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Başlık: Effect of tetrasodium pyrophosphate on the physicochemical properties of yogurt gels
Yazarlar: Horne, David
Uludağ Üniversitesi/Mühendislik Fakültesi/Gıda Mühendisliği Bölümü.
Özcan, Tülay
Lucey, John
AAG-8194-2021
25926089700
7103333007
Anahtar kelimeler: Microstructure
Rheology
Yogurt
Tetrasodium pyrophosphate
Glucono-delta-lactone
Skim milk gels
Rheological properties
Physical-properties
Calcium-phosphate
Whey separation
Micelles
Gelation
Ions
Citrate
Agriculture
Food science & technology
Yayın Tarihi: Ara-2008
Yayıncı: Elsevier Science
Atıf: Özcan, T. vd. (2008). "Effect of tetrasodium pyrophosphate on the physicochemical properties of yogurt gels". Journal of Dairy Science, 91(12), 4492-4500.
Özet: The effect of tetrasodium pyrophosphate (TSPP) on the properties of yogurt gels was investigated. Various concentrations (0.05 to 0.2%) of TSPP were added to preheated (85 degrees C for 30 min) reconstituted skim milk, which was readjusted to pH 6.50. Milk was inoculated with 2% starter culture and incubated at 42 C until the pH reached 4.6. Acid-base buffering profiles of milk and total and soluble calcium levels were measured. Turbidity measurements were used to indicate changes in casein dispersion. Storage modulus (G') and loss tangent (LT) values of yogurts were monitored during fermentation using dynamic oscillatory rheology. Large deformation properties of gels were also measured. Microstructural properties of yogurt were observed using fluorescence microscopy. The addition of TSPP resulted in the disappearance of the buffering peak during acid titration at pH similar to 5.1 that is due to the solubilization of colloidal calcium phosphate (CCP), and a new peak was observed at lower pH values (pH 4.0-4.5). The buffering peak at pH 6.0 during base titration virtually disappeared with addition of TSPP and a new peak appeared at pH similar to 4.8. The addition of TSPP reduced the soluble Ca content of milk and increased casein-bound Ca values. The addition of up to 0.125% TSPP resulted in a reduction in turbidity because of micelle dispersion but at 0.15%, turbidity increased and these samples exhibited a time-dependent increase in turbidity because of aggregation of casein particles. Gels made with 0.20% TSPP were very weak and had a very high gelation pH (6.35), probably due to complete dispersion of the micelle structure in this sample. The LT value of gels at pH 5.1 decreased with an increase in TSPP concentration, probably due to the loss of CCP with the addition of TSPP. The G' values at pH 4.6 of gels made with <= 0.10% TSPP were not significantly different but the addition of >= 0.125% TSPP significantly decreased G' values. The addition of 0.05 to 0.125% TSPP to milk resulted in a reduction in the yield stress values of yogurt compared with yogurt made without TSPP. Greater TSPP levels (> 0.125%) markedly reduced the yield stress values of yogurt. Lowest whey separation levels were observed in yogurts made with 0.10% TSPP. High TSPP levels (> 0.10%) greatly increased the apparent pore size of gels. Addition of very low levels of TSPP to milk for yogurt manufacture may be useful in reducing the whey separation defect, but at TSPP concentrations >= 0.125% very weak gels were formed.
URI: https://doi.org/10.3168/jds.2008-1292
https://www.sciencedirect.com/science/article/pii/S0022030208709159
http://hdl.handle.net/11452/25965
ISSN: 0022-0302
1525-3198
Koleksiyonlarda Görünür:PubMed
Scopus
Web of Science

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