GIDA (Gıda Teknolojisi Derneği Yayını) THE JOURNAL OF FOOD (Published by the Association of Food Technology; Turkey) Cilt / Volume: 35 Sayı / Number: 5 2010 İki ayda bir yayımlanır / Published bimonthly ISSN 1300-3070; ISSN 1309-6273 (GIDA on-line) Sahibi/ Owner Gıda Teknolojisi Derneği Adına / On behalf of the Association of Food Technology; Turkey Prof. Dr. A. Kadir HALKMAN Yönetim Kurulu Başkanı / President of the Association Editörler Kurulu / Editorial Board Baş Editör/ Editor-in Chief Halkman, A. Kadir Ankara University, Turkey Editörler / Co-Editors Çakır, İbrahim Abant İzzet Baysal University, Turkey Taban, Birce Gazi University, Turkey Tekin, Aziz Ankara University, Turkey Velioğlu, Y. Sedat Ankara University, Turkey Yönetim Yeri Adres / Address Büyükelçi Sokak No: 18/1 Kavaklıdere/ Ankara Turkey Tel: (+90) 312 596 1180 Faks: (+90) 312 317 8711 E-posta / E-mail: dergi@gidadernegi.org URL: http://www.gidadernegi.org/dergi.asp Yayın Türü: Yaygın süreli ve hakemli Basım Yeri / Printing House Pelin Ofset Tipo Matbaacılık San. ve Tic. Ltd. Şti. İvedik Organize Sanayi Bölgesi, Matbaacılar Sitesi 558. Sokak No: 28-30 Yenimahalle / Ankara Turkey Tel: (+90) 312 395 2580-81 Faks: (+90) 312 395 2584 www.pelinofset.com.tr Yayın Tarihi / Publication Date 15 10 2010 Danışma Kurulu / Advisory Board Alichanidis, Efstathios Aristotle University of Thessaloniki, Greece Aran, Necla Istanbul Technical University, Turkey Artık, Nevzat Ankara University, Turkey Baysal, Taner Ege University, Turkey Boyacı, İsmail Hakkı Hacettepe University, Turkey Certel, Muharrem Akdeniz University, Turkey Draughon, Ann Tennessee University, USA Ekşi, 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 Göğüş, Fahrettin Gaziantep University, Turkey Gümüşkesen, Aytaç Saygın 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 Şahin, Serpil Middle East Technical University, Turkey Üstünol, Zeynep Michigan State University, USA Yetişemiyen, Atila Ankara University, Turkey Bu dergi, uluslararası CAB Abstracts, Index Copernicus, EBSCO ve ULAKBİM (Tarım, Veteriner ve Biyoloji Bilimleri) veri tabanları kapsamındadır. This journal is covered by CAB Abstracts, Index Copernicus, EBSCO and ULAKBİM (National Agriculture, Veterinary and Biology) database systems.
İçindekiler / Content ACAR SOYKUT E, TUNAİL N; Morphological characterization of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus virulent phages ; Streptococcus thermophilus ve Lactobacillus delbrueckii subsp. bulgaricus virülent fajlarının morfolojik karakterizasyonu...317-323 GÜZELER N, SAY D, KAÇAR A; Compositional changes of Saanen x Kilis goats milk during lactation ; Laktasyon dönemi boyunca Saanen x Kilis keçi sütü bileşimindeki değişimler...325-330 USLU MK, ERBAŞ M, TURHAN İ, TETİK N; Nişasta miktarının ve çöven suyu ilavesinin lokumların bazı özellikleri üzerine etkileri ; Effects of starch ratios and soapwort extract addition on some properties of Turkish delight...331-337 TUNÇTÜRK Y, ANDİÇ S, OCAK E; Homojenizasyon ve pastörizasyonun beyaz peynir ve peyniraltı suyu bileşimine etkisi ; The effect of homogenization and pasteurization on white cheese and whey composition...339-345 ERBAY Z, KOCA N, ÜÇÜNCÜ M; Hellim peynirinin bileşimi ile renk ve dokusal özellikleri arasındaki ilişkiler ; The relation of composition to colour and textural characteristics of Halloumi cheese...347-353 TAMUÇAY ÖZÜNLÜ B, KOÇAK C; Süte farklı ısıl işlem uygulamalarının ayran kalitesine etkisi ; The effect of different heat treatments of milk on quality of ayran...355-362 ÜNLÜTÜRK S, BAYSAL AH, ATILGAN MR; UV-C uygulamasının sıvı yumurta beyazının mikrobiyolojik kalitesi üzerine etkisi ; Effect of UV-C application on the microbiological quality of liquid egg white...363-369 GÜNEŞER O, KARAGÜL YÜCEER Y; Gıdalarda aroma maddelerinin belirlenmesinde gaz kromatografisiolfaktometre (GCO) tekniklerinin kullanılması ; Use of gas chromatography-olfactometry (GCO) techniques to identify aroma compounds in foods...371-378 KARASU YALÇIN S, ŞENSES ERGÜL Ş, YEŞİM ÖZBAŞ ZY; Moleküler esaslı yöntemlerin gıda kaynaklı mayaların tanımlanmalarında kullanılmaları ; Use of molecular based methods for identification of foodborne yeasts...379-386 ÇAPANOĞLU GÜVEN E, TOYDEMİR OKTUN G, BOYACIOĞLU D; Flavonoidlerin biyoyararlılığını etkileyen faktörler ; Factors affecting bioavailability of flavonoids...387-394 Danone Tikveşli A.Ş., Gıda Dergisi nin basım ve yayımını desteklemektedir.
