Total Aerobic Bacterial Counts Research Articles

Effects of Electron Beam Irradiation and High-Pressure Treatment with Citrus Peel Extract on the Microbiological, Chemical and Sensory Qualities of Marinated Chicken Breast Meat

Chicken breast meat samples were injected with marinade solution (salt, sugar, phosphate, monosodium glutamate, and nucleic acid) with or without 2% citrus peel extract (CPE), and then a subset were irradiated with a 1 or 2 kGy electron beam (EB) and/or subjected to high-pressure (HP) at 300 or 400 MPa. The initial total aerobic bacterial (TAB) count of the control sample was 4.57 log CFU/g and reached 7.17 log CFU/g after 3 days of storage at <TEX>$4^{\circ}C$</TEX>. The 2 kGy EB reduced the TAB count to 4.61 log CFU/g after 7 days. The 400 MPa HP treatment was also effective in reducing the TAB count, but the effect was slightly less than that noted with the 2 kGy EB. The CPE, in combination with the EB and HP, decreased the TAB count by 1.71 and 1.32 log CFU/g at the initial stage and further decreased the count during storage. The 2 kGy EB and the HP (300 and 400 MPa) increased the thiobarbituric acid-reactive substances value, whereas the CPE did not show an antioxidative effect. The EB and HP caused no difference in the sensory qualities. In contrast, the CPE decreased all sensory qualities tested. Sensory panelists commented that the samples with CPE were not in the "rejection" category but were "unfamiliar" for chicken breast meat. In conclusion, the EB was more effective than HP in improving the microbial quality of marinated chicken breast meat. The use of CPE in the marinade solution may synergistically increase the shelf life; however, it is necessary to develop an appropriate formulation to ensure that the sensory qualities are maintained.

Dietary pomegranate seed pulp increases conjugated-linoleic and -linolenic acids in muscle and adipose tissues of kid

The effect of level of dried pomegranate seed pulp (PSP) in the diet of kids on meat quality and fatty acid profiles of intramuscular and subcutaneous fat was studied. Thirty two Mahabadi kids were randomly allocated to four dietary treatments: without PSP (control), containing 50g PSP/kg DM (PSP5), containing 100g PSP/kg DM (PSP10), and containing 150g PSP/kg DM (PSP15). At the end of the 84-day feeding trial, the kids were slaughtered and m. longissimus lumborum (LL) and subcutaneous adipose tissues were sampled. Addition of PSP linearly increased (P=0.01) fat content and decreased (P<0.01) shear force, drip loss, total aerobic bacterial count and lipid oxidation of LL muscle. Feeding PSP diets linearly increased the concentrations of C18:2 n-6 (P<0.01), C18:3 n-3 (P<0.001), n-6 polyunsaturated fatty acids (PUFA; P<0.01) and n-3 PUFA (P<0.001) and decreased (P<0.05) the ratio of n-6/n-3 in both muscle and adipose tissues. A linear increase was observed in vaccenic acid (VA, P<0.01), conjugated linoleic acid (CLA; P<0.001) and punicic acid (PUA; P<0.001) concentration in subcutaneous and intramuscular fat, with increasing PSP level in diet. In conclusion, PSP supplementation of kid's diet up to 150g/kg DM can improve the nutritional and functional properties of meat.

The use of atmospheric pressure plasma-treated water as a source of nitrite for emulsion-type sausage

We investigated the possible use of atmospheric pressure plasma-treated water (PTW) as a nitrite source in curing process. Emulsion-type sausages were manufactured with PTW, celery powder containing nitrite, and synthetic sodium nitrite at a concentration of nitrite ion 70mgkg−1. In terms of sausage quality, there were no noticeable effects of PTW on the total aerobic bacterial counts, color, and peroxide values of sausages compared with those of celery powder and sodium nitrite throughout 28days of storage at 4°C. Sausage with added PTW had lower concentrations of residual nitrite compared to those of added celery powder and sodium nitrite during the storage period (P<0.05). The sensory properties of PTW-treated and sodium nitrite-treated sausages were not different, whereas the sausage with added celery powder received the lowest scores in taste and acceptability. From the results, it is concluded that PTW can be used as a nitrite source equivalent to a natural curing agent.

