scholarly journals Indicator Organisms for Safety and Quality—Uses and Methods for Detection: Minireview

2003 ◽  
Vol 86 (6) ◽  
pp. 1208-1217 ◽  
Author(s):  
Mary L Tortorello
Keyword(s):  
Quality Indicators ◽  
Plate Count ◽  
Regulatory Agencies ◽  
Consumer Acceptability ◽  
Indicator Organisms ◽  
Increased Risk ◽  
Microbiological Testing ◽  
Risk Of Exposure ◽  
Aerobic Plate Count ◽  
Yeasts And Molds

Abstract Indicator organisms have been used for nearly a century to assess the microbiological status of water and foods. Beginning with their use in water sanitation programs, their applications have been extended over the years to other products, and they have become important components of the microbiological testing programs of both industry and regulatory agencies. Functionally, they may be viewed as safety or quality indicators. Safety indicators suggest the presence of conditions associated with increased risk of exposure to a pathogen. Quality indicators assess conditions of importance to product manufacture or consumer acceptability. This minireview summarizes the history, use, and analytical methods for the most commonly used indicator organisms, including the aerobic plate count, yeasts and molds, the coliform groups, Escherichia coli, Enterobacteriaceae, and Listeria.

Microbial Survey of Pennsylvania Surface Water Used for Irrigating Produce Crops

2016 ◽  
Vol 79 (6) ◽  
pp. 902-912 ◽  
Author(s):  
AUDREY D. DRAPER ◽  
STEPHANIE DOORES ◽  
HASSAN GOURAMA ◽  
LUKE F. LaBORDE
Keyword(s):  
Surface Water ◽  
Physicochemical Characteristics ◽  
Fecal Coliforms ◽  
Plate Count ◽  
Human Pathogens ◽  
Indicator Organisms ◽  
Environmental Characteristics ◽  
E Coli ◽  
Contaminated Irrigation Water ◽  
Aerobic Plate Count

ABSTRACT Recent produce-associated foodborne illness outbreaks have been attributed to contaminated irrigation water. This study examined microbial levels in Pennsylvania surface waters used for irrigation, relationships between microbial indicator organisms and water physicochemical characteristics, and the potential use of indicators for predicting the presence of human pathogens. A total of 153 samples taken from surface water sources used for irrigation in southeastern Pennsylvania were collected from 39 farms over a 2-year period. Samples were analyzed for six microbial indicator organisms (aerobic plate count, Enterobacteriaceae, coliform, fecal coliforms, Escherichia coli, and enterococci), two human pathogens (Salmonella and E. coli O157), and seven physical and environmental characteristics (pH, conductivity, turbidity, air and water temperature, and sampling day and 3-day-accumulated precipitation levels). Indicator populations were highly variable and not predicted by water and environmental characteristics. Only five samples were confirmed positive for Salmonella, and no E. coli O157 was detected in any samples. Predictive relationships between microbial indicators and the occurrence of pathogens could therefore not be determined.

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.

Microbial, Physical, and Chemical Quality of Packaged Ice in Florida†

1999 ◽  
Vol 62 (5) ◽  
pp. 526-531 ◽  
Author(s):  
RONALD H. SCHMIDT ◽  
GARY E. RODRICK
Keyword(s):  
Particulate Matter ◽  
Environmental Protection Agency ◽  
Water Hardness ◽  
The State ◽  
Plate Count ◽  
Label Information ◽  
Physical And Chemical Quality ◽  
Aerobic Plate Count ◽  
Yeasts And Molds ◽  
Physical And Chemical

