Prof. Dr. A. Kadir HALKMAN Yönetim Kurulu Baflkan / President of the Association. Danışma Kurulu / Advisory Board

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1 GIDA (G da Teknolojisi Derne i Yay n ) THE JOURNAL OF FOOD (Published by the Association of Food Technology; Turkey) Cilt / Volume: 39 Say / Number: ki ayda bir yay mlan r / Published bimonthly ISSN ; ISSN (GIDA on-line) Sahibi / Owner G da Teknolojisi Derne i Ad na / On behalf of the Association of Food Technology; Turkey Prof. Dr. A. Kadir HALKMAN Yönetim Kurulu Baflkan / President of the Association Editörler Kurulu / Editorial Board Baş Editör/ Editor-in Chief Halkman, A. Kadir Ankara University, Turkey Editörler / Co-Editors Çak r, brahim Abant zzet Baysal University, Turkey Taban, Birce Ankara University, Turkey Tekin, Aziz Ankara University, Turkey Velio lu, Y. Sedat Ankara University, Turkey Yönetim Yeri Adres / Address Büyükelçi Sokak No: 18/1 Kavakl dere/ Ankara Turkey Tel: (+90) Faks: (+90) E-posta / dergi@gidadernegi.org URL: Yayın Türü: Yayg n süreli ve hakemli Basım Yeri / Printing House Sim Matbaac l k Ltd. fiti vedik Organize San. Böl. Mat-Sit fl Mrk Sk. No:2/14 Yenimahalle / Ankara Turkey Tel : (+90) Faks: (+90) simmatbaasi@gmail.com Yayın Tarihi / Publication Date Danışma Kurulu / Advisory Board Alichanidis, Efstathios Aristotle University of Thessaloniki, Greece Aran, Necla Istanbul Technical University, Turkey Art k, Nevzat Ankara University, Turkey Baysal, Taner Ege University, Turkey Boyac, smail Hakk Hacettepe University, Turkey Certel, Muharrem Akdeniz University, Turkey Draughon, Ann Tennessee University, USA Ekfli, Aziz Ankara University, Turkey El Soda, Morsi University of Alexandria, Egypt Fogliano,Vincenzo University of Napoli Federico II, Italy Ghosh, Bikash C. National Dairy Research Institute, India Gollop, Natan The Volcani Center, ARO, Israel Gökmen, Vural Hacettepe University, Turkey Griffiths, Mansel University of Guelph, Canada Gö üfl, Fahrettin Gaziantep University, Turkey Gümüflkesen, Aytaç Sayg n Ege University, Turkey Güven, Mehmet Cukurova University, Turkey Heperkan, Dilek Istanbul Technical University, Turkey Ho, Chi-Tang The State University of New Jersey, USA Kaya, Mükerrem Atatürk University, Turkey Kaymak-Ertekin, Figen Ege University, Turkey Koçak, Celalettin Ankara University, Turkey Köksel, Hamit Hacettepe University, Turkey Morales, Francisco J. CSIC Instituto del Frío, Spain Mujtaba, Mustafa G. Florida Gulf Coast University, USA Ögel, Zümrüt Middle East Technical University, Turkey Özilgen, Mustafa Yeditepe University, Turkey Paalme, Toomas Tallinn University of Technology, Estonia Parlar, Harun Technical University of Munich, Germany Raspor, Peter University of Ljubljana, Slovenia Rezessy-Szabo, Judit M. Corvinus Universty of Budapest, Hungary fiahin, Serpil Middle East Technical University, Turkey Üstünol, Zeynep Michigan State University, USA Yetiflemiyen, Atila Ankara University, Turkey Bu dergi, uluslararas CAB Abstracts, Citefactor, Index Copernicus, EBSCO, ULAKBİM (Yaflam Bilimleri) FAO Agris ve DOAJ veri tabanlar kapsam ndad r. This journal is covered by CAB Abstracts, Citefactor, Index Copernicus, EBSCO, ULAKBİM (National Databases) FAO Agris and DOAJ database systems. i

2 İçindekiler / Content Tuncer BÖ, Tuncer Y; Exopolysaccharide Producer Streptococcus thermophilus St8.01 Strain; A Potential Probiotic Culture / Ekzopolisakkarit Üreticisi Streptococcus thermophilus St8.01 Suflu; Potansiyel Probiyotik Kültür Baysal T, Ergün AR, Akgün B, Karc G, Kaplan N; Dondurma flleminde Baz ön Uygulamalar n Çilek ve Mandalinan n Kalite Özelliklerine Etkilerinin ncelenmesi / Determining the Effects of some Pretreatments on the Quality Characteristics of Strawberry and Mandarin in Freezing Process K l ç Y, Yüksekda ZN, Yüksekda H; Lactobacillus ve Bifidobacterium Cinsi Bakterilerin Beta Galaktosidaz Enzim Aktivitelerinin Belirlenmesi / Beta Galactosidase Enzyme Activities of Lactobacillus and Bifidobacterium Genus Tahmaz H, Söylemezo lu G; Farkl Vinifikasyon Tekniklerinin Kalecik Karas fiaraplar ndaki Fenolik Bileflik çeriklerine Etkisi / Effects of different Vinification Techniques on Phenolic Compounds In Kalecik Karasi Wines Kamilo lu S, Pasl AA, Çapano lu E, Özçelik B; Kuru Meyvelerin Kuruyemifller ile Birlikte Tüketiminin Flavonoidlerin in vitro Biyoyararl l na Etkisinin ncelenmesi / Investigating the in vitro Bioavailability of Flavonoids During Consumption of Dried Fruits with Nuts Büyüks r t T, Kuleaflan H; Fourier Dönüflümlü K z lötesi (FTIR) Spektroskopisi ve G da Analizlerinde Kullan m / Fourier Transform Infrared (FTIR) Spectroscopy and Utilization in Food Arslan S, Erbafl M; Selüloz ve Selüloz Türevi Diyet Liflerin Özellikleri ve F r n Ürünlerinde Kullan m mkanlar / The Properties of Cellulose and Derivatives Dietary Fibers and Useability in Bakery Products Söbeli C, Kayard C; Et Kalitesini Belirlemede Yeni Teknikler / New Techniques for Predicting Meat Quality ii

3 Editörden, Merhaba, GIDA Dergisi Y l 2014; Cilt 39; Say 4 [Temmuz-A ustos 2014] 2014 Haziran ortas na gelmeden elektronik ortamda yay mland. Bir di er deyifl ile henüz 3. say matbaaya gitmeden önce 4. say m z da haz rland. Çok muhtemelen meslektafllar m za bas l dergi olarak 39/3 ve 39/4 say lar Temmuz 2014 bafl nda beraberce gönderece iz. GIDA Dergisi 2014 y l ; Cilt 39; Say 4'te 1 ngilizce ve 4 Türkçe araflt rma makalesi ile 3 derleme makalesi var. Dikkat çekebilir: lk olarak 2013 y l ; 38. cilt; 3. say da DOI numaral 3 makale yay mlad k. Devam nda 4. say da DOI numaral 5 makale ve sonras nda her dergide DOI numaral 8 makale olmak üzere bu güne geldik ama bu say da DOI numaras alm fl makale say s 7 dir. Yani bir eksi imiz bulunuyor. DOI numaras, bir anlamda uluslararas geçerli olan bir makale kimli idir. GIDA Dergisi olarak DOI numaras n çok yaklafl k 1 y l süre ile ticari bir kurulufltan ald k. Sonra kendimizin do rudan DOI numaras almas gereklili i ortaya ç kt. Gereken baflvurular m z yapt k ama hemen arkas ndan baflka bir sürece girdik. DOI numaras ile ilgili bu süreç içinde birkaç aksama olacak gibi görülüyor ancak elimizden gelen gayreti gösteriyoruz. Önümüzde Kas m 2013 tarihlerinde Kufladas Pine Bay Otelde yapaca m z 2. Uluslararas G da Teknolojisi Kongresi oldu unu ve adresinde kay tlar n devam etti ini hat rlatmak isterim. Kongre için bildiri özeti gönderilme süresi bitmifl de ildir ve bildiri özetleri gelmeye devam etmektedir. Sadece geç gönderilen bildiri özetleri kabul edilirse, yazarlar n n erken kay t ödeme flans azalmaktad r. Sevgi ve sayg lar mla, Prof. Dr. A. Kadir Halkman iii

4 A Message from the Editor-in-Chief Hello, The forth issue of volume 39 of the year 2014 has been published in electronic media before the midst of June. In other words; forth issue has also been prepared before the printing of the third issue. We will very probably send the printed 39/3 and 39/4 issues together to our colleagues at the beginning of July In addition to 1 research article in English and 4 research articles in Turkish, there are 3 review articles in the forth issue of volume 39 of the year It may receive attention: We published 3 articles with DOI number in the third issue of volume 38 of the year Subsequently, there are 5 articles with DOI in the forth issue and thenceforth we have come with 8 articles with DOI in each issue, but the number of article with DOI number in this issue is 7. In other words, we have one absent. DOI number, in a sense, is an article identifier that is valid internationally. The FOOD Journal has received its DOI number from a commercial entity for approximately 1 year. Then, the necessity of getting the DOI number directly by ourselves had come out. We made our application, but we have immediately entered another process after that. It seems that there will be a few disruptions in this process regarding the DOI number, but we strive our best. I would like to remind you once again that there will be the 2 nd International Congress on Food Technology at Pine Bay Hotel in Kufladas on November, 2013 and the registration has been continuing at The time for abstract submission for the Congress has not been finished yet and the submission of abstracts has been continuing. Only if late-submitted abstracts are accepted, the chance of early registration of their authors is decreased. Best Regards, Prof. A. Kadir Halkman iv

