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.

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.

Microbiological Quality of Commercial Tofu

1984 ◽  
Vol 47 (3) ◽  
pp. 177-181 ◽  
Author(s):  
T. G. REHBERGER ◽  
L. A. WILSON ◽  
B. A. GLATZ
Keyword(s):  
Microbiological Quality ◽  
Plate Count ◽  
Microbial Counts ◽  
Colony Forming Units ◽  
Low Levels ◽  
Microbial Groups ◽  
Yeasts And Molds ◽  
Processing Techniques

A study was done to investigate the microbiological quality of commercial tofu available in local retail outlets. A sampling method was first developed to obtain accurate and representative microbial counts of individual pieces of tofu. Plate count determination of total aerobic organisms, psychrotrophs, coliforms, sporeformers, yeasts and molds, and staphylococci were made on 60 tofu samples (representing three lots each of four different brands) obtained within 24 h after delivery to the retail store. In addition, for two brands that provided manufacturer's pull dates, the same microbial counts were obtained for samples stored in the laboratory at 10°C until the pull date. Of the tofu sampled immediately after purchase, 83% of the lots tested had total counts greater than 106 colony-forming units (CFU)/g and psychrotrophic counts greater than 104 CFU/g. In addition, 67% of the lots tested had confirmed coliform counts greater than 103 CFU/g. Very low levels (less than 10 CFU/g) of all other microbial groups tested for were found in the majority of lots. Samples held until the manufacturer's pull date contained higher total and psychrotrophic counts but lower or stable counts of other organisms compared with samples tested immediately after purchase. To improve the microbiological quality of tofu, processors need to reduce initial loads by improving sanitation and processing techniques, and retailers should provide more consistent and colder refrigerated storage.

Study of the Microbial Ecology of Wild and Aquacultured Tunisian Fresh Fish

2011 ◽  
Vol 74 (10) ◽  
pp. 1762-1768 ◽  
Author(s):  
MOUNA BOULARES ◽  
LOBNA MEJRI ◽  
MNASSER HASSOUNA
Keyword(s):  
Aeromonas Hydrophila ◽  
Microbiological Quality ◽  
Common Species ◽  
Microbial Populations ◽  
Plate Count ◽  
Gram Negative Bacteria ◽  
Fresh Fish ◽  
Psychrotrophic Bacteria ◽  
Aerobic Plate Count

Eighty samples of fresh fish were collected in Tunisia and analyzed for microbial load. Quality and hygienic safety of the meat and intestines of wild and aquacultured fresh fish were determined. The mesophilic aerobic plate count and populations of psychrotrophic lactic acid bacteria (LAB) and other psychrotrophic bacteria ranged from 5.67 to 7.29, 4.51 to 6, and 5.07 to 6.21 log CFU/g, respectively. For all microbiological determinations, bacterial counts were lower in meat than in the intestines of fresh fish. For all samples lower microbial populations were found in most of the wild fish than in the aquacultured fish. No isolates of the pathogenic genera Salmonella and Listeria were detected in any sample. Among the 160 strains of biopreservative psychrotrophic LAB and the 150 strains of spoilage psychrotrophic gram-negative bacteria identified by biochemical and molecular methods, Lactobacillus (six species) and Pseudomonas (six species) predominated. Lactococcus, Leuconostoc, Carnobacterium (C. piscicola and C. divergens), Aeromonas, and Photobacterium were the most common genera, and Lactococcus lactis, Lactobacillus plantarum, Pseudomonas fluorescens, and Aeromonas hydrophila were the most common species. These findings indicate that the microbiological quality of fresh fish in Tunisia can be preserved by controlling pathogenic and psychrotrophic bacteria.

Microbial Quality of Hoummos (Chickpea Dip) Commercially Produced in Jordan

1994 ◽  
Vol 57 (5) ◽  
pp. 431-435 ◽  
Author(s):  
MOHAMMED I. YAMANI ◽  
BASIM A. AL-DABABSEH
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Low Ph ◽  
Plate Count ◽  
Microbial Quality ◽  
Aerobic Plate Count ◽  
And Staphylococcus Aureus ◽  
Reference Samples ◽  
Hygienic Conditions

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 < 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 < 103/g, while the coliform and yeast counts were < 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 < 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.