Physicochemical, microbial and sensory quality of fresh-cut red beetroots in relation to sanization method and storage duration

Effects of sanitization and storage on fresh-cut beetroots ( Beta vulgaris L.) were evaluated following sanitation – peeling - cutting (SPC), peeling – sanitation – cutting (PSC) and peeling – cutting – sanitation (PCS) methods with (Cl), or without (TW), 100 ppm chlorine solution, then packaged in polyethylene bag and stored at 5°C for up to 14 days. Chroma values of fresh-cut beetroots significantly declined whereas whiteness index and titratable acidity values increased, however, texture and total soluble solid contents showed no significant variation. Betalain contents decreased gradually and total phenol content showed inconsistence trend. PCS-Cl treated samples accounted for higher betalains decline and received lower visual quality scores despite its lower total aerobic bacterial count. Minimum microbial population was observed in PSC-Cl methods along with higher levels of betalain contents. Considering pigment retention, microbial and visual qualities, beetroots sanitized with chlorine water following PSC method was the best processing way for fresh-cut beetroots and therefore, PSC-Cl treatment could commercially be used for processing of fresh-cut beetroots.

Microbiological quality of milk sold directly from producers to consumers

The aim of this study was to determine the microbiological quality of raw cow milk from direct sale points. Raw cow milk samples were collected from 5 randomly selected direct sale points for microbiological evaluation. The samples were analyzed to determine total aerobic bacterial count, somatic cell count (SCC), counts of Enterobacteriaceae, Enterococcus, Escherichia coli, and Staphylococcus, and presence of Salmonella, Listeria monocytogenes, and inhibitory substances. The mean counts of total aerobic bacterial in samples from all direct sale points were between 9.2×104 and 3.6×107 cfu/mL. Milk samples collected from 5 direct sale points revealed counts Enterobacteriaceae ranging from 6.4×101 to 1.7×106 cfu/mL. Escherichia coli were detected in 12 milk samples with counts ranging from 5.0×100 to 1.1×102 cfu/mL. Staphylococcus spp. bacteria were found in all milk samples, at counts ranging from 1.6×103 to 5.1×104 cfu/mL. Listeria monocytogenes bacteria were detected in 1 sample, and SCC in all samples ranged from 78,000 to 1,730,000/mL. The examined samples did not contain Salmonella rods or inhibitory substances. In the samples examined in this study, international hygiene standards were exceeded for total aerobic bacterial count (n=48) as well as for SCC (n=19). Two milk samples contained pathogenic bacteria (Listeria monocytogenes and Staphylococcus aureus) that pose a potential hazard for consumer health.

Histamine formation and the freshness of yellowfin tuna (Thunnus albacares) stored at different temperatures

AbstractThis study was conducted to investigate the effect of storage temperatures on the shelf life of yellowfin tuna (YFT) loins by studying of microbial, chemical and organoleptic changes. Shelf life of YFT was determined through changes in total aerobic bacterial plate counts (APC), total volatile basic nitrogen (TVB-N) trimethylamine (TMA), organoleptic properties and histamine development during storage at 0, 4 and 7°C. Based on TVB-N value indices, YFT maintained an acceptable shelf life for 21, 17 and 12 days at 0, 4 and 7°C, respectively. Nevertheless, YFT was rejected earlier by the sensory panellists than their TVB-N value indicated. Histamine development was found to be lower than the European Union safety level for 100 mg/kg fish during storage at 0 and 7°C for 21 and 17 days, respectively. Aerobic bacteria initially dominated the micro-flora on YFT; however, as storage time increased, aerobic bacteria became dominant at cold storage, but the numbers exceeded the International Commission on M...