5 GIDA (2014) 39 (4): doi: GD14015 Research / Araflt rma EXOPOLYSACCHARIDE PRODUCER STREPTOCOCCUS THERMOPHILUS ST8.01 STRAIN; A POTENTIAL PROBIOTIC CULTURE Banu Özden Tuncer 1 *, Yasin Tuncer 1 1 Faculty of Engineering, Department of Food Engineering, Süleyman Demirel University, Isparta, Turkey Received / Gelifl tarihi: Received in revised form /Düzeltilerek Gelifl tarihi: Accepted / Kabul tarihi: Abstract The aim of this study was to determine the probiotic potential of exopolysaccharide (EPS) producer Streptococcus thermophilus ST8.01 strain. This strain was able to survive at ph 3 and 1% bile salt. Viable counts were enumerated as 4.80±0.04 and 2.11±0.06 log cfu/ml after exposure to 0.4% phenol and gastric juice at ph 3, respectively. Strep. thermophilus ST8.01 was able to grow at 100 mg/l lysozyme and showed to have high autoaggregation (49.55±6.24%) and hydrophobicity abilities (67.23±7.16%). The ST8.01 strain was also found sensitive to most clinically important antibiotics. Results obtained in this study suggest that Strep. thermophilus ST8.01 strain may be used as a probiotic starter culture to produce dairy products. Keywords: Streptococcus thermophilus, exopolysaccharide, probiotic properties, antibiotic susceptibility EKZOPOLİSAKKARİT ÜRETİCİSİ STREPTOCOCCUS THERMOPHILUS ST8.01 SUŞU; POTANSİYEL PROBİYOTİK KÜLTÜR Özet Bu çal flman n amac, ekzopolisakkarit (EPS) üreticisi Streptococcus thermophilus ST8.01 suflunun probiyotik potansiyelinin belirlenmesidir. Bu sufl ph 3 ve %1 safra tuzunda hayatta kalma yetene ine sahiptir. %0.4 fenol ve ph s 3 e ayarlanm fl mide suyu uygulamas sonras canl hücre say s s ras yla 4.80±0.04 ve 2.11±0.06 log kob/ml olarak ölçülmüfltür. Strep. thermophilus ST8.01, 100 mg/l lizozim konsantrasyonunda geliflebilme ve yüksek otoagregasyon (%49.55±6.24) ve hidrofobisite (%67.23±7.16) yetene ine sahiptir. ST8.01 suflu ayn zamanda klinik olarak önemli olan antibiyotiklere karfl duyarl bulunmufltur. Bu araflt rmadan elde edilen sonuçlar, Strep. thermophilus ST8.01 suflunun süt ürünleri üretiminde probiyotik starter kültür olarak kullan labilece ini düflündürmektedir. Anahtar kelimeler: Streptococcus thermophilus, ekzopolisakkarit, probiyotik özellikler, antibiyotik duyarl l k * Corresponding author/ Yazışmalardan sorumlu yazar banutuncer@sdu.edu.tr (+90) (+90)

6 B. Özden Tuncer, Y. Tuncer INTRODUCTION The relation between nutrition and good health has become more interesting during the recent years. Researches have increased to defining of food and food components with this driving force of increasing conscious of population. Probiotic products were defined as foods that contain live microorganisms providing positive effects on health of consumers (1). Especially popularity of dairy products with probiotic bacteria have increased day by day and still be demanded on the functional food market (2). Briefly probiotics are defined as "Live microorganisms which when administered in adequate amounts confer a health benefit on the host" by WHO/FAO (3). Lactic acid bacteria, particularly the Lactobacillus and Bifidobacterium spp. are known as probiotics most extensively studied and widely used in dairy products. Besides these species, member of the genera Enterococcus, Streptococcus and Propionobacterium are also esteemed as probiotics (4). Strep. thermophilus is a common dairy starter extensively used in the production of yogurts, cheese and some fermented milk products. Strep. thermophilus which is recognized as safe (GRAS), can survive in the gastrointestinal system; even though it is known that the ability to attach to intestinal epithelial cells is relatively weak and it could be damaged in gastric acidic condition (5-7). Also it has some inherent functional properties important for food industry such as organoleptic, technological and nutritional advantages (8). Besides these beneficial effects it is indicated that Strep. thermophilus can promote the health of human and animals. Different researchers reported that Strep. thermophilus can improve the intestinal microflora, prevent diarrhea induced by using antibiotics, reduce the lactose intolerance and the risks of certain cancers, ulcers, imflammation, stimulate the immune system, and also it can be used for curing some atopic dermatitis (9-17). In addition many Strep. thermophilus strains have most of the probiotic characteristics (resistance to bile salts, low ph degrees and gastric juice, hydrophobisity activitiy, etc.) desired for starter culture development processes (18, 19). The goal of this study was to determine some probiotic properties and antibiotic susceptibility of Strep. thermophilus ST8.01 which was characterized as exopolysaccharide (EPS) producer previously (20) isolated from homemade yogurt. MATERIAL and METHODS Bacterial Strain and Growth Condition Streptococcus thermophilus ST8.01 strain used in this study was previously isolated from homemade yoghurt and characterized as EPS producer (20). Strain ST8.01 was grown in M17 broth (Merck KgaA, Darmstadt, Germany) with 5% glucose (GM17) during the experiments. Stock culture of the strain was maintained at -20 C in GM17 broth added with 15% glycerol. Bile Salt Resistance and Acid Tolerance Ability of tolerance for bile salts was determined based on the method of Gilliland and Walker (21) with slight modifications. Strep. thermophilus ST8.01 was inoculated (1 %, v/v) in GM17 broth supplemented with 0.3%, 0.5% and 1% (w/v) ox bile (Acumedia, Lansing, Michigan, USA) and without ox bile as a control incubated at 37 C. Survival of the strain was determined on the GM17 agar as colony forming units (cfu) at 0. h and 24. h. Inhibition (%) was calculated with the following equation: Inhibition % = {[(initial cfu/ml) - (final cfu/ml)] / [initial cfu/ml]} x 100 (1) For detecting of low ph tolerance, the ph of the 2 ml volume of sterile phosphate-buffered saline (PBS) was adjusted to 1, 3 and 5 with 1M HCl and ph 7.2 as control. Overnight culture of ST8.01 strain was harvested by centrifuged at 3000 g (10 min, 4 C) and washed once in sterile PBS. Pellet resuspended into PBS one-tenth of the culture volume was centrifuged. The 0.1 ml of suspension was added into 2 ml PBS at ph 1, 3 and 5 then incubated at 37 C. Viable cells were enumerated at 0., 1., 2., 3. and 4. h on GM17 agar plates (22). Tolerance to Simulated Gastric Juice Sterile saline solutiun (0.5%, w/v) with pepsin (Sigma-Aldrich, St Louis, Missouri, USA) (0.3%, w/v) adjusted to ph 2 and 3 were used to simulate gastric condition. 30 ml overnight culture was centrifuged at 6000 g at 5 C for 20 min. Pellet was washed twice with K 2 HPO 4 (50 mm, ph 6.5) and then resuspended in 3 ml of the same buffer. 1 ml of resuspended culture was centrifuged at g (5 min, 5 C) and resuspended in gastric juice (10 ml) ph 2 and 3. At the begining of incubation period and at the end of 3 h incubation 196

7 Exopolysaccharide Producer Streptococcus thermophilus... time viable cell counts were performed on GM17 agar (18). Inhibition (%) was calculated with equation 1. Resistance to Lysozyme and Survival in The Presence of Phenol The effect of lysozyme on the growth on Strep. thermophilus ST8.01 was examined by the method of Brennan et al. (23). The activated culture was inoculated (2%, v/v) into GM17 broth with and without 100 mg/l lysozyme (Sigma-Aldrich). Bacterial cells were counted on GM17 agar plates at 0., 3. and after 24 h incubation at 37 C. Survival of the Strep. thermophilus ST8.01 in the presence of phenol was determined based on the method of Teply (24). Overnight culture was inoculated (2%) into 10 ml GM17 broth with and without 0.4% phenol and incubated at 37 C. Viable cell numbers were determined at 0., 3. and 24. h of incubation on GM17 agar plates. Inhibition (%) was calculated with equation 1 for phenol treatment. Increase (%) was calculated with equation 2 for lysozyme treatment: Increase % = {[(final cfu/ml) - (initial cfu/ml)] / [final cfu/ml]} x 100 (2) Autoaggregation Assays Overnight culture was harvested by centrifugation at 7000 g (10 min, 20 C) and washed with sterile saline (0.85% NaCl, w/v). Cell consantration was adjusted A 660 nm = 0.3 within sterile saline and incubated at 37 C for 60 min. The end of the incubation period suspension was centrifuged at 300 g (2 min, 20 C) and absorbance of the supernatant (A 60 ) was measured (25). Autoaggregation was calculated with the following equation: Autoaggregation = (A 0 A 60 ) / A 0 x 100 (3) Hydrophobicity Bacterial culture was centrifuged at 5000 g for 15 min after growth in GM17 broth overnight. Pellet was washed twice in sterile PBS and resuspended in KNO 3 (0.1 M, ph 6.2) then absorbance of the cell suspension was adjusted at A 0 = (600 nm). 1 ml of xylene was added to cell suspension and incubated at room temperature for 10 min. After this preincubation time suspension was vortexed (2 min) to mix the two phase system and incubated at room temperature. At the end of the 20 min, aquase phase was removed carefully and its absorbance was measured at 600 nm (A 1 ) (26). The percentage of cell cerface hydrophobicity was determined using the following equation: Hydrophobicity = 1 (A 1 / A 0 ) x 100 (4) Antibiotic Susceptibility Disc diffusion method was used to determine antibiotic susceptibility of Strep. thermophilus ST8.01 against vancomycin (30 µg, Oxoid Ltd, Wade Road, Basingstoke, Hants, UK), tetracycline (30 µg, Oxoid), streptomycin (300 µg, Oxoid), penicillin G (10 units, Oxoid), erythromycin (15 µg, Oxoid), ampicillin (10 µg, Oxoid), chloramphenicol (30 µg, Oxoid), gentamicin (120 µg, Oxoid), norfloxacin (10 µg, Oxoid) and sulphamethoxazole/ trimethoprim ( µg, Oxoid). Inhibition zones were measured as diameter (mm) and results were expressed as susceptible, moderate susceptible and resistant by comparing with the interpretative zone diameters given by Clinical and Laboratuary Standards Institute (27). RESULTS and DISCUSSION Bile Salt Resistance and Acid Tolerance Bile tolerance has been described as an important factor for the survival and growth of LAB in the intestinal tract (21). Probiotic strains must be resistant to bile salt at 0.3% if these are to be used for human beings (28). In our study Strep. thermophilus ST8.01 maintained the viability at three concentrations of bile salt (0.3%, 0.5% and 1%, w/v) after 24 h incubation. The highest inhibition percentage of this strain was detected as at 1% bile salt (Figure 1). Similar to our results, Iyer et al. (29) showed that two Strep. thermophilus strains survived at 0.5%, 1% and 2% bile salt concentrations after 180 min. Conversely Vinderola and Reinheimer (18) informed that bile resistance of Strep. thermophilus strains was poor Figure 1. Effect of bile salt concentrations on the viability of Strep. thermophilus ST8.01 at 37 C for 24 h. 197

