Effect of temperature on recrystallization behavior of cocoa butter

Abstract

Crystallization of cocoa butter in the β phase directly from the melt is only possible by employing the memory effect of cocoa butter. Cocoa butter crystallized in the β phase, heated to the so-called maximal temperature (just above its melting end point), recrystallizes in the β phase after cooling to a crystallization temperature. The influence of the maximal and crystallization temperatures on the recrystallization behavior has been investigated for two cocoa butters. Rapid-starting recrystallization into the β(VI) phase and slow-starting recrystallization into the β(V) have been observed. It is concluded that rapid-starting recrystallization is induced by high-melting 1,3distearoyl-2-oleoyl-glycerol (SOS)-rich crystals. The two β phases were identified by X-ray powder diffraction and melting ranges. However, the X-ray powder diffraction patterns for the β phases depended on the composition of the cocoa butter and on the crystallization method used. Therefore, it was not possible to take any particular β(VI) X-ray powder diffraction pattern as a standard for the β(VI) phase of all cocoa butters.Paper no. J9843 in JAOCS 78, 919-925 (September 2001). KEY WORDS:Cocoa butter, crystallization, memory effect, seeding.Crystallization is a critical point in making chocolate and confectioneries. Poorly crystallized chocolate results in the formation of fat bloom, a grayish-white film at the chocolate surface. The chocolate seems aged and musty, which results in an increase in customer complaints to chocolate manufacturers. To obtain quality products, understanding and total control of the cocoa butter solidification process is indispensable. However, the crystallization behavior of cocoa butter is very complex, as cocoa butter may crystallize in many different polymorphic phases.Although this crystallization has been subject of thorough research for many years, no uniform nomenclature for the various phases of cocoa butter has been achieved. Vaeck (1) showed the existence of four phases and designated them by the Greek letters γ, α, β′, and β. Wille and Lutton (2) observed six different crystalline phases for cocoa butter, numbered with the Roman numbers I to VI. More recently, Van Malssen et al.(3) concluded from mechanically static solidification experiments that cocoa butter crystallizes in even more crystal modifications: a γ and an α phase, a β′ phase range, and two β phases were observed. In this chapter a combination of the nomenclature by Vaeck (1) and by Wille and Lutton (2) is used, resulting in the phases γ, α, β′, and two β phases: β(V) and β(VI). Each of the cocoa-butter phases has its own physical characteristics, such as diffraction properties, melting range, and relative stability.Since each phase gives a characteristic pattern in X-ray powder diffraction (XRPD), this technique is very well suited for identification of cocoa-butter phases (4; Fig. 1). Furthermore, in time-resolved XRPD experiments, phase transitions can be observed and monitored (3,5).The transitions from less stable to more stable phas...

Fat bloom in chocolate and compound coatings

“…Form bV is a relatively stable form found after appropriate cooling of a melted chocolate with shelf life often more than one year, but this depends on numerous (sometimes unknown) parameters [20]. The most stable form (bVI) cannot be produced directly from the melted chocolate (except by the addition of bVI CB seeds and under very well controlled conditions [21,22].…”

Monitoring Tempered Dark Chocolate Using Ultrasonic Spectrometry

“…The liquid CB was then placed in a precooled water bath (Fisher Scientific Isotemp 3006D) at 23°C to induce recrystallization of CB utilizing the crystal memory effect (van Malssen et al 1996;Langevelde et al 2001). Van Malssen found that crystallization of cocoa butter directly from the melt into β polymorphs is not possible.…”

Structure and transformation of low‐temperature phases of 1,3‐distearoyl‐2‐oleoyl glycerol

“…A complex mixture of TAGs in natural products creates a variety of polymorphic forms as a function of temperature [1,2]. The study of pure TAGs is an effective way to understand structural transformations taking place in natural fat products.…”