Effect of high pressure processing on the conversion of dihydroxyacetone to methylglyoxal in New Zealand mānuka (Leptospermum scoparium) honey and models thereof

The effect of high pressure processing (HPP) on the conversion of dihydroxyacetone (DHA) to methylglyoxal (MGO) was examined in New Zealand mānuka honey and models thereof. The objective was to confirm that previously reported increases of MGO with HPP treatment originated from conversion of DHA. RP-HPLC was used to quantify DHA, MGO and hydroxymethylfurfural (HMF) after derivatisation with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) or (in the case of MGO) separately with o-phenylenediamine (OPD). Fresh and stored mānuka honey, clover honey with DHA added and artificial 26 honey with DHA added were subjected to nine different pressures and holding times and compared to untreated samples. There was no consistent trend of decrease in DHA or increase in MGO for any of the samples with any treatment. Samples showed random change generally within 5-10% of an untreated sample for MGO, DHA and HMF. HPP does not accelerate the conversion of DHA to MGO in honey.