Browsing by Subject "marinoitu"

In Finland, most meat products are marinated, packaged under modified atmosphere (MA) and cold-storaged at temperatures below 6 °C. Marinades contain many additives such as spices and dried onion products. It has not been investigated whether these onion products are a source of spoilage bacteria typically associated with MA-packaged, cold-storaged meat products. Organisms that may cause spoilage in MA-packaged, cold-storaged meat products are mainly lactic acid bacteria and some enterobacteria. The majority of dried onion products used in Finland originate from few sources. Therefore, problems in the microbial quality of the onion products would have a widespread influence on the quality of Finnish meat products. We studied 30 samples of dried onions; onion powders, onion granules, onion grains and garlic powders. Lactic acid bacteria plate counts were determined on MRS-amfoterisin-B-agar and 193 lactic acid bacterium isolates were characterized by using a library employing 16S and 23S rRNA gene HindIII RFLP patterns as operational taxonomic units in numerical analyses. Enterobacterial plate counts were determined on VRBG-agar. All samples were incubated at 25 °C. Lactic acid bacterium levels varied between 6.7×103 to 4.4×106 CFU/g. Enterobacterial counts were more than 10 CFU/g in only 7 samples of 30, and their plate levels varied between 2.0×101 to 6.0×102 CFU/g. Of the 193 isolates, 34.7 % were identified as Weissella confusa, 35.8 % Weissella cibaria, 8.3% Enterococcus faecium and 6.2 % Pediococcus acidilactici. In addition, 5 isolates were characterized as Leuconostoc citreum and 2 as Lactobacillus plantarum. Lactobacillus brevis, Leuconostoc pseudomesenteroides and Weissella paramesenteroides were also detected. Out of 193 isolates 19 remained unidentified. Neither W. confusa nor W. cibaria, that were the main species identified in the onion samples, have been shown to cause spoilage in MA-packaged, cold-storaged meat products. None of the other LAB species that were identified in this study have been shown to cause spoilage in these products either. Because the enterobacterial levels in the onion products were low, we also conclude that dried onions cannot be considered as a source of psycrotrophic enterobacteria.