Microbiome Populations in Lebanese Slaughterhouse Settings

Lebanon has traditionally relied on small ruminants and cattle livestock production to generate meat and dairy food products for the region. Consumer interest and changing residential populations have increased demand for these products, and highlighted food safety concerns along the community chain. Traditional livestock production levels have been unable to meet population demand for meat, necessitating supplemental importation of Brazilian and European cattle for this purpose. While microbial assessment has been studied in dairy and poultry sector products and retail fast foods there are no published reports examining microbial populations in slaughterhouse environments or on cut raw red meat in Lebanon. We determined total aerobic bacterial counts per gram of minced muscle specimen and aerobic bacterial counts per Replicate Organism Detection and Counting Plates (RODAC) plate surfaces (using in-house constructed plates) to characterize microbial species populations found in cattle and sheep carcasses immediately after halal slaughter, and on facility floors and walls within two main Lebanese slaughterhouses located in urban Beirut and rural Baalbek, the Bekaa valley, respectively. We also examined the histological appearance of raw meat muscle using snap frozen Optimal Cutting Temperature (OCT) media-embedded muscle specimens placed in liquid nitrogen cooled isopentane. The most frequently isolated bacterial species were Staphylococcus aureus and Yersinia pseudotuberculosis. Statistical examination of microbial number comparisons including both sheep and cattle microbial counts from initial individual visits made to both slaughterhouses were not significantly different using individual Student’s t Tests. However, Chi Square comparison of separate cattle and sheep muscle microbial counts obtained at initial visits to the Beirut and Baalbek slaughterhouses evaluated at initial culture testing were highly significantly different to the 90th percent probability level (χ2 = 3.4225, degrees of freedom = 1, alpha 0.10 = 2.706 ). This is the first published study of this type in Lebanon. Examining aerobic microbial species and processing procedures exhibited in the slaughterhouse environment provides a basis upon which to assess current food safety preventive practices. Developing a surveillance testing system for food animal health and zoonotic disease should facilitate and to consider future Hazard Analysis and Critical Control Point (HACCP) planning critical control point sites for intervention within the Lebanese setting.

Industrial Applications of SelectedJFSArticles

Industrial Applications of Selected<i>JFS</i>Articles

The antimicrobial effect of spice-based marinades against Campylobacter jejuni on contaminated fresh broiler wings.

The antimicrobial effect of spice-based marinades against Campylobacter jejuni on inoculated fresh broiler wings was investigated. Experiments were carried out with 1 strain of C. jejuni and 6 marinades. Four experimental marinades were composed for the study and contained spices (thyme, rosemary, basil, marjoram, and so on) and different combination of bioactive compounds. Two marinades were commercial and contained spices (black pepper, sweet red pepper, and so on) and chemical additives (monosodium glutamate, sodium diacetate, calcium lactate), 1 commercial marinade was also enriched with bioactive compounds (linalool, cinnamaldehyde, lactic acid). Total aerobic bacterial count was examined to estimate the possible effect of tested marinades on the shelf-life of marinated broiler wings. Study revealed that thyme-based marinade was the most effective against C. jejuni on broiler wings and reduced the numbers of campylobacters by 1.04 log colony forming unit (CFU)/g (P ≤ 0.05) during storage for 168 h at 4°C temperature. Moreover, it was more effective against C. jejuni than commercial marinade with 0.47 log CFU/g (P ≤ 0.05) reduction effect. Both experimental and commercial marinades had very similar effect on the total aerobic bacterial count. Although experimental and commercial marinades had different effect on pH of broiler wings, this parameter did not show a major impact on the antimicrobial effect of tested marinades (P ≥ 0.05). Our study shows that experimental natural thyme-based marinade can reduce numbers of C. jejuni more effectively than tested commercial marinades.

