Reducing the level of added disodium phosphate alters the chemical and physical properties of processed cheese

Abstract

The intake of sodium in modern western diet is excessive, with potentially harmful effects on health. Consequently, there is a drive to reduce the sodium content of foods. A major source of sodium in processed cheeses (PCs) is the added emulsifying salts (sodium phosphates or citrates) which play a key role in product formation and stabilisation. The present study investigated the impact of reducing the level of disodium orthophosphate (DSP) on the properties of PC. PCs were formulated in triplicate with 0.35, 0.75, 1.29, 2.0, 2.7 or 3.4 g.100 g⁻¹ DSP, and standardised with respect to intact casein content, moisture, protein-to-fat ratio, calcium/casein ratio, and pH. DSP at ≥0.75 g.100 g⁻¹ was necessary to form a homogeneous, stable PC. Increasing DSP significantly increased the storage modulus (G'), firmness and fracture stress of the unheated PC, and reduced the flowability and fluidity (loss tangent max) of the heated PC. These changes coincided with a significant increase in the level of water-soluble protein (WSP) and reduction in the ratio of calcium to WSP in the water-soluble extract prepared using a PC/water at a ratio of 1:2. Our results indicate that there is scope to reduce the sodium level of PCs by reducing the level of added DSP to a minimum level (e.g., ≥0.75 g.100 g⁻¹ in current study), but that reduction from levels (grams per 100 grams) of 2.0–3.4 to 0.75–1.29 markedly alters the textural and cooking properties of the resultant PCs.

磷酸钠对再制干酪物化特性的影响

摘要 现代西方国家饮食中过量钠的摄入对人体健康造成了潜在的危害。因此很有必要减少食品中钠的含量。再制干酪中钠的主要来源是添加的乳化盐(磷酸钠或柠檬酸钠),这些钠盐对再制干酪的成型和稳定起着关键的作用。本文研究了降低磷酸氢二钠添加量对再制干酪特性的影响。再制干酪中磷酸氢二钠的添加量分别为0.35、0.75、1.29、2.0、2.7和3.4 g.100 g⁻¹,分别进行了三个重复,以酪蛋白含量、水分、蛋白与脂肪的比值、钙与酪蛋白的比值以及pH为评价标准。当磷酸氢二钠添加量≥ 0.75 g.100 g⁻¹时才能形成均一和稳定的再制干酪。增加磷酸氢二钠的添加量能够显著地增加未加热再制干酪的储能模量(G')、硬度和破裂应力,但是降低了加热再制干酪的流动性。在制干酪和水比例为1:2时提取的干酪液相中,这些性质的变化与水溶性蛋白含量的显著增加和钙与水溶性蛋白的比值下降相一致。实验结果表明通过减少磷酸氢二钠添加量来达到降低再制干酪中钠的含量是有限定范围的(如本研究的范围是≥ 0.75 g.100 g⁻¹)当磷酸氢二钠含量从2.0∼3.4 g.100 g⁻¹降低到0.75∼1.29 g.100 g⁻¹时,显著地改变了再制干酪的质地和烹饪特性。