International Journal of Food Science and Technology 2012, 47, 2063–2071
Original article The effect of different ternary mixtures of sodium phosphates on hardness of processed cheese spreads Frantisˇek Bunˇka,1* Lucie Doudova´,2 Eva Weiserova´,3 Dalibor Kucharˇ,4 Jaroslav Micha´lek,2,5 Sˇteˇpa´nka Slavı´kova´1 & Stanislav Kra´cˇmar6 1 Department of Food Technology and Microbiology, Faculty of Technology, Tomas Bata University in Zlin, na´m. T. G. Masaryka 5555, 760 01 Zlı´ n, Czech Republic 2 Department of Econometrics, Faculty of Economics and Management, University of Defence in Brno, Kounicova 65, 612 00 Brno, Czech Republic 3 Department of Fats, Tensides and Cosmetics Technology, Faculty of Technology, Tomas Bata University in Zlı´ n, na´m. T. G. Masaryka 5555, 760 01 Zlı´ n, Czech Republic 4 Research and Development Department, Fosfa PLC, Hranicˇnı´ 268, 691 41 Brˇ eclav, Czech Republic, Czech Republic 5 Department of Statistics and Optimization, Institute of Mathematics, Faculty of Mechanical Engineering, Brno University of Technology, Technicka´ 2896 ⁄ 2, 616 69 Brno, Czech Republic 6 Department of Food Analysis and Chemistry, Faculty of Technology, Tomas Bata University in Zlı´ n, na´m. T. G. Masaryka 5555, 760 01 Zlı´ n, Czech Republic (Received 1 February 2012; Accepted in revised form 2 April 2012)
Summary
The aim of this study was to describe the dependence of hardness of processed cheeses on the proportion of disodium hydrogenphosphate (DSP), tetrasodium diphosphate (TSPP) and ⁄ or sodium salts of polyphosphate (POLY) in ternary mixtures of emulsifying salts. The samples were observed during a 30-day storage period (at 6 C). On the second day of storage, hardness of the samples with the individual DSP, TSPP or POLY were in the range of 1.65–1.83 N, 2.42–2.81 N and 5.98–6.53 N, respectively. Within zero or a very low proportion of POLY in the mixture, hardness of the processed cheeses increased rapidly (up to 14 N) at a specific ratio of DSP to TSPP in range of 1:1–3:4. Hardness of the samples containing the above-mentioned specific ratio was decreasing with the rising content of POLY (up to 60%) in the ternary mixtures. Within the prevailing content of POLY in the ternary mixtures (more than 60%), the phenomenon of a specific ratio of DSP to TSPP was no longer observed. With the increasing storage period (up to 30 days), hardness of the processed cheeses was slightly rising (in range of 2–4 N).
Keywords
Emulsifying salts, hardness, processed cheese, regression analysis.
Introduction
Emulsifying salts are a key component for the production of homogeneous processed cheeses. Processed cheeses are made by heating a mixture of cheeses and other ingredients of dairy (butter, cream, curds, milk powder, caseins, etc.) and non-dairy (spice, meat components, mushrooms, hydrocolloids, etc.) origin with emulsifying salts under partial underpressure and constant stirring until a homogeneous mass of desired properties is formed (Guinee et al., 2004; Kapoor & Metzger, 2008). The traditional melt contains mainly milk proteins (casein fractions or their partial *Correspondent: Fax: 00420 577 210 172; e-mail:
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hydrolysates), dairy fat and water. Fat emulsification and water stabilisation in the processed cheese matrix are to be ensured mainly by the proteins present (especially caseins). In the basic material (cheese), casein fractions (and their partial hydrolysates) form a three-dimensional network in which they are connected by means of calcium bridges. However, these immobilised caseins cannot work as adequate emulsifiers and stabilisers in the melt. Therefore, the basic role of the emulsifying salts is to split off calcium from the cheese matrix and replace it by sodium ions. By means of exchanging sodium ions for calcium ions, insoluble calcium paracaseinate changes into more soluble sodium paracaseinate, which can function as an emulsifier and stabiliser in the melt. (Gupta et al., 1984; Guinee et al., 2004; Lu et al., 2008; Shirashoji et al., 2010; Wang et al., 2011).
doi:10.1111/j.1365-2621.2012.03070.x 2012 The Authors. International Journal of Food Science and Technology 2012 Institute of Food Science and Technology
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Ternary mixtures of phosphates F. Bunˇka et al.
Another role of emulsifying salts is, for example, a shift and ⁄ or stabilisation of pH values (optimal pH values of processed cheeses range within the interval of 5.6–6.1). Also, emulsifying salts participate in the process of creaming, which is characterised by an increase in melt viscosity and formation of the final structure of processed cheese during the melting process and subsequent cooling (Gupta et al., 1984; Guinee et al., 2004; Kawasaki, 2008). Commonly used emulsifying salts are sodium salts of phosphate, polyphosphates, citrates and their combination in the total amount of