Antimicrobial Effect of Lime Juice Treatment on the Shelf-Life of Zobo Drink

Zobo drink is an indigenous non-alcoholic drink made from hot water roselle calyces of Hibiscus sabdariffa. The drink has gained wide acceptance, as it is consumed by several millions of people from different socio-economic classes and background in West African sub-region. The greatest limitation for large-scale production of zobo drinks is the rapid deterioration of the drink. Its shelf-life is approximately 24 hours after production, if not refrigerated. The effect of lime juice on the microorganisms associated with zobo drink was investigated. Zobo drink was prepared by maintaining the appropriate hygienic standards. Microbiological analysis was carried out on the prepared sample, before treatment with lime juice, to determine its effect on the microbial quality of the drink. The mean total coliform count from the prepared sample was 0.1 x 10 -4 cfu/mL, aerobic bacterial count was 0.2 x10 cfu/mL and the fungal count was 0.4 x 10 cfu/mL. Microorganisms isolated from the prepared sample include Staphylococcus spp, Lactobacillus spp, Bacillus spp and Penicillium spp. The antimicrobial effect of the lime juice on the different isolates showed significant zone of inhibition even at 6.25% concentration. The total coliform and aerobic bacterial count generally decreased in value and showed no growth at 50-100% concentrations of lime juice for 3 days and 75-100% concentrations for 5 days. The findings from this study showed that lime juice Original Research Article Ezeigbo et al.; BMRJ, 6(3): 147-153, 2015; Article no.BMRJ.2015.067 148 can be used as natural preservative to prolong the shelflife of zobo drink for a period 5 days under normal room temperature.

Effect of Brewery Effluent on the Microbiological Quality of Ikpoba River and Surrounding Borehole Waters in Benin City, Nigeria

Aim: The microbiological quality of Ikpoba River, Benin City-Nigeria and the surrounding borehole waters was investigated to assess the extent of pollution from Guinness Nigeria Plc, Benin City. Methodology: Microbiological parameters analyzed were total bacterial, fungal and coliform counts, and identification for indicator organisms. Results: For river water samples (RW1-RW4), mean total viable aerobic bacterial, fungal and coliform counts ranged from 0.06x10

Microbiological Safety Assessment of Selected Smoked Fish in Lagos Metropolis

This research assessed the microbiological quality of smoked fish consumed around the Lagos metropolis to ascertain the safety for consumption. Four samples of selected smoked fish obtained from five market locations in Lagos, Nigeria were analyzed to dete rmine their bacteria loads. The selected smoked fish samples examined were Herring - Clupea harengus (“ Sawa ”), Horse Mackerel - Trachurus trachurus (“ Kote” ), Great Barracuda - Sphyraena barracuda (“Panla”) and Atlantic Mackerel - Scomber scombrus (“Titus” ). The examined fish samples that were obtained were contaminated with some bacteria species. The average total aerobic bacterial counts from all the samples ranged from 4.2 x 10

Bacteriological Assessment of Hawked Sorrel Drink (Zobo Drink) in Aba, South-East Nigeria

Bacteriological investigation of hawked Sorrel drink (zobo drink) was carried out in Aba, South-east Nigeria, between January and March, 2014. Zobo drink is a non-alcoholic local beverage made from different varieties of dried petals, acid succulent aqueous extract of calyx of roselle, Hibiscus sabdariffa . It is consumed in Nigeria and other parts of the world. Samples of zobo drink were randomly purchased from the open markets, for a period of three months and analyzed for bacteriological qualities using standard methods. The result revealed a total aerobic bacterial count ranging from 0.3 × 10 6

Evaluation of microbiological and physicochemical profile of some herbal preparations manufactured by pharmaceutical and herbal manufacturers in Bangladesh

The aim of this study was to scrutinize the physicochemical and qualitative microbial examination of 30 different (of various dosage forms) herbal medicinal products marketed by pharmaceutical and herbal manufacturers in Bangladesh. The microbial evaluation included total viable aerobic bacteria, Escherichia coli, fungi and Staphylococcus aureus count; physicochemical properties like weight variation, hardness, disintegration time, friability and density. The IMViC (indole, methyl red, Voges–Proskauer and citrate utilization) tests were frequently employed for identification of E. coli and S. aureus. Total viable aerobic bacterial counts in the samples analyzed were ranged from 3.8 × 104 to 3.2 × 108 CFU/ml or CFU/g and 36.67 % were within BP standard limit. S. aureus was detected in 53.33 % (16) of the samples, ranged from an estimated 3 × 102 to 9.2 × 106 CFU/ml or CFU/g which were above the USP standard. E. coli was detected in 40 % (12) of the samples, ranging from 1 × 102 to 4.8 × 104 CFU/ml or CFU/g that were above the USP standard. The ranges of the fungi counts were 3.4 × 103–3.1 × 106 CFU/ml or CFU/g and 46.67 % of which were within BP standard. Physicochemical properties of herbal products manufactured by pharmaceutical manufacturers were found better than that of the herbal manufacturers. From the label and pack insert of herbal products, definite release pattern information weren’t obtained and the majority of herbal products showed scattered disintegration time. In order to reduce the potential health related complications, there is necessity of constant monitoring and control of the standards of herbal medicine products available in the Bangladeshi market.