Editörden, Merhaba, Okurlarımız bu dergiyi aldıklarında ilk uluslararası kongremize sadece 2 hafta kalmış olacak. Dernek olarak 25-27 Nisan 1978 tarihinde gerçekleştirdiğimiz Türkiye 1. GIDA Kongresi ile başlayan ve 21-23 Mayıs 2008 tarihinde gerçekleştirdiğimiz Türkiye 10. GIDA Kongresi ile devam eden süreç; bir uluslararası kongre yapma sorumluluğunu bir anlamda bize yükledi. Açık söylemek gerekirse, 10 ulusal kongreden başarı ile çıkmış olmanın deneyimi olmasa idi zaten bu işe kalkışmazdık. Yine de çok zorlandık. Uluslararası kongre düzenlemek çok farklı bir uygulama. Bunun böyle olacağını işin başında biliyorduk. Kongreye alfabetik sıra ile ABD, Almanya, Arjantin, Avustralya, Avusturya, Belçika, Brezilya, Cezayir, Danimarka, Fas, Finlandiya, Hindistan, Hollanda, İngiltere, İran, İrlanda, İspanya, İsrail, İsviçre, İtalya, Japonya, Kazakistan, Kore, Letonya, Libya, Lübnan, Macaristan, Makedonya, Malezya, Mısır, Nijerya, Özbekistan, Polonya, Portekiz, Romanya, Sırbistan, Slovakya, Sri Lanka, Sudan, Tayland, Tayvan, Tunus, Türkiye, Ukrayna, Ürdün ve Yunanistan olmak üzere 46 farklı ülkeden çok yaklaşık 500 kadar katılımcı bekliyoruz. Kongrenin başarılı geçeceğine inancım tamdır. Şimdiden emeği geçen herkese içtenlikle teşekkürlerimi sunuyorum. Sevgi ve saygılarımla, Prof. Dr. A. Kadir Halkman iii
A Message from the Editor-in-Chief, Hello, When our readers receive this journal, it will be 2 weeks left for our international Congress. The period that began with the 1st National Food Congress on April 25 27 in 1978 and continued with the 10 th National Food Congress on May 21 23 in 2008 saddles us with a responsibility of holding an international Congress. In all fairness, we would not anyway set out to this unless we had an experience of making a success of 10 th National Food Congress. Anyway, we were coerced. Holding an international Congress is a different implementation but we all anticipated as much from the commencement of work. We are waiting approximately 500 participants from 46 different countries in alphabetical order as Algeria, Argentina, Australia, Austria, Belgium, Brazil, Denmark, Egypt, Finland, Germany, Greece, Hungary, India, Iran, Ireland, Israel, Italy, Japan, Jordan, Kazakhstan, Korea, Latvia, Lebanon, Libya, Macedonia, Malaysia, Morocco, Nigeria, Poland, Portugal, Romania, Serbia, Slovakia, Spain, Sri Lanka, Sudan, Switzerland, Taiwan, Thailand, the Netherlands, the UK, the USA, Tunisia, Turkey, Ukraine and Uzbekistan. I feel confident of success of the upcoming Congress 1st International Food Congress. I already tender my sincere thanks to everybody who pull their weight. Best Regards, Prof. A. Kadir Halkman iv
GIDA (2010) 35 (5): 317-323 GD09088 Research /Araştırma MORPHOLOGICAL CHARACTERIZATION OF STREPTOCOCCUS THERMOPHILUS AND LACTOBACILLUS DELBRUECKII SUBSP. BULGARICUS VIRULENT PHAGES Esra Acar Soykut *1, Nezihe Tunail 2 1 Hacettepe University, Faculty of Eng., Dept. of Food Engineering, Beytepe, Ankara, Turkey 2 Ankara University, Faculty of Eng., Dept. of Food Engineering Dışkapı, Ankara, Turkey Received / Geliş tarihi: 05.12.2009 Received in revised form / Düzeltilerek geliş tarihi: 11.02.2010 Accepted / Kabul tarihi: 14.02.2010 Abstract In this study, 25 phages of S. thermophilus and 25 phages of L. bulgaricus were inspected and identified morphologically by electron microscopy. In S. thermophilus phages the diameters of hexagonal heads were found to range between 47-74 nm, while non-contractile tails were 182 to 290 nm long and 7-14 nm wide. In these phages tail plaque, collar and fiber like structures were not found. Identified S. thermophilus phages were placed in the Siphoviridae family according to Ackermann s and/or Group B in Bradley s classification. Also for L. bulgaricus phages isometric hexagonal capsid and non-contractile tail structures were also determined. The capsids measured between 47-73 nm in diameter, and the tails were between 117-162 nm long and 7 to 13 nm wide. These phages were also placed in Siphoviridae family in Ackermann s classification and/or group B in Bradley s. Importantly, it was also determined that in some of these phages collar and tail plaque structures were present. It is thought that minor modifications in the preparation of the S. thermophilus and L. bulgaricus phages, and the type of electron microscope used were significant factors that affected the visibility of the tail structures. Keywords: S. thermophilus, L. bulgaricus, phage, morphological characterization, electron microscope STREPTOCOCCUS THERMOPHİLUS VE LACTOBACİLLUS DELBRUECKİİ SUBSP. BULGARİCUS VİRÜLENT FAJLARININ MORFOLOJİK KARAKTERİZASYONU Özet Bu çalışmada 25 adet S. thermophilus ve 25 adet L. bulgaricus fajının elektron mikroskobik incelemesi yapılarak morfolojik karakterizasyonu gerçekleştirilmiştir. S. thermophilus fajlarında izometrik, hegzagonal baş çapının 53-74 nm, kontraktil olmayan kuyruk uzunluğunun 182-290 nm ve kuyruk genişliğinin de 7-14 nm arasında değiştiği görülmüştür. Bu fajlarda yaka, kuyruk plağı ve fibril benzeri yapıya rastlanmamıştır. İncelenen tüm fajlar, elde edilen verilere dayanılarak diğer S. thermophilus fajları gibi Ackermann sınıflaması Siphoviridae familyasına ve/veya Bradley sınıflaması B grubuna dâhil edilmiştir. S. thermophilus fajlarında olduğu gibi Lb. bulgaricus fajlarında da izometrik, hegzagonal kapsit ve kontraktil olmayan kuyruk yapısı belirlenmiştir. Kapsit çapları 47-73 nm arasında değişirken, kontraktil olmayan kuyruk uzunlukları 117-162 nm ve kuyruk enleri 7-13 nm arasında bulunmuştur. Ackermann sınıflaması Siphoviridae familyasına ve/veya Bradley sınıflaması B grubuna dâhil edilen bu fajlarda yaka, kuyruk tablası ve fibril yapısının varlığı dikkat çekmiştir. S. thermophilus ve L. bulgaricus faj örneklerinin hazırlanmasındaki farklılıkların ve kullanılan elektron mikroskop tiplerinin kuyruk yapılarının görünebilirliğini etkilediği düşünülmüştür. Anahtar kelimeler: S. thermophilus, L. bulgaricus, faj, morfolojik karakterizasyon, elektron mikroskop * Corresponding author / Yazışmalardan sorumlu yazar ; - esraacar2@gmail.com, & (+90) 312 297 6146, 7 (+90) 312 297 6146 317
