Rheological properties of probiotic non-fat yogurt containing Lactobacillus reuteri: Effects of inulin addition, inoculum level and fermentation temperature

Document Type : Original research


Bioprocessing and Biodetection Laboratory, Department of Food Science and Engineering, University of Tehran, Karaj 31587-77871, Iran


The simultaneous effects of inulin addition (0-4%w/w), probiotic inoculum level (1-3%v/v) and fermentation temperature (37-45°C) on the dynamic rheological properties of probiotic non-fat yogurt were studied using response surface methodology. Frequency sweep tests were performed to measure structure strength and type of structure. Linear viscoelastic range in term of strain (LVE), structure strength (G¢ at LVE), yield stress (τy) and flow point (τf) of samples were measured doing strain sweep test. Results showed that Inulin concentration had the greatest influence on G' and τf, followed by fermentation temperature. A positive correlation between b value and level of syneresis was observed.


Amatayakul, T., Sherkat, F., & Shah, N. P. (2006). Physical characteristics of set yoghurt made with altered casein to whey protein ratios and EPS-producing starter cultures at 9 and 14% total solids. Food Hydrocolloids, 20(2–3), 314–324.
Aryana, K. J., & McGrew, P. (2007). Quality attributes of yogurt with Lactobacillus casei and various prebiotics. LWT-Food Science and Technology, 40(10), 1808–1814.
Cavallieri, A. L. F., & Da Cunha, R. L. (2008). The effects of acidification rate, pH and ageing time on the acidic cold set gelation of whey proteins. Food Hydrocolloids, 22(3), 439–448.
Delzenne, N. M., & Williams, C. M. (2002). Prebiotics and lipid metabolism. Current Opinion in Lipidology, 13(1), 61–67.
Fuller, R. (1989). Probiotics in man and animals. The Journal of Applied Bacteriology, 66(5), 365–378.
Gardiner, G. E., Heinemann, C., Baroja, M. L., Bruce, A. W., Beuerman, D., Madrenas, J., & Reid, G. (2002). Oral administration of the probiotic combination Lactobacillus rhamnosus GR-1 and L. fermentum RC-14 for human intestinal applications. International Dairy Journal, 12(2–3), 191–196.
Gee, V. L., Vasanthan, T., & Temelli, F. (2007). Viscosity of model yogurt systems enriched with barley β-glucan as influenced by starter cultures. International Dairy Journal, 17(9), 1083–1088.
Guggisberg, D., Cuthbert-Steven, J., Piccinali, P., Bütikofer, U., & Eberhard, P. (2009). Rheological, microstructural and sensory characterization of low-fat and whole milk set yoghurt as influenced by inulin addition. International Dairy Journal, 19(2), 107–115.
Guggisberg, D., Eberhard, P., & Albrecht, B. (2007). Rheological characterization of set yoghurt produced with additives of native whey proteins. International Dairy Journal, 17(11), 1353–1359.
Gun, O., & Isikli, N. D. (2007). Effect of fat and non‐fat dry matter of milk, and starter type, on the rheological properties of set during the coagulation process. International Journal of Food Science & Technology, 42(3), 352–358.
Guven, M., Yasar, K., Karaca, O. B., & Hayaloglu, A. A. (2005). The effect of inulin as a fat replacer on the quality of set‐type low‐fat yogurt manufacture. International Journal of Dairy Technology, 58(3), 180–184.
Haque, A., Richardson, R. K., & Morris, E. R. (2001). Effect of fermentation temperature on the rheology of set and stirred yogurt. Food Hydrocolloids, 15(4–6), 593–602.
Hekmat, S., Soltani, H., & Reid, G. (2009). Growth and survival of Lactobacillus reuteri RC-14 and Lactobacillus rhamnosus GR-1 in yogurt for use as a functional food. Innovative Food Science & Emerging Technologies, 10(2), 293–296.
Horne, D. S. (1998). Casein interactions: casting light on the black boxes, the structure in dairy products. International Dairy Journal, 8(3), 171–177.
Jenkins, D. J. A., Kendall, C. W. C., & Vuksan, V. (1999). Inulin, oligofructose and intestinal function. The Journal of Nutrition, 129(7), 1431S–1433S.
Keogh, M. K., & O’kennedy, B. T. (1998). Rheology of stirred yogurt as affected by added milk fat, protein and hydrocolloids. Journal of Food Science, 63(1), 108–112.
Kip, P., Meyer, D., & Jellema, R. H. (2006). Inulins improve sensoric and textural properties of low-fat yoghurts. International Dairy Journal, 16(9), 1098–1103.
Knudsen, J. C., Karlsson, A. O., Ipsen, R., & Skibsted, L. H. (2006). Rheology of stirred acidified skim milk gels with different particle interactions. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 274(1–3), 56–61.
Kristo, E., Biliaderis, C. G., & Tzanetakis, N. (2003). Modelling of rheological, microbiological and acidification properties of a fermented milk product containing a probiotic strain of Lactobacillus paracasei. International Dairy Journal, 13(7), 517–528.
