Reduction of Normal Flora by Irradiation and Its Effect on the Ability of Listeria monocytogenes to Multiply on Ground Turkey Stored at 7°C When Packaged under a Modified Atmosphere†

2000 ◽  
Vol 63 (12) ◽  
pp. 1702-1706 ◽  
Author(s):  
DONALD W. THAYER ◽  
GLENN BOYD
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Plate Count ◽  
Modified Atmosphere ◽  
Normal Flora ◽  
Total Plate Count ◽  
Dependent Inhibition ◽  
Gamma Irradiated

Listeria monocytogenes did not multiply faster during storage at 7°C on irradiated than on nonirradiated raw ground turkey, and there was a concentration-dependent inhibition of its multiplication by CO2. Ground turkey was gamma irradiated at 5°C to 0, 1.5, and 2.5 kGy and inoculated (∼100 CFU/g) after irradiation with a cocktail of L. monocytogenes ATCC 7644, 15313, 49594, and 43256. The meat was then packaged in air-permeable pouches or under atmospheres containing 30 or 53% CO2, 19% O2, and 51 or 24% N2 and stored at 7°C for up to 28 days. A dose of 2.5 kGy extended the time for the total plate count (TPC) to reach 107 CFU/g from 4 to 19 days compared to that for nonirradiated turkey in air-permeable pouches. Following a dose of 2.5 kGy at the end of the 28-day study, the TPCs were 106.42 and 104.98 under 25% and 50% CO2 atmospheres, respectively. Under air, 30% CO2, and 53% CO2 atmospheres, the populations of L. monocytogenes after 19 days incubation were 104.89, 103.60, and 102.67 CFU/g. The populations of lactic acid bacteria and anaerobic or facultative bacteria were also reduced by irradiation. Irradiating ground turkey did not decrease its safety when it was contaminated following processing with L. monocytogenes.

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©

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.

scholarly journals KARAKTERISTIK BAKTERI ASAM LAKTAT YANG DIISOLASI DARI SUSU KUDA SUMBA

2019 ◽  
Vol 7 (1) ◽  
pp. 85-92
Author(s):  
Annytha Detha
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Selective Medium ◽  
Plate Count ◽  
Gram Positive ◽  
Negative Results ◽  
Gram Staining ◽  
Total Plate Count ◽  
Agar Media ◽  
Veterinary Laboratory

The purpose of this study was to isolate and identify the lactic acid bacteria found in Sumba mares milk. This research will be carried out from September to November 2017 at the Veterinary Laboratory of the Livestock Service Office of East Nusa Tenggara Province. The research stages are isolation of lactic acid bacteria from Sumba mares milk by growing lactic acid bacteria on MRS agar media, and identifying lactic acid bacteria with gram staining, catalase test, motility test, and total plate count testing. Based on the results of the study, the presence of lactic acid bacteria originating from Sumba mares milk was characterized by the presence of colonies of lactic acid bacteria from Sumba mares milk which grew on MRS media agar as a selective medium for lactic acid bacteria. Based on the results of testing the characteristics of lactic acid bacteria Sumba mares milk has Gram positive, the negative results in the catalase test are characterized by not forming gas bubbles when the bacteria are added with H2O2. Based on the motility test obtained negative results or bacteria are non-motile and the number of lactic acid bacteria that can be a total picture of lactic acid bacteria that exist in Sumba mares milk in milliliter of milk. The conclusion are lactic acid bacteria isolated from Sumba mares milk has characteristic as Gram positive, basil or stem shaped, negative catalase and non motile, and has a total lactic acid bacteria of 3.5 x 108 cfu/ml (est).      

scholarly journals Total Lactic Acid Bacteria, Antioxidant Activity, and Acceptance of Herbal Soyghurt with Addition of Red Ginger (Zingiber officinale var Rubrum)

2019 ◽  
Vol 3 (1) ◽  
pp. 18
Author(s):  
Ninik Rustanti ◽  
Agung Dwi Prasetyo
Keyword(s):  
Antioxidant Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Zingiber Officinale ◽  
Plate Count ◽  
Acceptance Testing ◽  
Acceptance Test ◽  
Total Plate Count ◽  
Activity Test ◽  
Red Ginger

<p><em>This study aims to determine the effect of red ginger on total lactic acid bacteria, antioxidant activity and acceptance of herbal soyghurt. This study used the addition of red ginger concentration of 0%, 2% and 4% in soyghurt. The total lactic acid bacteria were calculated using Total Plate Count (TPC) method and antioxidant activity test was analyzed by DPPH </em>(<em>2,2-diphenyl-1-picrylhydrazyl</em>)<em> method. </em><em>The acceptance testing was performed by hedonic test.<strong> </strong>The addition of red ginger affected antioxidant activity and acceptance test in terms of taste, flavor, and color. The highest antioxidant activity in soyghurt with 4% red ginger is 11.36 ± 1.73%. The addition of red ginger has no effect on the total lactic acid bacteria and soyghurt texture.<strong> </strong>Soyghurt with 2% red ginger is the best of the acceptance test. It has an antioxidant activity of 10.68 ± 1.13%, and the total lactic acid bacteria 5.00 ± 5.29 x 10<sup>16</sup> CFU/ml.</em></p>