E.A. Soykut, N. Tunail INTRODUCTION Knowledge of thermophilic phages is quite restricted when compared to that of lactococcal phages (1), owing to the high incidence of phage infections in the cheese production industry (2). Thus lactococcal phages have been under investigation since first being determined by Whitehead and Cox in 1935 (3). However the first phage specific to Streptococcus thermophilus (S. thermophilus) was determined in 1952 (4) and a Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus) phage was isolated first by Reddy and Reinbold in 1974 with further investigations being done in 1982 (5). In addition, in recent years researches have focused more on thermophilic phages because of the frequent infections in cheese and yogurt plants which they cause (6). To this day, morphological studies have shown S. thermophilus and L. bulgaricus phages to have a single morphotype. All have a hexagonal capsid and a non-contractile tail, and all of them are placed in the Siphoviridae family according to Ackermann s classification and/or in group B in Bradley s classification (2, 5-9). A L. bulgaricus phage that shows a different morphotype from other thermophilic phages is the only phage having a contractile tail and is placed in the Myoviridae family according to Ackermann s classification (5). During the last 6 years, a thermophilic phage problem has periodically occurred in modern yogurt factories in Turkey (10). In order to solve the phage problem, it is important that, in addition to conventional prevention measures, factories should rotate between commercial strains the sensitivity of which has been tested against native phage collections (11, 12). It is also important that factories should use natural (indigenous) phage resistant strains because it has been shown that natural strains are much more resistant to phages than commercial strains (6). For this purpose 23 S. thermophilus and 25 L. bulgaricus phages were provided from our phage collection. This research focuses on the morphological characterization of these 48 phages using a transmission electron microscope (TEM). Owing to the limited data on the isolation of S. thermophilus phages from raw milk samples (12) the incidence of such phages in raw milk was also investigated. Two S. thermophilus phages isolated from raw milk samples were characterized morphologically and identified taxonomically along with other 48 phages. MATERIALS AND METHODS Phage and strain cultures Twenty three S. thermophilus phages and twenty five L. bulgaricus phages were provided from our collection. These phages had been isolated and purified from bulk, yogurt, whey and ayran-turkish buttermilk collected from dairy plants in the Ankara region. Bacterial strains (S. thermophilus B3, 709, 231 and L. bulgaricus Y4, V1, V2, 231) from which the phages were isolated were mixed starter cultures used industrially. The two S. thermophilus phages (Φ1B3-A, Φ2B3-A) from raw milk samples from the Afyon region were also isolated using the B3 industrial strain as a host organism. The isolation of all phages was carried out single plaque isolation technique as described previous study (13). To study the growth of S. thermophilus strains and their phages, modified M17 Broth (thml7 Broth), modified M17 Agar (th M17 Agar) and modified M17 Soft Agar (th M17 Soft Agar) (0.45% agar) were used (14). L. bulgaricus strains and their phages were grown in MRS Broth (Merck, Darmstadt, Germany), MRS Agar (1.5% agar) and MRS Soft Agar (0.6% agar). In order to achieve a better adsorption of L. bulgaricus phages, CaCl 2 (10 mmol/l) was added to all three types of culture medium (15). All cultures and phages were incubated for 18 h at 43 C. Electron microscopy of phages S. thermophilus and L. bulgaricus phages were concentrated through the centrifugation of phage lysates containing 10 7-10 8 phage particles (pfu/ ml) for 2 h at 20000 rpm at 4 C. Some of S. thermophilus phage pellets were dissolved in 20 μl 0.3 M ammonium acetate and an equal volume of dye solution (10 μl amonium molibdate and 10 μl sodium phosphotungstate, 2 % - 3 %, w/v, ph 5.0 ± 0.02, Sigma Chem. Co., USA) was added (16). The phage-dye mixture was then dropped on to 400 mesh grids covered with carbon formvar (3.05 mm, Agar Scientific Ltd. UK). After waiting for 15 minutes, the excess dye was removed. Electron micrographs were taken with TEM, models JEOL JEM S 100 and JEOL JEM 100-C under 80 kv power. The pellets of the other S. thermophilus (Ф1B3-A, Ф2B3-A, ФB3-X12, ФB3-X13, ФB3-X18, Ф231-X9, Ф231-X23) and all of the L. bulgaricus phages were suspended in 0.1 % (w/v) ammonium acetate first 318
Morphological Characterization Of Streptococcus... (17), then 20 μl 3 % phosphotungstate was added and finally they were placed on the grids (18). Fifteen minutes later, the grids were washed with deionised water and dried on a filter paper (19). Micrographs of the phages were taken under 80 kv power by using a LEO 906 E electron microscope. Phage size calculations are based on the averages of 5 to 10 measurements (20). RESULTS Morphology of S. thermophilus phages Phages isolated by using S. thermophilus 709, 231 and B3 industrial hosts had isometric, hexagonal and assumptively icosahedral capsids, 47-74 nm in diameter, and non-contractile tails 182-290 nm long and 7-14 nm wide (Table 1). None of the phages displayed collar, tail plaque or fiber structures. The presence of a plaque-like structure was suspected only in phages Ф231-X9 and ФB3-X18 (Figure 1a,b). The morphological characterization of 25 S. thermophilus phages showed that the phages belong to the Siphoviridae family in Ackermann s and/or in Group B in Bradley s classification. Figure 1. S. thermophilus phages. (a) Ф231-X9, 60000x; (b) ФB3-X18, 100000x; (c) Ф709-X4, 45 000x Morphology of L. bulgaricus phages The four industrial strains of L. bulgaricus were 231, Y4, V1 and V2, and were used as host organisms for these 25 phages. The capsids were 47 to 73 nm in diameter and isometric hexagonally shaped. It was determined that all of the phages carried non-contractile tails without a cover structure and the tails were 117 to 162 nm long and 7 to 13 nm wide (Table 2). While in the phages ФHV1 (Figure 2a), ФGV2, ФG1V2 and ФG4V2 the presence of the structures like collar pieces and tail plaques were determined, in the phages ФH2Y4, ФJY4, ФFY4 Table 1 Morphological properties of S. thermophilus phages Phage Code Capsid diameter (nm) Tail length (nm) Tail width (nm) Collar (nm) Tail plaque (nm) Fiber Ф709-X1 64 235 12-1 - - Ф709-X2 61 245 12 - - - Ф709-X3 63 190 8 - - - Ф709-X4 74 290 10 - - - Ф709-X5 67 220 12 - - - Ф231-X6 62 182 12 - - - Ф231-X7 69 290 12 - - - Ф231-X9 60 230 12 - - - Ф231-X10 68 221 12 - - - ФB3-X11 53 193 9 - - - ФB3-X12 53 214 9 - - - ФB3-X13 60 220 12 - - - ФB3-X14 55 235 13 - - - ФB3-X15 73 230 14 - - - ФB3-X16 54 234 11 - - - ФB3-X17 57 210 10 - - - ФB3-X18 54 220 10 - - - ФB3-X19 63 217 12 - - - ФB3-X20 47 224 10 - - - Ф231-X21 62 272 7 - - - Ф231-X22 67 230 10 - - - Ф231-X23 73 220 10 - - - Ф1B3-A 57 244 10 - - - Ф2B3-A 57 244 10 - - - 1 not exist 319