Labropoulos, A. E., Collins, W. F., & Stone, W. K. (1984). Effects of ultra-high temperature and vat processes on heat-induced rheological properties of yogurt. Journal of Dairy Science, 67(2), 405–409.
Lee, W. J., & Lucey, J. A. (2004). Structure and physical properties of yogurt gels: Effect of inoculation rate and incubation temperature. Journal of Dairy Science, 87(10), 3153–3164.
Lee, W.-J., & Lucey, J. A. (2006). Impact of gelation conditions and structural breakdown on the physical and sensory properties of stirred yogurts. Journal of Dairy Science, 89(7), 2374–2385.
Lee, W., & Lucey, J. A. (2003). Rheological properties, whey separation, and microstructure in set‐style yogurt: Effects of heating temperature and incubation temperature. Journal of Texture Studies, 34(5‐6), 515–536.
Lucey, J. A. (2002). Formation and physical properties of milk protein gels. Journal of Dairy Science, 85(2), 281–294.
Lucey, J. A., Van Vliet, T., Grolle, K., Geurts, T., & Walstra, P. (1997). Properties of acid casein gels made by acidification with glucono-δ-lactone. 1. Rheological properties. International Dairy Journal, 7(6–7), 381–388.
Lucey, J. A., Tamehana, M., Singh, H., & Munro, P. A. (1998). Effect of interactions between denatured whey proteins and casein micelles on the formation and rheological properties of acid skim milk gels. Journal of Dairy Research, 65(4), 555–567.
Mezger, T. G. (2006). The rheology handbook: for users of rotational and oscillatory rheometers. Vincentz Network GmbH & Co KG.
Myers, R. H., Montgomery, D. C., & Anderson-Cook, C. M. (2016). Response surface methodology: process and product optimization using designed experiments. John Wiley & Sons.
Ozcan-Yilsay, T., Lee, W.-J., Horne, D., & Lucey, J. A. (2007). Effect of trisodium citrate on rheological and physical properties and microstructure of yogurt. Journal of Dairy Science, 90(4), 1644–1652.
Paseephol, T., Small, D. M., & Sherkat, F. (2008). Rheology and texture of set yogurt as affected by inulin addition. Journal of Texture Studies, 39(6), 617–634.
Pereira, R. B., Singh, H., Munro, P. A., & Luckman, M. S. (2003). Sensory and instrumental textural characteristics of acid milk gels. International Dairy Journal, 13(8), 655–667.
Radke-Mitchell, L. C., & Sandine, W. E. (1986). Influence of temperature on associative growth of Streptococcus thermophilus and Lactobacillus bulgaricus. Journal of Dairy Science, 69(10), 2558–2568.
Reid, G., Charbonneau, D., Gonzalez, S., Gardiner, G., Erb, J., Poehner, R., & Bruce, A. W. (2002). Ability of Lactobacillus GR-1 and RC-14 to stimulate host defences and reduce gut translocation and infectivity of Salmonella typhimurium. Journal of Food Science and Nutrition, 7(2), 168–173.
Roberfroid, M. B., Van Loo, J. A. E., & Gibson, G. R. (1998). The bifidogenic nature of chicory inulin and its hydrolysis products. The Journal of Nutrition, 128(1), 11–19.
Schellhaass, S. M., & Morris, H. A. (1985). Rheological and scanning electron microscopic examination of skim milk gels obtained by fermenting with ropy and non-ropy strains of lactic acid bacteria. Food Structure, 4(2), 11.
Skriver, A., Roemer, H., & Qvist, K. B. (1993). Rheological characterization of stirred yoghurt: viscometry. Journal of Texture Studies, 24(2), 185–198.
Sodini, I., Remeuf, F., Haddad, S., & Corrieu, G. (2004). The relative effect of milk base, starter, and process on yogurt texture: a review. Critical Reviews in Food Science and Nutrition, 44(2), 113–137.
Staffolo, M. Dello, Bertola, N., & Martino, M. (2004). Influence of dietary fiber addition on sensory and rheological properties of yogurt. International Dairy Journal, 14(3), 263–268.
Steffe, J. F. (1996). Rheological methods in food process engineering. Freeman press.
Tahiri, M., Tressol, J. C., Arnaud, J., Bornet, F., Bouteloup‐Demange, C., Feillet‐Coudray, C., … Roussel, A. M. (2001). Five‐week intake of short‐chain fructo‐oligosaccharides increases intestinal absorption and status of magnesium in postmenopausal women. Journal of Bone and Mineral Research, 16(11), 2152–2160.
Tamime, A. Y. (2006). Fermented milks. Wiley Online Library.
Tungland, B. C., & Meyer, D. (2002). Nondigestible oligo‐and polysaccharides (Dietary Fiber): their physiology and role in human health and food. Comprehensive Reviews in Food Science and Food Safety, 1(3), 90–109.
Unal, B., Metin, S., & Işıklı, N. D. (2003). Use of response surface methodology to describe the combined effect of storage time, locust bean gum and dry matter of milk on the physical properties of low-fat set yoghurt. International Dairy Journal, 13(11), 909–916.
Wu, S., Li, D., Li, S., Bhandari, B., Yang, B., Chen, X. D., & Mao, Z. (2009). Effects of incubation temperature, starter culture level and total solids content on the rheological properties of yogurt. International Journal of Food Engineering, 5(2).