Microflora of Minimally Processed Frozen Vegetables Sold in Gaborone, Botswana

2006 ◽  
Vol 69 (11) ◽  
pp. 2581-2586 ◽  
Author(s):  
TINNA A. MANANI ◽  
ERNEST K. COLLISON ◽  
SISAI MPUCHANE
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Population Distribution ◽  
Cold Chain ◽  
Plate Count ◽  
Most Probable Number ◽  
Minimally Processed ◽  
Probable Number ◽  
The Mean ◽  
Yeasts And Molds

Two hundred samples of minimally processed, frozen, and prepacked potato chips, peas, corn, and a variety of combined vegetables from supermarkets in Gaborone, Botswana, were examined microbiologically. Determination of aerobic mesophilic plate count, aerobic psychrotrophic plate count, lactic acid bacteria, yeasts and molds, coliforms, Listeria spp., and Staphylococcus aureus were done. Chips had the lowest mean log values for all of the microorganisms enumerated except yeasts and molds. The mean log values for single vegetables ranged from 3.6 to 9.1, 3.4 to 8.9, 2.9 to 5.6, and 2.1 to 6.5 log CFU/g aerobic mesophilic plate count, aerobic psychrotrophic plate count, lactic acid bacteria, and yeasts and molds, respectively. The microbial profiles of peas and corn were almost similar (P < 0.001). The mean values for combined vegetables were clustered within 4.6 and 5.4 and 4.2 and 5.2 log CFU/g aerobic mesophilic plate count and aerobic psychrotrophic plate count, respectively. All of the vegetables had a coliform population distribution ranging from 0 to <104 most probable number per g. The predominant gram-negative bacteria isolated included members of Enterobacteriaceae and Pseudomonaceae (86.2%). Escherichia coli was not detected in all of the samples. The organisms isolated included those responsible for spoilage in frozen vegetables, namely Pseudomonas, Klebsiella, Corynebacterium, lactic acid bacteria, and Flavobacterium. The predominant lactic acid bacteria were Lactobacillus spp. (55.9%). Other spoilage organisms were yeasts, and Cryptococcus spp. (55.4%) was predominant. Pathogens, namely Listeria monocytogenes, were also isolated at a rate of 2 to 10%, of which 4% was from corn, 2% each from peas and country crop, and 10% from stir-fry. Bacillus cereus was also isolated and accounted for 7.7% of the microorganisms from corn. S. aureus was isolated from all of the vegetables. Enterotoxigenic strains were from corn, peas, mixed vegetables, and stir-fry, and all of them produced enterotoxin A. In addition, the isolates from stir-fry vegetables also produced enterotoxins B and C. The study reveals the presence of pathogens and emerging opportunistic pathogens in the ready-to-use or ready-to-eat vegetables. If E. coli is the only indicator for safety and acceptability, consumers may be exposed to foodborne diseases. Inclusion of other groups as indicator organisms is suggested. Retailers are urged to invest in standby generators to maintain the cold chain.

Comparison of the Microflora on Organically and Conventionally Grown Spring Mix from a California Processor

2005 ◽  
Vol 68 (6) ◽  
pp. 1143-1146 ◽  
Author(s):  
CHRISTIE A. PHILLIPS ◽  
MARK A. HARRISON
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Foodborne Pathogens ◽  
Period Analysis ◽  
E Coli ◽  
Psychrotrophic Bacteria ◽  
Microbial Group ◽  
The Mean ◽  
Yeasts And Molds ◽  
Organically Grown

Considerable speculation has occurred concerning the potential for higher numbers of foodborne pathogens on organically grown produce compared with produce not grown organically. The microflora composition of spring mix or mesclun, a mixture of multiple salad ingredients, grown either by organic or conventional means was determined. Unwashed or washed spring mix was obtained from a commercial California fresh-cut produce processor who does not use manure in their cultivation practices. Fifty-four samples of each type of product were supplied over a 4-month period. Analysis included enumeration of total mesophiles, psychrotrophs, coliforms, generic Escherichia coli, lactic acid bacteria, yeasts, and molds. In addition, spring mix was analyzed for the presence of Salmonella and Listeria monocytogenes. The mean populations of mesophilic and psychrotrophic bacteria, yeasts, molds, lactic acid bacteria, and coliforms on conventionally grown spring mix were not statistically different (P > 0.05) from respective mean populations on organically grown spring mix. The mean population of each microbial group was significantly higher on unwashed spring mix compared with the washed product. Of the 14 samples found to contain E. coli, eight were from nonwashed conventional spring mix, one was from washed conventional spring mix, and four were from nonwashed organic spring mix. Salmonella and L. monocytogenes were not detected in any of the samples analyzed.

