TAGS: Skin Care Sustainability / Natural Cosmetics
This is a sponsored article by AAK.
Tropical butters represent a versatile class of cosmetic and skincare ingredients derived from natural sources such as:
Renowned for their rich textures and nourishing properties, these ingredients have gained popularity for their ability to provide intense hydration and protection against environmental stressors.
With their exotic origins and luxurious feel, tropical butters offer a sensory indulgence while delivering essential moisture and nutrients to the skin. From body butters to makeup, these ingredients cater to a wide range of skincare needs, making them a staple in beauty routines worldwide.
Let's check out the innovative approach by AAK in formulating its soft butter variants, engineered for rapid crystallization and superior thermal resilience without added complexities.
Challenges for Thermally Stable Formulations
Achieving thermally stable formulations with the desired sensory qualities poses a significant challenge for formulators working with tropical butters. Bloom, characterized by a coarse and gritty texture in the final product, emerges as a common obstacle. Inadequate crystallization and fluctuations in temperature during shipping and storage contribute to the occurrence of bloom over time. The challenge of blooming intensifies when dealing with higher concentrations of tropical butters and/or anhydrous formulations, which are currently in vogue.
To address crystallization control in the personal care sector, two strategic approaches can be pursued:
- A controlled crystallization process: It requires heavily controlled cooling and stirring, bringing complexity to the product development and production process, or
- Optimizing the functionality of the tropical butter: AAK has applied its lipid expertise to optimize the melting and crystallization properties of three tropical butter variants, using an interesterification process to guarantee bloom-free formulations with improved temperature stability.
Introducing Three Soft Butter Variants by AAK
AAK's 'soft' butter variants have been
optimized using interesterification to give superior functionality compared to their respective standard refined butter equivalents. They offer the following characteristics and benefits to the formulations:
Rapid crystallization to the desired crystal form
The soft butter variants crystalize faster to a small, homogenous, stable crystalline network, which prevents the formation of bloom and grainy textures without the need for specialized equipment or the addition of texturizing agents (refer figure 1).
Refined shea butter at 20°C |
Traditional Butters
- It takes longer for the first crystals to be created
- Crystals grow to different sizes and when subject to thermal fluctuations will melt and recrystallize
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LIPEX® SheaSoft TR™ at 20°C
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Soft Technologies
- Small crystals are formed faster, which remain small with temperature fluctuations
- A homogenous crystal network is created, which provides thermal stability and structure to the formation
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Figure 1: AAK's Soft Technologies Crystalyze in Smaller Homogenous Crystals that Remain More Stable with Fluctuations of Temperature
LIPEX® CocoaSoft RA MB™ Compared to Standard Refined Cocoa Butter
In anhydrous formulations, the more stable crystalline network helps obtain smoother, glossier, less brittle products.
Temperature dependency
The soft butter variants have a flatter melting profile, indicating a less temperature-sensitive product as shown in graph 1. The melting profile of a
plant-based butter is a great tool to predict its thermal stability and sensorial, and functional attributes.
The melting profile reflects the amount of solid fat content at different temperatures which gives information on how the ingredient will be perceived and will perform in the jar and the skin.
Below, the melting profiles compare
AAK’s optimized soft butters with standard refined equivalents, revealing distinct differences despite sharing the same INCI name.
Graph 1: Melting Profile of Superior Crystallization Properties of LIPEX® CocoaSoft RA MB™ vs. Standard Refined Cocoa Butter (R)
Melting Profile of LIPEX® SheaSoft TR™ vs. Standard Refined Shea Butter (C)
Melting Profile of LIPEX® IllipeSoft™ vs. Standard Refined Illipe Butter (L)
- A lower solid fat content at room temperature (20°C) indicates softer, more pliable butter.
- A higher solid fat content at skin temperature (35°C) aids in lipid barrier protection and repair.
- Additionally, the increased solid fat content at 40°C offers thermal stability to formulations, simplifying upscaling. It helps stabilize emulsions at high temperatures, avoiding temperature-induced phase separation.
Refined shea butter at 40°C
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At 40°C the refined shea material is almost completely melted (SFC ca 1%).
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LIPEX® SheaSoft TR™ at 40°C
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With LIPEX® SheaSoft TR™ the homogenous crystal network is till maintained, providing emulsion with thermal stability at high temperature, which helps avoid temperature-induced phase separation
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Figure 2: At 40°C LIPEX® SheaSoft TR™ Still has a Homogeneous Crystal Network, While Refined Shea Butter is Almost Completely Melted
Interesterification for Enhanced Fat Crystallization
Interesterification is where the fatty acids of the triglycerides are cleaved off the glycerol backbone, shuffled, and then reattached to the glycerol again. This process causes a random rearrangement of the fatty acids and creates triglycerides with properties different from standard fat. The shuffling of the fatty acids can change the melting and crystallization behavior of the fat and alter the triglyceride composition while keeping the fatty acid composition the same.
When fat crystallizes, the triglyceride molecules are packed together in a crystal lattice. The solid fat can exist in three different polymorphic crystal forms: α, β’, and β, and will favor the most stable crystal form, which is the β form. Tropical butter contains primarily triglycerides that are symmetrical in fatty acid structure, and these triglycerides tend to crystalize in α or β’ and are slower to reach the β form compared to asymmetrical triglycerides.
Interesterification leads to a reduction in symmetrical triglycerides (slow stabilization) and an increase in asymmetrical triglycerides (quick stabilization), thereby improving the crystallization properties and contributing to a faster conversion between the β’and β form. Consequently, an interesterified tropical butter will crystallize quickly into a stable network of tiny fat crystals, reducing the tendency for bloom.
Differences Between the Same Formulation Made with LIPEX® CocoaSoft RA MB™ vs. Standard Refined Cocoa Butter
Example: Comparing tropical butter variants vs. standard butter
The picture below shows the difference between the same lipstick formulation made with
LIPEX® SheaSoft TR™ (on the right) and standard refined shea butter (on the left). Texture of the lipsticks, to showcase graininess:
Figure 3: Difference in Lipstick Formulation and Texture — LIPEX® SheaSoft TR™ (R) and Standard Refined Shea Butter (L)
Conclusion
All three shea, cocoa, and illipe soft butter variants undergo optimization to a rapid transition to the beta (β) crystalline form. This results in the formation of a uniform, stable crystalline network without the necessity for any specialized equipment. Consequently:
- the bloom is prevented,
- the requirement for additional texturizing agents is diminished, and
- the viscosity remains consistent over time
All three soft butter variants exhibit a melting profile that is flatter compared to their standard refined counterparts.
Discover
LIPEX® soft butter variants by AAK to solve crystallization and blooming challenges while formulating personal care products. Select the desired ingredient of your choice from the below-listed products to get technical assistance with ease.
Get in touch with AAK experts to discuss your needs for various formulations and get the optimal solution!
DISCLAIMER: All figures and graphs used in this article are copyright of AAK.