Chocolate frosting is a global problem that has plagued the confectionery industry for many years. At the beginning of the 19th century, people began to study chocolate frosting and had a preliminary understanding of frost formation.
There are many reasons for chocolate blooming, including processing conditions, raw oil composition, and storage temperature.
It is challenging to characterize blooming. One of the reasons is that blooming has various forms and complex composition.
On the other hand, the various forms of chocolate products make the frost’s scientific analysis more complicated.
The researchers used various methods to study the process of frosting and the characteristics of frost and put forward a series of theories to explain ice formation.
1. Reasonable Temperature Adjustment
Reasonable temperature adjustment can induce cocoa butter to crystallize in βV crystal form, and at the same time, eliminate the influence of other unstable crystal forms, thereby giving chocolate an excellent appearance and mouth-melt.
The degree of temperature adjustment directly affects the crystallization and melting properties of the product. Insufficient tempering or excessive tempering will cause the deterioration of chocolate quality, especially the chocolate with low tempering will frost in a short time.
Chocolate crystal network structure also varies with the degree of temperature adjustment. Insufficient temperature adjustment will cause a loose crystal structure and rearrangement and recrystallization. Grease composition, shear rate, temperature, and emulsifier will affect the temperature adjustment process, thereby affecting the product’s stability.
The chocolate tempering process’s complexity can be added to the chocolate to induce crystallization and speed up the tempering rate to obtain a better crystallization effect.
2. Control The Storage Temperature
An increase in temperature will increase the fluidity of the low-melting triglycerides in chocolate, causing blooming or quality degradation.
Some studies have found that the filled chocolate stored at 18°C has no frosting within eight weeks, while frosting occurs within two weeks when held at 30°C, and the oil migration speed increases, the texture properties of the chocolate decreases and crystallization occurs—type change.
Temperature fluctuations in the storage environment will reduce the induction time for blooming and promote rapid blooming of cocoa butter-based chocolate.
Therefore, the chocolate should store at a lower temperature, and the temperature fluctuation of the Chocolate Storage Tank should be strictly controlled.
3. Add Milk Fat And Its Melting Point Extract
Milk fat is the main component of milk chocolate and is often used in dark chocolate (generally <5%). At the same time, milk fat is also a component that effectively delays chocolate bloom, especially the high melting point milk fat fraction.
The milk fat fraction with a low melting point not only can not delay blooming but will induce chocolate blooming. This is attributed to the higher liquid fat content, which leads to increased fluidity of triglyceride molecules in the product.
The trace lipid components in milk fat (glycerides, monoglycerides, cholesterol, phospholipids, etc.) significantly affect fat crystallization, and chocolate is blooming.
However, milk fat has different effects on different chocolate products. When used in cocoa butter-based chocolate, it can not delay the frosting but will induce frost formation.
4. Add Seeds
Adding seed crystals can accelerate the crystallization of oil: SOS (β1)≈cocoa butter (type Ⅵ)≈cocoa butter (type Ⅴ)﹥SOS(false β′+β2)≈BOB(β2)≈BOB(false β′)? SSS (β).
If the homogeneous polycrystalline structure between the seed crystal and the host molecule is significantly different, the crystal interface’s steric hindrance will reduce the secondary nucleation rate.
The addition of cocoa butter (VI type), SOS (β1), and BOB (β2) seed crystals induces the crystallization of chocolate in variety V. It effectively delays blooming, especially the addition of BOB (β2) has the most significant anti-frost effect.
5. Add Emulsifier
Sorbitol ester, monoglyceride, and glycol diester will affect the crystallization process of oil.
Emulsifiers that are solid at room temperature can effectively delay cocoa butter transformation from type V to type VI. Among them, the effect of the mixture of Span60-Tween60 and Span60-Tween65 is the most obvious.
6. Delay Of Oil Migration
Establishing a crystal network to fix the liquid oil to delay and (or) reduce the migration of grease.
Increasing the reliable fat content in chocolate will significantly reduce the oil migration tendency. Reducing the particle size of non-lipid solids can provide a larger adsorption area.
Smaller particles exist in a tightly packed state, reducing the pores in the matrix, and contacting each other to form a network, thereby adsorbing grease or preventing grease movement.