Fungi in Foods

1975 ◽  
Vol 38 (12) ◽  
pp. 745-746 ◽  
Author(s):  
J. A. KOBURGER ◽  
A. R. NORDEN
Keyword(s):  
Food Samples ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number ◽  
Plate Count Agar ◽  
Yeasts And Molds ◽  
Surface Plate

It was possible to compare recovery of yeasts and molds from 30 food samples by three methods, employing plate count agar and broth with added antibiotics. Although the pour plate and surface plate methods gave comparable results, the Most Probable Number (MPN) procedure consistently yielded the highest counts. With some of the samples, the MPN method was the only one in which recovery occurred. It thus appears that this procedure is practical for detection of fungi and may be of use in survey work or when analyzing foods containing low numbers of microorganisms.

Microbial Hazards Associated with Bean Sprouting

1982 ◽  
Vol 65 (2) ◽  
pp. 241-248 ◽  
Author(s):  
Wallace H Andrews ◽  
Philip B Mislivec ◽  
Clyde R Wilson ◽  
Verneal R Bruce ◽  
Paul L Poelma ◽  
...  
Keyword(s):  
Aspergillus Flavus ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number ◽  
Before And After ◽  
Alternaria Species ◽  
Aerobic Plate Count ◽  
Yeasts And Molds ◽  
Mold Count ◽  
Total Yeast

Abstract The behavior of microorganisms was studied in mung beans and alfalfa seeds before and after germination in modified, commercially available bean-sprouting kits. The microorganisms were enumerated by the aerobic plate count (APC) and by total yeast and mold count procedures. Salmonella species were artificially inoculated into selected samples and were enumerated by the most probable number (MPN) method. After germination of the beans or seeds into mature sprouts, significant increases were noted in APCs and in MPN values of Salmonella species. Although counts of yeasts and molds did not increase significantly after germination, these samples showed an increase in toxic Aspergillus flavus and potentially toxic Alternaria species. The presence of toxic Penicillium cyclopium molds also increased substantially in 5 samples of a single brand of mung beans. Analysis of selected sprout samples, however, showed no presence of aflatoxin.

Microbiology of Fresh Comminuted Turkey Meat

1976 ◽  
Vol 39 (12) ◽  
pp. 823-829 ◽  
Author(s):  
LINDA S. GUTHERTZ ◽  
JOHN T. FRUIN ◽  
DELANO SPICER ◽  
JAMES L. FOWLER
Keyword(s):  
Staphylococcus Aureus ◽  
San Francisco ◽  
Clostridium Perfringens ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number ◽  
Selective Enrichment ◽  
Turkey Meat ◽  
Standard Plate ◽  
The Mean

Standard plate counts, coliform plate and most probable number (MPN) counts, Escherichia coli plate and MPN counts, Staphylococcus aureus MPN counts, and fecal streptococcus counts were determined for 75 samples of fresh ground turkey meat purchased from retail markets in the San Francisco Bay Area. The presence of Clostridium perfringens was determined by both direct plate count and enrichment techniques. Salmonellae were isolated using selective enrichment procedures. Samples were screened for presence of enteroviruses. Aerobic gram-positive and gram-negative organisms were isolated and identified. Clostridium perfringens and Salmonella sp. were isolated from 52% and 28% of the samples, respectively. The mean standard plate count was 84,000,000 per gram. The mean count for E. coli determined by the MPN method was 19 per gram. Fecal streptococci were isolated from 95% of the samples with a mean count of 18,000 per gram. Staphylococcus aureus was isolated from 80% of samples analyzed with a mean count of 34 per gram.

