ABSTRACT:
5-hydroxymethylfurfural (HMF) is formed during heat processing and\or storage of food. HMF is cytotoxic at high concentrations and could be metabolised to 5-sulfooxymethylfurfural making HMF potentially harmful in an extent unknown at present. Coffee is one of the most important sources of HMF. The aim of this study was to determine HMF in roasted ground coffee and instant coffee consumed in Syria, additionally to study the effect of brewing process, sugar addition and storage on HMF levels. Samples were analyzed by reversed-phase high-performance liquid chromatography RP-HPLC connected to UV detector. The concentrations were 26.16, 76.93, 174.93 mg/kg for hard, moderate and light roasted coffee, respectively, and between 526.56 – 1800.9 mg/kg in instant coffee. HMF contents in instant coffee were significantly higher than ground coffee. HMF content increased about 9.6% by increasing boiling time and 15.66% by heating the mixture of water and coffee until boiling. Additionally, HMF levels increased about 10.84%, 46.99%, 60.24% by the addition of 0.05, 0.1 and 0.3g sugar respectively, where the highest HMF content was formed by the highest sugar addition. HMF content increased about 36% during the first two hours of storage in heat isolator bottle, while remained almost stable in the second ten hours of storage.