8 B. Özden Tuncer, Y. Tuncer and most of the strains were inhibited at 0.5% bile salt. In addition some researchers indicated that many S. thermophilus were inhibited at 0.15% bile salt (30). Contrary of this statement Strep. thermophilus ST8.01 survived even after 24 h at 1% bile salt as specified by Mahmood et al. (31). The growth of Strep. thermophilus ST8.01 rapidly inhibited at ph 1 at the begining of the incubation and at the end of the two hours ST8.01 was completely inhibited. ph 3 represented less lethal environment to Strep. thermophilus ST8.01 than ph 1 but still cell viability was decreased during incubation and inhibition percentage of this strain was greater than >99.99% at ph 3. However, after 4 h at ph 5 Strep. thermophilus ST8.01 maintained its viability and the inhibition was detected at least (95.43%) for ph 5 among the low ph treatments (Figure 2). Previous studies showed that some Strep. thermophilus strains were dead when exposed to low ph degrees similar with our results (31-34). On the other hand Aswathy et al. (28) reported that most of the lactic acid bacteria isolates including Streptococcus grew at ph 5 and played a role during the fermentation of dairy milk and vegetables. Vinderola and Reinheimer (18) reported that Strep. thermophilus showed to have very poor survival under simulated gastric conditions. Controversially, Pilar et al. (35) and Iyer et al. (29) reported that Strep. thermophilus maintained the viability under the simulated gastrointestinal stress condition. On the other hand the evidence of viable Strep. thermophilus in human feces and so the transit from the gastrointestinal tract were observed from the volunteers consuming the yogurt samples (6, 7). Based on these data and maintanence the vitality of the strain ST8.01 (2.11 log cfu/ml) when exposed to ph 3 with 0.3% pepsin suggested that it may survive when consumed with fermented milk product such as yogurt but to prove that food applications should be done at the further studies. Figure 3. Tolerance to simulated gastric juice of Strep. thermophilus ST8.01 at 37 C. Figure 2. Effect of low ph on the viability of Strep. thermophilus ST8.01 at 37 C. Tolerance to Simulated Gastric Juice Gastric juice studies were done in 3 hours incubation for implementing residence time in stomach condition. Among the lactic acid bacteria Strep. thermophilus was known to show more sensitivity to simulated gastric juice (18). Strep. thermophilus ST8.01 showed significant decrease in the viable counts at ph 2 and ph 3 with 0.3% pepsin after 3 h incubation at 37 C (Figure 3). For simulated gastric juice experiments at ph 2 and ph 3, inhibition percentage of this strain were calculated as >99.99%. Similar to our results, Resistance to Lysozyme and Survival in The Presence of Phenol In this study we determined that Strep. thermophilus ST8.01 was grown even presence of lysozyme at the level of 100 mg/l (Figure 4). Increase percentages of control sample were calculated as 83.78% and 99.55% after first 3 h and 24 h incubation, respectively. For lysozyme experiment, increase percentages were exhibited as 69.80% and 95.32% after first 3 h and 24 h incubation, respectively. Lysozyme is used as attractive preservative to inhibit food spoilage bacteria which are harmful to human health. It is reported that using lysozyme at the levels up to 25 mg/l does not affect the growth of Streptococci and Lactobacilli. Vinderola et al. (36) determined that growth of the probiotic bacteria was not effected by the lysozyme treatment at the level of 25 mg/l and reported that high levels of lysozyme should be used for selecting probiotic starter bacteria. 198

9 Exopolysaccharide Producer Streptococcus thermophilus... On the other hand Xanthopoulos et al. (30) reported that some Strep. thermophilus showed resistance to 100 mg/l lysozyme. Figure 4. Resistance to lysozyme of Strep. thermophilus ST8.01 at 37 C. Phenols can be occured in the intestines because of the deamination of some aromatic amino acids from the digested foods through the agency of the bacteria. Therefore tolerance to phenols is a desired probiotic characteristic (21, 37). In the present study, growth of the Strep. thermophilus ST8.01 inhibited after 24 h presence of 0.4% phenol but at the end of the first 3 hours of incubation vitality of the strain ST8.01 was still retain (Figure 5). After 3 hours incubation, inhibition percentage of phenol treated sample was calculated as 64.52%. Different researchers reported that some lactic acid bacteria showed high tolerance to phenol ( %) (38, 39) but Strep. thermophilus was known as very sensitive to this chemical (30). Figure 5. Resistance to phenol (0.4%) of Strep. thermophilus ST8.01 at 37 C. Autoaggregation Ability Autoaggragation value of Strep. thermophilus ST8.01 was recorded as 49.55±6.24%. Among LAB various autoaggregation values were determined and it was indicated that the autoaggragation ability might be strain dependent. It was also reported that physochemical characteristics of cell surface (such as hydrophobicity) may affect the autoaggregation ability (40-42). The importance of autoaggregation ability for probiotics is that it might be necessary for their adhesion to the intestinal epithelial cells (43, 44). Based on the previous studies of Canzi et al. (45), Rahman et al. (46), and Kõll et al. (47), Strep. thermophilus ST8.01 has moderate autoaggregation but still this value might be considered to be higher then many of lactic acid bacteria. Hydrophobicity Determining of bacterial adherence to hydrocarbons was performed as described by Rosenberg (26) which is generally known as MATH or BATH test. Strep. thermophilus ST8.01 was showed 67.23±7.16% affinity to xylene. Previous studies indicated that lactic acid starter species have lower hydrophobicity (under 32%) than other lactic acid bacteria. However most of the probiotic bacteria among the lactic starters have higher affinity to hydrocarbons than 32% (18). Although studies for determining of hydrophobicity of Strep. thermophilus have been rarely done and it is reported that hydrophobicity of Strep. thermophilus varied from 24% to 98% depending on their source (48). In this study hydrophobicity value of Strep. thermophilus ST8.01 was also found higher than many of the Strep. thermophilus strains (67.23±7.16%) as similar with the study of Iyer et al. (29). Antibiotic Susceptibility Strep. thermophilus ST8.01 was assayed to 10 antibiotics using disc diffusion method. Strain ST8.01 exhibited complete susceptibility to nine antibiotics. This strain showed moderate susceptibility to only sulphamethoxazole/ trimethoprim. Previous studies confirmed that Strep. thermophilus is usually showed susceptibility to tetracycline, erythromycin, chloramphenicol, cephalothin, quinupristin/dalfopristin and ciprofloxacin while it has moderate susceptibility to high resistance to gentamicin, kanamycin and streptomycin (49-51). It is also reported that Strep. thermophilus used in yoghurt production has not been resistant to ampicillin and penicilin (31, 52), as strain ST8.01. Tosi et al. (53) determined that Strep. thermophilus strains can show atypic antibiotic resistance patterns. In their study some strains were shown resistant to tetracycline and clindamycin while some other resistant to 199

10 B. Özden Tuncer, Y. Tuncer tetracycline and sensitive to erythromycin at the same time. The major problem is considered as the antibiotic genes might be transferred to pathogenic bacteria including Streptococci, Listeria and Enterococci in the gastrointestinal tract or in digested foods. For this reason complete susceptibility to clinically important antibiotics of Strep. thermophilus ST8.01 is adventageous. CONCLUSION In this study, maintenance the vitality of Strep. thermophilus ST8.01 under some gastrointestinal stress conditions (bile salt, lysozyme, phenol and situmulated gastric juice); having autoaggregation and hydrophobicity abilities are required properties for probiotic cultures. Besides these features, if we consider rapid acidification, good proteolitic activity and good flavour compound production of EPS-producing Strep. thermophilus ST8.01 (20), this strain may be a candidate for probiotic starter culture. REFERENCES 1.Shah NP Functional foods from probiotics and prebiotics. Food Technol, 55: Agrawal R Probiotics: an emerging food supplement with health benefits. Food Biotechnol, 19: FAO/WHO. Report of a Joint FAO/WHO Working Group on Drafting Guidelines for the Evaluation of Probiotics in Food ftp://ftp.fao.org/es/ esn/food/wgreport2.pdf. (Eriflim tarihi ) 4.Sanders ME, In t Veld JH Bringing a probiotic-containing functional food to the market: Microbiological, product, regulatory and labeling issues. Antonie Leeuwenhoek, 76: Brigidi P, Swennen E, Vitali B, Rossi M, Matteuzzi M PCR detection of Bifidobacterium strains and Streptococcus thermophilus in feces of human subjects after oral bacteriotherapy and yogurt consumption. Int J Food Microbiol, 81: Mater DDG, Bretigny L, Firnesse O, Flores MJ, Mogenet A, Bresson JL, Corthier G Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus survive gastrointestinal transit of healthy volunteer consuming yogurt. FEMS Microbiol Lett, 250: Elli M, Callegari ML, Ferrari S, Bessi E, Cattivelli D, Soldi S Survival of yogurt bacteria in the human gut. Appl Environ Microbiol, 72: Leroy F, De Vuyst L Lactic acid bacteria as functional starter cultures for the food fermentation industry. Trends Food Sci Tech, 15: Pool-Zobel BL, Munzner R, Holzapfel H Antigenotoxic properties of lactic acid bacteria in the S. Typhimurium Mutagenicity assay. Nutr Cancer, 20: Naidu AS, Bidlack WR, Clemens RA Probiotic spectra of lactic acid bacteria (LAB). Crit Rev Food Sci, 38: Pochapin M The effect of probiotics on Clostridium difficile diarrhea. Am J Gastroenterol, 95: Rizkalla SJ, Luo W, Kabir M, Chevalier A, Pacher N, Slama G Chronic consumption of fresh but not heated yogurt improves breath-hydrogen status and short-chain fatty acid profiles: A controlled study in healthy men with or without lactose maldigestion. Am J Clin Nutr, 72: Wollowski I, Rechkemmer G, Pool-Zobel BL Protective role of probiotics and prebiotics in colon cancer. Am J Clin Nutr, 73: Isolauri E, Sutas Y, Kankaanpää P, Arvilommi H, Salminen S Probiotics: effects of immunity. Am J Clin Nutr, 73: Bojrab G Composition, of L. bulgaricus and S. thermophilus, for the treatment of gastrointestinal disorders, hyperlipidemia, autoimmune diseases, and obesity. A61K35/74+M European patent application EP A2, Lacpro Ind Llc (US). 16.Di Marzio L, Centi C, Cinque B, Masci S, Giuliani M, Arcieri A, Zicari L, De Simone C, Cifone MG Effect of the lactic acid bacterium Streptococcus thermophilus on stratum orneum ceramide levels and signs and symptoms of atopic dermatitis patients. Exp Dermatol, 12: Adolfsson O, Meydani SN, Russell RM Yoghurt and gut function. Am J Clin Nutr, 80: Vinderola CG, Reinheimer JA Lactic acid starter and probiotic bacteria: a comparative in vitro study of probiotic characteristics and biological barrier resistance. Food Res Int, 36:

