Tuğba KÖK TAŞ, Burcu BOZOVA, Zeynep B. GUZEL SEYDİM

Kefir Tozu Zenginleştirmesinin Yoğurt Kalitesi Üzerine Etkisi

Bu araştırmanın amacı sade pıhtısı kırılmamış yoğurdun fonksiyonel ve duyusal özelliklerinin iyileştirilmesidir. Sütlerin toplam kuru madde standardizasyonu (% 15 w v-1), uygulama grubunda (KTYO) doğal kefir tozuyla, kontrol grubunda (YKON) süt tozuyla yapılmıştır. Kefir tozu kefir danelerinden üretilen doğal kefirin liyofilize edilmesiyle üretilmiştir. Soğuk depolama süresince yoğurt örneklerinin mikrobiyolojik, kimyasal, duyusal ve fiziksel özellikleri belirlenmiştir. Örneklerin pH, titrasyon asitliği, serum ayrılması, duyusal değerlendirmesi, renk değerleri ve flavor bileşenleri çalışılmıştır. Kefir tozu veya süt tozu içeren yoğurt örneklerinin tümünde Lactobacillus spp. içeriği benzer olarak tespit edilmiş ve soğuk depolama sürecinde de önemli bir değişim gözlenmemiştir. KTYO örneğinin L. acidophilus ve Bifidobacterium spp. içeriği soğuk depolama süresince sırasıyla 5.79-6.93 log cfu g-1 ve 4.05-4.83 log cfu g-1 olarak tespit edilmiştir. Soğuk depolama süresince bu bakterilerin içeriğinde azalma tespit edilmemiştir (P>0.05). Kefir tozu ilaveli yoğurt örneklerinin duyusal değerlendirme bulguları süt tozu ilaveli yoğurt örneklerinin duyusal değerlendirmeleri ile benzer tespit edilmiştir (P>0.05).

Effects of Kefir Powder Fortification on Yogurt Quality

The aim of this research was to improve functional properties and sensory of plain set type yogurt since yogurt bacteria have low probiotic properties. Total solid standardization (to 15% w v-1) of milks was made with either using natural kefir powder as a treatment group (KTYO) or milk powder as a control group (YKON). Kefir powder was produced with freeze-dried kefir made from kefir grains. Microbial, chemical, sensory and physical properties of yogurts were determined during cold storage. The attributes determined on the yogurts were pH, total solids, titratable acidity, whey separation, sensory properties, color parameters and flavor. Numbers of Lactobacillus spp. in yogurt samples contained either kefir powder or milk powder were similar and did not change significantly during cold storage. L. acidophilus and Bifidobacterium spp. contents of KTYO ranged between 5.79-6.93 log cfu g-1 and 4.05-4.83 log cfu g-1 during the cold storage, respectively. There was no significant reduction in the number of L. acidophilus and Bifidobacterium spp. during the storage (P>0.05). In general, sensory properties of the YKON and KTYO were similar (P>0.05).

PDF

___

Yılmazer M & Seçilmiş H (2006). Gaz kromatografisi headspace sistemi ile süt ürünlerinde bazı aroma bileşenlerinin analizi. Türkiye 9. Gıda Kongresi, 24-26 Mayıs, Abant İzzet Baysal Üniversitesi, Bolu, s. 625-628
Yalçın S (1985). Yogurtta aroma ve lezzet bileşiklerinin oluşumu. A.U. Veteriner Fakültesi Dergisi 32: 237-249.
Routray W & Mishra H N (2011). Scientific and technical aspects of yogurt aroma and taste. Comprehensive Reviews in Food Science and Food Safety 10: 208-220
Ranadheera C S, Evans C A, Adams M C & Baines S K (2012). Probiotic viability and physico-chemical and sensory properties of plain and stirred fruit yogurts made from goat`s milk. Food Chemistry 135: 1411-1418
Özer B H, Uzun Y S & Kırmacı H A (2008). Effect of cell immobilization on viability of Lactobacillus acidophilus LA-5 and Bifidobacterium bifidum BB12 in kasar cheese. International Journal of Dairy Technology 61: 237-244
Mossel D A A, Corry J E L, Stuijk C B & Baird R M (1995). Essential of the microbiology of food: a texbook for advance studies (1th ed.). John Wiley, New York
Meilgaard M, Civille G V & Carr B T (1999). Sensory Evaluation Techniques. 3rd Ed. USA: CRC Press, LLC
Kök Taş T, Ekinci F Y & Guzel-Seydim Z B (2012). Identification of microbial flora in kefir grains produced in Turkey using PCR. International Journal of Dairy Technology 65: 126-131
Lourens-Hattingh A & Viljoen B C (2001). Yogurt as probiotic carrier food. International Dairy Journal 11: 1-17
Guzel-Seydim Z B, Kok-Taş T, Greene A K & Seydim A C (2011). Review: Functional properties of kefir. Food Science and Nutrition 51: 261-268
Guzel-Seydim Z B, Sezgin E & Seydim A C (2005). Influences of exopolysaccharide producing cultures on the quality of plain set type yogurt. Food Control 16: 205-209
Dave R I & Shah N P (1997). Viability of yoghurt and probiotic bacteria in yoghurts made from commercial starter cultures. International Dairy Journal 7: 31-41
Cais-Sokolinska D & Pikul J (2006). Use of colour measurement to evaluate yoghurt quality during storage. Itallian Journal of Food Science 18: 63-71
Atamer M & Sezgin E (1986). Yoğurtlarda kurumadde artırımının pıhtının fiziksel özellikleri üzerine etkisi. Gıda 11: 327-331
Ashraf R & Shah N P (2011). Selective and differential enumerations of Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium spp. in yoghurt. International Journal of Food Microbiology 149: 194-208
AOAC International (1992). Official Methods of Analysis. 14th ed. AOAC International, Arlington, VA
Ahmed Z, Yanping W, Asıf A, Salman T K, Mehrun N, Hajra A & Asma A (2013). Kefir and health, a contemporary perspective. Critical Reviews in Food Science and Nutrition 53: 422-434