Anhydrous Goat's Milk Fat: Thermal and Structural Behavior. 1. Crystalline Forms Obtained by Slow Cooling
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- 作者：Wafa Ben Amara-Dali ; Nadia Karray ; Pierre Lesieur ; and Michel Ollivon
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2005
- 出版时间：December 28, 2005
- 年：2005
- 卷：53
- 期：26
- 页码：10018 - 10025
- 全文大小：411K
- 年卷期：v.53,no.26(December 28, 2005)
- ISSN：1520-5118
文摘
The thermal and structural behaviors of anhydrous goat's milk fat (AGMF) have been determined asa function of temperature using a powerful technique allowing simultaneous time-resolved synchrotronX-ray diffraction as a function of temperature (XRDT) and high-sensivity differential scanningcalorimetry (DSC) measurements from the same sample. This first paper, aiming at the characterizationof the physical properties of AGMF, we examine crystalline organizations made by triacylglycerols(TG) upon slow cooling at 
dT/dt = 0.1 
C/min from 45 to -20 C in order to approach systemequilibrium. Three overlapped exotherms were observed by DSC upon cooling, whereas fourendotherms were found on the subsequent heating at 1 C/min. XRDT evidenced that AGMFcrystallizes under four different lamellar structures, two with double-chain length packings at 41.5and 38.2 Å and two with triple-chain lengths of 72 and 64.7 Å stacking. Simultaneous wide-angleXRDT has shown that initial nucleation mainly occurs in a packing of 
' type from ~26 C, althoughsome transient presence of 
was detected. The absence of polymorphic transition, on heating, untilfinal melting (~40 C) demonstrated the relative stability of the structures formed.Keywords: Goat's milk fat; polymorphism; X-ray diffraction; differential scanning calorimetry, TGcomposition
dT/dt = 0.1 C/min from 45 to -20 C in order to approach systemequilibrium. Three overlapped exotherms were observed by DSC upon cooling, whereas fourendotherms were found on the subsequent heating at 1 C/min. XRDT evidenced that AGMFcrystallizes under four different lamellar structures, two with double-chain length packings at 41.5and 38.2 Å and two with triple-chain lengths of 72 and 64.7 Å stacking. Simultaneous wide-angleXRDT has shown that initial nucleation mainly occurs in a packing of ' type from ~26 C, althoughsome transient presence of was detected. The absence of polymorphic transition, on heating, untilfinal melting (~40 C) demonstrated the relative stability of the structures formed.Keywords: Goat's milk fat; polymorphism; X-ray diffraction; differential scanning calorimetry, TGcomposition