BACTERIOLOGICAL ASSESSMENT OF SOME AUTOMATED TELLER MACHINE (ATM) KEYPADS IN ILORIN METROPOLIS

An investigation was conducted on the level of bacterial contaminants on the metallic keypads of automated teller machines (ATMs) in Ilorin metropolis.&nbsp; Total of 32 samples were collected in eight banks and sampling was done at two times of the day using standard microbiological methods.&nbsp; Results showed that total aerobic bacterial count on the ATM keypads ranged from 2.6 x101 cfu/m2 to 2.13 x 102 cfu/m2 in the morning, while it ranged from 2.9 x 101 cfu/m2 to 8.3 x 101 cfu/m2 in the afternoon. The results indicated the possibility of cross-contamination during usage of the machines with pathogens such as: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus aerogenes, Escherichia coli, Lactobacillus fermentii, Lactobacillis casei and Klebsiella pneumoniae. Proper cleaning regimen to sanitize these facilities regularly and public education on their hygienic usage are therefore recommended to reduce the associated risks.

Bacterial Counts and Oxidative Properties of Chicken Breast Inoculated with Salmonella Typhimurium Exposed to Gaseous Ozone

AbstractPoultry meats are highly perishable due to bacterial contamination; thus, elimination of bacterial contaminants is a challenge for food safety industry. This study was designed to evaluate the bacterial counts and oxidative properties of chicken breast contaminated with Salmonella Typhimurium (ST) exposed to gaseous ozone during refrigerated storage. Slices of chicken breast were inoculated with ST by immersing them in peptone water containing 1.0 × 107 cfu of ST per milliliter peptone water. Samples were placed in a container with normal air (no ozone) or in a container equipped with an ozone generator that produce a continuous flux of ozone (10 × 10−6 kg O3/m3/h) and negative ions. Gaseous ozone exposure significantly reduced ST and the total aerobic and anaerobic bacterial counts during storage compared with the nontreatment group (P &lt; 0.05). Gaseous ozone exposure significantly reduced CIE L* and increased CIE b* surface color values after 3 and 2 days of storage, respectively (P &lt; 0.05). Gaseous ozone exposure significantly inhibited catalase and glutathione peroxidase activity after 3 days (P &lt; 0.05). A higher TBARS (2‐thiobarbituric acid reactive substances) value (P &lt; 0.05) was found in chicken breast subjected to ozone exposure after 3 days of storage. In conclusion, gaseous ozone exposure reduced the bacterial counts in chicken breast from the beginning of the study and affected the oxidative properties on the last day of the study.Practical ApplicationsThis study shows that gaseous ozone exposure can be used as an antimicrobial agent for refrigerated meat. This information will be useful in the development of an effective ozone generator inside a refrigerator. Further studies regarding the appropriate ozone concentrations are needed.

Effect of packaging method and storage time on physicochemical characteristics of dry-cured pork neck products at 10°c.