E.A. Soykut, N. Tunail Table 2 Morphological properties of L. bulgaricus phages Phage Code Capsid diameter (nm) Tail length (nm) Tail width (nm) Collar (nm) Tail plaque (nm) Fiber H2Y4Ф(X1) 54 134 11-1 30x15 - MY4Ф(X2) 55 151 11 - - - JY4Ф(X3) 55 138 13-32x15 - FY4Ф(X4) 55 141 13-24x13 - H3Y4Ф(X5) 58 131 13-22x13 - H1Y4Ф(X6) 49 128 11-22x14 - IY4Ф(X7) 56 156 10 - + 2 - SİYY4Ф(X8) 58 142 9 - + - 709BY4Ф(X9) 50 138 9-15x9 - SİBY4Ф(X10) 55 138 11-22x12 - GY4Ф(X11) 73 127 10 - + - PY4Ф(X12) 56 151 10 - + - F231Ф(X17) 53 147 9 - + - HV1Ф(X19) 55 143 11 30x7 19x11 - FV1Ф(X20) 52 144 11 + 22x13 - GV2Ф(X21) 57 137 11 34x15 28x19 - G1V2Ф(X22) 54 136 11 38x7 24x13 - G3V2Ф(X23) 47 133 7 - - - G4V2Ф(X24) 56 143 9 30x9 24x13 - G5V2Ф(X25) 58 162 8 - + - GKV2Ф(X26) 51 133 9 - - - KV2Ф(X27) 54 145 10 - - - LV2Ф(X28) 53 117 10-34x13 - AV2Ф(X29) 58 138 9 - - - SİYV2Ф(X30) 51 149 10 - + - 1 not exist 2 exist but can not be measured (Figure 2b), ФH3Y4, ФH1Y4, Ф709BY4, ФSIBY4, ФFV1, ФLV2 only the presence of tail plaque was observed. Also, the presence of these structures was suspected in the phages ФIY4, ФSIYY4, ФGY4 (Figure 2c), ФPY4, ФF231, ФG5V2, ФSIYV2. There was no evidence of contractile tail covers in any of the phages. In the light of the characterization studies these 25 native L. bulgaricus phages were placed in the Siphoviridae family in Ackermann s classification and/or Group B in Bradley s. Figure 2. L. bulgaricus phages (a) ФHV1, 60000x; (b) ФFY4, 60000x; (c) ФGY4, 60000x. DISCUSSION It was observed that all of S. thermophilus phages had isometric hexagonal heads. Although it is possible to determine the taxonomical characteristics of the phages through the use of electron micrographs, it is difficult to identify whether the capsid structures were icosahedral, octahedral or dodecahedral (15). In addition, regarding the characteristics mentioned by Ackermann and DuBow (17), in electron micrographs of S. thermophilus phages Ф709-X5, Ф231-X7, Ф231-X21, Ф231-X22, Ф231-X23, ФB3-X11, ФB3-X18 (Figure 1b) and ФB3-X19, hexagonal and pentagonal profiles were observed together while, importantly, hexagonal and spherical profiles were present together in the micrographs of Ф709-X4 (Figure 1c) and ФB3-X20. It can thus be said that the phages have an icosahedral head structure. In electron micrographs of other S. thermophilus phages, only hexagonal capsid profiles were determined. Furthermore, the tails penetrated the capsids, which is 320
Morphological Characterization Of Streptococcus... a sign of icosahedral head structure, in the cases of phages Ф231-X9 (Figure 1a), Ф231-X22, ФB3-X12, ФB3-X13 and ФB3-X14. On the other hand, the determination of the pentagonal capsid only in tailed phages (17) increases the probability of them being placed in the Siphoviridae family with an isometric hexagonal profile having icosahedral capsid members. In this study, depending on the increasing number of the phages examined, the values of capsid diameter, tail length and tail width generally differed within wider limits. However, the 5 nm tail width determined by Kivi et al. (16) in one of 9 S. thermophilus phages and the 42 nm capsid diameter determined by Benbadis et al. (20) in one of 7 phages, differed from our phages in their extremely low values. In S. thermophilus phages, the diameter of the capsids were found to be between 45 to 65 nm, the tails were 210-270 nm long and 7-13 nm wide (1, 14, 16, 19-25). Among the phages that we examined, the shortest (182 nm) and the longest tail (290 nm) was about 30 nm longer or shorter than the values found by other researchers. A phage determined by Reinbold et al. (5) also had a 290 nm long tail. In addition to that Suárez et al. (6) and Quiberoni et al. (2) finally isolated a phage having a 330 nm long tail. In another study electron microscopic analysis showed that phage 2972 had a 55-nm-diameter isometric capsid and a 260-nm-long noncontractile tail (25). Among 25 native S. thermophilus phages that were inspected morphologically, the presence of tail plaque was suspected in only two of the phages (Ф231-X9 and ФB3-X18) (Figure 1a,b) but in none of the phages were fiber or collar structures determined. Moreover Krusch et al. (14), Kivi et al. (16) and Prevots et al. (21) did not determine any collar structures out of 59, 7 and 9 phages they examined respectively. Krusch et al. (14) determined tail plaque structures in all of the phages they examined. It is known that fiber structures are rarely found (14, 22), and it is speculated that this is because these fragile structures are easily detached by mechanical effects or that perhaps mutants without fibers frequently occur. (26). However, in some S. thermophilus phages tail plaque and fibers were shown clearly (19, 21). In this study while collar and tail plaques were observed in many of the L. bulgaricus phages, these structures could not be seen in S. thermophilus phages although the micrographs were taken at the same magnification. The reason for this may be either the modifications in the dying procedure or the use of three different electron microscopes. L. bulgaricus phages had also isometric hexagonal heads and noncontractile tails. In one exceptional case Reinbold et al., isolated and micrographed a L. bulgaricus phage having a contractile cover. This phage was categorised in Myoviridae in Ackermann s classification (5). The temperate phages mvl and mv4 were studied by Cluzel et al. (27), and the morphology of the ch2 virulent phage was determined by Chow et al. (28). The lb 539 temperate phage was examined by Auad et al. (15). These four phages were also placed in Group B in Bradley s classification. The capsid diameters (50 nm) of the mv1 and mv4 phages (27) were the same as in the case of the ch2 virulent phage (28). Their tail lengths were also close to each other, being 180 nm and 170 nm respectively. However in the lb 539 temperate phage the diameter of the capsid was 47 nm and the tail was 159 nm long (15). The new virulent phage phildb which was isolated by Wang et al. has an icosahedral capsid of 47.7±0.9 nm in diameter and a long noncontractible tail of 129.8±2 nm and several fibres (9). 25 native L. bulgaricus phages examined in this study were found to have a wider range of capsid diameter (47-73 nm), tail length (117-162 nm) and width (7-13 nm). In this study, the capsid diameters and tail width determined in L. bulgaricus phages were similar to the other L. bulgaricus phages. However when the tail lengths were compared, it was found that they had smaller tails. Only the lb 539 (15) and phildb (9) phages with 159 and 129 nm tail length lay in between the values that we measured, respectively. One other difference was clearly apparent in collar and tail plaque structures. According to the measurements of Chow et al. (28), both collar and tail plaque structures showed considerably higher values (Figure 2a). However it is thought that the differences in the values are not because of the structural differences of the native phages originating in Turkey, but because tail structures are not clearly identified since the micrographs in this study were taken at a lower magnification. The frequency of thermophilic phage isolation from raw milk In our former studies using native and industrial strains, although the lactococcal phages were isolated from raw milk at a high frequency (29, 30), a lack of success in the isolation of S. thermophilus and L. bulgaricus phages with native and indus- 321
