Characterization of Different Types of Crystallization from Cocoa Butter by Using Terahertz Spectroscopy

Abstract

Three different cocoa butter polymorphs have been determined by X-ray diffraction (XRD) and terahertz spectroscopy in the range of 0–11 THz. Specific procedures to produce different types of crystallization were detailed. The results from XRD analysis showed that the three polymorphic forms of cocoa butter were α, β′ (III), and β (V) forms. Terahertz spectroscopy showed different features according to different types of crystallization forms. An observable sharp peak at 6.80 THz can be detected from β (V) type and original samples, whilst α type presented the broad peak at this frequency, respectively. Peaks at 4.25 THz and 5.21 THz were detected in β type (V) form, whilst no noticeable peaks were observed from other samples at those frequencies. This study innovatively showed a great potential to apply terahertz spectroscopy to control the tempering during chocolate manufacturing.

Keywords

• cocoa butter
• crystallization
• terahertz spectroscopy
• X-ray diffraction
• noninvasive detection