alpha-Melt Structure of 1,3-Dipalmitoyl-2-oleoyl-sn-glycerol (POP) under a Thermal Thawing Process Studied by Infrared Spectroscopy

作者：Yui Hiroharu^*; Isozaki Yuuki; Morisaku Toshinori

来源：Analytical Sciences, 2017, 33(1): 75-78.

DOI：10.2116/analsci.33.75

• Triacylglycerols
• melt
• crystal
• IR
• ATR

The temperature thawing, as called tempering, of triacylglycerols (TAGs) is an important processing method in food productions, such as chocolates, cream, confections, and spreads. Especially, melt-mediation by temperature thawing is famous in chocolate production for controlling the polymorphic crystalline forms and accelerating crystallization. In the present study, we investigated the alpha-melt structure of 1,3-dipalmitoyl-2-oleoyl-sn-glycerol (POP), one of the major continuants of cacao butter, under a phase transition from its melt to gamma-crystal with in-situ attenuated total reflection-infrared (ATR-IR) spectroscopy. The differential IR spectrum between alpha-melt via temperature thawing (a-melt mediation) and melt via simple cooling revealed that crystal-like local ordered structures remained in part in the alpha-melt, and that they acted as nuclei for a rapid phase transition to the gamma-crystal. The changes to the gamma-crystal occur in the local ordered structures at first from the glycerol moiety to the acyl chains in the crystallization, providing an important suggestion concerning the mechanism for the acceleration of crystallization to the gamma-form via a-melt mediation.

• 出版日期2017-1