11 Exopolysaccharide Producer Streptococcus thermophilus Guarner F, Perdigon G, Corthier G, Salminen S, Koletzko B, Morelli L Should yoghurt cultures be considered probiotic? Brit J Nutr, 93: Özden-Tuncer B, Tuncer Y Properties of exopolysaccharide producer Streptococcus thermophilus ST8.01 isolated from homemade yoghurt. J Food Nutr Res, 50: Gilliland SE, Walker DK Factors to consider when selecting a culture of Lactobacillus acidophilus as a dietary adjunct to produce a hypocholesterolemic effect in humans. J Dairy Sci, 73: Conway PL, Gorbach SL, Goldin BR Survival of lactic acid bacteria in the human stomach and adhesion to intestinal cells. J Dairy Sci, 70: Brennan M, Wansmail B, Johnson BC, Ray B Cellular damage in dried Lactobacillus acidophilus. J Food Protect, 49: Teply M Ciste mlekarske kultury. Phara. SNTL Nakladatelstvi. Technicke Litertury. In: Starters for Fermented Milks, Kurmann JA (chief ed), IDF Bulletin 227; pp Basson A, Flemming LA, Chenia HY Evaluation of adherence, hydrophobicity, aggregation characteristics and biofilm development of Flavobacterium johnsoniae-like isolates from South African aquaculture systems. Microb Ecol, 55: Rosenberg M, Gutnick D, Rosenberg E Adherence of bacteria to hydrocarbons: a simple method for measuring cell-surface hydrophobicity. FEMS Microbiol Lett, 9: CLSI M100-S Performance Standards for Antimicrobial Susceptibility Testing 21 th Informational Supplement. Clinical and Laboratory Standards Institute, Wayne PA, USA. 28.Aswathy RG, Ismail B, John RP, Nampoothiri KM Evaluation of the probiotic characteristics of newly isolated lactic acid bacteria. Appl Biochem Biotech, 151: , Iyer R, Tomar SK, Kapila S, Mani J, Singh R Probiotic properties of folate producing Streptococcus thermophilus strains. Food Res Int, 43: , Xanthopoulos V, Ipsilandis CG, Tzanetakis N Use of a selected multi-strain potential probiotic culture for the manufacture of set-type yogurt from caprine milk. Small Ruminant Research, 106 : Mahmood T, Masud T, Imran M, Ahmed I, Khalid N Selection and characterization of probiotic culture of Streptococcus thermophilus from dahi. Int Food Sci Nutr, 64 (4): Haller D, Colbus H, Gänzle MG, Scherenbacher P, Bode C, Hammes WP Metabolic and functional properties of lactic acid bacteria in the gastro-intestinal ecosystem: a comparative in vitro study between bacteria of intestinal and fermented food origin. Syst Appl Microbiol, 24: Maurad K, Meriem K Probiotic characteristics of Lactobacillus plantarum strains from traditional butter made from camel milk in arid regions (Sahara) of Algeria. Grasas Aceites, 59: Khalil R Evidence for probiotic potential of a capsular-producing Streptococcus thermophilus CHCC 3534 strain. Pol J Microbiol, 58: Pilar F, Paloma L, Angel LC, Carmen P, Teresa R Probiotic strains: survival under simulated gastrointestinal conditions, in vitro adhesion to Caco-2 cells and effect on cytokine secretion. Eur Food Res Technol, 227: Vinderola CG, Mocchiutti P, Reinheimer JA Interactions among lactic acid starter and probiotic bacteria used for fermented dairy products. J Dairy Sci, 85: Suscovic J. Brkic B, Matosic S, Maric V Lactobacillus acidophilus M92 as potential probiotic strain. Milchwissenschaft, 52: Xanthopoulos V, Litopoulou-Tzanetaki E, Tzanetakis N Characterization of Lactobacillus isolates frominfant faeces as dietary adjuncts. Food Microbiol, 17: Acharya MR, Shah R Selection of human isolates of Bifidobacteria for their use as probiotics. Appl Biochem Biotech, : Kos B, Suskovic J, Vukovic S, Simpraga M, Frece J, Matosic S Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92. J Appl Microbiol,

12 B. Özden Tuncer, Y. Tuncer 41.Vlkova E, Rada V, Smehisova J, Killer J Auto-aggregation and co-aggregation ability in Bifidobacteria and Clostridia. Folia Microbiol, 53: Todorov SD, von Mollendorff JW, Moelich E, Moelich E, Muller N, Witthuhn RC, Dicks LMT Evaluation of potential probiotics properties of Enterococcus mundtii, its survival in boza and in situ bacteriocin production. Food Technol Biotech, 47: Asl m B, Onal D, Beyatl Y Factors influencing autoaggregation and aggregation of Lactobacillus delbrueckii subsp. bulgaricus isolated from handmade yogurt. J Food Protect, 70: Collado MC, Meriluoto J, Salminen S Adhesion and aggregation properties of probiotic and pathogen strains. Eur Food Res Technol, 226: Canzi E, Guglielmetti S, Mora D, Tamagnini I, Parini C Conditions affecting cell surface properties of human intestinal bifidobacteria. Antonie Leeuwenhoek, 88: , Rahman MM, Kim WS, Kumura H, Shimazaki, K Autoaggregation and surface hydrophobicity of bifidobacteria. World J Microb Biot, 24: Kõll P, Mändar R, Smidt I, Hutt P, Truusalu K, Mikelsaar RH, Shchepetova J, Krogh-Andersen K, Marcotte H, Hammarström L, Mikelsaar M Screening and evaluation of human intestinal Lactobacilli for the development of novel gastrointestinal probiotics. Curr Microbiol, 61: Flint SH, Brooks JD, Bremer PJ The influence ofcell surface properties of thermophilic Streptococci on attachment to stainless steel. J Appl Microbiol, 83: Katla AK, Kruse H, Jhonsen G, Herikstad H Antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products. Int J Food Microbiol, 67: Temmerman R, Pot B, Huys G, Swings J Identification and antibiotic susceptibility of bacterial isolates from probiotic products. Int J Food Microbiol, 81: Asl m B, Beyatli Y Antibiotic resistance and plasmid DNA contents of Streptococcus thermophilus strains isolated from Turkish yogurts. Turk J Vet Anim Sci, 28: Hummel AS, Hertel C, Holzapfel WH, Franz CM Antibiotic resistances of starter and probiotic strains of lactic acid bacteria. Appl Environ Microb, 73: Tosi L, Berruti G, Danielsen M, Wind A, Huys G, Morelli L Susceptibility of Streptococcus thermophilus to antibiotics. Antonie Leeuwenhoek, 92:

13 GIDA (2014) 39 (4): doi: /gida GD Araflt rma /Research Özet DONDURMA İŞLEMİNDE BAZI ÖN UYGULAMALARIN ÇİLEK ve MANDALİNANIN KALİTE ÖZELLİKLERİNE ETKİLERİNİN İNCELENMESİ Taner Baysal, Ahsen Rayman Ergün*, Berrin Akgün, Gözde Karcı, Nazmiye Kaplan Ege Üniversitesi, Mühendislik Fakültesi, G da Mühendisli i Bölümü, Bornova, zmir Gelifl tarihi / Received: Düzeltilerek Gelifl tarihi / Received in revised form: Kabul tarihi / Accepted: Dondurma prosesinde; yenilebilir filmle (pullulan) kaplama, fleker flurubuna (%40 l k) dald rma ve kalsiyum klorür (CaCl 2 ) çözeltisine dald rma ön ifllemlerinin ürün kalitesine etkilerinin incelendi i bu çal flmada çilek ve mandalina örnekleri ay kland ktan ve y kand ktan sonra befl gruba ayr lm flt r. Bu gruplar; kontrol grubu (hiçbir ifllem uygulanmam fl), fleker flurubu, flurup+cacl 2, pullulan ve pullulan+cacl 2 gruplar d r. Meyve gruplar ifllemler sonras nda -18 C de dondurulmufl ve ard ndan so uk hava deposunda (-24 C), 15 gün süreyle depolanm flt r. Depolama süresince 0. ve 15. günlerde, örneklerde; a rl k ve s z nt kayb, titre edilebilir asitlik, ph, suda çözünür kuru madde, sertlik ölçümü analizleri gerçeklefltirilmifl ayr ca renk ve duyusal özellikler incelenmifltir. Bu analizler sonucunda; a rl k kayb, s z nt kayb, ph ve suda çözünür kuru madde de erlerinin flurup+cacl 2 ve pullulan+cacl 2 uygulamalar nda daha iyi korundu u belirlenmifltir. Sonuç olarak meyvelere uygulanan, fleker flurubuna dald rma ve yenilebilir film kaplamalar n tek bafl na uygulanmas na k yasla bunlara ek olarak CaCl 2 eklenmesinin daha iyi sonuçlar verdi i ve bu ön ifllemlerin tüketime haz r meyve kalitesi üzerinde olumlu etki sa lad gözlenmifltir. Anahtar kelimeler: Dondurma, çilek, mandalina, fleker flurubu, yenilebilir filmle kaplama, pullulan, CaCl 2. DETERMINING THE EFFECTS of SOME PRETREATMENTS on THE QUALITY CHARACTERISTICS of STRAWBERRY and MANDARIN in FREEZING PROCESS Abstract In this study, the aim is to evaluate the effects of pretreatments, such as an edible film coating with pullulan and the immersion of fruit into a sugar solution before the freezing process on the quality of the fruits. In order to investigate the advantage of immersion into a CaCl 2 solution the pretreatments were combined; strawberries and mandarins were separated into five different groups after a washing and cleaning processes. These groups were: the control (without any pretreatments), sugar syrup, syrup+cacl 2, pullulan, and pullulan+cacl 2. After the different pretreatments, the fruits were frozen at -18 C and stored at -24 C for 15 days. The analyses were done after production and at the 15th day of freezing. The raw material and products were analyzed for weight and drip loss, titratable acidity, ph, soluble dry matter, hardness, colour, and sensory tests. According to the results of the analysis; the weight and drip loss, ph, and soluble dry matter properties were protected better in the group of syrup+cacl 2 and pullulan+cacl 2. As a result, better results were obtained by adding CaCl 2 additionally to the application of sugar syrup and edible film coatings and these pre-treatments provided a positive impact on the quality of the fruits. Keywords: Freezing, strawberry, mandarin, sugar syrup, edible film coating, pullulan, CaCl 2. *Yazışmalardan sorumlu yazar / Corresponding author; ahsenrayman@hotmail.com, (+90) , (+90)