Survey of the Bacterial Populations of Bologna Products1,2

1978 ◽  
Vol 41 (9) ◽  
pp. 692-695 ◽  
Author(s):  
JOHN T. FRUIN ◽  
JAMES F. FOSTER ◽  
JAMES L. FOWLER
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Foodborne Pathogens ◽  
High Volume ◽  
Plate Count ◽  
Retail Market ◽  
Bacterial Populations ◽  
Retail Markets ◽  
Aerobic Plate Count

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 < 5 × 106/g is a realistic criterion for bologna products at the time of delivery to retail markets.

scholarly journals Changes of Quality of Minimally-Processed Pineapple (Ananas comosus, var. ‘Queen Victoria’) during Cold Storage: Fungi in the Leading Role

2020 ◽  
Vol 8 (2) ◽  
pp. 185 ◽  
Author(s):  
Charlène Leneveu-Jenvrin ◽  
Baptiste Quentin ◽  
Sophie Assemat ◽  
Mathilde Hoarau ◽  
Jean-Christophe Meile ◽  
...  
Keyword(s):  
Cold Storage ◽  
Microbiological Quality ◽  
Fungal Species ◽  
Ananas Comosus ◽  
Minimally Processed ◽  
Leading Role ◽  
Queen Victoria ◽  
Processing Step ◽  
Yeasts And Molds

Minimally-processed pineapple stored under refrigerated conditions is highly perishable. We aimed to characterize the evolution of physicochemical, sensory and microbiological quality during cold storage. Pineapple batches were sampled from several locations in Reunion Island and then minimally processed. In the processing step, the variability of firmness and counts of yeasts and molds were observed. Moreover, correlations between the sampling season and pH and b* color component, as well as between fungal population and b* parameter were observed. During storage, the visual aspect of pineapple cuts changed to brown and shiny, whereas olfactive descriptors shifted from fruity descriptors and fresh to fermented, alcoholic and milky. The values for pH, TA and TSS did not significantly vary according to storage time. A decrease in firmness and C* color parameter was observed. Yeast and mold counts were significantly higher after 7 days of storage. The diversity in yeasts and molds was mainly dependent on the considered batches observed from PCR-DGGE profiles. Fungal species were isolated from spoiled pineapple cuts. The implication of Penicilllium citrtrinum, Talaromyces amestolkiae, Rhodotorula mucilaginosa, Saccharomyces cerevisiae, and Meyerozyma caribbica in the spoilage of minimally-processed pineapple cuts was further demonstrated.

Relationships of Microbial Quality of Retail Meat Samples and Sanitary Conditions1

1980 ◽  
Vol 43 (5) ◽  
pp. 385-389 ◽  
Author(s):  
C. JANE WYATT ◽  
V. GUY
Keyword(s):  
Bacterial Load ◽  
Microbiological Quality ◽  
Plate Count ◽  
Microbiological Analysis ◽  
Food Stores ◽  
Aerobic Plate Count ◽  
Quality Of Products ◽  
Meat Samples ◽  
Sanitary Conditions

A sanitation profile scoring form for evaluating sanitation in retail food stores was designed. The profile was tested in 10 Oregon retail markets to evaluate its ability to reflect sanitary conditions. At the time of inspection, samples of meat processed in-store were purchased for microbiological analysis to explore the feasibility of bacterial quality as a measurement of sanitary conditions. Microbiological tests performed included total aerobic plate count (A PC), coliform, Escherichia coli, Staphylococcus aureus, Clostridium perfringens, and Salmonella. Certain deficiencies were noted in the profile designed; however, it provides a means for objective, uniform measurement of sanitary conditions. Data show no correlation exists between microbiological quality of products processed in the store and total store profile sanitary conditions. Fifty percent of the products sampled exceeded bacterial load guidelines currently enforced in Oregon. These “high” counts appear to be directly related to poor temperature control.

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.

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