scholarly journals A Fast, Reliable, and Sensitive Method for Detection and Quantification ofListeria monocytogenesandEscherichia coliO157:H7 in Ready-to-Eat Fresh-Cut Products by MPN-qPCR

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Pasquale Russo ◽  
Giuseppe Botticella ◽  
Vittorio Capozzi ◽  
Salvatore Massa ◽  
Giuseppe Spano ◽  
...  
Keyword(s):  
Shelf Life ◽  
Pathogenic Bacteria ◽  
Limit Of Detection ◽  
Raw Materials ◽  
Minimally Processed ◽  
E Coli ◽  
Biochemical Assays ◽  
Fresh Cut ◽  
Minimally Processed Vegetables ◽  
Detection And Quantification

In the present work we developed a MPN quantitative real-time PCR (MPN-qPCR) method for a fast and reliable detection and quantification ofListeria monocytogenesandEscherichia coliO157:H7 in minimally processed vegetables. In order to validate the proposed technique, the results were compared with conventional MPN followed by phenotypic and biochemical assays methods. WhenL. monocytogenesandE. coliO157:H7 were artificially inoculated in fresh-cut vegetables, a concentration as low as 1 CFU g−1could be detected in 48 hours for both pathogens. qPCR alone allowed a limit of detection of 101 CFU g−1after 2 hours of enrichment forL. monocytogenesandE. coliO157:H7. Since minimally processed ready-to-eat vegetables are characterized by very short shelf life, our method can potentially address the consistent reduction of time for microbial analysis, allowing a better management of quality control. Moreover, the occurrences of both pathogenic bacteria in mixed salad samples and fresh-cut melons were monitored in two production plants from the receipt of the raw materials to the early stages of shelf life. No sample was found to be contaminated byL. monocytogenes. One sample of raw mixed salad was found positive to an H7 enterohemorrhagic serotype.

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.

A novel approach for calculating shelf life of minimally processed vegetables

2006 ◽  
Vol 106 (1) ◽  
pp. 69-73 ◽  
Author(s):  
Maria Rosaria Corbo ◽  
Matteo Alessandro Del Nobile ◽  
Milena Sinigaglia
Keyword(s):  
Shelf Life ◽  
Minimally Processed ◽  
Novel Approach ◽  
Minimally Processed Vegetables

Efficacy of Cetylpyridinium Chloride in Immersion Treatment for Reducing Populations of Pathogenic Bacteria on Fresh-Cut Vegetables

2001 ◽  
Vol 64 (12) ◽  
pp. 2071-2074 ◽  
Author(s):  
HONG WANG ◽  
YANBIN LI ◽  
MICHAEL F. SLAVIK
Keyword(s):  
Escherichia Coli ◽  
High Performance Liquid Chromatography ◽  
Salmonella Typhimurium ◽  
High Performance ◽  
Pathogenic Bacteria ◽  
Room Temperature ◽  
Cetylpyridinium Chloride ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Fresh Cut

The efficacy of cetylpyridinium chloride (CPC) immersion to reduce the numbers of three pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7) on three different fresh-cut vegetables (broccoli, cauliflower, and radishes) was studied. The fresh-cut vegetables were inoculated with one of the three pathogenic bacteria at a concentration of 105 CFU/ml for 1 h at room temperature and then treated with 0.1 or 0.5% CPC immersion for 1 min. Both Salmonella Typhimurium and E. coli O157:H7 plates were incubated from 48 to 72 h at 37°C, and L. monocytogenes plates were incubated from 72 to 96 h before being counted. The results of three experiments showed that for the average of the three vegetables treated with 0.1 and 0.5% CPC, L. monocytogenes was reduced by 2.85 and 3.70 log CFU/g, Salmonella Typhimurium by 2.37 and 3.15 log CFU/g, and E. coli O157:H7 by 1.01 and 1.56 log CFU/g, respectively, in comparison with the vegetables treated with water only. The 0.5% CPC treatment was significantly different (P < 0.05) from the 0.1% CPC treatment on reduction of L. monocytogenes, Salmonella Typhimurium, and E. coli O157:H7. The CPC residual on the treated vegetables and their washing solutions were evaluated by using high-performance liquid chromatography.

