Evaluation of the Effect of Ultrasound Application on the Microbiological and Some Physicochemical Properties of Yoghurt at Different Stages of Production

Öz

In this study, it was aimed to evaluate the effects of ultrasound application applied to yoghurt samples produced in laboratory environment at different stages of production (before and after fermentation) on the water holding capacity, homogenization and shelf life of yoghurts. In order to achieve this aim, microbiological and physicochemical analyzes were performed on the 1st, 7th and 15th days of the yoghurt groups at 2-4 ° C cold storage. It was determined that there was an increase of 0.5 log in the number of L. delbrueckii subsp. bulgaricus in each group on the 7th day. According to the results of the 7th day in the I + U group, it was found that there was a 1 log decrease in the number of S. thermophilus. The highest yeast count was determined at 5.02 log cfu / g in 15th day samples of again I + U group. The water holding capacity in the control, U + I and I + U groups was determined respectively 28.45%, 52.96%, 46.48% in the first day analyzes, 34.49%, 48.17%, 50,52% in the 7th day analyzes, and 31.34%, 54.84% and 47.84% in the 15th day analysis. Also in homogenization efficiency a significant difference between the control group, U + I and I + U groups has been determined. The highest homogenization efficiency was detected in I + U group at 3.03% level. In the control, U + I and I + U groups L value averages,in color analysis on the 15th day were determined as 81.55; 85.56; and 84.46 respectively. As a result, it was determined that yoghurt bacterial counts, pH and titration acidity values did not cause a defect that would affect taste and aroma during storage under cold storage conditions. In addition, in terms of water holding capacity, homogenization efficiency and L value during storage, it has been determined that ultrasound applications improve the rheological properties of yoghurt and increase its durability under cold storage conditions.

Anahtar Kelimeler

• Ultrasound
• yoghurt
• shelf life
• water holding capacity
• homogenization.

YOĞURT ÜRETİMİNİN FARKLI AŞAMALARINDA ULTRASON UYGULAMASININ YOĞURTLARIN MİKROBİYOLOJİK VE BAZI FİZİKOKİMYASAL ÖZELLİKLERİ ÜZERİNE ETKİSİNİN DEĞERLENDİRİLMESİ

Öz

Bu çalışmada laboratuvar ortamında üretilen yoğurt örneklerine üretimin farklı aşamalarında (mayalamadan önce ve sonra) uygulanan ultrason işleminin yoğurtların su tutma kapasitesi, homojenizasyon ve raf ömrü üzerine etkilerinin değerlendirilmesi amaçlanmıştır. Bu amaca yönelik olarak yoğurt gruplarına 2-4 °C soğuk soğukta muhafazanın 1., 7. ve 15. günlerinde mikrobiyolojik ve fizikokimyasal analizler yapılmıştır. L. delbrueckii subsp. bulgaricus sayısında her grupta 7. günde yaklaşık 0,5 log artışın olduğu belirlenmiştir. İ+U grubunda 7. gün sonuçlarına göre S. thermophilus sayısında 1 log azalmanın olduğu saptanmıştr. En yüksek maya sayısı yine bu grupta İ+U grubunda 15. gün örneklerinde 5,02 log kob/g düzeyinde saptanmıştır. Kontrol, U+İ ve İ+U gruplarında su tutma kapasitesi 1. gün analizlerinde ortalama sırasıyla % 28,45, % 52,96, %46,48 olarak, 7. gün analizlerinde %34,49, %48,17, %50,52 olarak, 15. gün analizlerinde ise %31,34, %54,84 ve %47,84 olarak belirlenmiştir. Homojenizasyon etkinliğinde ise kontrol grubu, U+İ ve İ+U grupları arasında anlamlı bir fark olduğu belirlenmiştir. Homojenizasyon etkinliği en yüksek %3,03 düzeyinde İ+U grubunda tespit edilmiştir. Kontrol, U+İ ve İ+U gruplarında 15. gün renk analizlerinde L değeri ortalamaları sırasıyla 81,55; 85,56; 84,46 olarak belirlenmiştir. Sonuç olarak soğuk muhafaza koşullarında depolama süresince yoğurt bakteri sayıları, pH ve titrasyon asitliği değerlerinin tat ve aromayı etkileyecek bir kusur oluşturmadığı saptanmıştır. Bunun yanı sıra depolama süresince su tutma kapasitesi, homojenizasyon etkinliği ve L değeri bakımından değerlendirildiğinde ultrason uygulamalarının yoğurdun reolojik özelliklerini geliştirdiği ve soğuk muhafaza koşullarında dayanma süresini arttırdığı tespit edilmiştir.