In a statewide survey, ice samples purchased at retail were evaluated for labeling information and microbiological, chemical, and physical quality. Only 11% of bags from on-premises manual facilities, compared to 79% for off-premises mechanical facilities, had appropriate label information. One ice sample exceeded the state regulatory limit for aerobic plate count (APC) (<500 CFU/ml). Yeasts and molds were detected in 12% of the samples. No Listeria monocytogenes were found in any of the samples. Coliform counts exceeding the state regulatory limit (<1/100 ml) were observed in 13.5% of manual, on-premises facilities compared to 3.6% of samples from mechanical, off-premises facilities. No significant differences were detected between samples from on- and off-premises facilities with regard to chemical composition (e.g., aluminum, ammonium, boron, barium, calcium, cadmium, chloride, copper, iron, lead, magnesium, manganese, nickel, nitrate, phosphorus, potassium, sodium, silicon, and zinc), electrical conductivity, or pH. All samples analyzed were in compliance with appropriate Environmental Protection Agency drinking water standards. In general, all ice samples were acceptable in terms of water hardness values. Approximately 33% of samples from off-premises facilities and 62% of the on-premises samples had detectable particulate matter. None of the off-premises samples, compared to 8% of the on-premises samples, had particulate matter in the “pronounced” category.

scholarly journals Optimization of Extrusion Conditions for Production of Instant Millet-Soybean Blended Flour

2020 ◽  
Vol 9 (1) ◽  
pp. 42
Author(s):  
Natukunda Sheila ◽  
Kamoga Kenneth Ryan ◽  
Kizza Mawanda David ◽  
Faith M. Namayengo ◽  
Muyonga John Herbert
Keyword(s):  
Response Surface ◽  
Water Solubility ◽  
Correlation Coefficients ◽  
Nutritional Composition ◽  
Quadratic Model ◽  
Plate Count ◽  
Consumer Acceptability ◽  
Soybean Flour ◽  
Feed Moisture ◽  
Yeasts And Molds

This study developed an optimized protocol for production of instant millet-soybean flour with high solubility. Response surface methodology was used to determine optimal processing conditions for desired water absorption index (WAI) and water solubility index (WSI). Three levels of extrusion temperature (130, 150 and 180 °C) and feed moisture (15, 20 and 25%) were used. Nutritional composition, consumer acceptability and shelf stability of millet-soybean blend produced using optimal extrusion conditions were determined. Analysis of variance showed that the contribution of a quadratic model was significant for WAI and WSI, with high correlation coefficients (R2 = 0.80 and 0.75, respectively). Response surface plots showed that increase in temperature significantly increased both WAI and WSI, while increase in feed moisture significantly increased WAI and decreased WSI. The optimal extrusion conditions were found to be: barrel temperature 159 °C and feed moisture of 25% with product predicted WAI of 2.124 g H2O/g and WSI of 51.30%. Experimental values for responses of products made using optimized conditions were in agreement with the predicted values. Gruels made using the extruded millet-soybean flour were acceptable but with lower consumer acceptability (p < 0.05) scores than the commercially available and extruded millet only flour. Yeasts and molds as well as coliforms were not detected. Total plate count results ranged from 1.35 to 2.9 log cfu/g within one month of storage. This study provides information on the conditions that are suitable for processing an acceptable highly soluble instant millet-soybean flour.

scholarly journals The Effect of Dietary Dry Distilled Rose Petals or Dihydroquercetin Supplementation on the Oxidative Stability and Quality of Lamb Muscles and Fat

2021 ◽  
Vol 11 (4) ◽  
pp. 4280-4293
Keyword(s):  
Oxidative Stability ◽  
Color Difference ◽  
Plate Count ◽  
Longissimus Dorsi ◽  
Control Group ◽  
Rose Petals ◽  
Aerobic Plate Count ◽  
Yeasts And Molds ◽  
Higher Doses

The study's objective was to determine the changes in oxidative stability of m. Longissimus dorsi, m. Semimembranosus and perirenal adipose tissue from lambs fed a diet supplemented by 7.5 mg dihydroquercetin/kg life wight/d or 545 mg dry distilled rose petals (DDRP)/kg life wight/d.The experiments were performed with 30 male lambs aged 65 days. They were divided into three groups of 10 animals fed 50 days ad libitum: the control group (with ground alfalfa + granulated compound feed) and two experimental ones (with the same diet + phytonutrients). Samples stored 7 days at 0-4°C were examined. After 7 d of storage in both muscles, the addition of 545 mg DDRP/kg life wight/d contributed to the reduction of α-aminoacidic nitrogen with approximately 0.5 mg Leu/g and the FFA with 0.5-2%. The addition of 7.5 mg dihydroquercetin contributed to the reduction of TBARS with 0.14-0.21 mg MDA/kg, the total color difference, and a slight increase in the share of the MUFA more pronounced in m. Longissimus dorsi. The reduction of aerobic plate count and total yeasts and molds count were determined too. Further studies with higher doses of phytonutrient’s supplementation are needed to determine if it will provoke a more pronounced oxidative stability.

