scholarly journals Expiration Date of Ready-to-Eat Salads: Effects on Microbial Load and Biochemical Attributes

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 941
Author(s):  
Panayiota Xylia ◽  
George Botsaris ◽  
Panagiotis Skandamis ◽  
Nikolaos Tzortzakis
Keyword(s):  
Shelf Life ◽  
Foodborne Pathogens ◽  
Carbon Dioxide Production ◽  
Microbial Load ◽  
Expiration Date ◽  
Postharvest Management ◽  
Minimally Processed Vegetables ◽  
Yeasts And Molds ◽  
Staphylococcus Spp ◽  
Spoilage Microorganisms

When minimally processed vegetables reach their expiration date, expose an increased microbial load. This includes mainly spoilage microorganisms but also foodborne pathogens, thus affecting the quality and safety of highly consumed ready-to-eat salads. A total of 144 ready-to-eat salads from the Cypriot market were analyzed in an attempt to determine the effects of the expiration date on the microbial load and plant metabolic variables of the salads. Possible correlations between them were also investigated for the first time. Furthermore, the impacts of the season (winter, summer), salad producing companies and type of salad and/or their interactions with the tested parameters were investigated. Results revealed that the microbial load (mainly spoilage microorganisms, such as Pseudomonas spp., yeasts and molds) increased towards the end of the shelf life. The microbial load was differentiated among the five salad producers and/or the salad types, highlighting the importance of a common and safe sanitation-processing chain in the preparation of ready-to-eat salads. Summer was the season in which Escherichia coli counts were found to be higher for plain lettuce, while Staphylococcus spp. was increased numbers for the lettuce+endive/radicchio, lettuce+rocket and lettuce+chives type of salads. Additionally, an increased Staphylococcus spp. was observed for plain rocket salads in winter. All samples examined were found negative for Salmonella enterica and Listeria monocytogenes. Moreover, carbon dioxide production and damage indexes (hydrogen peroxide and lipid peroxidation) increased on expiration date on both winter and summer seasons, indicating plant tissue stress at the end of shelf life. These findings indicate that the expiration date and relevant shelf life of processed vegetables are important parameters to be considered when postharvest management is applied to these products, ensuring safety and quality.

scholarly journals Changes of microbial load in packet orange juice after expiration date

2019 ◽  
Vol 8 (1) ◽  
pp. 27-29
Author(s):  
Farahnaaz Feroz
Keyword(s):  
Orange Juice ◽  
Fruit Juice ◽  
Market Potential ◽  
Microbial Load ◽  
Food Handler ◽  
Steady Increase ◽  
Expiration Date ◽  
Product Packaging ◽  
Viable Bacteria ◽  
Staphylococcus Spp

Fruit juice is popular product in the markets worldwide, with a market potential of approximately 230 million liters. Fruit juice although nutritious and beneficial for health can also serve as a vehicle for foodborne diseases. Most commercially available products are labelled with a use by date. These are applicable at a consumer and food handler levels, instructing them on the amount of days after opening within which a product must be consumed. It is important to identify the changes that occur after expiration date to have a better understanding of when food spoilage occurs and how long foods may be preserved, in order to reduce food wastage. The current study attempted to identify the changes that occur in orange juice after the expiration date printed on the product packaging. One to seven days after expiration results showed very little change. Increase in the microbial load was observed after day 14, after which a steady increase was observed in total viable bacteria, fungus, E. coli, and Staphylococcus spp. No changes were observed in other examined organisms. Stamford Journal of Microbiology, Vol.8(1) 2018: 27-29

Efficacy of Commercial Natural Antimicrobials Alone and in Combinations against Pathogenic and Spoilage Microorganisms

2014 ◽  
Vol 77 (2) ◽  
pp. 269-275 ◽  
Author(s):  
CHAYAPA TECHATHUVANAN ◽  
FATIMA REYES ◽  
JAIRUS R. D. DAVID ◽  
P. MICHAEL DAVIDSON
Keyword(s):  
Shelf Life ◽  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Microbial Control ◽  
Antagonistic Effect ◽  
Synergistic Activity ◽  
Natural Antimicrobials ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Spoilage Microorganisms

