrot between the 1st n 10th ys, t the en of storge, n importnt erese ws observe (Figure 7). These results show tht there is goo orreltion between time n synersis in higher totl soli onentrtions. by inresing the totl soli onentrtion of yogurt hrness inrese. The results show tht there ws orreltion between synersis n hrness, s hrness inreses the synersis erese. Cherry e yogurt showe signifint inrese in hrness uring storge oring to other yogurt smples. The hrness of yogurt with inrese solis inreses. Reserhers further foun tht erese protein ontent (3.52 to 3.31%) in yogurt mix 63

Life Siene Journl 2014;11(4) http://www.lifesienesite.om erese sein-sein n sein-whey intertions n erese hrness of yogurt (Megenis et l., 2006). The ition of some fruit or herbs to milk n the formtion of ggregtes by intertion with sein mielles rete more rigi gel struture in yogurt. It is known tht yogurt texture is highly epenent on totl solis ontent s well s on protein ontent n type (Puvnenthirn et l., 2002). Figure 7. The hnges in the hrness properties of yogurt smples uring storge As result of the stuy, it n be si tht yogurt n be flvore with some fruit or spies n onentrte. This proess prolongs its shelf-life. Yogurt smples hve highly eptle sensory properties n sprele funtionlity. The struturl properties of the flvore sprele yogurt smples re better thn norml yogurt. Thus, yogurt hs been proue s more nutritionl n funtionl. Aknowlegement This projet ws supporte by the Reserh Fun of Skry University, n grute of GURLIN mster stuy. Corresponing Author: Dr.Ahmet Ayr Skry University Engineering Fulty, Foo engineering Dep. Serivn, Skry,Turkey E-mil: yr@skry.eu.tr Referenes 1. Akin MS, Konr A. A reserh on physiohemil n sensory properties of fruit yoghurt proue from ow n got milk n store for 15 ys. Journl of Agriulture n Forestry 1999;23:557-567. 2. Anonymous. Turkish Foo Coex. Communition No: 2001/21. Communiqué on Fermente Milk The Offiil Gzette, 03.09.2001-24512. 2001. 3. AOAC. Offiil methos of nlysis. 16th e. Asso. Off. Anl. Chem., Arlington, VA. 1995. 4. Ayr A, Sert D, Klyonu İH. The hemil, rheologil n sensory properties proue yogurt with ifferent fruit. Foo n Fee Siene-Tehnology 2005;2:11 19. 5. Ayr A. A reserh on hemil omposition n sensory qulity of rnberry fruit e yoghurt. Turkey 7 Foo Congress 791-798, Ankr, Turkey. 2002. 6. Brtoo SA, Brie N. Physiohemil, nutritionl n sensory qulity of stirre golen pple (Sponis ythere sonn) yogurts. Interntionl Journl of Foo Sienes n Nutrition 2005; 56: 445 454. 7. Bourne MC. Foo Texture n Visosity. 1st e. Aemi Press, New York. 1982. 8. Deeth HC, Tmime AY. Yogurt: Nutritive n Therpeuti Aspets. Journl of Foo Protetion 1981;44:78-86. 9. Domgł J, Sy M, Greg T, Bonzr G. The influene of storge time on rheologil properties n texture of yoghurts with the ition of ot-mltoextrin s the ft substitute. Interntionl Journl of Foo Properties 2005;8:439-448. 10. Gri-Perez FJ, Lrio Y, Fernnez-Lopez J, Sys E, Perez-Alvrez JA, Senr E. Effet of ornge fiber ition on yogurt olor uring fermenttion n ol storge. Color Reserh n Applition 2005;30:457 463. 11. Guzmn-Gonzlez M, Moris F, Rmos M, Amigo L. Influene of skimme milk onentrte replement by ry iry prouts in low ft set-type yoghurt moel system. I: Use of whey protein onentrtes, milk protein onentrtes n skimme milk power. Journl of the Siene of Foo n Agriulture 1999;79:1117-1122. 12. Hshim IB. Chrteristis n Aeptne of Yogurt Contining Dte Plm Prouts. Seon Interntionl Conferene on Dte Plms, Al-Ain, Unite Ar Emirtes, 25-26 Mrh, 2001; 842-849. 13. Hurşit K, Temiz H. The omprison of fruit yoghurt proution tehnologies. OMU Agriulturl Fulty Journl 1999;14:151-165. 14. Kilspthy K, Hrmstorf I, Phillips M. Survivl of Ltobillus iophilus n Bifiobterium nimlis ssp. ltis in stirre fruit yogurts. LWT-Foo Siene n Tehnology 2008; 41:1317-1322. 15. Kmruzzmn M, Islm MN, Rhmn MM. Shelf life of ifferent types of hi t room n refrigertion temperture. Pkistn Journl of Nutrition 2002;1:234-237. 64

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