14 T. Baysal, A. R. Ergün, B. Akgün, G. Karcı, N. Kaplan GİRİŞ G dalar aras nda en kolay ve h zl bozulanlar, meyve ve sebzelerdir. Bunun nedeni di er g dalara oranla yap lar nda %98 e ulaflabilen miktarlarda su içermeleridir. Dondurma ifllemi sayesinde g dalar n içerdikleri su, buz kristallerine dönüflünce bozulmaya yol açan mikroorganizmalar n aktiviteleri durmakta ya da yavafllamakta böylece kimyasal ve biyokimyasal de iflimler asgariye indirilerek g dalar n en do al haliyle korunmas sa lanmaktad r. Bu özelli i ile dondurma ifllemi g dalar n kalite, tat, koku ve besin de erinin en iyi korundu u g da saklama yöntemi olarak kabul edilmektedir (1). fieker ilavesi, meyveler için oksijen ile temas engelleyerek, renk ve görünüflün korunmas n sa lamas yönünden son derece önemli bir ön ifllemdir. Genellikle meyveyi kaplamak amac yla oksijen iletimine ve esmerleflmeye karfl bir bariyer olarak hareket eden, %30-60 konsantrasyon aral nda fleker fluruplar kullan l r. Çeflitli çal flmalar ön ifllem olarak flekerle muamelenin; dondurma ifllemi s ras nda tat, koku, renk ve besin de eri üzerine koruyucu etkisini göstermifltir (2). G dalar n raf ömürlerini uzatmak amac yla dondurma ifllemi öncesi uygulanabilecek yöntemlerden biri de yenilebilir film ve kaplamalar n kullan lmas d r. Bu uygulama ile üründen su kayb önlenebilece i gibi çevreyle gaz al flveriflinin de engellenmesi sonucunda, solunum h z da yavafllat labilmektedir. Özellikle son y llarda, taze, dondurulmufl veya ifllenmifl birçok ürünün raf ömürlerini uzatmak ve kalitesini gelifltirmek amac yla yenilebilir kaplamalar n kullan m ile ilgili çal flmalar daha yo un bir flekilde yürütülmektedir (3-5). Yenilebilir g da filmleri üretiminde kullan lan kaynaklar; jelâtin, kazein ve zein gibi proteinler ile selüloz ve dekstrin karakterli maddeler, alginat, mumlar, doymufl ya asitleri, monogliseritler ve bunlar n baz türevlerinden oluflmaktad r (6, 7). Pullulan filmler ekstraselüler mikrobiyel polisakkarit filmlerdir ve kokusuz, berrak bir film oluflturmaktad rlar. Bu filmler, düflük ba l nemde iyi bir oksijen bariyer özelli i göstererek, g dan n raf ömrünün uzat lmas amac yla kullan lmaktad rlar. Yüksek ya ve düflük su içeri ine sahip g dalarda da ac laflma ve oksidasyonun önlenmesi amac yla kullan l rlar (8, 9). Ayr ca, meyvelere dondurma öncesi uygulanacak ifllemler aras nda çözündürme sonras dokunun korunmas amac yla Ca + ilave edilmesi de birçok çal flmada araflt r lm flt r (10). Bu çal flmada dondurma ifllemi öncesi çilek ve mandalina segmentlerine uygulanan; pullulan film ile kaplama, fleker flurubu ve kalsiyum uygulamas gibi ön ifllemlerin, dondurulmufl meyvelerin kalite özellikleri üzerine etkisinin belirlenmesi amaçlanm flt r. MATERYAL VE YÖNTEM Materyal Yerel marketlerden temin edilen çilek (Fragaria vesca, cv. Selva) ve mandalina örnekleri (C. Reticulata, cv. Satsuma) Ege Üniversitesi, Meyve Sebze flleme pilot tesislerinde ifllenmifltir. Yöntem fieker flurubu, CaCl 2 çözeltisi ve pullulan çözeltisi haz rlanmas amac yla yap lan ön denemeler sonras nda kalite aç s ndan en olumlu sonuçlar n elde edildi i fleker flurup konsantrasyonu (%40 l k) seçilmifl ve Sakaroz (Merck Darmstadt, F.R, Germany) kullan larak haz rlanm flt r (11). Yap lan literatür araflt rmalar nda %1 lik konsantrasyondan daha yüksek oranda kullan lan CaCl 2 çözeltisinin örnekte tat bozuklu una yol açt belirtilmifltir (12-14). Bu nedenle, çal flmada CaCl 2 (Merck, Darmstadt, F.R, Germany) çözeltisinin konsantrasyonu %1 olarak seçilmifltir. Hem çilek hem mandalina için 50 ml %2,6 l k pullulan (P1-20 Hayashibara Co., Ltd., Okoyama, Japan), çözeltisi haz rlanm flt r. Bu çözeltiye, Pullulan+ CaCl 2 gruplar nda kullan lmak üzere 0.5 ml %1 lik CaCl 2 çözeltisi ilave edilmifltir. Çilek ve mandalina segmentleri; y kama, ay klama, kabuk soyma gibi ön ifllemlerinden sonra; pullulan, pullulan + CaCl 2, fleker flurubu, fleker flurubu+ CaCl 2 kaplama uygulamalar na tabi tutulmufltur. Tüm kaplama uygulamalar için meyveler 2 dakika (dk.) kaplama çözeltisinin içerisine dald r lm fl ve yaklafl k 20 C de 30 dk. kurumaya b rak lm flt r. Kuruma ifllemi tamamland ktan hemen sonra örnekler iki gruba ayr lm flt r (150 fler gram). 0. gün analizleri yap lacak örnekler dondurulmadan hemen laboratuvara al n rken di er örnekler dondurma ifllemi sonras nda 15 gün boyunca depoda (-24 C) muhafaza edilmifl ve 15. günde analizler gerçeklefltirilmifltir. Çileklerin dondurma iflleminde, bafllang ç s cakl 10 C, mandalinalar n ise bafllang ç s cakl 3.5 C olarak ölçülmüfltür. Çilekler 25 dk., mandalina 204

