Physicochemical properties of eleven monofloral honey samples produced in Morocco

The present study was undertaken to determine the physicochemical characteristics of eleven Moroccan honey samples from various floral origins (acacia, carob, eucalyptus, harmal, jujube, lavender, orange, reseda, rosemary, spurge and thyme). The water content was found to be between 14.55 and 20.99%; the water activity level varied between 0.49 and 0.58% while the total acidity which is directly associated to pH and free acidity, presented values from 23.55 to 43.53meq/kg and revealed the absence of inappropriate fermentation. Citric acid was the predominant organic acid followed by lactic, malic, succinic and oxalic acids and trace amount of fumaric acid. The highest ratio of fructose to glucose (>1.5) belonged to eucalyptus and reseda honey samples. Based on diastase activity, proline content and hydroxymethylfurfural content, rosemary honey showed the best quality. Strong and positive correlation between ash content and colour, therefore harmal which is a dark amber contained high mineral content. Potassium was the predominate mineral followed by Na, Ca and Mg which were found in a highest amount in carob honey. Iron, zinc, manganese and cupper were found also in analysed honeys but in trace amount. Quite low amounts of Pb, Cd and Ni found in these honeys indicate the uncontaminated environment where they are produced. The results demonstrated that nine of eleven examined samples appeared to be within the limits established by the European legislation. Moreover, there is great a variability in the composition of honey from different species. However, it was not possible to identify the real factor influencing its features.