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

2015 ◽  
Vol 78 (4) ◽  
pp. 812-818 ◽  
Author(s):  
SE HUI JEON ◽  
NAM HEE KIM ◽  
MOON BO SHIM ◽  
YOUNG WOOK JEON ◽  
JI HYE AHN ◽  
...  

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.

Author(s):  
SHERIDAN S. BREWER ◽  
COURTNEY A. LOWE ◽  
LARRY R. BEUCHAT ◽  
Ynes R. Ortega

Survival and growth of Salmonella and Shiga toxin-producing Escherichia coli (STEC) in kombucha prepared from four brands of commercially available kombucha kits intended for use by home brewers were investigated. Changes in microbiota responsible for fermentation were also determined. An initial population of Salmonella (6.77 log CFU/mL) decreased to below the detection limit (0.30 log CFU/mL) within 10 d in kombucha prepared from two of the four test brands. Populations of 1.85 and 1.20 log CFU/mL were detected in two brands fermented for 14 d. An initial population of STEC (7.02 log CFU/mL) decreased to <0.30 log CFU/mL in two of the four brands within 14 d; 0.20 and 0.87 log CFU/mL were detected in kombucha prepared from the other two brands. Salmonella and STEC increased in populations within 1 d in three brands of base tea used to prepare kombucha, and were stable throughout 14 d of incubation. Both pathogens steadily declined in base tea prepared from one brand of kombucha kit. Inactivation of the pathogens occurred as the pH of kombuchas decreased, but a clear correlation between rates of inactivation and decrease in pH was not evident when comparing kombuchas prepared from the four kits. Growth and peak populations of mesophilic aerobic microorganisms, yeasts, lactic acid bacteria, and acetic acid bacteria varied, depending on the kombucha kit brand. There was not strong evidence to correlate the behavior of Salmonella and STEC with any of these groups of indigenous microbiota. Results of this study show that the ability of Salmonella and STEC to survive in kombucha and base tea used to prepare kombucha is dependent on inherent differences in commercially available kombucha kits intended for use in home settings. Strict application of hygienic practices with the goal of preventing contamination with Salmonella or STEC is essential for reducing the risk of illness associated the consumption of kombucha.


2019 ◽  
Vol 6 (1) ◽  
pp. 21
Author(s):  
Eko Heri Purwanto ◽  
Sigit Setyabudi ◽  
Supriyanto Supriyanto

<em>Microbial activities in cocoa pulp decomposition is key in cocoa beans fermentation. </em>Ragi tape<em> is widely used </em><em>as a source of microbes (starters). The study aimed to investigate the pattern of changes in the number of microbes, substrate degradation activities and primary metabolites production during fermentation with the addition of ragi tape. The study was conducted at the laboratories within the Faculty of Agriculture Technology and Integrated Laboratory of Experiment and Research, UGM from March to October 2018 . Fermentation experiment used 2 kg of fresh cacao beans stored in a plastic box per batch, its temperature was set daily. The amount of microbes was enumerated using total plate count (TPC), whereas substrate degradation and primary metabolites were analyzed using high performance liquid chromatography (HPLC) and gas chromatography (GC). Temperature, pulp and seed pH, and fermentation index were observed. The results showed that adding </em>ragi tape<em> </em><em>for fermentation generated a maximum amount of yeast, lactic acid bacteria (LAB) and acetic acid bacteria (AAB) of 9.03<span style="text-decoration: underline;">+</span>0.85; 9.05<span style="text-decoration: underline;">+</span>0.17; and 9.15<span style="text-decoration: underline;">+</span>0.89 log cfu/g of cocoa pulp respectively, with substrate degradation in the form of sucrose reduced by 97%, glucose 98.6%, fructose 97%, and citric acid 71% on the third day. Maximum production of primary metabolites of ethanol is 27.84<span style="text-decoration: underline;">+</span>21.85 mg/g of cocoa pulp, lactic acid 4.18<span style="text-decoration: underline;">+</span>3.16 mg/g of cocoa pulp and acetic acid 3.38<span style="text-decoration: underline;">+</span>5.43 mg/g of cocoa pulp. Fermentation with the addition of </em>ragi tape<em> accelerates the process to three days with a fermentation index value of 1.05<span style="text-decoration: underline;">+</span>0.06 and seed pH of 5.97<span style="text-decoration: underline;">+</span>0.20.</em>


2011 ◽  
Vol 74 (5) ◽  
pp. 820-825 ◽  
Author(s):  
YOEN JU PARK ◽  
JINRU CHEN

This study was conducted to evaluate the abilities of five neutralizing agents, Dey-Engley (DE) neutralizing broth (single or double strength), morpholinepropanesulfonic acid (MOPS) buffer, phosphate-buffered saline (PBS), and sodium thiosulfate buffer, in mitigating the activities of acetic or lactic acid (2%) and an alkaline or acidic sanitizer (a manufacturer-recommended concentration) againt the cells of Shiga toxin–producing Escherichia coli (STEC; n = 9). To evaluate the possible toxicity of the neutralizing agents to the STEC cells, each STEC strain was exposed to each of the neutralizing agents at room temperature for 10 min. Neutralizing efficacy was evaluated by placing each STEC strain in a mixture of sanitizer and neutralizer under the same conditions. The neutralizing agents had no detectable toxic effect on the STEC strains. PBS was least effective for neutralizing the activity of selected organic acids and sanitizers. Single-strength DE and sodium thiosulfate neutralized the activity of both acetic and lactic acids. MOPS buffer neutralized the activity of acetic acid and lactic acid against six and five STEC strains, respectively. All neutralizing agents, except double-strength DE broth, had a limited neutralizing effect on the activity of the commercial sanitizers used in the study. The double-strength DE broth effectively neutralized the activity of the two commercial sanitizers with no detectable toxic effects on STEC cells.


