What is NPA in Manuka Honey?

While all types of honey have some level of antibacterial activity, Manuka honey stands out for its Non-Peroxide Activity (NPA), a measurement of its specific antibacterial potency.

NPA is determined by the level of a compound called methylglyoxal (MGO) in the honey, which is particularly high in Manuka honey due to the unique properties of the Manuka tree. In this article, we will explore the concept of NPA in Manuka honey, including how it is measured, what different NPA ratings mean, and why it is important for consumers to pay attention to NPA when purchasing Manuka honey.

What is NPA?

NPA stands for Non-Peroxide Activity, which is a measurement of the antibacterial potency of Manuka honey. Unlike other types of honey, Manuka honey contains a unique antibacterial compound called methylglyoxal (MGO) that gives it its distinctive antibacterial properties.

NPA is a measure of the level of MGO in the honey, and is used to determine its antibacterial strength. The higher the NPA rating of Manuka honey, the greater its antibacterial potency. NPA is an important quality indicator for Manuka honey, as it ensures that the honey is not only genuine, but also has the desired antibacterial activity.

The New Zealand government has established a system to regulate and verify NPA ratings in Manuka honey, and consumers are encouraged to look for Manuka honey with a reputable NPA rating to ensure that they are getting a quality product.

How is NPA Measured?

NPA, or Non-Peroxide Activity, is measured by testing the ability of Manuka honey to inhibit the growth of bacteria in a laboratory setting. The specific procedure for measuring NPA may vary depending on the laboratory or testing facility, but the general steps involved are as follows:

  1. Dilution: A sample of Manuka honey is diluted with sterile water to create a series of honey dilutions with known concentrations.
  2. Inoculation: A standardized strain of bacteria, usually Staphylococcus aureus or Escherichia coli, is added to each of the honey dilutions.
  3. Incubation: The honey-bacteria mixture is incubated at a specific temperature for a set period of time, typically 18-24 hours.
  4. Measurement: The level of NPA is determined by comparing the amount of honey needed to inhibit bacterial growth with that of a standard solution of phenol. The concentration of phenol that has the same inhibitory effect as the honey sample is known as the phenol equivalence.
  5. Calculation: The NPA rating of the honey sample is calculated as the ratio of the phenol equivalence to the actual concentration of the honey dilution, multiplied by 100. For example, if a honey dilution of 10% has the same antibacterial activity as a phenol solution of 30%, the NPA rating would be calculated as (30/10) x 100 = 300.

The NPA rating of Manuka honey can range from 5 to 30+ depending on its antibacterial potency. Higher NPA ratings correspond to greater antibacterial activity, and are indicative of a more potent and high-quality Manuka honey product.

What do different NPA ratings mean?

Different NPA (Non-Peroxide Activity) ratings in Manuka honey indicate varying levels of antibacterial potency, with higher ratings corresponding to greater potency. Here’s a breakdown of what different NPA ratings mean:

  1. NPA 5+: This is the lowest NPA rating and indicates that the honey has a mild antibacterial activity. It may be suitable for general use and as a sweetener but may not provide the full range of health benefits associated with Manuka honey.
  2. NPA 10+: This is a moderate NPA rating and indicates that the honey has some level of antibacterial activity. It may be suitable for general use and minor ailments such as sore throats and wounds.
  3. NPA 15+: This is a high NPA rating and indicates that the honey has a strong antibacterial activity. It may be suitable for supporting immune health and for more serious health conditions such as bacterial infections.
  4. NPA 20+ and higher: These are the highest NPA ratings and indicate that the honey has an extremely high level of antibacterial activity. These products are considered the most potent and may be suitable for treating severe bacterial infections or for wound healing.

Conclusion

In conclusion, NPA (Non-Peroxide Activity) is an important measurement of the antibacterial potency of Manuka honey. NPA indicates the level of methylglyoxal (MGO), a unique antibacterial compound, in the honey, which is responsible for its antibacterial properties.

Different NPA ratings in Manuka honey correspond to varying levels of antibacterial activity, with higher ratings indicating greater potency. Consumers should look for Manuka honey with a reputable NPA rating to ensure that they are getting a quality product.

The New Zealand government has established a system to regulate and verify NPA ratings in Manuka honey, which can provide further assurance of the honey’s quality.

Clinical Nutritionist | + posts

Cara Hayes is an experienced natural health practitioner with a Masters in Clinical Nutrition & Dietetics from the University of Sydney. She has been writing for New Zealand Honey since 2020 and loves manuka in her morning tea.