E.A. Soykut, N. Tunail trial hosts, led us to reconsider raw milk as a highly suitable isolation source for these phages (31). Since there is only a limited literature on this subject (12) a minor trial study was conducted; first, 18 raw milk samples were compared with 3 S. thermophilus (B3, 709, 231) strains, 2 phages (Ф1B3-A and Ф2B3-A), which were effective only with the B3 host, were isolated from 2 raw milk samples and their morphological characterization was undertaken with the other phages in the collection. Then 9 industrial S. thermophilus (231, 632, 709, V1, V2, Y1, Y4, CH-1, B3) strains were used as a host. However, out of 3 raw milk samples, no phage could be isolated. Additionally, the same 3 samples were tried with a total of 6 L. bulgaricus strains, five of which were industrial (Y1, Y4, V1, V2, 231) and one being a reference strain (Lactobacillus bulgaricus ATTC 11842), from the 2 raw milk samples 7 of the phages which were effective with V1, V2, Y4 and L. bulgaricus ATTC 11842 strains could be isolated. In the light of the data, phages specific to L. bulgaricus are more frequently isolated than the phages specific to S. thermophilus from raw milk. However it is much more difficult and less common to isolate thermophilic phages from raw milk samples. ACKNOWLEDGMENT We thank The Scientific and Technological Research Council of Turkey for the financial support. (Project No: TÜBİTAK/TARP 2106). REFERENCES 1. Larbi D, Colmin C, Rousselle L, Decaris B, Simonet JM. 1990. Genetic and biological characterization of nine Streptococcus salivarius subsp. thermophilus bacteriophages. Lait, 70, 107-116. 2. Quiberoni A, Auad L, Binetti AG, Suárez VB, Reinheimer JA, Raya RR. 2003. Comparative analysis af Streptococcus thermophilus bacteriophages isolated from a yogurt industrial plant. Food Microbiol, 20, 461-469. 3. Moineau S, Borkaev M, Holler BJ, Walker SA, Kondo JK, Vedamuthu ER, Vanderbergh PA. 1996. Isolation and characterization of Lactococcal bacteriophages from cultured buttermilk plants in the United States. J Dairy Sci, 70, 2104-2111. 4. Reinbold GW. 1974. Bacteriophage For Italian Cheese Cultures. 11 th Annual Marschall Invitational Italian Cheese Seminer, Wisconsin. 5. Reinbold GW, Reddy MS, Hammond EG. 1982. Ultrastructures of bacteriophages active against Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus lactis and Lactobacillus helveticus. J Food Protect, 45 (2), 119-124. 6. Suárez VB, Quiberoni A, Binetti AG, Reinheimer JA. 2002. Thermophilic lactic acid bacteria phages isolated from Argentinian dairy industries. J Food Protect, 65 (10), 1597-1604. 7. Le Marrec C, Sinderen D, Walsh L, Stanley E, Vlegels E, Moineau S, Heinze P, Fitzgerald G, Fayard B. 1997. Two groups of bacteriophages Streptococcus thermophilus can be distinguished onthe basis mode packaing and genetic determinants for major structural proteins. Appl Environ Microbiol, 63 (8), 3246-3253. 8. Neve H, Freudenberg W, Diestel-Feddersen F, Ehlert R, Heller KJ. 2003. Biology of the temperate Streptococcus thermophilus bacteriophage TP-J34 and physical characterization of the phage genome. Virology, 315, 184 194. 9. Wang S, Kong J, Gao C, Guo T, Liu X. 2010. Isolation and characterization of a novel virulent phage (phildb) of Lactobacillus delbrueckii. Int J Food Microbiol, 137, 22 27. 10. Durlu-Özkaya F, İç N, Tunail N. 1999. The thermophilic starter cultures resistant to their phages and rotation. Special Issue for the 11 th Congress of KÜKEM, 23 (2), 7-8. 11. Olsen JV. 1990. The Dairy Cultures of Chr. Hansen s. The latest development of dairy cultures. Dairy Seminar, Ankara Üniversity, Agricultural Faculty. 12. Bruttin A, Desiere F, d Amico N, Guerin JP, Sidoti J, Huni B, Lucchini S, Brüssow H. 1997. Moleculer ecology of Streptococcus thermophilus bacteriophage infections in a cheese factory. Appl Environ Microbiol, 63, 3144-3150. 13. Kaleli D, Tunail N, Acar E. 2004. Virulent bacteriophages of Streptococcus thermophilus and lysogeny. Milchwissenschaft, 59 (9/10), 487-491. 14. Krusch U, Neve H, Luschei B, Teuber M. 1987. Characterization of virulent bacteriophages of Streptococcus salivarius subsp. thermophilus by host specifity and electron microscopy. Kieler Milch. Forschungsberichte, 39 (3), 155-167. 15. Auad L, Holgado R, Forsman P, Alatossava T, Raya RR. 1997. Isolation and characterization of a new Lactobacillus delbrueckii subsp. bulgaricus temperate bacteriophage. J Dairy Science, 80, 2706-2712. 16. Kivi S, Peltomäki T, Luomala K, Sarimo SS. 1987. Some properties of Streptococcus thermophilus bacteriophages. Fotra Microbiol, 32, 101-106. 17. Ackermann HW, DuBow MS. 1987. Viruses of Prokaryotes, Vol. 1: General Properties of Bacteriophages. CRC Press, Boca Raton, Florida. 18. Zhang X, Kong J, Qu Y. 2006. Isolation and characterization of a Lactobacillus fermentum temperate bacteriophage from Chinese yogurt. J Appl Microbiol, 101, 857 863. 322
Morphological Characterization Of Streptococcus... 19. Brüssow H, Frémont M, Bruttin A, Sidoti J, Constabla A, Fryder V. 1994. Detection and classification of Streptococcus thermophilus bacteriophages isolated from industrial milk fermentation. Appl Environ Microbiol, 60 (12), 4537-4543. 20. Benbadis L, Faelen M, Slos P, Fazel A, Mercenier A. 1990. Characterization and comparison of virulent bacteriophages of Streptococcus thermophilus isolated from yogurt. Biochimie, 72, 855-862. 21. Prevots F, Relano P, Mata M, Ritzenthaler P. 1989. Close relationship of virulent bacteriophages of Streptococcus salivarius subsp. thermophilus at both the protein and the DNA level. J General Microbiol, 135, 3337-3344. 22. Fayard B, Haefliger M, Accolas JP. 1993. Interaction of temperate bacteriophages of Streptococcus salivarius subsp. thermophilus with lysogenic affect phage DNA restriction pattern and host ranges. J Dairy Res, 60, 385-399. 23. Stanley E, Fitzgerald GF, Le Marrec C, Fayard B, Sinderen D. 1997. Sequence analysis and characterization of Φ01205, a temperate bacteriophage infecting Streptococcus thermophilus CNRZ1205. Microbiology, 143, 3417-3429. 24. Tremblay DM, Moineau S. 1999. Complete genomic sequence of the lytic bacteriophage DT1 of Streptococcus thermophilus. Virology, 255, 63-76. 25. Le vesque C, Duplessis M, Labonte J, Labrie S, Fremaux C, Tremblay D, Moineau S. 2005. Genomic Organization and Molecular Analysis of Virulent Bacteriophage 2972 Infecting an Exopolysaccharide-Producing Streptococcus thermophilus Strain. Appl Environ Microbiol, 71 (7), 4057 4068. 