15 Dondurma İşleminde Bazı Ön Uygulamaların... örnekleri ise 11 dk. süre ile IQF dondurucuda (Frigoscandia, Helsinborg, Sweden) dondurulmufltur. Merkez s cakl -10 C s cakl a ulaflt anda ürünler su geçirgenli i düflük ve s l yap flabilme özelli i olan polietilen pofletlere koyularak depolama (-24 C) yap lm flt r. 15 günün sonunda meyveler 4 C de buzdolab nda çözündürülmüfl ve analize al nm flt r. Uygulaman n 0. ve 15. gününde ürünün Briks, ph, asitlik, renk, a rl k ve s z nt kayb, sertlik ve duyusal özellikleri belirlenmifl ve her meyve için kalite özellikleri aç s ndan 0. gün ve 15. gün kendi içerisinde, ayr ca günler aras nda da karfl laflt rmalar yap lm flt r. Yapılan Analizler ve Yöntemleri A rl k kayb, dondurulan meyvelerin dondurucudan ç kart ld ktan sonraki a rl ile çözündükten sonraki a rl aras ndaki fark n, bafllang ç a rl na oranlanmas (%) fleklinde hesaplanm flt r. S z nt kayb ise dondurucudan ç kar lan örneklerin tart ld ktan sonra oda s cakl nda 24 saat bekletildi inde ç kan su miktar n n hesaplanmas ile bulunmufltur (15). Çilek ve mandalina segmentleri, Sorvall Omni- Mixer (Kennesaw, GA, ABD) model parçalay c yard m yla püre haline getirildikten sonra, toplam asitlik, NaOH kullan larak (Emir Kimya, Ankara, Türkiye); titrimetrik yöntemle susuz sitrik asit (SSA) cinsinden (16), ph de eri, WTW marka InoLab model (Weilheim, Almanya) ph-metre ile (17), suda çözünür kuru madde ( Briks) de eri ise dijital el tipi A. Kruss DR model (Hamburg, Almanya) refraktometre ile belirlenmifltir (16). Sertlik nitelikleri penetrometre Sur Penetrometre PNR-6 (Berlin, Almanya) ile ölçülmüfl ve meyvelerin penetrometre de erleri kodlu uç kullan larak saptanm flt r. Meyveler penetrometre i nesiyle tabla aras na s k flt r lm fl ve i nenin meyve içinde 5 saniyede ald yol (mm) belirlenmifltir. Renk analizi Hunterlab marka Colorflex (CIELAB 10*/D 65, Road Reston, VA, ABD) renk ölçüm cihaz yla yap lm flt r. L*, a*, b*, de erleri kaydedilmifltir. Kaydedilen L*, a*, b*, de erleri 1 ve 2 nolu formüllerden yararlanarak E (Toplam renk fark ), ve Hue aç s de erleri hesaplanm flt r (18). Hue Angle = tan -1 (b/a) [2] Ayr ca haz rlanan tüm çilek ve mandalina örnekleri 6 adet e itimli panelist taraf ndan görünüfl ve [1] tekstür aç s ndan s ralama testine tabi tutularak duyusal olarak de erlendirilmifltir ve 0.05 güven aral nda istatistiksel analiz gerçeklefltirilmifltir (19). Ürünlerin fiziksel ve kimyasal analiz sonuçlar n n istatistiksel olarak de erlendirilmesi amac yla ise SPSS 15.0 paket program kullan lm flt r. ANOVA uygulan larak her bir örnek grubu Tukey testine göre 0.05 güven aral nda birbirleriyle karfl laflt r lm flt r (20). SONUÇLAR ve TARTIŞMA Ağırlık Kaybı Çilek ve mandalina örnekleri üzerine yap lan a rl k ve s z nt kayb analizlerinin sonuçlar Çizelge 1 de gösterilmifltir. 15. gün sonunda çilek örnekleri, kontrol örnekleri ile karfl laflt r ld nda en az a rl k kayb flurup+cacl 2 ve pullulan+cacl 2 uygulamalar nda saptanm flt r. statistiksel olarak ise a rl k kayb aç s ndan flurup+cacl 2 grubuyla kontrol grubu aras ndaki fark n önemli oldu u bulunmufltur (P<0.05). Benzer bir flekilde, Han ve ark., (2004), kitosan film ile kaplanan çileklerde kontrol (kaplanmam fl) örneklerine göre depolama (2 C- %88 RH) sonucu a rl k kayb n n azald n bildirmifllerdir (21). Farkl kaplama çözeltileri ile çal fl lan baflka bir araflt rmada, kaplanan çilek örnekleri (0 5 C) de %85 90 relatif rutubette depolanm flt r. 20 gün boyunca çileklerde gerçekleflen a rl k kayb kontrol edilmifltir. Sonuçta, kalsiyum ilave edilerek polisakkarit temelli filmlerle kaplanan çilekte hiçbir ön ifllem uygulanmayan örne e göre çok daha az a rl k kayb oldu u görülmüfltür. Bu sonuçlar kalsiyum varl n n taze çileklerde hasat sonras a rl k ve doku sertli indeki kay plar geciktirdi ini belirten çal flmay destekler niteliktedir (22). Benzer bir çal flmada yine dondurma öncesi gluten film ile kaplanan çileklerde a rl k kayb n n daha az oldu u sonucuna var lm flt r (23). Mandalina segmentleri üzerine yap lan a rl k kayb analizinde, çilek örneklerinde oldu u gibi tüm uygulamalarda a rl k kayb n n kontrol grubuna göre azald gözlenmifl ve en az kayb n fleker flurubu+cacl 2 ve pullulan+cacl 2 uygulamalar nda oldu u belirlenmifltir. Bu sonuç Amal ve ark., (2010) n n yapt bir çal flmada kalsiyum uygulamas n n hücre duvarlar nda Ca +2 miktar n artt r p kalsiyum pektat oluflumunu sa lamas ve 205

16 T. Baysal, A. R. Ergün, B. Akgün, G. Karcı, N. Kaplan Çizelge 1. Uygulanan Farkl Kaplama fllemlerinin A rl k ve S z nt Kayb De erleri Üzerine Etkisi Table 1. Effects of different coating applications on the weight and drip loss of samples Örnek (Sample) Çilek % A rl k Kayb S z nt Kayb % A rl k Kayb % S z nt Kayb % Strawberry weight loss Strawberry Drip loss Mandarin weight loss Mandarin drip loss Kontrol (Control) 16.34a± a ± a ± a ±0.001 fiurup+cacl (Syrup+CaCl 2 ) b ± b ± b ± b ±0.001 fieker fiurubu (Sugar Syrup) ab ± a ± ab ± b ±0.001 Pullulan+CaCl ab ± b ± ab ± b ±0.002 Pullulan (Pullulan) ab ± a ± ab ± a ±0.003 bu sayede sertlik sa lay p a rl k kayb n önlemesi yorumu ile aç klanabilmektedir (10). Ayr ca yenilebilir film olarak kullan labilen pullulan n a rl k kayb n s n rland rd Chlebowska-Smigiel ve ark. (2007) n n yapt klar bir çal flma ile de desteklenmektedir (24). Elmalar n %15 ve %20 lik pullulan çözeltileri ile kapland klar bir çal flmada ise, elmalar 4 C s cakl kta-%75 ba l nemde buzdolab nda, 22 C deki oda s cakl nda ve %58 ba l nemde depolanm flt r. Pullulan filmle kaplama yap lan elmalarda, kaplama yap lmayan elmalara göre daha düflük a rl k kayb oldu u saptanm flt r. Pullulan uygulamas n n a rl k kayb n azaltmada etkili oldu u tespit edilmifltir (24). Baflka çal flmada mandalinalar karboksimetil selüloz ile kaplama sonras numunelerde gözlenen a rl k kayb yaklafl k %17 iken kontrol grubunda %30 olarak bulunmufltur. Sonuç olarak, meyveye uygulanan kaplamalar n görünümü gelifltirdi i ve kontrole göre daha az a rl k kayb na sebep oldu u saptanm flt r (25). Sızıntı Kaybı En az s z nt kayb ; fleker flurubu+cacl 2 ve pullulan+ CaCl 2 uygulamalar nda gözlenmifltir. En fazla s z nt kayb hiçbir ön ifllem uygulanmayan kontrol örne inde belirlenmifltir. fieker flurubu uygulamas ile çileklerde, fleker dehidrasyona sebep olarak çileklerin serbest su içeri ini azalt p daha az doku deformasyonuna sebep olmufl ve böylece ifllem görmemifl (kontrol) olanlara göre, fleker flurubu uygulanan örneklerde, çözündürme sonras daha az kay p oldu u belirlenmifltir (12). Pullulan kaplanan gruplarda ise yine çözünme sonras doku korundu u için az miktarda s z nt kayb görülmüfltür. Yap lan bir baflka çal flmada, -20 C deki CaCl 2 çözeltisiyle, ürün merkezi -18 C olacak flekilde CaCl 2 çözeltisine dald rma ifllemi gerçeklefltirilmifltir. Bu ifllem grubu ile yavafl dondurma ifllemi uygulanm fl örnek (hava sirkülasyonu olmadan, merkez s cakl -18 C olan) karfl laflt r ld nda CaCl 2 çözeltisinin %51 oran nda çözünme kayb n engelledi i tespit edilmifltir (26). Mandalina segmentleri için de en az s z nt kayb çileklerde oldu u gibi fleker flurubu+cacl 2 ve pullulan+cacl 2 uygulamalar nda gözlenmifltir. Çilek örneklerinde, kontrol ve CaCl 2 ile kombine edilen fleker flurubu ve pullulan gruplar aras ndaki fark n istatistiksel aç dan önemli oldu u saptanm flt r (P<0.05). Yap lan bu çal flma araflt rmalar destekler niteliktedir. Örne in kalsiyum ile muamele edilen çilek örneklerinin dokusunda çözündürme sonras daha az kay p oldu u görülmüfltür (10). A rl k kayb nda da oldu u gibi Ca +2 un meyvelerin hücre duvar yap s n n korunmas n sa lay p, pektik asitle ba land, hücre duvarlar nda kalsiyum pektat oluflturdu u ve böylece dokuyu koruyarak kayb engelledi i düflünülmektedir. Titre Edilebilir Asitlik Değişimi Çilek ve mandalina örnekleri üzerine yap lan asitlik analizlerinin sonuçlar Çizelge 2 de gösterilmifltir. fieker flurubu+cacl 2, pullulan+cacl 2 ve pullulan uygulamalar n n yap ld örneklerin asitliklerinde art fl gözlenmifltir. 15 gün depolaman n ard ndan yap lan analizlerde ise dondurma öncesi de erlerle k yasland nda kontrol ve fleker flurubu uygulamalar nda bir art fl gözlenirken, di er örneklerde azalma tespit edilmifltir. Yap lan bu çal flma kaplama iflleminin, depolama sonras titre edilebilir asitlikte azalmaya neden oldu unu belirten El Gaouth ve ark., (1991) n n çal flmas n destekler niteliktedir (27). Kaplamalar; iç atmosferi modifiye ederek O 2 konsantrasyonunu azaltm flt r (28). statistiksel olarak fleker flurubu+cacl 2, pullulan+cacl 2 ve fleker flurubu örnek gruplar nda depolamada asitlik de erleri aras ndaki fark n önemli olmad belirlenmifltir (P>0.05). Mandalina segmentleri üzerine yap lan asitlik analizlerinde, çilek gruplar n n aksine 0. gün analizlerinde tüm örneklerin asitlik de erlerinde kontrole k yasla 206

