In this graphic above, MGO doubled in concentration in the first month of storage and many tripled in under 4 months of storage.
Claiming MGO is an indicator of the quantity of manuka honey would mean that the manuka quantity had doubled after a month of storage.
In an effort to discourage producers from storing honey to increase MGO levels, it has been suggested that over time all the DHA will turn into MGO which in turn will then dissipate, leaving low or no MGO. Again, this would then mean that the actual manuka honey content had vanished over time.
Both results show that MGO/NPA or UMF® rating is not an indicator of manuka quantity or “manuka-ness”
Grahpic reproduced from The origin of methylglyoxal in New Zealand manuka (Leptospermum scoparium) honey.
Christopher J. Adams a, Merilyn Manley-Harris a,*, Peter C. Molan b