Microbial control strategies are needed in the food industry to prevent foodborne illnesses and outbreaks and prolong product shelf life. The aim of this study was to investigate and compare the efficacy of the commercial natural antimicrobials white mustard essential oil (WMEO), citrus flavonoid and acid blend (CFAB), olive extract (OE), Nisaplin (a compound containing nisin), and lauric arginate (LAE) alone and in combinations against foodborne pathogens and spoilage microorganisms. MICs of individual and combined antimicrobials against Escherichia coli, Salmonella Enteritidis, Enterobacter aerogenes, Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus were determined at pH 6.0 and 25°C. WMEO was most effective against B. cereus and S. aureus, with MICs of 250 and 500 mg/liter, respectively. CFAB inhibited all tested microorganisms, requiring only 12 to 35 mg/liter for gram-positive bacteria. For OE, 2,000 mg/liter was needed to achieve microbial inhibition. Nisaplin at 400 to 1,200 mg/liter inhibited only gram-positive bacteria. LAE was effective at low concentrations and required only 20 to 50 mg/liter to inhibit all tested microorganisms. When WMEO was combined with other antimicrobials, the effects were usually additive except for WMEO plus Nisaplin and WMEO+OE, which had synergistic activity against L. monocytogenes and Salmonella Enteritidis, respectively. An antagonistic effect was observed for WMEO+CFAB against E. aerogenes. For WMEO+LAE+CFAB, additive antimicrobial effects were noted against all strains tested except S. aureus, where a synergistic effect occurred. These findings suggest that these commercial natural antimicrobials have potential to enhance food safety by inhibiting foodborne pathogens and extending product shelf life.

scholarly journals Antimicrobial Activity of Fermented Vegetable Byproduct Extracts for Food Applications

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1092
Author(s):  
Annalisa Ricci ◽  
Gaia Bertani ◽  
Antonietta Maoloni ◽  
Valentina Bernini ◽  
Alessia Levante ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Shelf Life ◽  
Foodborne Pathogens ◽  
Antimicrobial Agents ◽  
Foodborne Diseases ◽  
Salmonella Spp ◽  
Food Applications ◽  
Natural Preservatives ◽  
Spoilage Microorganisms

To prevent foodborne diseases and extend shelf-life, antimicrobial agents may be used in food to inhibit the growth of undesired microorganisms. In addition to the prevention of foodborne diseases, another huge concern of our time is the recovery of agri-food byproducts. In compliance with these challenges, the aim of this work was to more deeply investigate the antimicrobial activity of extracts derived from fermented tomato, melon, and carrot byproducts, previously studied. All the fermented extracts had antimicrobial activity both in vitro and in foodstuff, showing even higher activity than commercial preservatives, tested for comparison against spoilage microorganisms and foodborne pathogens such as Salmonella spp., L. monocytogenes, and B. cereus. These promising results highlight an unstudied aspect for the production of innovative natural preservatives, exploitable to improve the safety and shelf-life of various categories of foodstuff.

Evaluation of Gaseous Chlorine Dioxide as a Sanitizer for Killing Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Yeasts and Molds on Fresh and Fresh-Cut Produce

2005 ◽  
Vol 68 (6) ◽  
pp. 1176-1187 ◽  
Author(s):  
KAYE V. SY ◽  
MELINDA B. MURRAY ◽  
M. DAVID HARRISON ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Chlorine Dioxide ◽  
Foodborne Pathogens ◽  
Escherichia Coli O157 ◽  
Gaseous Chlorine Dioxide ◽  
Sensory Qualities ◽  
A Cell ◽  
Fresh Cut ◽  
Yeasts And Molds

Gaseous chlorine dioxide (ClO2) was evaluated for effectiveness in killing Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes on fresh-cut lettuce, cabbage, and carrot and Salmonella, yeasts, and molds on apples, peaches, tomatoes, and onions. Inoculum (100 μl, ca. 6.8 log CFU) containing five serotypes of Salmonella enterica, five strains of E. coli O157:H7, or five strains of L. monocytogenes was deposited on the skin and cut surfaces of fresh-cut vegetables, dried for 30 min at 22°C, held for 20 h at 4°C, and then incubated for 30 min at 22°C before treatment. The skin surfaces of apples, peaches, tomatoes, and onions were inoculated with 100 μl of a cell suspension (ca. 8.0 log CFU) containing five serotypes of Salmonella, and inoculated produce was allowed to dry for 20 to 22 h at 22°C before treatment. Treatment with ClO2 at 4.1 mg/liter significantly (α = 0.05) reduced the population of foodborne pathogens on all produce. Reductions resulting from this treatment were 3.13 to 4.42 log CFU/g for fresh-cut cabbage, 5.15 to 5.88 log CFU/g for fresh-cut carrots, 1.53 to 1.58 log CFU/g for fresh-cut lettuce, 4.21 log CFU per apple, 4.33 log CFU per tomato, 1.94 log CFU per onion, and 3.23 log CFU per peach. The highest reductions in yeast and mold populations resulting from the same treatment were 1.68 log CFU per apple and 2.65 log CFU per peach. Populations of yeasts and molds on tomatoes and onions were not significantly reduced by treatment with 4.1 mg/liter ClO2. Substantial reductions in populations of pathogens on apples, tomatoes, and onions but not peaches or fresh-cut cabbage, carrot, and lettuce were achieved by treatment with gaseous ClO2 without markedly adverse effects on sensory qualities.