Chemical and Bacteriological Characteristics of Pichtogalo Chanion Cheese and Mesophilic Starter Cultures for Its Production

1998 ◽  
Vol 61 (6) ◽  
pp. 688-692 ◽  
Author(s):  
DEMETRIOS K. PAPAGEORGIOU ◽  
AMIN ABRAHIM ◽  
MINA BORI ◽  
SPIROS DOUNDOUNAKIS
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Starter Culture ◽  
Salt Content ◽  
Starter Cultures ◽  
Most Probable Number ◽  
Probable Number ◽  
Goat’S Milk ◽  
Two Samples ◽  
Goat's Milk

Sixty-two samples of Pichtogalo Chanion cheese traditionally produced in Crete, a few (3 to 6) days old, were analyzed for some chemical and bacteriological characteristics. The results of physicochemical analyses were as follows: (1) moisture content 61.63% (standard deviation 4.67); (2) fat in dry matter 54.03% (SD 7.73); (3) protein content 14.23% (SD 1.72); (4) salt content 1.02% (SD 0.38); (5) water activity (aw) 0.990 (SD 0.003); and (6) pH 4.36 (SD 0.25). None of the samples yielded Salmonella spp. Listeria monocytogenes and coagulase-positive staphylococci were present in 6.45% of the samples. Bacillus cereus and sulfite-reducing clostridia were isolated from 14.51% and 40.32% of the samples, respectively. High populations of coliforms were determined in the cheese samples. In 11.3% of the samples, Escherichia coli was not detected, while 88.7% of the samples yielded E. coli most probable number levels from 1.32 to 5.66 log10/g. The log10 CFU/g counts of enterococci were 6.89 (SD 0.84), of yeasts 6.79 (SD 0.61), of molds 4.68 (SD 0.69), and of psychrotrophic bacteria 7.63 (SD 0.62). The log10 CFU/g counts of lactic acid streptococci and lactococci were 7.91 (SD 0.68) and of lactobacilli 8.11 (SD 0.65). Lactic acid bacteria, mainly mesophilic, were isolated and confirmed using API 50 CH test trips. A pasteurized mixture of ewe's and goat's milk was made into Pichtogalo Chanion cheese according to standard procedure at 23°C, after the addition of 4% commercial mesophilic starter culture or 2%, 3%, and 4% starter culture of the isolated and confirmed lactic acid bacteria and the addition of rennet. Results of this work indicated that high quality of Pichtogalo Chanion cheese can be produced using a pasteurized mixture of ewe's and goat's milk and 4% (vol/vol) of mesophilic starter culture.

Isolation and identification of lactic acid bacteria in Bakasang as fermented microbe starter

2013 ◽  
pp. 48
Author(s):  
J Aquarista Ingratubun ◽  
Frans G Ijong ◽  
Hens Onibala
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Pathogenic Bacteria ◽  
Raw Materials ◽  
Fermented Food ◽  
Plate Count ◽  
Local Market ◽  
Bacillus Sp ◽  
Isolation And Identification ◽  
Total Plate Count

