Implications of wash water chlorination and temperature for the microbiological and sensory properties of fresh-cut iceberg lettuce

2004 ◽  
Vol 31 (1) ◽  
pp. 81-91 ◽  
Author(s):  
Pascal J Delaquis ◽  
Lana R Fukumoto ◽  
Peter M.A Toivonen ◽  
Margaret A Cliff
Keyword(s):  
Sensory Properties ◽  
Wash Water ◽  
Iceberg Lettuce ◽  
Water Chlorination ◽  
Fresh Cut

scholarly journals High carbon-di-oxide modified atmospheric packaging on quality of ready-to-eat minimally processed fresh-cut iceberg lettuce

2021 ◽  
Author(s):  
Md. Azizul Haque ◽  
Md. Asaduzzaman ◽  
Md. Sultan Mahomud ◽  
Md. Rizvi Alam ◽  
Alin Khaliduzzaman ◽  
...  
Keyword(s):  
Modified Atmosphere Packaging ◽  
Storage Condition ◽  
Modified Atmosphere ◽  
High Carbon ◽  
Modified Atmospheric Packaging ◽  
Iceberg Lettuce ◽  
Microbial Development ◽  
Fresh Cut ◽  
Intact Surface

AbstractFresh-cut lettuce is a very well-known salad for today's routines because it obliges minimal preparation to minimize the loss of health beneficial vitamins, minerals, antioxidants and other phytochemicals. It is a prodigious challenge to serve its consumers fresh. Quality of freshly processed lettuce under high CO2 modified atmosphere packaging (MAP) has been investigated as a realistic alternative technique for its preservation. Storage under high CO2 atmospheric treatments exhibited a significant impact in microbial development, electrolyte leakage, volatile metabolites and sensory quality of fresh-cut iceberg lettuce. This storage condition (MAP 1: 5 kPa O2 and 20 kPa CO2 balanced by N2 at 7 °C for 6 days) inhibited the growth of mesophilic bacteria and yeasts; delayed the enzymatic browning (cut-edges and intact surface) of fresh-cut iceberg lettuce and overall visual quality was also in acceptance limit. The development of off-odors was perceived in high CO2 MAP as a consequence of volatiles (ethanol and acetaldehyde) accumulation which was persisted at an inexcusable level during 6 days of storage periods.

Tracking an Escherichia coli O157:H7–Contaminated Batch of Leafy Greens through a Pilot-Scale Fresh-Cut Processing Line

2014 ◽  
Vol 77 (9) ◽  
pp. 1487-1494 ◽  
Author(s):  
ANNEMARIE L. BUCHHOLZ ◽  
GORDON R. DAVIDSON ◽  
BRADLEY P. MARKS ◽  
EWEN C. D. TODD ◽  
ELLIOT T. RYSER
Keyword(s):  
Escherichia Coli ◽  
Membrane Filtration ◽  
Fluorescent Protein ◽  
Pilot Scale ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Leafy Greens ◽  
Iceberg Lettuce ◽  
Processing Line ◽  
Fresh Cut

Cross-contamination of fresh-cut leafy greens with residual Escherichia coli O157:H7–contaminated product during commercial processing was likely a contributing factor in several recent multistate outbreaks. Consequently, radicchio was used as a visual marker to track the spread of the contaminated product to iceberg lettuce in a pilot-scale processing line that included a commercial shredder, step conveyor, flume tank, shaker table, and centrifugal dryer. Uninoculated iceberg lettuce (45 kg) was processed, followed by 9.1 kg of radicchio (dip inoculated to contain a four-strain, green fluorescent protein–labeled nontoxigenic E. coli O157:H7 cocktail at 106 CFU/g) and 907 kg (2,000 lb) of uninoculated iceberg lettuce. After collecting the lettuce and radicchio in about 40 bags (~22.7 kg per bag) along with water and equipment surface samples, all visible shreds of radicchio were retrieved from the bags of shredded product, the equipment, and the floor. E. coli O157:H7 populations were quantified in the lettuce, water, and equipment samples by direct plating with or without prior membrane filtration on Trypticase soy agar containing 0.6% yeast extract and 100 ppm of ampicillin. Based on triplicate experiments, the weight of radicchio in the shredded lettuce averaged 614.9 g (93.6%), 6.9 g (1.3%), 5.0 g (0.8%), and 2.8 g (0.5%) for bags 1 to 10, 11 to 20, 21 to 30, and 31 to 40, respectively, with mean E. coli O157:H7 populations of 1.7, 1.2, 1.1, and 1.1 log CFU/g in radicchio-free lettuce. After processing, more radicchio remained on the conveyor (9.8 g; P < 0.05), compared with the shredder (8.3 g), flume tank (3.5 g), and shaker table (0.1 g), with similar E. coli O157:H7 populations (P > 0.05) recovered from all equipment surfaces after processing. These findings clearly demonstrate both the potential for the continuous spread of contaminated lettuce to multiple batches of product during processing and the need for improved equipment designs that minimize the buildup of residual product during processing.

