Crystallization and Polymorphism of Triacylglycerols Contribute to the Rheological Properties of Processed Cheese

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• 作者：Hela Gliguem ; Dorra Ghorbel ; Christelle Lopez ; Camille Michon ; Michel Ollivon ; Pierre Lesieur
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2009
• 出版时间：April 22, 2009
• 年：2009
• 卷：57
• 期：8
• 页码：3195-3203
• 全文大小：373K
• 年卷期：v.57,no.8(April 22, 2009)
• ISSN：1520-5118

文摘

The thermal, rheological, and structural behaviors of a spreadable processed cheese were studied by complementary techniques including differential scanning calorimetry (DSC), rheology, and X-ray diffraction as a function of temperature. In this product, fat is present as a dispersed phase. Thermal and rheological properties were studied at different cooling rates between 0.5 and 10 °C min⁻¹ from 60 to 3 °C. Crystallization properties of fat were monitored at a cooling rate of −2 °C min⁻¹ from 60 to −10 °C. Fat triacylglycerols (TGs) crystallized at 15 °C in a triple-chain length 3Lα (72 Å) structure correlated to exothermic events and to the sudden increase in the rheological moduli G′ and G′′. Upon heating at 2 °C min⁻¹, the polymorphic transition of TGs evidence the melting of the 3Lα structure and the formation of a 2Lβ′ (36.7−41.5 Å) structure. Melting of the latter follows. These transformations coincide with thermal events observed by DSC and the decrease in two steps of the rheological moduli. The influence of fat crystallization, melting, and polymorphism upon the viscoelastic properties is clearly demonstrated upon both heating and cooling.