Edible Film Coatings to Extend the Shelf-Life of Fresh-Cut Pineapple

2021 ◽  
Vol 885 ◽  
pp. 67-74
Author(s):  
Giuseppina Gullifa ◽  
Stefano Materazzi
Keyword(s):  
Shelf Life ◽  
Complete Characterization ◽  
Coating Material ◽  
Processed Foods ◽  
Minimally Processed ◽  
Film Coatings ◽  
Volatile Organic ◽  
Fresh Cut

This study proposes an innovative coating material and procedure to extend the shelf-life of fresh-cut pineapple classified as “minimally processed foods”. The novelty of this work consists of the using of biodegradable cases for the storage of fruits during the experiments under refrigerated conditions. In addition, the application of the coating process was evaluated over a period of 15 days and a complete characterization of the Volatile Organic Compounds (VOCs) was performed by gaschromatography coupled to mass spectrometry (GC-MS) to assess the effect of the coating material on the flavor, the appearance and the quality of the fruits. Results demonstrated that the application of carboxymethyl cellulose and ascorbic acid on pretreated fresh-cut pineapple is able to reduce the aging process and prolonge the shelf-life of pineapple without requiring conventional PVC cases for storage.

Fate of Escherichia coli O157:H7 and Salmonella on Fresh and Frozen Cut Pineapples

2010 ◽  
Vol 73 (3) ◽  
pp. 418-424 ◽  
Author(s):  
LAURA K. STRAWN ◽  
MICHELLE D. DANYLUK
Keyword(s):  
Escherichia Coli ◽  
Shelf Life ◽  
Escherichia Coli O157 ◽  
Acid Adaptation ◽  
Selective Media ◽  
E Coli ◽  
Ambient Storage ◽  
Fresh Cut ◽  
Salmonella Survival ◽  
Postharvest Processing

Pineapples have been associated with outbreaks of Escherichia coli and Salmonella. Little is known about the behavior of E. coli O157:H7 and Salmonella on cut pineapple. The objectives of this study were to evaluate the fate of E. coli O157:H7 and Salmonella on fresh and frozen cut pineapples and the influence of acid adaptation on Salmonella survival on fresh cut pineapple at ambient storage (23°C). Cut pineapples were spot inoculated with a four-strain cocktail of E. coli O157:H7 or a five-strain cocktail of Salmonella. Inoculated samples were air dried, placed in containers, and stored at 4, 12, 23, and −20°C. Samples were stomached and then enumerated on nonselective and selective media at days 0, 1, 3, 5, 7, 10, 14, 21, and 28 (4 and 12°C); 0, 1, 3, 5, and 7 (23°C); and 0, 7, 14, 21, 28, 60, 90, 120, 150, and 180 (−20°C). E. coli O157:H7 and Salmonella inoculated onto pineapple did not grow but survived for the shelf life at each temperature, with improved survival at lower temperatures. E. coli O157:H7 and Salmonella can survive on frozen cut pineapples for at least 180 days. Acid adaptation of Salmonella did not allow growth and did not increase survival. Fresh and frozen cut pineapples are potential vectors for E. coli O157:H7 and Salmonella transmission and preventive procedures should be implemented during production and postharvest processing.

scholarly journals Development of a Quantitative Competitive PCR Assay for Detection and Quantification of Escherichia coliO157:H7 Cells

2001 ◽  
Vol 67 (7) ◽  
pp. 3291-3294 ◽  
Author(s):  
Wenli Li ◽  
Mary Anne Drake
Keyword(s):  
Pathogenic Bacteria ◽  
Skim Milk ◽  
Viable Cell ◽  
Quantitative Detection ◽  
Competitive Pcr ◽  
Pcr Assay ◽  
E Coli ◽  
Cell Counts ◽  
Cell Densities ◽  
Detection And Quantification

ABSTRACT A quantitative competitive PCR (QC-PCR) assay was developed to detect and quantify Escherichia coli O157:H7 cells. From 103 to 108 CFU of E. coli O157:H7 cells/ml was quantified in broth or skim milk, and cell densities predicted by QC-PCR were highly related to viable cell counts (r 2 = 0.99 and 0.93, respectively). QC-PCR has potential for quantitative detection of pathogenic bacteria in foods.

scholarly journals Suitability of Borago officinalis for Minimal Processing as Fresh-Cut Produce

Horticulturae ◽  
2019 ◽  
Vol 5 (4) ◽  
pp. 66 ◽  
Author(s):  
Claudia Miceli ◽  
Alessandra Moncada ◽  
Filippo Vetrano ◽  
Fabio D’Anna ◽  
Alessandro Miceli
Keyword(s):  
Weight Loss ◽  
Ascorbic Acid ◽  
Shelf Life ◽  
Leafy Vegetables ◽  
Nitrate Content ◽  
Leaf Color ◽  
Minimally Processed ◽  
Minimal Processing ◽  
Borago Officinalis ◽  
Fresh Cut