26. Neve H, Krusch U, Teuber M. 1989. Classification of virulent bacteriophages of Streptococcus salivarius subsp. thermophilus isolated from yogurt and Swiss-type cheese. Appl Microbiol Biotechnol, 30, 624-629. 27. Cluzel PJ, Veaux M, Rousseau M, Accolas JP. 1987. Evidence for temperate bacteriophages in two strains of Lactobacillus bulgaricus. J Dairy Res, 54, 397-405. 28. Chow J, Batt CA, Sinskey AJ. 1988. Characterization of Lactobacillus bulgaricus bacteriophage ch2. Appl Environ Microbiol, 54 (5), 1138-1142. 29. Aydar LY, Tunail N. 1995. Isolation and electron microscopic investigation of lactic phages which isolated from Turkey. Milchwissenschaft, 50 (6), 312-316. 30. Durlu F, Tunail N. 1991. Resistance of commercial cheese starter cultures to domestic bacteriophages in Turkey. The Third International Congres on Food Industry, 4-8 November, Kuşadası, İzmir, Turkey, 125-139. 31. Rio B, Binetti AG, Martı na MC, Ferna ndeza M, Magada na AH, Alvarez MA. 2007. Multiplex PCR for the detection and identification of dairy bacteriophages in milk. Food Microbiol, 24, 75 81. 323
Yazım Kuralları GIDA (2009) 34 (1): 55-58 www.gidadernegi.org / Gıda Dergisi / Yayın kuralları Makale Gönderimi ve Telif Hakkı Devir Formu GIDA (2009) 34 (1): 65 www.gidadernegi.org / Gıda Dergisi / Makale Gönderimi ve Telif Hakkı Devir Formu Son Kontrol Listesi GIDA (2009) 34 (1): 66 www.gidadernegi.org / Gıda Dergisi / Son Kontrol Listesi adreslerinden erişilebilir. Yazarlar, makale göndermeden önce yazım kurallarını tam olarak okumalı ve makalelerini burada verilen kurallara göre hazırlamalıdırlar.
GIDA (2010) 35 (5): 325-330 GD10011 Research / Araştırma COMPOSITIONAL CHANGES OF SAANEN X KİLİS GOATS MILK DURING LACTATION Nuray Güzeler 1, Dilek Say 2 *, Ali Kaçar 1 1 Department of Food Eng, Faculty of Agriculture, University of Çukurova, Adana, Turkey 2 Vocational School of Pozantı, University of Çukurova, Adana, Turkey Abstract Received / Geliş tarihi : 06.01.2010 Received in revised form / Düzeltilerek geliş tarihi: 22.06.2010 Accepted / Kabul tarihi: 01.07.2010 Milks of 220 Saanen x Kilis goats were taken during 22 weeks of lactation. Chemical compositions, energy values and mineral contents of goats milk samples were determined. As results of the goats milk samples analyses, the mean values were determined as 12.12% for dry matter; 3.45% for fat; 3.81% for protein; 4.12% for lactose and 261.5 kj/100g for energy value, 6.86 for ph, 6.71 SH for titratable acidity and 1.031 g/cm3 for specific gravity during lactation. The mineral contents of the samples were similarly found to be 220.5 mg/100g for calcium; 108.8 mg/100g for phosphorus; 153.5 mg/100g for potassium, 20.1 mg/100g for magnesium and 67.5 mg/100g for sodium. Results of the statistical analyses indicated significant lactational effects on the contents of total solids, fat, non-fat dry matter, protein, lactose, energy value, titratable acidity, ph, specific gravity (P<0.01) and sodium (P<0.05), but there was no similar effect on the contents of calcium, phosphorus, magnesium and potassium values of goats milk (P<0.05). Keywords: Goat milk, lactation, chemical, energy value, minerals LAKTASYON DÖNEMİ BOYUNCA SAANEN X KİLİS KEÇİ SÜTÜ BİLEŞİMİNDEKİ DEĞİŞİMLER Özet Laktasyon dönemindeki 220 Saanen x Kilis keçilerinden haftada bir kez olmak üzere 22 hafta boyunca süt örnekleri alınmıştır. Keçi sütü örneklerinin kimyasal bileşimleri, enerji değerleri ve mineral içerikleri belirlenmiştir. Analiz sonuçlarında keçi sütlerinin bileşimleri ortalama olarak; kurumadde için %12.12, yağ için %3.45, protein için %3.81, laktoz için %4.12, enerji değeri için 261.5 kj/100g, ph için 6.86, titrasyon asitliği için 6.71 SH ve özgül ağırlık için 1.031 g/cm3 olarak bulunmuştur. Aynı şekilde süt örneklerinin mineral madde içeriği; kalsiyum için 220.5 mg/100g, fosfor için 108.8 mg/100g, potasyum için 153.5 mg/100g, magnezyum için 20.1 mg/100g ve sodyum için 67.5 mg/100g olarak belirlenmiştir. Yapılan istatistiksel analiz sonucu laktasyon döneminin keçi sütlerinin kurumadde, yağ, yağsız kurumadde, protein, laktoz, enerji değerleri, asitlik, ph, özgül ağırlık (P<0.01) ve sodyum (P<0.05) değerlerine etkisinin önemli, kalsiyum, fosfor, magnezyum ve potasyum değerlerine etkisinin önemli olmadığı belirlenmiştir (P>0.05). Anahtar Kelimeler: Keçi sütü, laktasyon, kimyasal, enerji değeri, mineraller * Correspondence author / Yazışmalardan sorumlu yazar ; - dsay@cu.edu.tr & (+90) 322 581 2180 7 (+90) 322 581 2190 325
N. Güzeler, D. Say, A. Kaçar INTRODUCTION Of the milk Turkey produces annually, cow s milk makes up 91.47%, goat s milk 1.93%, sheep s milk 6.35% and buffalo s milk 0.25%. In the world, 12601944 tons of goat milk is produced per year and in this respect Turkey is the 13th leading country with its 237487 tons of goat milk production (1). Goat milk is of great importance for milk technology and nutrition. Goat milk is more digestible because of its small-sized globules, uniform protein and fat distribution. Modified goat milk can also be used in baby feeding (2). Goat milk provides a healthy and a balanced diet for the children who are allergic to cow milk, as the symptoms may disappear with goat milk consumption (3). As it is known, nutritional value of milk is closely related with its composition, which is highly affected by factors such as breed, feed, stage of lactation, season, etc. (3, 4). Particularly during lactation there are significant changes in the amount and composition of goat milk (5). Like cow milk, goat milk is an excellent source of calcium, phosphorus and potassium. It is also a good source of magnesium, sodium and iron (6-8). One of the local breeds in Turkey is Kilis breed. Their total number is estimated to be around 60000 heads. The goats are known with high milk yield. Lactation milk yields of Kilis goat are 200-300 kg in lactation periods of 190-230 days (9). Saanen goat, originated in Switzerland, is one of the preferred dairy goats primarily because of their consistency in producing large quantities of milk in conjunction with their sturdiness, easy keepability and capacity to tolerate environmental changes. They produce 750 kg milk in their lactation period of 280 days. (10). For improving of goat population, Saanen breed was used as the improver breed and crossed with Kilis breed in Turkey (11). Although there are many studies on the changes of major constituents in goat milk during lactation, only little is known about nutritional value and mineral contents of goat milk. In this respect, this study aims to determine the nutritional value and mineral contents of goat milk. It also aims to determine the nutritional and mineral content changes during lactation period. MATERIALS AND METHODS For this study