1994 ◽  
Vol 57 (5) ◽  
pp. 431-435 ◽  
Author(s):  
MOHAMMED I. YAMANI ◽  
BASIM A. AL-DABABSEH

Sixty samples of fresh hoummos (chickpea dip) from 15 restaurants were examined in winter and summer to find out numbers and types of microorganisms present. Five reference samples, produced by the investigators under hygienic conditions, were examined for comparison. The microbial load of commercial hoummos was high, and spherical lactic acid bacteria (LAB) belonging to Lactococcus, Enterococcus and Leuconostoc were the predominant microorganisms. The means of the aerobic plate count (APC) and the counts of LAB and coliforms (1.9 × 108, 1.6 × 108 and 2.9 × 105/g, respectively) in summer samples were significantly higher (p &lt; 0.05) than the averages of the same counts in winter samples (2.7 × 107, 1.6 × 107 and 2.2 × 103/g). The average summer and winter yeast counts were 4.2 × 104 and 1.5 × 104g, respectively. In reference samples of hoummos, APC and LAB counts were &lt; 103/g, while the coliform and yeast counts were &lt; 10/g and 102/g, respectively, indicating lack of hygienic practices during the production of commercial hoummos. Salmonella was not detected in any sample, and Escherichia coli and Staphylococcus aureus counts of all samples were &lt; 10/g. The relatively low pH of hoummos (the average pH of all samples was 5.1) and the rapid growth of LAB, possibly accompanied by production of inhibitory substances, may explain the predominance of these bacteria, and could have contributed to the absence of the pathogens examined.


1978 ◽  
Vol 41 (9) ◽  
pp. 692-695 ◽  
Author(s):  
JOHN T. FRUIN ◽  
JAMES F. FOSTER ◽  
JAMES L. FOWLER

Bologna products most frequently are stored and consumed as refrigerated products. Thus bacteria that survive processing or those that contaminate the product subsequent to processing are not destroyed. Ten types of presliced, vacuum-packaged bologna products were purchased from a high-volume retail market and analyzed for total aerobic plate count (APC) and common foodborne pathogens. No Salmonella were isolated. Less than 1% of the 419 samples analyzed contained either Clostridium perfringens or Escherichia coli, Staphylococcus aureus was isolated from 4% of the samples, but only one sample contained more than 1000/g. Just over 5% of the samples contained coliform organisms. The manufacturer appeared to play an important role in bacterial quality of the finished items. An APC &lt; 5 × 106/g is a realistic criterion for bologna products at the time of delivery to retail markets.


2016 ◽  
Vol 79 (8) ◽  
pp. 1341-1347 ◽  
Author(s):  
JOSEPH M. BOSILEVAC ◽  
RONG WANG ◽  
BRANDON E. LUEDTKE ◽  
TOMMY L. WHEELER ◽  
MOHAMMAD KOOHMARAIE

ABSTRACT During site visits of veal processors, the U.S. Department of Agriculture, Food Safety Inspection Service (FSIS) has reported processing deficiencies that likely contribute to increased levels of veal contamination. Here, we report the results of measuring aerobic plate count bacteria (APC), Enterobacteriaceae, coliforms (CF), and Escherichia coli during eight sample collections at five veal processors to assess contamination during the harvest of bob veal and formula-fed veal before (n = 5 plants) and after (n = 3 plants) changes to interventions and processing practices. Hides of veal calves at each plant had mean log CFU/100 cm2 APC, Enterobacteriaceae, CF, and E. coli of 6.02 to 8.07, 2.95 to 5.24, 3.28 to 5.83, and 3.08 to 5.59, respectively. Preintervention carcasses had mean log CFU/100 cm2 APC, Enterobacteriaceae, CF, and E. coli of 3.08 to 5.22, 1.16 to 3.47, 0.21 to 3.06, and −0.07 to 3.10, respectively, before and 2.72 to 4.50, 0.99 to 2.76, 0.69 to 2.26, and 0.33 to 2.12, respectively, after changes were made to improve sanitary dressing procedures. Final veal carcasses had mean log CFU/100 cm2 APC, Enterobacteriaceae, CF, and E. coli of 0.36 to 2.84, −0.21 to 1.59, −0.23 to 1.59, and −0.38 to 1.45 before and 0.44 to 2.64, −0.16 to 1.33, −0.42 to 1.20, and −0.48 to 1.09 after changes were made to improve carcass-directed interventions. Whereas the improved dressing procedures resulted in improved carcass cleanliness, the changes to carcass-directed interventions were less successful, and veal processors are urged to use techniques that ensure uniform and consistent delivery of antimicrobials to carcasses. Analysis of results comparing bob veal to formula-fed veal found bob veal hides, preintervention carcasses, and final carcasses to have increased (P &lt; 0.05) APC, Enterobacteriaceae, CF, and E. coli (with the exception of hide Enterobacteriaceae; P &gt; 0.05) relative to formula fed veal. When both veal categories were harvested at the same plant on the same day, similar results were observed. Since identification by FSIS, the control of contamination during veal processing has started to improve, but challenges still persist.