Uji Antifungi Susu Fermentasi Komersial pada Candida non-albicans

SCISCITATIO ◽  
2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Nur Khikmah ◽  
Nunung Sulistyani
Keyword(s):  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Antifungal Activity ◽  
Lactic Acid Bacteria ◽  
Organic Acids ◽  
Oral Candidiasis ◽  
Fermented Milk ◽  
Plate Count ◽  
Diffusion Method ◽  
Total Plate Count

Bakteri Asam Laktat (BAL) yang terkandung dalam susu fermentasi akan menghasilkan asam-asam organik, hidrogen peroksida, diasetil, asetaldehid, asetoin, reutinin, reuterisiklin dan bakteriosin, dapat sebagai anti-Candida. Spesies Candida non-albicans seperti C. tropicalis dan C. glabrata sebagai penyebab kandidiasis oral cenderung meningkat. Tujuan penelitian ini mengetahui aktivitas antifungi susu fermentasi komersial pada Candida non-albicans dan viabilitas bakteri asam laktat di dalam susu fermentasi komersial. Aktivitas antifungi pada Candida non-albicans dilakukan dengan metode difusi sumuran. Viabilitas bakteri asam laktat dihitung berdasarkan jumlah bakteri asam laktat sebagai jumlah bakteri total (Total Plate Count). Hasil penelitian menunjukkan bahwa susu fermentasi komersial lebih mampu menghambat C. tropicalis dibandingkan C. glabrata. Viabilitas bakteri asam laktat dalam susu fermentasi komersial 107-1010 CFU/mL. Lactic Acid Bacteria (LAB) contained in fermented milk will produce organic acids, hydrogen peroxide, diacetyl, acetaldehyde, acetoin, reutinin, reuterycline and bacteriocin, as anti-Candida. Candida non-albicans species such as C. tropicalis and C. glabrata as causes of oral candidiasis tend to increase. The aim of this research was to determine the antifungal activity of commercial fermented milk against Candida non-albicans and viability of lactic acid bacteria in commercial ermented milk. The antifungal activity was determined using well diffusion method. Viability of lactic acid bacteria is calculated as Total Plate Count. The results showed that commercial fermented milk was more able to inhibit C. tropicalis compared C. glabrata. Viability of lactic acid bacteria 107-1010 CFU/mL.

scholarly journals Behavior of Listeria monocytogenes and Other Microorganisms in Sliced Riojano Chorizo (Spanish Dry-Cured Sausage) during Storage under Modified Atmospheres

2021 ◽  
Vol 9 (7) ◽  
pp. 1384
Author(s):  
Elena Gonzalez-Fandos ◽  
Maria Vazquez de Vazquez de Castro ◽  
Alba Martinez-Laorden ◽  
Iratxe Perez-Arnedo
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Potential Risk ◽  
Meat Product ◽  
Meat Products ◽  
Modified Atmosphere ◽  
Microbial Counts ◽  
Modified Atmospheres ◽  
Contamination Levels

Sliced ready-to-eat meat products packaged under modified atmospheres are often marketed since they cover consumer demands. The slicing process could be a potential risk for consumers since contamination with Listeria monocytogenes could occur during this stage. The current study evaluated the behavior of L. monocytogenes and other microorganisms in commercial sliced Riojano chorizo. This meat product was sliced and inoculated with L. monocytogenes (3.5 log CFU/g) before packaging under different atmospheres (air, vacuum, 100% N2, 20% CO2/80% N2 and 40% CO2/60% N2) and stored at 4 °C for up to 60 days. Samples were taken on days 0, 7, 21, 28 and 60 of storage. L. monocytogenes, mesophiles, Enterobacteriaceae, lactic acid bacteria, Micrococcaceae, molds and yeast counts were evaluated. Additionally, water activity, humidity and pH were determined. L. monocytogenes counts decreased in inoculated sliced chorizo during storage. Packaging conditions and day of storage influenced microbial counts. After 60 days, a significant reduction (p ≤ 0.05) in the initial Listeria contamination levels (3.5. log CFU/g) between 1.1 and 1.46 logarithmic units was achieved in the sausages packaged in modified atmosphere. The highest reductions were observed in slices packaged in 40% CO2/60% N2 after 60 days of storage at 4 °C.