Food fermentation is one of various food processing techniques that has sufficient benefits of nutrition values, and also contains lactic acid bacteria which potentially inhibit pathogenic bacteria, thus prolong shelf life of  products. Bakasang is a traditional fermented food from North Sulawesi since many years ago. Reported research of bakasang previously had described that lactic acid bacteria was the dominant isolates and therefore current research  aimed to isolate and identify the lactic acid bacteria which associated during fermentation day 1 and day 15, respectively. Raw materials used were 5 kg intestine and liver of skipjack brought from local market Bersehati Manado. The intestine and liver of skipjack were washed and smashed and mixed with 10% salt  and 5% rice  from weight of the samples and then filled into bottle to be fermented for 15 days. Every 3 days (1,3,6,9,12,15), the samples were collected and analyzed for total lactic acid bacteria by using Total Plate Count Method on de Mann Rogosa Sharpe Agar after incubation at 37°C for 24 h. The colonies  grown were transferred to Tryptic Soy Broth and followed by streaking them on Tryptic Soy Agar and the free growing colony on agar medium were isolated into slant agar which were used for biochemical test such as Gram’s staining, motility test, catalase test, oksidase test, H2S test, IMVIC test (Indole, Methyl Red, Voges Proskauer, Citrate) and carbohydrate fermentation. The results showed that Lactobacillus sp., Bacillus sp., Eubacterium sp., and Bifidobacterium sp. All these four bacteria were distributed from day 1 to day 15 of the fermentation process© Fermentasi bahan pangan merupakan salah satu dari sekian banyak teknik pengolahan makanan yang mempunyai banyak manfaat dari kualitas gizi, mengandung bakteri asam laktat sehingga menghambat bakteri patogen sehingga daya simpan lebih panjang. Bakasang merupakan makanan fermentasi tradisional masyarakat Sulawesi Utara yang sudah ada sejak lama. Penelitian yang telah dilakukan terhadap bakasang menghasilkan informasi bahwa terdapat bakteri asam laktat pada bakasang sehingga menjadi tujuan untuk mengisolasi dan identifikasi bakteri asam laktat selama proses fermentasi 1-15 hari. Bahan baku bakasang ialah jeroan (usus dan hati) ikan cakalang Katsuwonis pelamis sebanyak 5 kg yang diambil dari pasar Bersehati Manado. Sampel jeroan dibersihkan kemudian dihancurkan, ditambahkan garam 10% dan nasi 5% kemudian difermentasi selama 15 hari dengan mengambil tiap-tiap sampel setiap 1, 3, 6, 9, 12, dan 15 untuk dihitung jumlah bakteri asam laktat dengan menggunakkan metode Total Plate Count pada media de Mann Rogosa Sharpe Agar dan koloni yang tumbuh di tumbuhkan  kembali pada media Tryptic Soy Broth  dan digores kembali pada media Tryptic Soy Agar, koloni yang tumbuh digores pada media slant agar yang selanjutnya diidentifikasi bakteri asam laktat berdasarkan uji biokimia yaitu uji pewarnaan Gram, uji motility, uji katalase, uji oksidase, uji H2S dan uji IMVIC (Indole, MethylRed, Voges Proskauer, Citrate). Hasil menunjukkan bahwa selama proses fermentasi berlangsung terdapat 4 genera bakteri asam laktat sesuai yaitu Lactobacillus sp., Bacillus sp., Eubacterium sp., dan Bifidobacterium sp., ke 4 genera ini tersebar pada fermentasi hari 1 sampai hari ke 15©

scholarly journals ANALISA MIKROBIOLOGI CEMARAN BAKTERI COLIFORM DAN SALMONELLA SP PADA TAHU DI KECAMATAN DELTA PAWAN

2019 ◽  
Vol 6 (1) ◽  
pp. 61
Author(s):  
Nenengsih Verawati ◽  
Nur Aida ◽  
Ridha Aufa
Keyword(s):  
Coliform Bacteria ◽  
Plate Count ◽  
Most Probable Number ◽  
Food Ingredient ◽  
Probable Number ◽  
West Kalimantan ◽  
Safety Standards ◽  
Confirmatory Tests ◽  
Food Safety Standards ◽  
Positive Results

Tofu is a high-protein soy-based food ingredient that is widely consumed in Indonesia. Tofu producers in Delta Pawan Subdistrict are dominated by small and medium-sized entrepreneurs whose hygiene and sanitation aspects in production activities are very under-taken. This study aims to determine the presence of Coliform and Salmonella Sp bacteria on tofu produced in Delta Pawan sub-district, Ketapang, West Kalimantan and compare with SNI01-3142-1998. The method used to detect the presence of Coliform bacteria in this study uses the Most Probable Number (MPN) method, which consists of estimator and confirmatory tests using Lactosa Broth (LB) media for the Brilliant Green Lactose Broth (BGLB) assay test for confirmation . Whereas to detect the amount of Salmonella Sp using the method of Total Plate Count (TPC) with selective media Salmonella Shigella Agar (SSA). The results of Coliform analysis in both industries found Coliform MPN values ​​of more than 2400 AMP / g samples, which indicated that they did not meet the standards set by SNI. While the results of the analysis of Salmonella Sp obtained positive results, so the two industries did not meet food safety standards.

