Biochemical properties and microbial analysis of honey from North-Western regions of Iran: seasonal effects on physicochemical properties of honey

In the present study, physicochemical properties (pH, ash, commercial glucose, starch, reducing sugars and moisture) and microbial (yeast and enterobacterial) contaminations of 263 honey samples from North-western regions of Iran were evaluated in a 2 year period in different seasons of 2010 and 2011. Levels of reducing sugars and sucrose showed significant seasonal differences, with the highest levels observed in summer samples. No commercial glucose or starch was detected in any of the samples; but levels of reducing sugars and sucrose content of 1.52 and 6.84% samples were unacceptable, respectively. Moisture, ash content (0.4±0.01%) and pH values (4.44±0.02) of all samples were in the required standard range and did not significantly vary in different seasons. Of all the samples evaluated, only seven samples (2.66%) contained yeast, and two samples (0.76%) were contaminated with bacteria from family Enterobacteriaceae (2 samples with both contaminations). None of the isolates were found to be of major pathogenic importance.