2010 ◽  
Vol 58 (13) ◽  
pp. 7731-7739 ◽  
Author(s):  
Lorena Diez ◽  
Zenaida Guadalupe ◽  
Belén Ayestarán ◽  
Fernanda Ruiz-Larrea

2007 ◽  
Vol 73 (6) ◽  
pp. 1809-1824 ◽  
Author(s):  
Nicholas Camu ◽  
Tom De Winter ◽  
Kristof Verbrugghe ◽  
Ilse Cleenwerck ◽  
Peter Vandamme ◽  
...  

ABSTRACT The Ghanaian cocoa bean heap fermentation process was studied through a multiphasic approach, encompassing both microbiological and metabolite target analyses. A culture-dependent (plating and incubation, followed by repetitive-sequence-based PCR analyses of picked-up colonies) and culture-independent (denaturing gradient gel electrophoresis [DGGE] of 16S rRNA gene amplicons, PCR-DGGE) approach revealed a limited biodiversity and targeted population dynamics of both lactic acid bacteria (LAB) and acetic acid bacteria (AAB) during fermentation. Four main clusters were identified among the LAB isolated: Lactobacillus plantarum, Lactobacillus fermentum, Leuconostoc pseudomesenteroides, and Enterococcus casseliflavus. Other taxa encompassed, for instance, Weissella. Only four clusters were found among the AAB identified: Acetobacter pasteurianus, Acetobacter syzygii-like bacteria, and two small clusters of Acetobacter tropicalis-like bacteria. Particular strains of L. plantarum, L. fermentum, and A. pasteurianus, originating from the environment, were well adapted to the environmental conditions prevailing during Ghanaian cocoa bean heap fermentation and apparently played a significant role in the cocoa bean fermentation process. Yeasts produced ethanol from sugars, and LAB produced lactic acid, acetic acid, ethanol, and mannitol from sugars and/or citrate. Whereas L. plantarum strains were abundant in the beginning of the fermentation, L. fermentum strains converted fructose into mannitol upon prolonged fermentation. A. pasteurianus grew on ethanol, mannitol, and lactate and converted ethanol into acetic acid. A newly proposed Weissella sp., referred to as “Weissella ghanaensis,” was detected through PCR-DGGE analysis in some of the fermentations and was only occasionally picked up through culture-based isolation. Two new species of Acetobacter were found as well, namely, the species tentatively named“ Acetobacter senegalensis” (A. tropicalis-like) and “Acetobacter ghanaensis” (A. syzygii-like).


2018 ◽  
Vol 6 (2) ◽  
pp. 273-283 ◽  
Author(s):  
WAN NORHANA MD NOORDIN ◽  
NANNTHINI SHUNMUGAM ◽  
NURUL HUDA ◽  
FREDERICK ADZITEY

The objectives of this study were to determine the effects of Essential Oils (EOs) and Organic Acids (OAs) on microbiological and physicochemical qualities of whole shrimps stored at 4°C. Shrimps of 1.1 kg were dipped in solutions of Eos (cinnamon oil, garlic oil and lime oil) and Organic Acids (lactic acid, tartaric acid and sodium diacetate) at 1:2 shrimp/treatment solution (w/w) at 25ºC for 30min. Concentration of sodium metabisulfite and distilled water (DH2O) were used as positive and negative controls, respectively. Shrimps were drip-dried for 5 minutes, packaged and stored in a chiller (4°C) for 10 days. They were analyzed for microbiological (Total Aerobic Plate Count) and physicochemical (pH, colour and texture) properties at days 0, 2, 5, 7 and 10. Total Aerobic Plate Count (TPC) of shrimps decreased immediately after dipping in solutions containing EOs, OAs and their mixture ratios. However, the TPC of shrimps continued to increase during storage and at day 10, TPC was significantly (P<0.05) higher compared to other days. Mixtures of tartaric acid and cinnamon oil was the best in controlling TPC in shrimps. pH of shrimps ranged from 6.60 to 7.86. Most of the treatments had significantly lower pH compared to DH2O treated shrimp. L* values (Lightness), a* values (Redness) and b* values (Yellowness) ranged from 32.57-42.27, -1.90-4.39 and 3.14-10.67, respectively. The texture (hardness value) of the shrimps ranged from 1135.4-2511.8 and decreased throughout storage period except solutions of lactic acid and lime. Storage of shrimps in EOs and organic acids can serve as an alternative for the preservation of shrimps other than low temperature storage.


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