scholarly journals Seasonality, shelf life and storage atmosphere are main drivers of the microbiome and E. coli O157:H7 colonization of post-harvest lettuce cultivated in a major production area in California

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Susan R. Leonard ◽  
Ivan Simko ◽  
Mark K. Mammel ◽  
Taylor K. S. Richter ◽  
Maria T. Brandl
Keyword(s):  
Shelf Life ◽  
Cold Storage ◽  
Population Change ◽  
Recursive Partitioning ◽  
Modified Atmosphere Packaging ◽  
Metagenomic Sequencing ◽  
Microbiome Composition ◽  
C Storage ◽  
Storage Atmosphere ◽  
Production Area

Abstract Background Lettuce is linked to recurrent outbreaks of Shiga toxin-producing Escherichia coli (STEC) infections, the seasonality of which remains unresolved. Infections have occurred largely from processed lettuce, which undergoes substantial physiological changes during storage. We investigated the microbiome and STEC O157:H7 (EcO157) colonization of fresh-cut lettuce of two cultivars with long and short shelf life harvested in the spring and fall in California and stored in modified atmosphere packaging (MAP) at cold and warm temperatures. Results Inoculated EcO157 declined significantly less on the cold-stored cultivar with short shelf life, while multiplying rapidly at 24 °C independently of cultivar. Metagenomic sequencing of the lettuce microbiome revealed that the pre-storage bacterial community was variable but dominated by species in the Erwiniaceae and Pseudomonadaceae. After cold storage, the microbiome composition differed between cultivars, with a greater relative abundance (RA) of Erwiniaceae and Yersiniaceae on the cultivar with short shelf life. Storage at 24 °C shifted the microbiome to higher RAs of Erwiniaceae and Enterobacteriaceae and lower RA of Pseudomonadaceae compared with 6 °C. Fall harvest followed by lettuce deterioration were identified by recursive partitioning as important factors associated with high EcO157 survival at 6 °C, whereas elevated package CO2 levels correlated with high EcO157 multiplication at 24 °C. EcO157 population change correlated with the lettuce microbiome during 6 °C storage, with fall microbiomes supporting the greatest EcO157 survival on both cultivars. Fall and spring microbiomes differed before and during storage at both temperatures. High representation of Pantoea agglomerans was a predictor of fall microbiomes, lettuce deterioration, and enhanced EcO157 survival at 6 °C. In contrast, higher RAs of Erwinia persicina, Rahnella aquatilis, and Serratia liquefaciens were biomarkers of spring microbiomes and lower EcO157 survival. Conclusions The microbiome of processed MAP lettuce evolves extensively during storage. Under temperature abuse, high CO2 promotes a lettuce microbiome enriched in taxa with anaerobic capability and EcO157 multiplication. In cold storage, our results strongly support a role for season and lettuce deterioration in EcO157 survival and microbiome composition, suggesting that the physiology and microbiomes of fall- and spring-harvested lettuce may contribute to the seasonality of STEC outbreaks associated with lettuce grown in coastal California.

scholarly journals Effect of 1-Methyl Cyclopropane and Modified Atmosphere Packaging on the Storage of Okra (Abelmoschus esculentus L.): Theory and Experiments

2020 ◽  
Vol 12 (18) ◽  
pp. 7547 ◽  
Author(s):  
Rabia Kanwal ◽  
Hadeed Ashraf ◽  
Muhammad Sultan ◽  
Irrum Babu ◽  
Zarina Yasmin ◽  
...  
Keyword(s):  
Shelf Life ◽  
Cold Storage ◽  
Combined Treatment ◽  
Chilling Injury ◽  
Modified Atmosphere Packaging ◽  
Storage Conditions ◽  
Modified Atmosphere ◽  
Overall Acceptability ◽  
Reduce Weight Loss ◽  
The Individual

Okra possesses a short shelf-life which limits its marketability, thereby, the present study investigates the individual and combined effect of 1-methylcyclopropene (1-MCP) and modified atmosphere packaging (MAP) on the postharvest storage life of okra. The treated/ untreated okra samples were stored at ambient (i.e., 27 °C) and low (i.e., 7 °C) temperatures for eight and 20 days, respectively. Results revealed that the 1-MCP and/or MAP treatment successfully inhibited fruit softening, reduction in mucilage viscosity, and color degradation (hue angle, ∆E, and BI) in the product resulting in a longer period of shelf-life. However, MAP with or without 1-MCP was more effective to reduce weight loss in okra stored at both ambient and cold storage conditions. Additionally, ascorbic acid and total antioxidants were also retained in 1-MCP with MAP during cold storage. The 1-MCP in combination with MAP effectively suppressed respiration rate and ethylene production for four days and eight days at 27 °C and 7 °C temperature conditions, respectively. According to the results, relatively less chilling injury stress also resulted when 1-MCP combined with MAP. The combined treatment of okra pods with 1-MCP and MAP maintained the visual quality of the product in terms of overall acceptability for four days at 20 °C and 20 days at 7 °C.

