Restricted accessResearch articleFirst published online 2006-12
The Effects of Fat and Non Fat Dry Matter Concentration and Storage Time on the Physical Properties and Acidity of Yoghurts Made with Probiotic Cultures
The effects of fat and non fat dry matter (NFDM) concentration and storage time on the physical properties and acidity of yoghurts made using commercial probiotic cultures (ABY and ABT-1) were investigated by using response surface methodology. All yoghurts made with ABY and ABT-1 cultures exhibited shear thinning behaviour. The power low model was used to describe the shear thinning behaviour of yoghurt samples. The flow behaviour index (n) and the consistency coefficient (m) were determined. NFDM levels in milk strongly affected syneresis, apparent viscosity at a constant speed of 100rpm, flow behaviour index and the consistency coefficient. Titratable acidity and pH were mainly affected by the storage time. Under all conditions examined, yoghurt made with ABT-1 culture had higher apparent viscosity, consistency coefficient and pH value than those of the yoghurt made using ABY culture.
Abraham A.G. , Antoni G.L.D. and Anon M.C. (1993) Proteolytic activity of Lactobacillus bulgaricus grown in milk . Journal of Dairy Science76: 1498–1505 .
2.
Abu-Jdayil B. and Mohameed H. (2002). Experimental and modelling studies of flow properties of concentrated yoghurt as affected by storage time . Journal of Food Engineering52: 359–365 .
3.
Adhikari K. , Mustapha A. , Grün I.U. and Fernando L. (2000). Viability of microencapsulated bifidobacteria in set yoghurt during refrigerated storage . Journal of Dairy Science83: 1946–1951 .
4.
Dannenberg F. and Kessler H.G. (1988). Effect of denaturation of β-lacto globulin on texture properties of set-style non fat yoghurt. 2. Firmness and flow properties . Milchwissenschaft43: 700–704 .
5.
Dave R.I. and Shah N.P. (1996). Evaluation of media for selective enumeration of Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus, and bifidobacteria . Journal of Dairy Science79: 1524–1536 .
6.
De Lorenzi L. , Pricl S. and Torriano G. (1995) Rheological behaviour of low-fat and full-fat yoghurt .International Dairy Journal5: 661–671 .
7.
Diniz F.M. and Martin A.M. (1996). Use of response surface methodology to describe the combined effects of pH, temperature and E/S ratio on the hydrolysis of dogfish (Squalus acanthias) muscle . International Journal of Food Science and Technology31: 419–426 .
8.
Farooq K. and Haque Z.U. (1992). Effect of sugar esters on the textural properties of non-fat low calorie yoghurt . Journal of Dairy Science75: 2676–2680 .
9.
Goldin B. (1996) Metabolic activities of the intestinal micro flora and its role in colon cancer . Nutrition Today3: 24–27 .
10.
Hassan A.N. , Frank J.F. , Schmidt K.A. and Shalabi S.I. (1996a). Textural properties of yoghurt made with encapsulated nonropy lactic cultures . Journal of Dairy Science79: 2098–2103 .
11.
Hassan A.N. , Frank J.F. , Schmidt K.A. and Shalabi S.I. (1996b). Rheological properties of yoghurt made with encapsulated no ropy lactic culture . Journal of Food Science79: 2091–2097 .
12.
Hess S.J. , Roberts R.F. and Ziegler G.R. (1997). Rheological properties of non-fat yoghurt stabilized using Lactobacillus delbrueckii spp. bulgaricus producing exopolysaccharide or using commercial stabiliser systems . Journal of Dairy Science80: 252–263 .
13.
Katsiari M.C. , Voutsinas L.P. and Kodyli E. (2002). Manufacture of yoghurt from stored frozen sheep's milk . Food Chemistry77: 413–420 .
14.
Keogh K.M. and O'Kennedy B.T. (1998). Rheology of stirred yoghurt as affected by added milk fat, protein and hydrocolloids . Journal of Food Science63: 108–112 .
15.