Borage (Borago officinalis L.) is a wild vegetable appreciated as a folk medicine and for culinary preparations. The introduction of borage as a specialized cultivation would allow for the diversification of vegetable crops and would widen the offerings of raw and minimally processed leafy vegetables. Thus, the aim of the research was to evaluate the quality and shelf-life of fresh-cut borage stored at different temperatures. Borage plants were grown during the autumn–winter season and immediately minimally processed after harvest. Fresh-cut borage leaves packed in sealed bags were stored at 2 or 6 °C for 21 d. Weight loss, total soluble solids (TSS), titratable acidity (TA), ascorbic acid, nitrates, leaf color characteristics and overall quality were determined through the storage period. Borage plants were deemed suitable for minimal processing. Storage temperature significantly influenced the rate of quality loss. Borage leaves had an initial nitrate content of 329.3 mg kg−1 FW that was not affected by temperature or storage. TSS and TA were higher in leaves stored at 6 °C. TSS, TA and ascorbic acid content increased during storage. Minimally processed borage leaves stored at 2 °C had lower weight loss and leaf color modifications during storage and a longer shelf life than those stored at 6 °C, so were still marketable after 21 d of storage.

Consumer perceptions and motivations in choice of minimally processed vegetables

2015 ◽  
Vol 117 (3) ◽  
pp. 970-986 ◽  
Author(s):  
Federico Nassivera ◽  
Sandro Sillani
Keyword(s):  
Structural Equation ◽  
Purchase Intentions ◽  
Marketing Strategies ◽  
Equation Modeling ◽  
Minimally Processed ◽  
Content Type ◽  
Different Types ◽  
Managerial Implications ◽  
Fresh Cut ◽  
Minimally Processed Vegetables

Purpose – The purpose of this paper is to examine the usefulness of integrating measures of motivations in predicting purchase intentions of fresh cut products. In order to gain this purpose the authors developed a field study that involved about 425 consumers of fresh cut vegetables products. Design/methodology/approach – Questionnaire data were gathered in Italy on a Likert scale. Questions focussed on intentions to purchase fresh cut lamb’s lettuce from environmental sustainable farms, simulating a fresh cut product with an Eco-label. Data were analyzed using structural equation modeling (SEM). The SEM technique is used to develop propositions representing a theoretical approach in the context of the process for purchasing fresh cut products. With regard to distinguishing between the motives, the authors referred to the approach that sets out two different types of motive: health and green. Findings – The resulting managerial implications make it possible to assess how much the different types of motive influence the attitude and affect the choices and the behavior of the consumers. Originality/value – This implies important managerial implications for new marketing strategies for minimally processed food products, with the opportunity to take advantage of the potential adoption of an Eco-label.

scholarly journals Potential of thyme essential oil on arugula sanitization

2019 ◽  
Vol 43 ◽  
Author(s):  
Roseli Jacobi Veloso ◽  
Nei Fronza ◽  
Alvaro Vargas Júnior ◽  
Vânia Silva Carvalho ◽  
Miriam Fumiko Fujinawa ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Shelf Life ◽  
Sodium Hypochlorite ◽  
Active Chlorine ◽  
Minimally Processed ◽  
E Coli ◽  
Thyme Essential Oil

ABSTRACT Essential oils from plants are an important alternative source of antimicrobial compounds against important pathogens for food safety. This study aimed to evaluate the in vitro antimicrobial activity of thyme essential oil (Thymus vulgaris) and to apply it in the sanitization of minimally processed arugula (Eruca sativa), aiming to increase the safety and shelf life of arugula. The in vitro antibacterial activity of the essential oil was evaluated by disc diffusion assays and determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against different foodborne pathogens. Thereafter, a “challenge test” was carried out to evaluate the antibacterial activity of the thyme essential oil (0.2%) on the sanitization of arugula inoculated with Escherichia coli (3 log CFU mL-1) compared to sodium hypochlorite (120 ppm of active chlorine). Afterwards, an experiment of applying the thyme essential oil (0.2%) as a sanitizing agent in minimally processed arugula was carried out to evaluate the vegetable shelf life compared to sodium hypochlorite (120 ppm of active chlorine). The arugula was stored at 8 °C for 7 days, and periodically, the number of aerobic mesophilic microorganisms, pH and titratable acidity were determined, and the color of the samples was evaluated. The thyme essential oil had strong antimicrobial activity in vitro against all species of bacteria tested. In the experiments in situ, the thyme essential oil (0.2%) and sodium hypochlorite (120 ppm of active chlorine) were not efficient in eliminating the inoculated E. coli from minimally processed arugula, and they did not result in an extension of the shelf life of the arugula in comparison to the control (p>0.05). However, the growth rate of the E. coli population over time on the arugula samples sanitized with the thyme essential oil (0.2%) was low, which indicates a positive effect of the essential oil, which may be optimized with future adjustments in the concentration and immersion time for the arugula sanitization.

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