The effect of dietary dry distilled rose petals or dihydroquercetin supplementation on the oxidative stability and quality of lamb muscles and fat.

2021 ◽  
Author(s):  
Desislava B. Vlahova-Vangelova ◽  
Desislav K. Balev ◽  
Nikolay D. Kolev ◽  
Margarita N. Terziyska ◽  
Stefan G. Dragoev
Keyword(s):  
Color Difference ◽  
Monounsaturated Fatty Acids ◽  
Inhibitory Effect ◽  
Plate Count ◽  
Longissimus Dorsi ◽  
Control Group ◽  
Rose Petals ◽  
Aerobic Plate Count ◽  
Yeasts And Molds

Abstract The objective of this study was to determine the changes in the quality of m. Longissimus dorsi and m. Semimembranosus and perirenal adipose tissue from lambs fed a diet supplemented by 7.5 mg dihydroquercetin/kg/day or 545 mg dry distilled rose petals (DDRP)/kg/d. The experiments were performed with 30 male lambs aged 65 days. They were divided into three groups of 10 animals fed 50 days ad libitum: control group (with ground alfalfa + granulated compound feed) and two experimental ones (with the same diet + phytonutrients). Samples stored for 1 and 7 days at 2 ± 2°C were examined. After 7 d of storage, the addition of 545 mg DDRP/kg/d contributed to a decrease in pH by 2-6% in both types of tissues and reduced the accumulation of α-aminoacidic nitrogen by 7-14% and TBARS by more than 20% in both muscles tested. The lambs' diet supplementation with both phytonutrients led to a reduction in the aerobic plate count and total combined yeasts and molds count. The addition of dihydroquercetin was found to be responsible for the reduction of FFA and the total color difference as well as for approx. a 5% increasing the amount of monounsaturated fatty acids. This influence is more pronounced in m. Longissimus dorsi. Further studies are needed to determine whether the application of higher doses of DDRP and dihydroquercetin as dietary supplements in lambs will provoke a more pronounced inhibitory effect on lipid oxidation and the fatty acid composition of lamb and fats.

scholarly journals Effect of Gamma Irradiation on Microbial Quality of Minimally Processed Product in Tunisia: A Case of Ready to Eat Salad

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Rahmani F ◽  
◽  
Yahya M ◽  
Jebri S ◽  
Amri I ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Plate Count ◽  
Irradiation Effect ◽  
Minimally Processed ◽  
Potential Health ◽  
Peeling Process ◽  
Aerobic Plate Count ◽  
Yeasts And Molds ◽  
Staphylococcus Spp

The use of gamma irradiation in food safety management as a tool to improve the microbiological quality of food products. Minimally processed product may contain a large number of spoilage microorganisms that constitute a potential health risk. In this study, raw carrot samples and fresh-cut products after each processing steps: water chlorination, peeling process and citric acid treatment were analyzed for the total aerobic plate count, Staphylococcus spp., yeasts and molds. Ready to eat products were also analyzed for these selective pathogens. The freshly packaged carrot salads were irradiated at various doses (0.5, 1.0, 2.0 kGy) and analyzed during 15 days storage period. The obtained results showed that raw carrots were highly contaminated by total aerobic plate count (7.23 Log10/25g), Staphylococcus spp. (3.77 Log10/25g), yeasts (5.62 Log10/25g) and molds (5.54 Log10/25g). Washing treatment and peeling process, were able to reduce the concentration of total aerobic plate count by 2.23 Log10 and to remove Staphylococcus spp. and molds. The mean concentrations of total aerobic plate count, Staphylococcus spp. yeasts and molds were 4.87, 2.08, 7.47 and 2 Log10/25g respectively for packaged salads. These results suggest that the contamination of carrot salads might occur through chain transformation. Regarding gamma irradiation effect, an optimal dose of 2kGy offered a pathogen-free, hygienic product in comparison with controls. Furthermore it increased shelf-life by 4 to 9 days at refrigeration temperature. The validity of the processing treatment at 2kGy was challenged by artificially inoculating Staphylococcus aureus in the product.