morning milk was collected from a herd, which consisted of 220 Saanen x Kilis goats in Çukurova University, Faculty of Agriculture, Animal Husbandry Department during 22 weeks in 2006. After 22 weeks, the milking of goats was not sufficient for collecting. Saanen x Kilis goats produce 500-600 kg milk in their 150-220 days of lactation. When 60 days of kid feeding was eliminated from this period, goat milk could be collected during 155 days of lactation. Total population of them in Çukurova University farm is approximately 300-500 heads. After parturition, the animals were fed 600 g dairy feed which consists of 18% crude protein and 2600 kcal metabolisable energy in kg dry matter as addition to pasture during the study. Three milk samples were taken every week during the period and then analyzed. In the samples, the level of dry matter was determined gravimetrically. The fat content was obtained using the Gerber method. Kjeldahl procedure was used for determination of protein and Lane Eynon procedure was used for determination of lactose. ph measurements were carried out using Beckman ph meter. Titratable acidity was determined according to alkali titration. Specific gravity was measured by lactometer (12, 13). The amounts of fat, protein and carbohydrate were multiplied by co-efficient and summed for energy content. To determine mineral content, milk samples were analyzed for Ca, K, Mg and Na by using PV9100 atomic absorption spectrophotometer and they were analyzed for P by using Varian DMS 1005 UV Visible Spectrophotometer (14). The results were statistically evaluated using analysis of variance (one-way ANOVA). The differences between the samples were determined by the test of LSD (15). RESULTS AND DISCUSSION Table 1 shows the composition of goats milk analyzed during 22 weeks of lactation. As seen from Figure 1, average of dry matter value was stable during the early weeks of lactation and it started to decrease after the 6th week. Starting to increase after the 9th week, dry matter content had a higher value than that of early weeks of lactation (P<0.01). During the last weeks of lactation, total solids value remained stable. Zahraddeen et al. (16) observed non-significant difference in total solid content of Nigeria goat milk during stage of lactation. Güler et al. (17) reported high values for dry matter for 10 Damascus goats and 8 German fawn x Hair goat 326
Compositional Changes Of Saanen X Kilis... B-1 crossbreds during lactation. When the results of this study are compared to results of the previous studies, it can be said that they are lower than the values reported by the researchers (4, 18). However, the values obtained in this study are higher than those observed by Merin et al (3) and Sawaya et al. (19). The highest non-fat dry matter value was obtained in the 19th week of lactation. The non-fat dry matter was affected during the lactation period. Kondyli et al. (20) reported similar observation for goat milk of 145 indigenous Greek breed. The non-fat dry matter value of Saanen x Kilis goats was higher than that of white Polish goats (21) and Alpine and Saanen goats in lactation periods (22). Table 1. Composition of goats milk during 22 weeks of lactation Min Mean ± S.D. Max Dry matter (%) 9.94 12.12±1.14 13.58 Fat (%) 2.00 3.45±0.92 4.50 Non-fat dry matter (%) 7.94 8.69±0.37 9.13 Protein (%) 3.30 3.81±0.30 4.52 Lactose (%) 3.45 4.12±0.38 4.72 Energy value (kj/100g) 194.9 261.5±38.2 306.2 ph 6.70 6.86±0.09 6.96 Titratable aciditidy (SH) 7.78 6.71±0.29 6.19 Specific gravity (g/cm 3 ) 1.030 1.031±0.01 1.033 Calcium (mg/100g) 118.0 220.5±59.52 299.0 Phosphorus (mg/100g) 58.0 108.8±21.52 133.0 Ca/P (mg/100g) 0.95 2.13±0.85 4.90 Magnesium (mg/100g) 16.0 20.1±2.48 27.0 Sodium (mg/100g) 55.0 67.5±7.55 87.0 Potassium (mg/100g) 124.0 153.5±19.21 192.0 Na/K (mg/100g) 0.33 0.45±0.07 0.61 (%) 14,00 13,00 12,00 11,00 10,00 9,00 8,00 7,00 Dry matter Non fat dry matter 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Weeks Figure 1. Dry Matter and non-fat matter in goats milk during lactation Fat, protein and lactose values in goat milk during lactation are presented in Figure 2. Fat content started to decrease after the 3rd week. The value started to rise in the 7th week and reached its maximum in the 12th week (P< 0.01). There were no significant changes in fat value during late lactation. The results found in this study are lower than the results found by other researchers for African dwarf goats (5) and 20 Maltese-local cross goats (18), white Polish goats (21). The mean value of fat found in this study is close to mean value reported by Voutsinas et al. (23) for Alpine goats and higher than mean value reported by Güler et al. (17) for Damascus goats and German fawn x Hair goat B-1 crossbreds (3, 19). Brendehaug and Abrahemsen (24) found that fat content decreased over the first 4 months of lactation and increased during the mountain pasture period. A researcher determined that fat content was affected by breed, stage of lactation and season. Moreover, this value decreased as lactation progressed (16). (%) 5 4 3 2 1 Fat Protein Lactose 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Weeks Figure 2. Fat, protein and lactose in goats milk during lactation Although protein content changed over the whole period of lactation, an increase in this value was only recorded during late lactation (P<0.01). When the results of the study are compared to results of the previous study, it is found that they are lower than the value reported by Wuschko and Seifert (5) in 150 days of lactation period. However, the values obtained in this study were determined to be higher than the values reported by Gnan et al. (18) for 20 Maltese-local cross goats, Simos et al. (25) for 164 native Greek goats and Kudeka (21) for white Polish goats. Brendehaug and Abrahamsen (24) found that protein value decreased during the first 4 months and then increased until the end of lactation. 327