scholarly journals Combined Effect of Dipping in Oxalic or in Citric Acid and Low O2 Modified Atmosphere, to Preserve the Quality of Fresh-Cut Lettuce during Storage

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 988
Author(s):  
Bernardo Pace ◽  
Imperatrice Capotorto ◽  
Michela Palumbo ◽  
Sergio Pelosi ◽  
Maria Cefola
Keyword(s):  
Citric Acid ◽  
Respiration Rate ◽  
Modified Atmosphere Packaging ◽  
Packaging Material ◽  
Combined Effect ◽  
Modified Atmosphere ◽  
Iceberg Lettuce ◽  
Fresh Cut ◽  
Main Factor

Leaf edge browning is the main factor affecting fresh-cut lettuce marketability. Dipping in organic acids as well as the low O2 modified atmosphere packaging (MAP), can be used as anti-browning technologies. In the present research paper, the proper oxalic acid (OA) concentration, able to reduce respiration rate of fresh-cut iceberg lettuce, and the suitable packaging materials aimed to maintaining a low O2 during storage, were selected. Moreover, the combined effect of dipping (in OA or in citric acid) and packaging in low O2 was investigated during the storage of fresh-cut iceberg lettuce for 14 days. Results showed a significant effect of 5 mM OA on respiration rate delay. In addition, polypropylene/polyamide (PP/PA) was select as the most suitable packaging material to be used in low O2 MAP. Combining OA dipping with low O2 MAP using PP/PA as material, resulted able to reduce leaf edge browning, respiration rate, weight loss and electrolyte leakage, preserving the visual quality of fresh-cut lettuce until 8 days at 8 °C.

scholarly journals Dynamic changes in the physicochemical properties of fresh-cut produce wash water as impacted by commodity type and processing conditions

PLoS ONE ◽  
2019 ◽  
Vol 14 (9) ◽  
pp. e0222174 ◽  
Author(s):  
Jie Li ◽  
Zi Teng ◽  
ShihChi Weng ◽  
Bin Zhou ◽  
Ellen R. Turner ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Wash Water ◽  
Processing Conditions ◽  
Dynamic Changes ◽  
Fresh Cut

scholarly journals Can UV absorbance rapidly estimate the chlorine demand in wash water during fresh-cut produce washing processes?

2018 ◽  
Vol 142 ◽  
pp. 19-27 ◽  
Author(s):  
S. Van Haute ◽  
Y. Luo ◽  
I. Sampers ◽  
L. Mei ◽  
Z. Teng ◽  
...  
Keyword(s):  
Wash Water ◽  
Uv Absorbance ◽  
Fresh Cut ◽  
Chlorine Demand

Efficacy of Sodium Hypochlorite and Peroxyacetic Acid To Reduce Murine Norovirus 1, B40-8, Listeria monocytogenes, and Escherichia coli O157:H7 on Shredded Iceberg Lettuce and in Residual Wash Water

2009 ◽  
Vol 72 (5) ◽  
pp. 1047-1054 ◽  
Author(s):  
LEEN BAERT ◽  
ISABELLE VANDEKINDEREN ◽  
FRANK DEVLIEGHERE ◽  
ELS VAN COILLIE ◽  
JOHAN DEBEVERE ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Sodium Hypochlorite ◽  
Tap Water ◽  
Bacterial Pathogens ◽  
Wash Water ◽  
Escherichia Coli O157 ◽  
Murine Norovirus ◽  
Peroxyacetic Acid ◽  
Iceberg Lettuce

The efficiency of sodium hypochlorite (NaOCl) and peroxyacetic acid (PAA) to reduce murine norovirus 1 (MNV-1), a surrogate for human norovirus, and Bacteroides fragilis HSP40–infecting phage B40-8 on shredded iceberg lettuce was investigated. The levels of removal of viruses MNV-1 and B40-8 were compared with the reductions observed for bacterial pathogens Listeria monocytogenes and Escherichia coli O157:H7. Two inoculation levels, one with a high organic load and the other containing a 10-fold lower number of pathogens and organic matter, showed that the effectiveness of NaOClwas greatly influenced by the presence of organic material, which was not observed for PAA. Moreover, the present study showed that 200 mg/liter NaOCl or 250 mg/liter PAA is needed to obtain an additional reduction of 1 log (compared with tap water) of MNV-1 on shredded iceberg lettuce, whereas only 250 mg/liter PAA achieved this for bacterial pathogens. None of the treatments resulted in a supplementary 1-log PFU/g reduction of B40-8 compared with tap water. B40-8 could therefore be useful as an indicator of decontamination processes of shredded iceberg lettuce based on NaOCl or PAA. Neither MNV-1, B40-8, nor bacterial pathogens could be detected in residual wash water after shredded iceberg lettuce was treated with NaOCl and PAA, whereas considerable numbers of all these microorganisms were found in residual wash water consisting solely of tap water. This study illustrates the usefulness of PAA and NaOCl in preventing cross-contamination during the washing process rather than in causing a reduction of the number of pathogens present on lettuce.

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