At INOLEX we embrace the challenge of the changing preservation landscape by innovating for safety, sustainability, and efficacy, centered around the Hurdle Technology approach.
What is Hurdle Technology?
Hurdle Technology was first popularized as a preservation approach in the food industry. It is an intelligent combination of different preservation techniques ("hurdles") to achieve broad spectrum, mild and reliable preservation effects.1 In BPC formulations, we combine multiple techniques to create an environment that is inhospitable to microbial growth. These techniques include ingredient benefits and processing procedures:
- Common ingredient functions that create hurdles include membrane disruption and iron chelation.
- Formulation hurdles include low pH and employment of GMP principles.
Membrane Disruptors: Medium Chain Terminal Diols
MCTDs are effective preservation components because they interact with cell membrane lipids leading to disruption of the cell membrane. This allows other ingredients to enter the cells and water to leak out of the cells, leading to eventual cell collapse. MCTDs alone are very effective against bacteria.
Iron Chelation: Organic Acids
Organic acids are a hurdle technology component often employed in combination with MCTDs to provide increased efficacy against yeast and mold.
Caprylhydroxamic Acid (Zeastat™) is a biostatic organic acid that can be a crucial component of effective broad spectrum preservation systems due to its multiple mechanisms of action. Metal ion chelation is a critical mechanism for controlling microbial growth, particularly in yeast and mold. Iron is an important nutrient for these microorganisms, and microorganisms that are deprived of iron by chelation cannot proliferate or survive. Caprylhydroxamic Acid also has a short alkyl chain (C8) which provides similar membrane disruption effects as MCTDs.
The Effect of pH on Organic Acid Efficacy
Formulation pH has a significant effect on the efficacy of organic acids as preservation ingredients. To be effective, organic acids must be in the undissociated (or acid) form. This poses a challenge when formulating products with consumer-friendly preservation ingredients because most organic acids begin to dissociate at pH > 4. As a result, the concentration of the acid, the ingredient providing a preservation benefit in formulation, continues to decrease at higher formulation pH.
Caprylhydroxamic Acid remains undissociated up to pH 8. ~99% of the concentration is present in formulation and providing preservation effects from pH 3 - 8. This enables formulating with functional ingredients that are required to be at pH > 4 while still having safe and effective preservation of your formulation.
Unique Benefits of Caprylhydroxamic Acid (CHA)
- Effective chelating agent and membrane disruptor for efficacy against yeast and mold
- High pKa organic acid for effective preservation at low use levels from pH 3 – 8
- 100% Natural origin, derived from coconut oil and atmospheric nitrogen and hydrogen
- Combining CHA with MCTDs creates a highly effective ingredient combination with broad spectrum microbial growth protection
Caprylhydroxamic Acid and MCTD Combinations (Spectrastat™ series)
Combination products of CHA and MCTDs allow formulators to easily achieve broad spectrum preservation efficacy by adding just one ingredient to your formulation.
There are various preservation efficacy test criteria, including EP-A and EP-B, the CTFA (PCPC), and the ISO11930 criteria. INOLEX's CHA-MCTD combinations have been evaluated in a range of formulation types and demonstrated to pass all 4 test criteria. Recommended use levels are based on these preservative efficacy test (PET) data.
Combination of CHA with MCTDs like Caprylyl Glycol (Spectrastat™), Glyceryl Caprylate (Spectrastat™ G2 Natural MB), or Methylheptylglycerin (Spectrastat™ MHG Natural MB) creates complete ingredient systems that enable broad spectrum formulation preservation. These combinations are optimized for use in a variety of formulation types, meeting specific formulation design criteria, including 100% natural, water solubility, cold processability, and a variety of other parameters.
The Safe Preservation portfolio from INOLEX offers expansive innovation in safe, sustainable, and effective preservation.
References
- Leistner, L. (2000). Basic aspects of food preservation by hurdle technology. International Journal of Food Microbiology, 55, 181-186. Doi.10.1016/s0168-1605(00)00161-6.