N. Güzeler, D. Say, A. Kaçar Zahraddeen et al. (16) reported that protein and lactose were significantly affected by breed, stage of lactation and their content decreased with advancing lactations. Lactose value decreased slowly from the beginning until the 9th week of lactation. Although the value was high between the 10th and the 13th weeks, it started to decrease again (P<0.01) and remained stable during the last weeks of lactation. Wuschko and Seifert (5) and Brendehaug and Abrahamsen (24) reported similar observations. The average lactose value obtained in the study was lower than the values reported by Gnan et al. (18) for 20 Maltese-local cross goats, Simos et al. (25) for 164 animals in their 2nd and 3rd lactation of the native Greek goat, Mariani et al. (26) for 53 Alpine goats and 18 Alpine x Saanen goats, Voutsinas et al. (23) for Alpine goats and Kudeka (21) for white Polish goats and the same as value reported by Sawaya et al. (19) for Masri and Aardi goats of Saudi Arabia. The energy value of goats milk was minimum on the 7th week of lactation (see Figure 3). The values were low at the beginning but increased during lactation (P<0.01). Like other total solid constituents, energy value remained stable during the last weeks of lactation. Energy value changes as a result of the variations in the amount of the fat. The mean value is close to that found by Haenlein (4). Energy value (kj/100g) 400 300 200 100 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Weeks Figure 3. Energy value in goats milk during lactation ph and titratable acidity values in goats milk are presented Figure 4. ph values rose consistently during lactation (P<0.01). This finding is in contrast to that of Zahraddeen et al. (16). Titratable acidity decreased during lactation in parallel to the changes in ph value (P<0.01). Mean values of titratable acidity were lower than those of Simos et al. s reported (25) for native Greek goats during the period after weaning (mid Marc) until drying-off (end of July). As seen in Figure 5 specific gravity decreased inconsistently during lactation period (P<0.01). Specific gravity decreases as a result of the variations in the amount of fat. This value is similar to those reported by Merin (3), Voutsinas et al. (23), El-Zayat et al. (27) and lower than the value reported by Kudeka (21). 8,00 7,50 7,00 6,50 6,00 5,50 5,00 ph Titratable acidity (SH) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Weeks Figure 4. ph and titratable acidity in goats milk during lactation Specific gravity (g/cm 3 ) 1,0340 1,0320 1,0300 1,0280 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Weeks Figure 5. Specific gravity in goats milk during lactation The changes in calcium, phosphorus, potassium and magnesium values of goats milk during lactation were not found statistically significant (P>0.05). When compared to other studies, the content of calcium recorded in this study is higher than the values reported by the researchers (4, 6, 23, 25, 27, 28). Some researchers have mentioned that phosphorus, potassium, sodium, calcium and magnesium increase during lactation (29). Some researchers found out that there occurs a simultaneous decrease in calcium content (25). However, other researchers reported that these minerals (Na, K, Ca and Mg) remain stable during lactation (5). Antunac et al. (22) reported that significantly higher contents of calcium and phosphorus were determined at the beginning of lactation in comparison with the middle of lactation. Whereas in one study, it was reported that phosphorus concentration was higher at the beginning of lactation (30), in another 328
Compositional Changes Of Saanen X Kilis... reported study, phosphorus content was low at the beginning and increased by 3.4% during lactation (29). Researchers stated that the amount of potassium was at higher level during mid lactation (30). During lactation, magnesium content slightly increased (29). Significant change was observed in sodium content during lactation (P<0.05). As seen from Figure 6, sodium was highest in 2nd week and then became equal to its initial value towards the end of lactation. The mean value for sodium content was found higher than the values reported by Gnan et al. (18) for native Libya goat, Simos et al. (25) for native Greek goat, Voutsinas et al. (23) for Alpine goat. It was reported that the amount of sodium increased during lactation period (7, 29). Sodium (mg/100g) 100 80 60 40 20 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Figure 6. Sodium in goats milk during Lactation The profile of Ca/P and Na/K ratios were obtained at stages of lactation. The mean values of these ratios were higher than the values reported by Kondyli et al. (20) for goat milk of the indigenous Greek breed. Voutsinas et al. (23) founded significant changes in Ca/P and Na/K ratios in the milk between lactation stages. CONCLUSIONS This study showed that fat, protein, energy value and ph content in goats milk increased during lactation periods. However, lactose, titratable acidity and specific gravity decreased during lactation. Calcium, phosphorus, potassium and magnesium values did not vary. However, sodium value varied during lactation. REFERENCES Weeks 1. FAO. 2007. Agricultural data base production. http:// www.fao.org (Accessed 04 January 2010) 2. Desjeux TF. 1993. Value nutriannelle du lait de chevre. Lait, 73: 573-580. 3. Merin U, Rosenthal I, Maltz E. 1988. The composition of goat milk as affected by nutritional parameters. Milchwissenschaft, 43: 363-365. 4. Haenlein GFW. 1980. Mineral nutrition of goats. J Dairy Sci, 63: 1729-1748. 5. Wuschko S, Seifert H. 1992. Lactation curve, milk yield and milk composition in African Dwarf Goats. Reihe Agrarwissenschaften, 41: 49-55. 6. Lopez A, Collins WF, Williams HL. 1985. Essential elements, cadmium and lead in raw and pasteurized cow and goat milk. J Dairy Sci, 68: 1878-1886. 7. Boros V, Herian K, Krcal Z. 1989. Variations in mineral content of goat milk during lactation. Prumysl Potravin, 40: 312-314. 8. Rincon F, Moreno R, Zurera G, Amaro M. 1994. Mineral composition as a characteristic for the identification of animal origin of raw milk. J Dairy Res, 61: 151-154. 9. Yalçin BC. 1986. Sheep and Goats in Turkey. FAO Animal Production and Health Paper, No: 60, Rome, Italy, 168 p. 10. Ceyhan A. 2007. Dünyada Yetiştiriciliği Yapılan Önemli Sütçü Keçi Irkları. Marmara Hayvancılık Araştırma Enstitüsü, Hayvan Yetiştirme ve Islahı Bölümü, Bandırma, Balıkesir. www.marmarahae.gov.tr/index. php?sid=ciftci_1 (Erişim tarihi 16 June 2010) 11. Yener SM. 1989. Milk Production from Goats. Options Méditerranéennes - Série Séminaires - n.o 6, 149-157. http://ressources.ciheam.org/om/pdf/a06/ CI000477.pdf (Accessed 14 June 2010) 12. Ling RL. 1963. Dairy Chemistry. Vol. 1-2 Chapman and Hall Ltd. London, 227 p. 13. AOAC. 1970. Official Methods of Analysis of the Association of Official Agricultural Chemist. P. O. Box: 540, Washington DC, USA, 1015 p. 14. Kosikowski FV, Kindstedt PS. 1985. Improved complexametric determination of calcium in cheese. J Dairy Sci, 68: 806-809. 15. Steel RGD, Torrie JH. 1980. Principles and Procedures of Statistics. McGraw Hill Book Co., New York, 640 p. 16. Zahraddeen D, Butswat ISR, Mbap ST. 2007. Evaluation of some factors affecting milk composition of indigenous goats in Nigeria. LRRD, 19: 1-8. 17. Güler Z, Keskin M, Masatçioğlu T, Gül S, Biçer O. 2007. Effects of breed and lactation period on some characteristics and free fatty acid composition of raw milk from Damascus goats and German fawn x Hair goat B-1 crossbreds. Turk J Vet Anim Sci, 31: 347-354. 329