Dry-cured pork neck samples were stored at 10°C for 90 days under vacuum packaging (VP) or modified atmosphere packaging (MAP; 25% CO2+75% N2) conditions. The pH, moisture, water activity, total aerobic bacteria, and Enterobacteriaceae counts of dry-cured pork neck products with MAP were significantly lower than those with VP (p<0.05) after 90 days of storage. However, CIE b* and 2-thiobarbituric acid reacted substance (TBARS) values of the pork product with MAP were significantly higher (p<0.05) than those with VP. Total aerobic bacterial counts and Enterobacteriaceae counts of samples with MAP were lower than those with VP after 30 days of storage. Sensory results indicated that aroma, flavor and tenderness scores of the samples with both VP and MAP decreased during storage and the scores after >60 days of storage were lower than those at Day 1. In conclusion, despite presenting higher lipid oxidation, the samples stored in packages containing 25% CO2 for 90 days at 10°C have lower bacterial counts than vacuum-packed samples. Therefore, further studies should be performed on the packaging of dry-cured meat at adjusted concentrations of CO2.

Peroxide Test Strips Detect Added Hydrogen Peroxide in Raw Milk at Levels Affecting Bacterial Load

Hydrogen peroxide (H2O2) has a long-established history of use as a preservative in milk worldwide. The use of H2O2 to activate the inherent lactoperoxidase enzyme system has dramatically improved the quality of raw dairy products in areas in which cooling is not widely available. In the United States, however, where refrigeration is widely available, the addition of H2O2 to milk is not permitted, with the exception of certain applications prior to cheesemaking and during the preparation of modified whey. Due to the relatively quick deterioration of H2O2 in fluid milk, the detection of raw milk adulterated with the compound can be challenging. In this study we evaluated (i) total aerobic bacterial counts and (ii) ability of peroxide test strips to detect H2O2 in raw milk with various concentrations (0, 100, 300, 500, 700, and 900 ppm) of added H2O2, incubated at both 6 and 21°C for 0, 24, and 48 h. Results showed that at both 6 and 21°C the H2O2 concentration and time had a significant effect on bacterial loads in raw milk. Additionally, commercially available test strips were able to detect H2O2 in raw milk, with predicted probability of >90%, immediately after addition and after 24 and 48 h for the higher concentrations used, offering a viable method for detecting raw milk adulteration with H2O2.

Microbial safety and quality attributes of milk following treatment with atmospheric pressure encapsulated dielectric barrier discharge plasma

Abstract This study evaluated the microbial and physicochemical characteristics of milk that was treated with encapsulated dielectric barrier discharge (DBD) plasma. Encapsulated DBD plasma was generated in a plastic container (250 W, 15 kHz, ambient air) and DBD plasma treatment was applied to milk samples for periods of 5 and 10 min. The total aerobic bacterial count in the untreated control sample was 0.98 log CFU/mL. Following plasma treatment, no viable cells were detected in the milk samples. When milk samples were inoculated with Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium, plasma treatment for 10 min resulted in a reduction in bacterial counts by approximately 2.40 log CFU/mL. The pH of the sample milk was found to decrease after the 10-min plasma treatment. Hunter color L* and b* values of milk increased, and the a* value decreased as a result of the plasma treatment. The production of 2-thiobarbituric acid reactive substances increased slightly, but not significantly, following plasma treatment. The results of this study indicate that encapsulated DBD plasma treatment for less than 10 min improved the microbial quality of milk with slight changes in physicochemical quality of milk.

Impact of High Hydrostatic Pressure Treatment on Microbial Communities in Chinese Water-Boiled Salted Duck

The objective of this study was to determine the impact of high hydrostatic pressure (HHP) treatment on microbial communities in Chinese water-boiled salted duck (CWBSD) and the synergistic effect of HHP and mild heat treatment. In this work, the bacterial diversity was evaluated by using both a culture-dependent method and denaturing gradient gel electrophoresis. The total aerobic bacterial counts in pressure-treated samples were significantly lower than those in controls, which indicated that HHP could extend the shelf life of CWBSD. Weissella hellenica and Enterobacteriaceae, the predominant bacteria found in CWBSD, were not detected after HHP treatment. On the other hand, Staphylococcus spp. and Bacillus spp. became the predominant bacteria in HHP-treated samples. Moreover, the inhibitory effect was greater at 400 MPa than at 200 MPa combined with mild heat at 40°C. This study investigated the diversity of bacteria in HHP-treated CWBSD, and the information derived from this research may help to understand the bacterial ecology and develop effective HHP treatments to extend the shelf life of CWBSD.