17 Dondurma İşleminde Bazı Ön Uygulamaların... Çizelge 2. Uygulanan Farkl Kaplama fllemlerinin Asitlik De erleri (%SSA), Briks, Sertlik ve Toplam Renk Fark De iflimi Üzerine Etkisi Table 2. Effects of different coating applications on acidity, Brix, texture and total color difference values of samples (%) Çilek (Strawberry) Mandalina (Mandarin) 0. gün 15. gün 0. gün 15. gün Day 0 15 th day Day 0 15 th day %SSA Kontrol (Control) 0.64 a ± a ± a ± a ±0.03 fiurup+cacl2 (Syrup+CaCl2) 0.78 ab ± a ± b ± ab ±0.03 fieker fiurubu (Sugar Syrup) 0.84 ab ± a ± b ± b ±0.03 Pullulan+CaCl b ± a ± b ± ab ±0.04 Pullulan (Pullulan) 0.81 b ± a ± b ± a ±0.03 BRIX( ) Kontrol (Control) 6.75 ab ± a ± a ± a ±0.10 fiurup+cacl2 (Syrup+CaCl2) 7.25 c ± b ± b ± b ±0.07 fieker fiurubu (Sugar Syrup) 6.35 bc ± a ± c ± a ±0.07 Pullulan+CaCl a ± b ± d ± a ±0.05 Pullulan (Pullulan) 5.90 d ± c ± bc ± c ±0.07 SERTL K Kontrol (Control) a ± a ± a ± a ±1.44 fiurup+cacl2 (Syrup+CaCl2) 8.34 a ± a ± a ± a ±1.04 fieker fiurubu (Sugar Syrup) 8.60 a ± a ± a ± a ±1.27 Pullulan+CaCl a ± a ± a ± a ±0.95 Pullulan (Pullulan) 9.06 a ± a ± a ± a ±1.11 Toplam renk fark fiurup+cacl2 (Syrup+ CaCl2) a ± a ± a ± a ±0.04 fieker fiurubu (Sugar Syrup) b ± b ± b ± a ±0.03 Pullulan+CaCl d ± c ± c ± a ±0.02 Pullulan (Pullulan) c ± d ± d ± a ±0.02 *Ayn sütundaki farkl harflerle ( a,b ) ifade edilen de erler P<0.05 düzeyindeki istatistiksel fark göstermektedir. * Statistically significant difference shown levels a, b compared with same column (P<0.05). bir azalma gözlenmifltir. 15 gün depolaman n ard ndan fleker flurubu+cacl 2, pullulan+cacl 2 ve pullulan uygulamalar nda kontrole göre asitlik art fl gözlenmifl, fleker flurubu uygulamas nda ise asitlik de erlerinde azalma gözlenmifltir. Bu sonuçlardan yola ç karak, ilave edilen CaCl 2 ün s z nt kayb n azaltarak, organik asit kayb n da engelledi i düflünülmüfltür. Ayr ca yap lan bir çal flmada; film kaplamalara kalsiyum ilave edildi inde mikrobiyel geliflmeyi etkin bir flekilde azaltt bildirilmifltir (24). Bu sayede titre edilebilir asitlik de erlerindeki düflüflün önüne geçilmifltir. Kavunlara, dondurulma öncesi (%60 w/w) sakaroz flurubu kullan larak dehidrasyon ifllemi uygulanm fl ve -20 C de 4 ay depolama sonras, 4 C de 16 saatte çözündürme ifllemi yap lm flt r. Bu çal flman n sonucunda; bu uygulaman n kuru maddede art fla neden oldu u, toplam titre edilebilir asitli i ise düflürdü ü tespit edilmifltir (29). Bir baflka çal flmada, fleker pancar posas ndan elde edilen bir hidrofilik polimer olan karboksimetil selülozun, mandalinalar n bozulmas n geciktirerek raf ömrü üzerine etkisi araflt r lm flt r. Örneklerde, kontrol örne ine k yasla daha az suda çözünür kuru madde kayb oldu u ve titre edilebilir asitli in kontrole göre daha düflük oldu u belirtilmifltir (25). Baflka bir çal flmada çileklerde farkl kaplama materyallerinin kullan ld ve 7-10 C s cakl klarda depolama sonucunda kontrol örne inde %1.60±0.12 asitlik bulunurken; glutenle kaplanm fl örneklerde %1.13±0.09 olarak bulundu u; 16. günde asitlik de erinin ise %0.67±0.07 olarak saptand belirtilmifltir. Kontrol örne inde bu de er 0.88±0.09 olarak saptanm flt r (23). ph değeri Çilek örnekleri için 15 gün depolama sonras nda tüm gruplar n ph de erlerinde art fl gözlenmifltir. En az ph art fl n n pullulan+cacl 2 grubu örneklerinde oldu u görülmüfltür. En fazla art fl ise kontrol ve fleker flurubu uygulamalar nda olmufltur. Pullulan ve CaCl 2 uygulamalar n n ph de erinin artmas nda en az role sahip oldu u belirlenmifltir. Bu sonuç asitlikteki art flla uyum göstermektedir. Çilekte oldu u gibi mandalina segmentleri üzerine yap lan 207

18 T. Baysal, A. R. Ergün, B. Akgün, G. Karcı, N. Kaplan ph analizi sonuçlar nda da tüm gruplarda bir art fl gözlenmifl ve en fazla art fl kontrol grubunda, ikinci olarak da fleker flurubu grubunda gözlenmifltir. 0. günde kontrol ile di er örnekler aras ndaki fark istatistiksel aç dan önemli iken 15. günde ise kontrol ile pullulan+cacl 2 grubu aras ndaki fark önemsiz, di er gruplar aras ndaki fark önemli olarak bulunmufltur (P<0.05). Mandalina örneklerinde ise 0.günde pullulan ile pullulan+ CaCl 2 grubu aras nda istatistiksel olarak fark bulunmazken di er gruplarla bu iki grup aras ndaki fark istatistiksel olarak önemlidir. Depolaman n etkisi ise her grup için istatistiksel aç dan önemli olarak bulunmufltur (P<0.05). Bu çal flmaya benzer olarak yap lan bir çal flmada çilek ve mandalina üzerinde pullulan n O 2 bariyeri sa lamas ve solunumu yavafllatmas, CaCl 2 uygulamas n n ise dokular n daha stabil kalmas n sa lamas ile mikroorganizmalar n geliflimini engelledi i ve böylece ph de erinin daha az artmas na sebep oldu u belirtilmifltir (3). Suda Çözünür Kuru Madde ( Briks) Değişimi Çileklerde gerçeklefltirilen Briks tayininde; pullulan ve pullulan+cacl 2 uygulamalar n n, Briks de erlerinde azalmaya neden oldu u tespit edilmifltir. Pullulan n su içerisinde çözülerek haz rlanmas nedeniyle çilekler üzerine bafllang çta Briks de erlerini düflürücü etkisi olabilece i düflünülmektedir. fieker flurubu ve fleker flurubu+ CaCl 2 uygulamalar nda ise fleker konsantrasyonun yüksek olmas nedeniyle art fl gözlenmifltir. Çileklerin, 15 gün depolaman n ard ndan, Briks de erleri tekrar ölçüldü ünde en yüksek de er fleker flurubu+cacl 2 grubunda ve ikinci olarak pullulan+cacl 2 uygulamalar nda gözlenmifltir (Çizelge 2). CaCl 2 uygulamas pektinin yap s n n bozulmas n engelleyerek kalsiyum pektat köprüleri oluflturmufl ve böylece meyvenin hücre duvar nda Ca+2 iyonlar art fl göstermifl ve suda çözünür kuru madde içeri i korunmufltur. fieker flurubu ve pullulan uygulamalar n n Briks de erlerinin daha düflük ç kmas n n sebebi ise çileklerin sürünücü bir meyve olmas ve buna ba l olarak da solunumun dondurulma aflamas nda bile devam ediyor olmas fleklinde aç klanmaktad r (10). Farkl kaplama çözeltileri ile çal fl lan bir araflt rmada; çilekler kaplanarak, (0 5 C de) %85 90 relatif rutubette 20 gün depolanm flt r. Kalsiyum klorür ilave edilmifl filmlerle kaplanan çileklerde suda çözünür kuru madde içeri inde daha az de ifliklik görülmüfltür (23). Mandalina segmentlerinde suda çözünür kuru madde de erlerinde 0. günde tüm gruplar n Briks de erlerinde kontrole göre azalma gözlenmifltir. 15 gün depolaman n ard ndan ise pullulan+cacl 2 ve fleker flurubu uygulamalar nda Briks de erlerinde bir yükselme gözlenirken fleker flurubu+cacl 2 uygulamas nda, Briks de erinin azald gözlenmifltir. Sonuçlar incelendi inde Briks de erinin en iyi korundu u örneklerin pullulan+cacl2 ve fleker flurubu gruplar oldu u söylenebilir. Sertlik Değişimi Yap lan bu çal flmaya göre tüm uygulamalar n sertli inde 0. günde kontrol grubuna göre art fl gözlenmifltir (Çizelge 2). 15 gün depolamadan sonra sertlik aç s ndan en düflük de ere sahip olan gruplar, pullulan+cacl 2 ve fleker flurubu+ CaCl 2 uygulamalar nda tespit edilmifltir. Çilekte 15 gün depolama sonunda sertlik de erinde en az de iflimin (yumuflaman n en az oldu u) pullulan+ CaCl 2 uygulamas nda oldu u belirlenmifltir. Mandalina segmentlerinde ise 0. günde tüm uygulamalarda kontrole göre sertliklerde art fl gözlenmifltir. 15. günün sonunda ise en yüksek sertlik de eri, fleker flurubu+cacl 2 uygulamas nda elde edilmifltir. statistiksel olarak hem çilek hem mandalina örnekleri için sertlik de erleri aç s ndan fark bulunamazken, depolamada da mandalina için 0. gün ile 15. gün aras ndaki fark n önemli olmad belirlenmifltir (P>0.05). Yap lan çal flmalarda CaCl 2 uygulamas n n ürün tekstürü üzerinde olumu etki sa lad vurgulanm flt r. Ahududu ve bö ürtlen üzerine yap lan araflt rmada, meyveler onar gruba ayr lm fl ilk 3 grup 1, 10 ve 100 mm l k CaCl 2 le, di er üç grup; %0,1, %0,2 ve %0.3 konsantrasyonlarda düflük metoksilli pektinle (LMP), kalan dört grup da hem LMP hem de CaCl 2 ile muamele edilmifltir ve -40 C de s v azot buhar nda zorlamal konveksiyonla ve -18 C de dondurma ifllemine tabi tutulmufltur. Kontrol grubu di erleriyle birlikte -18 C s cakl kta dondurulmufltur. -40 C de s v azot buhar nda zorlamal konveksiyonla dondurulmufl ürünlerin daha yüksek objektif tekstür parametresi ve daha çok sertlik gösterdi i tespit edilmifltir. Bu çal flman n sonucunda ahududu ve bö ürtlende, CaCl 2 uygulamas n n, LMP olsa da olmasa da dondurma ve çözündürmeden kaynaklanan sertlik kayb n önleyebilece i görülmüfltür (30). 208