Bacterial Contamination of Recirculating Brine Used in the Commercial Production of Moisture-Enhanced Pork†

2004 ◽  
Vol 67 (1) ◽  
pp. 185-188 ◽  
Author(s):  
G. GORDON GREER ◽  
FRANCES NATTRESS ◽  
BRYAN DILTS ◽  
LYNDA BAKER
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lemon Juice ◽  
Plate Count ◽  
Pork Production ◽  
Total Plate Count ◽  
Spoilage Bacteria ◽  
Large Populations ◽  
Brochothrix Thermosphacta ◽  
Commercial Process

In a commercial process for the production of moisture-enhanced pork, boneless pork loins were conveyed through a recirculating injection apparatus, and brine (sodium phosphate, sodium chloride, and lemon juice solids) was pumped into the meat through banks of needles inserted automatically into the upper surfaces of cuts. Brine samples were collected at intervals during the production process and analyzed to determine the total plate count and the numbers of lactic acid bacteria, pseudomonads, Brochothrix thermosphacta, and Enterobacteriaceae. Listeria monocytogenes numbers in the brine were determined using a PCR with primers for the hemolysin gene in combination with a most probable numbers determination. Maximum numbers of bacteria (log CFU/ml) recovered from the brine after 2.5 h of recirculation were as follows: total plate count, 4.50; lactic acid bacteria, 2.99; pseudomonads, 3.95; B. thermosphacta, 2.79; and enterics, 3.01. There was an increase in the number of L. monocytogenes in the recirculating brine with time, reaching a maximum of 2.34 log CFU/100 ml after 2.5 h of moisture-enhanced pork production. Thus, recirculating brines can harbor large populations of spoilage bacteria and L. monocytogenes and are an important source of contamination for moisture-enhanced pork.

scholarly journals Evaluation of physical and chemical composition of concentrated fermented cabbage juice

2021 ◽  
Author(s):  
Liene Jansone ◽  
◽  
Solvita Kampuse ◽  
Zanda Kruma ◽  
Ivo Lidums
Keyword(s):  
Ascorbic Acid ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Total Phenol ◽  
Soluble Solids ◽  
Plate Count ◽  
Total Phenol Content ◽  
Phenol Content ◽  
Sustainable Solutions ◽  
Total Plate Count

Fermented products have gained worldwide popularity for their nutritional and health aspects. Many studies have been done on this topic, including fermented cabbage (sauerkraut). Yet little or no studies are done on evaluation of fermented cabbage juice which is considered as by-product of sauerkraut production, still rich in bioactive compounds. In order to reduce food waste, sustainable solutions are being searched for to preserve valuable fermented cabbage juice. The aim of this study was to evaluate chemical and physical composition of concentrated fermented cabbage juice and their changes after storage. The fermented cabbage juice was concentrated on falling film evaporator from 9.2 till 34.3 °Brix. Physio-chemical (moisture, pH, total soluble solids, total phenol content, antiradical activity by DPPH and ABTS+, ascorbic acid, total sugar profile, nitrates and minerals) and microbiological (lactic acid bacteria, total plate count) analyses were carried out. Concentrated fermented cabbage juice is a source of minerals and phenol compounds as well as salt substitute in food applications. After 6 months of storage there is significant degradation of ascorbic acid but total phenol content is not affected. The evaporation process did not inhibit microbiological activity; as a result, there is a decrease in lactic acid bacteria but increase in total plate count.

scholarly journals Efficacy of Cetylpyridinium Chloride against Listeria monocytogenes and Its Influence on Color and Texture of Cooked Roast Beef†

2005 ◽  
Vol 68 (11) ◽  
pp. 2349-2355 ◽  
Author(s):  
M. SINGH ◽  
H. THIPPAREDDI ◽  
R. K. PHEBUS ◽  
J. L. MARSDEN ◽  
T. J. HERALD ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Cetylpyridinium Chloride ◽  
Meat Products ◽  
Plate Count ◽  
Bacterial Populations ◽  
Plate Counts ◽  
Roast Beef ◽  
Aerobic Plate Count

Sliced (cut) and exterior (intact) surfaces of restructured cooked roast beef were inoculated with Listeria monocytogenes, treated with cetylpyridinium chloride (CPC; immersion in 500 ml of 1% solution for 1 min), individually vacuum packaged, and stored for 42 days at 0 or 4°C. Noninoculated samples were similarly treated, packaged, and stored to determine effects on quality (color and firmness) and on naturally occurring bacterial populations, including aerobic plate counts and lactic acid bacteria. Immediately after CPC treatment, regardless of inoculation level, L. monocytogenes populations were reduced (P = 0.05) by about 2 log CFU/cm2 on sliced surfaces and by about 4 log CFU/cm2 on exterior surfaces. Throughout 42 days of refrigerated storage (at both 0 and 4°C), L. monocytogenes populations on CPC-treated samples remained lower (P = 0.05) than those of nontreated samples for both surface types. After 42 days of storage at both 0 and 4°C, aerobic plate count and lactic acid bacteria populations of treated samples were 1 to 1.5 log CFU/cm2 lower (P = 0.05) than those of nontreated samples for both surface types. CPC treatment resulted in negligible effects (P &gt; 0.05) on the color (L*, a*, and b* values) of exterior and sliced roast beef surfaces during storage. For both sliced and exterior surfaces, CPC-treated samples were generally less firm than nontreated samples. CPC treatment effectively reduced L. monocytogenes populations on roast beef surfaces and resulted in relatively minor impacts on color and texture attributes. CPC treatment, especially when applied to products prior to slicing, may serve as an effective antimicrobial intervention for ready-to-eat meat products.

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