A Field Study of the Microbiological Quality of Fresh Produce†‡

2005 ◽  
Vol 68 (9) ◽  
pp. 1840-1847 ◽  
Author(s):  
LYNETTE M. JOHNSTON ◽  
LEE-ANN JAYKUS ◽  
DEBORAH MOLL ◽  
MARTHA C. MARTINEZ ◽  
JUAN ANCISO ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
Geometric Mean ◽  
Microbiological Quality ◽  
Disease Outbreaks ◽  
Plate Count ◽  
Indicator Organisms ◽  
E Coli ◽  
Leafy Greens ◽  
Microbiological Methods ◽  
Aerobic Plate Count

The Centers for Disease Control and Prevention has reported that foodborne disease outbreaks associated with fruits and vegetables increased during the past decade. This study was conducted to characterize the routes of microbial contamination in produce and to identify areas of potential contamination from production through postharvest handling. We report here the levels of bacterial indicator organisms and the prevalence of selected pathogens in produce samples collected from the southern United States. A total of 398 produce samples (leafy greens, herbs, and cantaloupe) were collected through production and the packing shed and assayed by enumerative tests for total aerobic bacteria, total coliforms, total Enterococcus, and Escherichia coli. These samples also were analyzed for Salmonella, Listeria monocytogenes, and E. coli O157:H7. Microbiological methods were based on methods recommended by the U.S. Food and Drug Administration. For all leafy greens and herbs, geometric mean indicator levels ranged from 4.5 to 6.2 log CFU/g (aerobic plate count); less than 1 to 4.3 log CFU/g (coliforms and Enterococcus); and less than 1 to 1.5 log CFU/g (E. coli). In many cases, indicator levels remained relatively constant throughout the packing shed, particularly for mustard greens. However, for cilantro and parsley, total coliform levels increased during the packing process. For cantaloupe, microbial levels significantly increased from field through packing, with ranges of 6.4 to 7.0 log CFU/g (aerobic plate count); 2.1 to 4.3 log CFU/g (coliforms); 3.5 to 5.2 log CFU/g (Enterococcus); and less than 1 to 2.5 log CFU/g (E. coli). The prevalence of pathogens for all samples was 0, 0, and 0.7% (3 of 398) for L. monocytogenes, E. coli O157:H7, and Salmonella, respectively. This study demonstrates that each step from production to consumption may affect the microbial load of produce and reinforces government recommendations for ensuring a high-quality product.

Microbial Stability and Fate of Salmonella Enteritidis in Halva, a Low-Moisture Confection

1998 ◽  
Vol 61 (2) ◽  
pp. 181-185 ◽  
Author(s):  
P. KOTZEKIDOU
Keyword(s):  
Staphylococcus Aureus ◽  
Salmonella Enteritidis ◽  
Room Temperature ◽  
Plate Count ◽  
Prolonged Storage ◽  
Salmonella Spp ◽  
Microbial Stability ◽  
Aerobic Plate Count ◽  
Yeasts And Molds ◽  
Lipolytic Microorganisms

A traditional low-moisture confectionery, halva, was studied with respect to microbial stability over prolonged storage. It was kept under refrigeration or at room temperature in air-sealed or vacuum packaging in moisture-proof material. Microbial stability of commercial samples was evaluated with regard to the following groups of microorganisms: aerobic plate count, Enterobacteriaceae, enterococci, sulfite-reducing clostridia, aerobic mesophilic and thermophilic sporeformers, staphylococci, Staphylococcus aureus, Salmonella spp., lipolytic microorganisms, yeasts and molds. In all samples tested the above microorganisms were in acceptable levels, while sulfite-reducing clostridia, Salmonella spp., and molds were not detected. The potential for survival of Salmonella Enteritidis in the product was evaluated by artificial contamination. Inoculum surviving after the immediate significant decrease was still recovered after 8 months of storage. The reduction of salmonellae during storage cannot be predicted on the basis of the aw alone.

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