Behavior of Listeria monocytogenes in Skim Milk during Fermentation with Mesophilic Lactic Starter Cultures

1988 ◽  
Vol 51 (8) ◽  
pp. 600-606 ◽  
Author(s):  
MICHELLE M. SCHAACK ◽  
ELMER H. MARTH
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Skim Milk ◽  
Starter Cultures ◽  
Plate Count ◽  
Inoculum Level ◽  
Plate Count Agar ◽  
Streptococcus Lactis ◽  
Streptococcus Cremoris

The ability of Listeria monocytogenes to grow and compete with mesophilic lactic acid bacteria was examined. Autoclaved skim milk was inoculated with 103 cells of L. monocytogenes (strain V7 or Ohio)/ml, and with 5.0, 1.0, 0.5 or 0.1% of a milk culture of either Streptococcus cremoris or Streptococcus lactis. Inoculated milks were fermented for 15 h at 21 or 30°C, followed by refrigeration at 4°C. Samples were plated on McBride Listeria Agar to enumerate L. monocytogenes and on either APT Agar or plate count agar to enumerate lactic acid bacteria. L. monocytogenes survived in all fermentations, and commonly also grew to some extent. Incubation at 30°C with 5% S. lactis as inoculum appeared to be the most inhibitory combination for strain V7, causing 100% inhibition in growth based on maximum population attained. S. cremoris at the 5.0% and 0.1% inoculum levels, was slightly less inhibitory to L. monocytogenes at 37°C, but it was slightly more inhibitory to L. monocytogenes at the 1.0% inoculum level than was S. lactis. In general, S. lactis reduced the pH of fermented milks more than did S. cremoris. The population of L. monocytogenes began to decrease before 15 h in only one test combination, which was use of a 5.0% inoculum of S. cremoris and 30°C incubation. In most instances, growth of the pathogen appeared to be completely inhibited when the pH dropped below 4.75.

Levels and Enterotoxigenicity of Clostridium perfringens in Pozole, Tamales, and Birria

2005 ◽  
Vol 68 (2) ◽  
pp. 331-335 ◽  
Author(s):  
V. NAVARRO-HIDALGO ◽  
E. CABRERA-DÍAZ ◽  
H. ZEPEDA ◽  
L. MOTA DE LA GARZA ◽  
A. CASTILLO ◽  
...  
Keyword(s):  
Clostridium Perfringens ◽  
Cell Elongation ◽  
Cytotoxic Effect ◽  
Cell Lysis ◽  
Vero Cells ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number ◽  
Quantitative Survey ◽  
Plate Counts

A quantitative survey of Clostridium perfringens in typical foods served at local restaurants was conducted for 18 months in Guadalajara, Mexico. A total of 151 samples, including goat's birria (50), pozole (50), and beef tamales (51), were collected from small restaurants in Guadalajara. Samples were tested for C. perfringens by the most probable number (MPN) method and for mesophilic aerobic plate counts (MAPCs) and coliform, yeast, and mold counts by plate count methods. Isolates confirmed as C. perfringens were further sporulated and tested for cytotoxic or cytotonic effect against Vero cells as an indication of enterotoxin production. C. perfringens was detected in 78 (52%) of all samples at concentrations that ranged from 2.3 to 5.4 log MPN/g. Average MAPCs were 1.3 to 2.7 log CFU/g, depending on the type of dish. Coliform counts ranged from less than 1.0 to 1.5 CFU/g, and yeast and mold counts were less than 1.0 log CFU/g in all cases. A total of 118 isolates of C. perfringens were tested for enterotoxic effect on Vero cells; 82 (70%) showed activity against Vero cells. Of them, 31 isolates induced cell lysis, indicating cytotoxic effect; 41 induced cell elongation, indicating cytotonic effect; and 10 produced both cytotoxic and cytotonic effect. Dilution of the bacterial filtrates that were still producing an effect on Vero cells ranged from 1:80 to 1:5,120. These results underscore the importance of determining enterotoxigenicity when testing for C. perfringens in foods.

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