Quality evaluation of Portuguese honey

The present work was conducted to evaluate the quality of 25 brands of hone y commercially available on the Portuguese market, in a total of 50 samples . The brands included unifloral and multifloral honeys, which were studied arid botanically typified. Carbohydrate composition was determined by HPLC- RI to evaluate the contents of monosaccharides fructose and glucose; the di saccharides saccharose, maltose and trehalose and of the trisaccharide meli zitose. 5-Hydroxymethyl-2-furfuraldehyde (HMF) was quantified by HPLC-UV and other physicochemical quality parameters were also carried out according to the E uropean (Directive 74/409/EC) and Portuguese Regulations (Decreto-lei No. 1 31/85, 1985) in order to determine moisture, ash content, diastase activity , free acidity, free acidity and water-insoluble solids. All samples were o rganoleptically and microscopically examined. Only 13 brands were found to meet all major national and international spec ifications, the remaining 12 did not agree with one or more of the analysed parameters (HMF, diastase activity, or carbohydrate composition); such obs ervations may reflect an inadequate manufacturing or storing process and a certain ageing of these honeys. (C) 1998 Elsevier Science Ltd. All rights r eserved.