Anahtar Kelimeler

• Ultrason
• yoğurt
• raf ömrü
• su tutma kapasitesi
• homojenizasyon.

Kaynakça

1. Aryana, K. J., & Olson, D. W. (2017). A 100-year review: Yogurt and other cultured dairy products. Journal of Dairy Science, 100(12), 9987-10013. https://doi.org/10.3168/jds.2017-12981
2. Barukčić, I., Jakopović, K. L., Herceg, Z., Karlović, S., & Božanić, R. (2015). Influence of high intensity ultrasound on microbial reduction, physico-chemical characteristics and fermentation of sweet whey. Innovative Food Science & Emerging Technologies, 27, 94-101.
3. Bosiljkov, T., Tripalo, B., Ježek, D., Brnčić, M., Karlović, S., & Dujmić, F. (2012). Influence of high intensity ultrasound treatments on physical properties of sheep milk. Croatian Journal of Food Technology, Biotechnology, 7(special issue), 44-48.
4. Delgado, K., Vieira, C., Dammak, I., Frasão, B., Brígida, A., Costa, M. & Conte-Junior, C. (2020) Different ultrasound exposure times influence the physicochemical and microbial quality properties in probiotic goat milk yogurt. Molecules, 25(20), 4638. https://doi.org/10.3390/molecules25204638 .
5. Drakopoulou, S., Terzakis, S., Fountoulakis, M. S., Mantzavinos, D., & Manios, T. (2009). Ultrasound-induced inactivation of gram-negative and gram-positive bacteria in secondary treated municipal wastewater. Ultrasonics Sonochemistry, 16(5), 629-634. https://doi.org/10.1016/j.ultsonch.2008.11.011.
6. Gholamhosseinpour, A., & Hashemi, S. M. B. (2019). Ultrasound pretreatment of fermented milk containing probiotic Lactobacillus plantarum AF1: Carbohydrate metabolism and antioxidant activity. Journal of Food Process Engineering, 42(1), e12930. https://doi.org/10.1111/jfpe.12930.
7. Gıda, Tarım ve Hayvancılık Bakanlığı. (2009). Türk Gıda Kodeksi Fermente Süt Ürünleri Tebliği, 25, Ankara, Türkiye.
8. Gursoy, O., Yilmaz, Y., Gokce, O., & Ertan, K. (2016). Effect of ultrasound power on physicochemical and rheological properties of yoghurt drink produced with thermosonicated milk. Emirates Journal of Food and Agriculture, 28, 235-241.

