Using Papaya Enzyme (Papain) in Soap Formulas

Using Papaya Enzyme (Papain) in soap formulas, especially traditional liquid soap, presents several challenges primarily related to the enzyme's stability.

Standard Papain, such as Papaya Enzyme (Papain), is an effective exfoliant but is sensitive to its environment. It requires a specific pH range, typically between 5.5 and 7.0, for optimal stability. Traditional soaps often have a higher, alkaline pH, which can quickly degrade the enzyme and reduce its effectiveness. Additionally, standard Papain's efficiency decreases continuously when dissolved in water, making it less suitable for liquid formulations.

More stable forms exist, like Linked Papain (e.q. X-PRESSIN C), which is cross-linked to improve stability in water. However, it still requires a pH within the 5.0-7.0 range and should not be exposed to heat above 40 degrees Celsius. Soap making processes often involve higher temperatures.

HyaCap™ Papain 16K (Encapsulated Papaya Enzyme) is an encapsulated form designed for better stability, even in formulas containing surfactants. While it offers improved resistance, it is highly stable in non-ionic surfactants but advises against using high concentrations of anionic surfactants. Traditional soaps are typically made with anionic surfactants, which could still pose a challenge for the enzyme's stability in such a base.

Given these limitations, incorporating Papain into a traditional liquid soap formula is difficult if you want the enzyme to remain active for an extended period. A powder cleanser formulation, where the Papain is kept dry until use, might be a more suitable option for standard Papain to maintain its activity.

In summary, while the exfoliating benefits of Papain are desirable, the conditions in most soap formulations (high pH, heat, presence of anionic surfactants) are generally not conducive to maintaining the enzyme's stability and activity. Consider the specific type of Papain and the soap base carefully, or explore alternative product formats like powder cleansers.