Organic honey from Trás-Os-Montes region (Portugal): Chemical, palynological, microbiological and bioactive compounds characterization

Abstract

a b s t r a c tAt the present time, the quality, integrity, sanitation and nutritional value of honeys receive attention on an international level due to the increasing content of chemicals in the aforementioned matrix. This work was conducted to evaluate the quality of 75 organic honey samples from the Trás-Os-Montes region (Portugal). Mean values obtained for physico-chemical parameters were: pH 3.7; 15.6% moisture; 0.26 mS/cm electrical conductivity; 0.25% ash; 1.1 mg/kg HMF; 15.3 Gothe diastase activity; 40.3 meq/kg free acidity; 67.8% invert sugars and 2.7% apparent sucrose. All honey samples can be classified as monofloral Erica sp., as showed by pollen features. The amounts of phenols and flavonoids in the samples were also determined. In respect to sanitary quality (fecal coliforms) and safety (sulfite-reducing clostridia and Salmonella), all organic honey samples were negative. Furthermore, yeast and molds were detected in low counts, with mean values obtained of 5.5 cfu/g and the value of total aerobic mesophiles obtained from honeys was established in 1.3 Â 10 2 cfu/g ± 7.5 Â 10 1 cfu/g. The levels of flavonoids had a stronger impact on both mesophiles (p = 0.0004) and molds (p = 0.0138) than the sucrose concentration (p = 0.001 and 0.0278; respectively). The results reported in this study should be introduced in the organic honey label, and may help beekeepers, the industry, researchers and consumers better understand honey properties.

Characterisation of Moroccan Spurge (Euphorbia) honeys by their physicochemical characteristics, mineral contents and colour

“…Therefore, the characterisation of honeys is necessary in order to better our response to consumer demands (Pires et al, 2009;Fea´s et al, 2010;Estevinho et al, 2012;Iglesias et al, 2012). Some unifloral honeys have specific chemical or physical properties, which may be used to confirm the results of microscopical analysis.…”

Microorganisms in Honey

“…Potato dextrose agar and yeast extract glucose chloramphenicol agar are media normally used for aerobic count and the total fungi (yeasts and molds), while Violet Red Bile and MacConkey medium agars are normally used for counting coliforms, which can also be done by the most probable number technique [119,141,142]. These media have recently been used to monitor the efficiency of a new filter-based method based in reducing the microbial burden and to improve the microbiological quality of honey [143].…”

“…Potato glucose agar in Brazil was also used for monitoring the honey contamination by yeast and fungi [144]. Standard plate count agar is used for monitoring of mesophilic bacteria, such as that was done in honey samples of Portugal [141,142] and Argentina [119,145].…”

Techniques for the Evaluation of Physicochemical Quality and Bioactive Compounds in Honey

“…Ash content expresses the richness of honey in mineral content [30][31][32]. The minerals calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu), cadmium (Cd) and zinc (Zn) in the form of sulfate (SO 4 2− ) and chloride (Cl − ) [24] are found in small amounts.…”