Microbiological Diversity and Prevalence of Spoilage and Pathogenic Bacteria in Commercial Fermented Alcoholic Beverages (Beer, Fruit Wine, Refined Rice Wine, and Yakju)

Abstract

The present study examined 469 commercially available fermented alcoholic beverages (FABs), including beer (draft, microbrewed, and pasteurized), fruit wine (grape and others), refined rice wine, and yakju (raw and pasteurized). Samples were screened for Escherichia coli and eight foodborne pathogens (Bacillus cereus, Campylobacter jejuni, Clostridium perfringens, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Yersinia enterocolitica), and the aerobic plate count, lactic acid bacteria, acetic acid bacteria, fungi, and total coliforms were also enumerated. Microbrewed beer contained the highest number of microorganisms (average aerobic plate count, 3.5; lactic acid bacteria, 2.1; acetic acid bacteria, 2.0; and fungi, 3.6 log CFU/ml), followed by draft beer and yakju (P < 0.05), whereas the other FABs contained , 25 CFU/25 ml microorganisms. Unexpectedly, neither microbial diversity nor microbial count correlated with the alcohol content (4.7 to 14.1%) or pH (3.4 to 4.2) of the product. Despite the harsh conditions, coliforms (detected in 23.8% of microbrewed beer samples) and B. cereus (detected in all FABs) were present in some products. B. cereus was detected most frequently in microbrewed beer (54.8% of samples) and nonpasteurized yakju (50.0%), followed by pasteurized yakju (28.8%), refined rice wine (25.0%), other fruit wines (12.3%), grape wine (8.6%), draft beer (5.6%), and pasteurized beer (2.2%) (P < 0.05). The finding that spore-forming B. cereus and coliform bacteria can survive the harsh conditions present in alcoholic beverages should be taken into account (alongside traditional quality indicators such as the presence of lactic acid-producing bacteria, acetic acid-producing bacteria, or both) when developing manufacturing systems and methods to prolong the shelf life of high-quality FAB products. New strategic quality management plans for various FABs are needed.

The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods

“…Fermented foods that contain appreciable levels of fermentationproduced organic acids (>100 mM), combined with low water activity, salt, nitrite and other antimicrobials, have a long record of food safety 78 . Likewise, beverages containing 4% or more alcohol and pH values less than 4.5 are also considered microbiologically safe 79 . Many LAB, whether part of the autochthonous microbiota or added as starter cultures, are known to produce bacteriocins that inhibit undesirable bacteria, including Listeria, Staphylococcus and Clostridium 80 .…”

Raw ready-to-eat seafood safety: microbiological quality of the various seafood species available in fishery, hyper and online markets

“…All microbiological analyses were performed according to the US Food and Drug Administration Bacteriological Analytical Manual (USFDA 2011) and the Korea Food Code (MFDS 2012), with some modifications as described previously (Choi et al 2014;Jeon et al 2015).…”

Control ofBacillus cereusspore germination and outgrowth in cooked rice during chilling by nonorganic and organic apple, orange, and potato peel powders

“…To place the results of the present study in proper perspective, selected reported studies on the contamination of raw and processed rice products by B. cereus are being briefly mentioned. These include Korean raw rice affected by production area and degree of milling (Kim et al, ); Korean rice during storage (Zhang et al, ); cooked rice (Dong, ; Hariram & Labbé, ; Jawad & Mutalib, ; Jawad, Mutalib, & Abdullah, ; Rachtanapun, Tantala, Klinmalai, & Ratanasumawong, ; Wang, Ding, & Oh, ); fried rice (Jawad, Mutalib, & Abdullah, ); rice cake (Wang, Park, Choi, Ha, & Oh, ); and refined and turbid rice wines (Jeon et al, ; Kim et al, ).…”