19 Dondurma İşleminde Bazı Ön Uygulamaların... Renk Değişimi Çilekler için, tüm örnekler kontrol ile k yaslanm fl ve toplam renk fark de eri için 0. günde en düflük de er fleker flurubu uygulamas nda elde edilirken, en yüksek de er pullulan+cacl 2 uygulamas nda gözlenmifltir (Çizelge 2). 15 gün sonras nda yap lan de erlendirmede ise en düflük de er fleker flurubu+ CaCl 2, en yüksek de er ise pullulan uygulamas nda bulunmufltur. Mandalinalar kontrol grubu ile k yasland nda 0.gün toplam renk fark sonuçlar nda en düflük de er pullulan+cacl 2, en yüksek de er, fleker flurubu uygulamalar nda gözlenmifltir. 15. gün için çilek ve mandalina örnek gruplar n n kendi içlerinde, toplam renk fark de erleri aras ndaki fark n istatistiksel aç dan önemli oldu u belirlenmifltir (P<0.05). Çile in a* ve b* de erleri kullan larak hesaplanan hue aç s de erlerine bak ld nda 0. gün pullulan uygulamas nda kontrol örne ine k yasla hue aç s de erinde azalma oldu u gözlenmifl ve di er uygulamalarda ise bir art fl meydana gelmifltir. 15. gün sonunda yap lan renk analizlerinde tüm uygulamalarda 0. güne göre hue aç s de erinin artt gözlenmifl olup, çileklerin renginde koyulaflma oldu u kan s na var lm flt r. Mandalinada ise 0. günde hue aç s de erleri azalm fl; fakat 15 gün depolaman n ard ndan tüm örneklerde hue aç s de erlerinde art fl gözlenmifltir. 15. günde örnekler aras nda hue aç s de erleri aras ndaki fark n istatistiksel olarak önemli olmad saptanm flt r (P>0.05). Benzer bir çal flmada kitosan ile kaplanan çileklerde de hue aç s de erindeki art fl n antosiyaninlerin depolama boyunca sentezlenmesi ile antosiyaninlerin kalsiyum ve kitosanla iliflkisi sonucu gerçekleflti i belirtilmifltir (21). Ayr ca yine kaplaman n renge etkisinin incelendi i bir çal flmada; 0 C de %90-95 ba l nemde 15 gün depolanm fl çileklerin en iyi görünüfl ve renk de erlerinin, soya ve gluten proteini temelli yenilebilir filmlerle kaplanan çileklerde oldu u tespit edilmifltir (10). Duyusal Değerlendirme Çilekler üzerine yap lan 0. gün duyusal de erlendirme sonucunda, görünüfl olarak en be enilen gruplar fleker flurubu+cacl 2, fleker flurubu ve pullulan gruplar olurken; görünüfl olarak en az be enilen grup, kontrol grubu olmufltur. Örnekler aras ndaki fark n istatistiksel olarak önemli olmad belirlenmifltir (P>0.05). Tekstür aç s ndan ise en be enilen grup kontrol grubu olmufltur. 15 gün dondurucuda depolaman n ard ndan, hem görünüfl hem tekstür aç s ndan bak ld nda en çok be enilen grubun, pullulan+ CaCl 2 oldu u gözlenmifltir. Bu grup ile di er gruplar n tekstür ve görünüfl özellikleri aras ndaki fark n istatistiksel aç dan önemli oldu u belirlenmifltir (P<0.05). Mandalina örneklerinde ise 0. gün duyusal de erlendirme sonucunda görünüfl olarak örnekler aras nda fark olmad belirlenmifltir (P>0.05). Tekstür aç s ndan de erlendirildi inde, pullulan+cacl 2 grubu en az be enilen, fleker flurubu uygulamas ise en çok be enilen grup olmufltur. fieker flurubu+cacl 2 uygulamas ise her iki aç dan da be enilen ikinci gruptur. 15. gün sonunda hem görünüfl hem de tekstür aç s ndan en be enilen grup pullulan+ CaCl 2 uygulamas olurken, en be enilen ikinci grup ise fleker flurubu uygulamas olmufltur. fieker flurubunun mandalina örneklerinde, çilek örneklerinin aksine duyusal kaliteyi iyilefltirdi i tespit edilmifltir. SONUÇ Yap lan a rl k kayb, s z nt kayb, ph, suda çözünür kuru madde analizlerinde elde edilen verilere göre en yüksek kalite özellikleri pullulan+ CaCl 2 ve fleker flurubu+cacl 2 uygulamalar nda elde edilmifltir. CaCl 2 içerisine dald r lma yap lan meyvelerde hücre duvar nda pektinin parçalanmas n engelleyen kalsiyum pektat yap s n n oluflumu ile sertlik korunmufl, s z nt kayb ve a rl k kayb azalt lm flt r. Duyusal ve tekstür analizi sonuçlar de erlendirildi inde de en çok be enilen uygulaman n; pullulan+cacl 2 uygulamas oldu u belirlenmifltir. Sonuç olarak; meyvelere yap lan fleker flurubu ve yenilebilir film kaplamalar n tek bafl na uygulanmas yeterli görülmemifl bunlara ilaveten CaCl 2 eklenmesinin daha iyi sonuçlar meydana getirdi i tespit edilmifltir. KAYNAKLAR 1. Delgado AE, Sun DW Heat and mass transfer for predicting freezing processes, a review. J Food Eng. 47: Gutschmidt J Principles of freezing and low temperature storage, with particular reference to fruits and vegetables, Low Temperature Biology of Foodstuff. Recent Adv Food Sci. Vol. 4. Pergamon Press, London. 209

20 T. Baysal, A. R. Ergün, B. Akgün, G. Karcı, N. Kaplan 3. Kester JJ, Fennema OR Edible films and coatings: A review. Food Technol. 40 (12): Gontard N, Guilbert S, Cuq JL Edible wheat gluten film: Influence of the main process variable on film properties using response surface methodology. J of Food Sci 57: Baldwin EA, Nisperos- Carriedo, MO, Baker, RA Use of edible coating to preserve quality of lighly and slightly processed products. Crit Rev Food Sci Nutr. 35(6): Guilbert S Technology and application of edible protective films. In Mathlouthi, M. (Ed.), Food packaging and preservation, London, UK: Elsevier Applied Science. p Batu A. ve Serim F Tar msal Kökenli Yenebilir G da Film ve Kaplamalar n Özellikleri ve Kullan m Alanlar. Dünya-G da (Ekim) Gontard N, Thibault R, Cuq B, Guilbert S Influence of relative humidity and film composition on oxygen and carbon dioxide permeabilities of edible films J Agric Food Chem. 44 : Krochta CM, De Mulder- Johnston, C edible and biodegredable polymer films: Challenges and opportunities. Food Technol. 51(2): Amal SH, Atress MM, El-Mogy, HE, Aboul- Anean and Alsanius BW Improving Strawberry Fruit Storability by Edible Coating As a Carrier of Thymol or Calcium Chloride. J Hortic Sci Ornamental Plants 2(3): Kendall P Freezing vegetables. Colorado State University Cooperative Extension. 12. Suutarinen J, Heiska K, Moss P, Autio K, 1999, The effects of calcium chloride and sucrose prefreezing treatments on the structure of strawberry tissues. Lebensm.-Wiss. u.-technol. 33: Alonso J, Rodriguez T, Canet W, Effect of calcium pretreatments on the texture of frozen cherries, role of pectinesterase in the changes in the pectic materials. J Agric Food Chem. 43: Chen F, Liu H, Yang H, Lai S, Cheng X, Xin Y, Yang B, Hou H, Yao Y, Zhang S, Bu G, Deng Y Quality Attributes and Cell Wall Properties of Strawberries (Fragaria Annanassa Duch.) Under Calcium Chloride Treatment. Food Chem. 126: Cemero lu, B G da Analizleri, Bizim Büro Bas mevi. 2. Bas m. Ankara. 16. Anon AOAC. Official Methods Of Analysis Of AOAC International (16th Ed.). 17. Anon AOAC. In: (15th Edn. Ed.), Official Methods Of Analysis, Association Of Official Analytical Chemists, Arlington, VA. 18. Kramer A. and Twigg BA Quality Control for the Food Industry. Volume 1, Avi Publishing Company Inc., Connecticut, 556 p. 19. Altu T Duyusal Test Teknikleri, E.Ü Mühendislik Fakültesi Ders Kitaplar Yay n No:28, zmir, 56 s. 20. SPSS 15.0 for Windows Version; SPSS Inc., Chicago, Ill. 21. Han C, Zhao Y, Leonard SW, Traber MG Edible Coatings To Improve Storability and Enhance Nutritional Value of Fresh and Frozen Strawberries (Fragaria x Ananassa) And Raspberries (Rubus Ideaus). Postharvest Biol Tec Ribeiro C, Vicente AA, Teixeira JA, Miranda C Optimization of edible coating composition to retard strawberry fruit senescence. Postharvest Biol Tec. 44: Tanada PS Effect of edible wheat glutenbased films and coatings on refrigerated strawberry (Fragaria ananassa) quality. Postharvest Biol Tec. 36: Chlebowska-Smigiel A, Gniewosz M, Swinczak E An attempt to apply a pullulan and pullulan-protein coatings to prolong apples shelflife stability. Acta Sci Pol Technol. Aliment To rul H, Arslan N Carboxymethyl cellulose from sugar beet pulp cellulose as a hydrophilic polymer in coating of mandarin. J Food Eng. 62: Galetto CD, Verdini RA, Zorrilla SE, Rubiolo AC Freezing of Strawberries By Immersion In CaCl 2 Solutions. Food Chem. 123: El Gaouth A, Arul J, Ponnampalam R, Boulet M Chitosan coating effect on storability and quality of fresh strawberries. J Food Sci. 12: Lowings PH, Cutts DF The preservation of fresh fruits and vegetables. Proc. Inst. Food Sci. Technol. Annual Symp. July Nottingham, U.K. 29. Maestrelli A, Scalzo R, Lupi D, Bertolo G, Torreggiani D Partial removal of water before freezing: Cultivar and pre-treatments as quality factors of frozen muskmelon (Cucumis melo, cv reticulatus Naud.). J Food Eng. 49: Sousa MB, Canet W, Alvarez MD, Ferna ndez C Effect of processing on the texture and sensory attributes of raspberry (cv. Heritage) and blackberry (cv. Thornfree). J Food Eng