9. Hekmat, S., & Reid, G. (2006). Sensory properties of probiotic yogurt is comparable to standard yogurt. Nutrition Research, 26, 163–166.
10. Holzapfel, W. H., Geisen, R., & Schillinger, U. (1995). Biological preservation of foods with reference to protective cultures, bacteriocins and food-grade enzymes. International Journal of Food Microbiology, 24(3), 343-362. https://doi.org/10.1016/0168-1605(94)00036-6.
11. Huang, G., Chen, S., Dai, C., Sun, L., Sun, W., Tang, Y., Xiong, F., He, R. & Ma, H. (2017). Effects of ultrasound on microbial growth and enzyme activity. Ultrasonics Sonochemistry, 37, 144–149, https://doi.org/10.1016/j.ultsonch.2016.12.018.
12. Mattila-Sandholm, T., & Saarela, M. (Eds.) (2003). Functional dairy products. New York: Crc Press.
13. Metin, M. (1998). Süt teknolojisi: Sütün bileşimi ve işlenmesi. Ege Üniversitesi Mühendislik Fakültesi Yayınları, No: 33, İzmir.
14. Niamah, A. K. (2019). Ultrasound treatment (low frequency) effects on probiotic bacteria growth in fermented milk. Future of Food: Journal on Food, Agriculture and Society, 7(2), 103.
15. O’connell, J. E., & Fox, P. F. (2001). Significance and applications of phenolic compounds in the production and quality of milk and dairy products: A review. International Dairy Journal, 11(3), 103-120. https://doi.org/10.1016/S0958-6946(01)00033-4.
16. Paniwnyk, L. (2017). Applications of ultrasound in processing of liquid foods: A review. Ultrasonics Sonochemistry, 38, 794-806. https://doi.org/10.1016/j.ultsonch.2016.12.025.
17. Potoroko, I., Kalinina, I., Botvinnikova, V., Krasulya, O., Fatkullin, R., Bagale, U., & Sonawane, S. H. (2018). Ultrasound effects based on simulation of milk processing properties. Ultrasonics Sonochemistry, 48, 463-472. https://doi.org/10.1016/j.ultsonch.2018.06.019.
18. Preedy, V. R., Srirajaskanthan, R., & Patel, V. B. (2013). Handbook of Food Fortification and Health. New York: Humana Press. Riener, J., Noci, F., Cronin, D. A., Morgan, D. J., & Lyng, J. G. (2010). A comparison of selected quality characteristics of yoghurts prepared from thermosonicated and conventionally heated milks. Food Chemistry, 119(3), 1108-1113. https://doi.org/10.1016/j.foodchem.2009.08.025 .
19. Riener, J., Noci, F., Cronin, D. A., Morgan, D. J., & Lyng, J. G. (2009). The effect of thermosonication of milk on selected physicochemical and microstructural properties of yoghurt gels during fermentation. Food Chemistry, 114(3), 905-911. https://doi.org/10.1016/j.foodchem.2008.10.037.
20. Sfakianakis, P., Topakas, E. & Tzia, C. (2015). Comparative study on high-intensity ultrasound and pressure milk homogenization: Effect on the kinetics of yogurt fermentation process. Food and Bioprocess Technology, 8, 548–557. https://doi.org/10.1007/s11947-014-1412-9.
21. Şengül, M., Başlar, M., Erkaya, T., & Ertugay, M. F. (2009). Ultrasonik homojenizasyon işleminin yoğurdun su tutma kapasitesi üzerine etkisi. Gıda, 34(4), 219-222.
22. Türk Standartları Enstitüsü. (2006). TS 1330 Yoğurt. Türk Standartları Enstitüsü, Ankara.
23. Türk Standartları Enstitüsü. (2010) TS ISO 9232, Yoğurt- Yoğurda özgü mikroorganizmaların (Lactobacillus delbrueckii subsp. bulgaricus ve Streptococcus thermophilus) belirlenmesi. Türk Standartları Enstitüsü, Ankara.
24. Türkiye İstatistik Kurumu. (2021). Süt ve süt ürünleri üretimi, Aralık 2020. Çevrimiçi https://data.tuik.gov.tr/Bulten/Index?p=Sut-ve-Sut-Urunleri-Uretimi-Aralik-2020-37231.
25. Wu, H., Hulbert, G. J., & Mount, J. R. (2000). Effects of ultrasound on milk homogenization and fermentation with yogurt starter. Innovative Food Science & Emerging Technologies, 1(3), 211-218.
26. Yu, H., Liu, Y., Li, L., Guo, Y., Xie, Y., Cheng, Y., et al. (2020). Ultrasound-involved emerging strategies for controlling foodborne microbial biofilms. Trends in Food Science & Technology, 96, 91–101.
27. Yuan, S., Li, C., Zhang, Y., Yu, H., Xie, Y., Guo, Y., & Yao, W. (2021). Ultrasound as an emerging technology for the elimination of chemical contaminants in food: A review. Trends in Food Science & Technology, 109, 374–385. https://doi.org/10.1016/j.tifs.2021.01.048