Microflora in paperboard with various contents of recycled fibers

Both recycled paper and the aqueous environment necessary for its industria l processing harbor a large quantity of various microorganisms. Some microb ial species survive industrial processing and reduce the purity of the prod uct. Within the Council of Europe a limit for the number of microorganisms present in paper har been debated. In the present study the cultivable micr oflora in paperboard containing various amounts of recovered and virgin fib res was examined. Samples were obtained in accordance with international st andards and the microflora present in disintegrated paperboard samples were quantified and characterized under the guidelines for food-borne pathogeni c microorganisms. The composition of raw materials has a significant impact on the total microflora found in board. Among the pathogens in foodstuff, only the spore-forming Bacillus cereus could be detected in quantities exce eding those stipulated for food. In conclusion, the re-use of paper increas es the microbial charge in the industrial process, which has a negative imp act on product purity and quality. However, the industrial process decrease s the number of food-borne pathogens in the paper effectively. A possible n egative impact caused by the remaining microbes on the human health could n ot be fully excluded.