6533b853fe1ef96bd12ad348

RESEARCH PRODUCT

Influence of the storage conditions on some physicochemical and mycological parameters of honey

subject

description

The authors studied the changes in yeast and mould counts, pH, free and lactone acidity, colour and sugar composition undergone by honeys with water contents of 169, 188 and 220 g kg-1 on storage at refrigeration temperature (4–7°C), room temperature and 28°C for two years. Of the solid culture media assayed, honey agar and osmophilic medium fostered yeast growth while malt-extract agar and yeast-extract-malt-extract agar allowed for better development of filamentous fungi. The yeasts isolated belonged to the genera Saccharomyces, Schizosaccharomyces and Zygosaccharomyces, while filamentous moulds were of the genera Aspergillus, Penicillium, Fusarium and Alternaria. The honeys studied underwent no visible microbial alternations under any of the conditions tested, although yeast population increased significantly with time. Free and lactone acidity increased slightly but the pH was practically constant. The honeys darkened gradually with time, the effect increasing with the storage temperature. The analysis of various sugars carried out by capillary column gas chromatography of their trimethylsilyloxime derivatives indicated that all of them changed significantly after 2 years. Levels of fructose, glucose, sucrose, maltose, kojibiose, isomaltose and trisaccharides decreased with time whereas those of maltulose and turanose increased over the same period.