SPECIES-DEPENDENT 5′-HYDROXYMETHYLFURFURAL FORMATION IN SLOWLY DRIED FRUITS

Abstract

The aim of the work was to determine 5-hydoxymethylfurfural (HMF) content in fruit samples dried by slow convective method. Additionally, the nutritional value, mineral composition and antioxidant activity were investigated as parameters confirming the quality of the product. Seven different kinds of dried fruits certified as ecological products (apricot, gooseberry, cherry, cornel, blackcurrant, plum and apple) were tested. Analysis covered: reducing sugars, protein content, moisture content, energy value, antioxidant activity, total phenolics content, mineral composition and HMF content (chromatographic and spectrophotometric method). Samples were abundant in reducing sugars (25–51% of dry weight), protein (1.0–5.4%), minerals (Ca, K, Fe, Mg) and were heavy metals-free. The strongest antioxidant activity for blackcurrant and the weakest for dried apple were observed. The highest average content of HMF was found in blackcurrant fruits (3102.2 mg/kg), while the lowest in apple (75.6 mg/kg). Results obtained by Winkler’s and HPLC methods were strongly correlated (r = 0.976). It was found that applied slow convective drying method provide to obtain dried fruits rich in health-promoting properties and HMF quantified in examined fruits was found on the safety level for recommended daily consumption.