scholarly journals Effects of Malting and Fermentation on Anti-Nutrient Reduction and Protein Digestibility of Red Sorghum, White Sorghum and Pearl Millet

2013 ◽  
Vol 2 (1) ◽  
pp. 41 ◽  
Author(s):  
C. A. Onyango ◽  
S. O. Ochanda ◽  
M. A. Mwasaru ◽  
J. K. Ochieng ◽  
F. M. Mathooko ◽  
...  
Keyword(s):  
Shelf Life ◽  
Nutritive Value ◽  
Protein Digestibility ◽  
Nutrient Reduction ◽  
Organoleptic Properties ◽  
Optimum Time ◽  
Mineral Absorption ◽  
Ph Values ◽  
Fermentation Period ◽  
Spoilage Microorganisms

<p>Sorghum and millet and their products require specialized treatment in order to improve their nutritive value, organoleptic properties and shelf-life. They contain anti-nutrients which are the major phytochemicals which negatively affects their nutritive values. The phytochemicals of concern include tannins and phytates, which interfere with mineral absorption, palatability and protein digestibility. Malting and fermentation treatments were applied to reduce the anti-nutrients, improve protein digestibility, and acidity to increase the products shelf life. The effects of malting and fermentation on the cereals nutritive value and anti-nutrient reduction were studied and evaluated for a period of 8 days. A treatment combining malting for 3 days and fermentation for 2 days respectively both at room temperatures (25°C) was employed. Tannins and phytates were significantly reduced (p ? 0.05) by malting and fermentation. Protein digestibility was significantly (p ? 0.05) improved by malting and fermentation treatments; malted cereals digestibility ranged between 34.5-68.1% while the fermented flours protein digestibility range was 97.4-98.3%. The pH values were lowered to below 4.0, a level at which they could effectively inhibit spoilage microorganisms at the end of the fermentation period. A combination of optimum time treatments of malting and fermentation for 3 days and 2 days respectively were effective in reducing tannins and phytates and improving protein digestibility of the cereals.</p>

Microbiological and Sensory Quality of Fresh Ready-to-Eat Artichoke Hearts Packaged under Modified Atmosphere

2017 ◽  
Vol 80 (5) ◽  
pp. 740-749 ◽  
Author(s):  
Nuria García-Martínez ◽  
Pedro Andreo-Martínez ◽  
Luis Almela ◽  
Lucía Guardiola ◽  
José A. Gabaldón
Keyword(s):  
Shelf Life ◽  
Storage Temperature ◽  
Modified Atmosphere Packaging ◽  
Threshold Value ◽  
Plate Count ◽  
Vacuum Impregnation ◽  
Modified Atmosphere ◽  
Minimally Processed ◽  
Sensory Qualities ◽  
Minimally Processed Vegetables

ABSTRACT In recent years the sales of minimally processed vegetables have grown exponentially as a result of changes in consumer habits. The availability of artichoke buds as a ready-to-eat product would be, therefore, highly advantageous. However, minimally processed artichoke hearts are difficult to preserve because of their rapid browning and the proliferation of naturally occurring microorganisms. We developed artichoke hearts prepared as ready-to-eat products that maintain the characteristics of the fresh product. The microbiological stability, sensory qualities, and shelf life of the processed artichoke hearts were determined. During the shelf life, Salmonella, Listeria monocytogenes, and Escherichia coli counts were below the limits legally established by European regulations for minimally processed vegetables. The pH played an important role in microbial growth. Artichoke hearts had lower microbial counts in experiments conducted at pH 4.1 than in experiments conducted at pH 4.4, although the recommended threshold value for total plate count (7 log CFU/g) was not exceeded in either case. Sensory parameters were affected by the microorganisms, and artichoke products at lower pH had better sensory qualities. Vacuum impregnation techniques, modified atmosphere packaging, and low storage temperature were very effective for increasing the shelf life of minimally processed artichokes. The average shelf life was approximately 12 to 15 days.

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