FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY




Microbiological quality of dried fruits hermetically packed and sold in bulk


The demand for dried fruits grows both in the Polish and the global market. About 2.5 million tons thereof (mainly raisins) are produced all over the world, and about 8 thousand tons in Poland (mainly apples and plums). Dried  fruits that are sold in stores are often contaminated with mesophilic microorganisms, which develop owing to the inadequate storage of the raw material and improper technological processing. The objective of the research study  was to evaluate the microbiological condition of dried fruits available on the Polish market and to determine the  impact of packaging on the microbiological quality of those products. There were examined the hermetically  packaged and sold in bulk fruits. Under the microbiological analysis performed, determined was the following:  total count of mesophilic microorganisms, total count of sporulating aerobic bacteria and moulds, coagulase- positive staphylococci, bacteria of the Enterobacteriaceae family, including the coliform bacteria of Salmonella and Shigella. Microbiological tests were carried out using a bacteria culture method as set in the PN-EN ISO standards. Filamentous fungi were identified on the basis of macroscopic and microscopic observations. It was found that the dominant microflora to contaminate the dried fruits were mesophilic bacteria and moulds of the Aspergillus  genus. Based on the results obtained, no coagulase-positive staphylococci were reported nor the Salmonella and Shigella bacteria. The most contaminated products were raisins and dates. The cleanest product were apricots,  both those packaged by their producers and those sold in bulk; the same was reported as regards the cranberries  and dried plums. On the other hand, it was generally found that the level of microbiological contamination of the  dried fruits tested was low and the level of contamination of hermetically packaged fruits was lower than that of  those sold in bulk.


dried fruits, microorganisms, microbiological quality, packaging