Labropoulos A.E. , Collins W.F. and Stone W.K. (1983). Effects of ultra-high temperature and vat process on heat-induced rheological properties of yoghurt . Journal of Dairy Science67: 405–409 .
16.
Lucey J.A. , Munro P.A. and Shing H.H. (1998). Rheological properties and microstructure of acid milk gels as affected by fat content and heat treatment . Journal of Food Science63: 660–664 .
17.
Modler H.M. , Larmond M.E. , Lin C.S. , Froehlich D. and Emmons D.B. (1983). Physical and sensory properties of yoghurt stabilized with milk proteins . Journal of Dairy Science66: 422–429 .
18.
Mohameed H.A. , Abu-Jdayil B. and Al-Shawabkeh A. (2004). Effect of solids concentration on the rheology of labneh (concentrated yoghurt) produced from sheep milk . Journal of Food Engineering61: 347–352 .
19.
Myers R. and Montgomery D.C. (2002).Response Surface Methodology. New York: John Wiley & Sons .
20.
Oliveira M.N. , Sodini I. , Remeuf F. and Corrieu G. (2001). Effect of milk supplementation and culture composition on acidification, textural properties, and microbiological stability of fermented milks containing probiotic bacteria .International Dairy Journal11: 935–942 .
21.
Parnell-Clunies E. , Kakuda Y. , de Man J.M. and Cazzola F. (1988). Gelation profiles of yoghurt as affected by heat treatment of milk . Journal of Dairy Science71: 582–588 .
22.
Ray B. (1996). Fundamental Food Microbiology. Boca Raton, FL: CRC Press .
23.
Rajagopal S.N. and Sandine W.E. (1990). Associative growth and proteolysis of Streptococcus thermophilusand Lactobacillus bulgaricus in skim milk . Journal of Dairy Science73: 894–899 .
24.
Rhom H. and Schmid W. (1993). Influence of dry matter fortification on flow properties of yoghurt 1. Evaluation of flow curves . Milchwissenschaft48: 556–559
25.
Rizvi S.S.H. and Mittal G.S. (1992). Experimental Methods in Food Engineering. New York: AVI , pp. 40–42.
26.
Sanchez C. , Zuiga-Lopez R. , Schmitt C. , Despond S. and Hardy J. (2000). Microstructure of acid-induced skim milk-locust bean gum-xanthan gels . International Dairy Journal10: 199–212 .
27.
Salminen S.J. and Saxelin M. (1996). Comparison of successful probiotic strains . Nutrition Today31(6): 32–34 .
28.
Saxelin M. (1996). Colonization of the human gastrointestinal tract by probiotic bacteria . Nutrition Today31(6): 5–8 .
29.
Sodini I. , Lucas A. , Oliveira M.N. , Remeuf F. and Corrieru G. (2002). Effect of milk base and starter culture on acidification, texture, and probiotic cell counts in fermented milk processing . Journal of Dairy Science85: 2475–2488 .
30.
Stat Soft Inc. (1995). Statistica for Windows. Release 50. Tulsa, OK: Stat Soft .
31.
Ünal B. , Metin S. and Develi Işikli N. (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 Journal13: 909–916 .
32.
Varnam A.H. and Sutherland J.P. (1994). Milk and Milk Products. London, New York and Tokyo: Chapman & Hall , pp. 359–360.
33.
Vinderola C.G. , Gueimonde M. , Delgado T. , Reinheimer J.A. and Gravilán C.G.R. (2000). Characteristics of carbonated fermented milk and survival of probiotic bacteria . International Dairy Journal10: 213–220 .
34.
Voutsinas L.P. , Katsiari M.C. , Pappas C.P. and Mallatou H. (1996). Production of yoghurt from sheep's milk which had been concentrated by reverse osmosis and stored frozen. 2. Compositional, microbiological, sensory and physical characteristics of yoghurt . Food Research International29: 411–416 .
35.
Walstra P. , Greurts T.J. , Noomen A. , Jellema A. and van Boekel M.A.J.S. (1999). Dairy Technology. New York and Basel: Marcel Dekker Inc. , pp. 517–537.