Prolonged Shelf Life and Reduced Drip Loss of Chicken Filets by the Use of Carbon Dioxide Emitters and Modified Atmosphere Packaging

2014 ◽  
Vol 77 (7) ◽  
pp. 1133-1141 ◽  
Author(s):  
ASKILD L. HOLCK ◽  
MARIT K. PETTERSEN ◽  
MARIE H. MOEN ◽  
ODDVIN SØRHEIM
Keyword(s):  
Carbon Dioxide ◽  
Shelf Life ◽  
Production Efficiency ◽  
Modified Atmosphere Packaging ◽  
Storage Period ◽  
Co2 Concentration ◽  
Life Extension ◽  
Modified Atmosphere ◽  
Drip Loss ◽  
C Storage

Modified atmosphere packaging containing CO2 is widely used for extending the shelf life of chicken meat. Active packaging by adding CO2 emitter sachets to packages of meat is an alternative to traditional modified atmosphere packaging. The purpose of the study was to investigate the shelf life of chicken filets under different CO2 concentrations at 4°C storage. The inhibition of microbial growth was proportional to the CO2 concentration. Storage in 100% CO2 both with and without a CO2 emitter sachet gave a microbiological shelf-life extension of 7 days compared with 60% CO2. Carnobacterium divergens, Carnobacterium sp., and Lactococcus sp. were the dominating species at the end of the storage period. During storage in pure CO2, the carbon dioxide dissolved in the meat and caused the collapse of the packages. The resulting squeeze of the meat lead to a severe increase in drip loss. The drip loss was reduced profoundly by using the CO2 emitting sachet in the packages. The addition of CO2 emitters can easily be implemented at industrial packaging lines without reduction in production efficiency.

scholarly journals Modified Atmosphere and Humidity Film Reduces Browning Susceptibility of Oriental Melon Suture Tissue during Cold Storage

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1329
Author(s):  
Me-Hea Park ◽  
Eun-Ha Chang ◽  
Hae-Jo Yang ◽  
Jung-Soo Lee ◽  
Gyung-Ran Do ◽  
...  
Keyword(s):  
Shelf Life ◽  
Cold Storage ◽  
Chilling Injury ◽  
Modified Atmosphere Packaging ◽  
Summer Season ◽  
Modified Atmosphere ◽  
Display Condition ◽  
Browning Index ◽  
Oriental Melon ◽  
Retail Display

Oriental melons have a relatively short shelf life as they are harvested during the summer season and susceptible to cold-induced injuries. Typical chilling injury when stored at 4 °C is expressed as browning of the fruit suture. To prolong the shelf life and reduce browning of the fruit, the effects of modified atmosphere packaging (MAP), X-tend modified atmosphere (MA)/modified humidity (MH) bulk packaging (XF), and polyethylene (PE) packaging, on oriental melons were investigated during storage at 4 °C and 10 °C for 14 days and under retail display conditions at 20 °C. The O2 concentrations in PE packages stored at 4 °C and 10 °C ranged from 17.4 to 18.5%, whereas those in XF packages were reduced to 16.3–16.6%. The CO2 content of XF package (4.2–4.6%) was higher than that of PE package (1.4–1.9%) stored at 4 °C or 10 °C. Relative humidity (RH) saturated in the PE packages but not in the XF packages after seven days of storage. Furthermore, PE packages performed better at maintaining melon weight and firmness than XF packages during storage at 10 °C for 14 days and under retail display conditions at 20 °C. PE and XF packages effectively reduced the browning index of the peel and white linear sutures of oriental melons compared with the unpackaged control during cold storage at 4 °C, and this observation was maintained at the retail display condition at 20 °C. The enhanced CO2 levels, reduced O2 levels, and optimal RH values that were provided by the MAP, prevented the browning symptoms, and improved the marketability and shelf life of oriental melons.

scholarly journals Effects of MAP Treatment on Aroma Compounds and Enzyme Activities in Flat Peach during Storage and Shelf Life

HortScience ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 511-523 ◽  
Author(s):  
Hui-Juan Zhou ◽  
Zheng-Wen Ye ◽  
Ming-Shen Su
Keyword(s):  
Low Temperature ◽  
Shelf Life ◽  
Cold Storage ◽  
Storage Time ◽  
Modified Atmosphere Packaging ◽  
Aroma Compounds ◽  
Hydroperoxide Lyase ◽  
Modified Atmosphere ◽  
And Control ◽  
Internal Browning

Cold storage is used to delay the senescence of peaches, but it can also lead to internal browning and aroma loss. Modified atmosphere packaging (MAP) has been reported to inhibit the internal browning and prolong the storage time. Four MAP treatments in the present study were set as follows: I: O2 1% to 3%, CO2 3% to 5%, and N2 92% to 96%; II: O2 3% to 5%, CO2 3% to 5%, and N2 90% to 94%; III: O2 6% to 8%, CO2 3% to 5%, and N2 87% to 91%; and control (CK): O2 21%, CO2 0.03%, and N2 79%. The concentration of sugars, acids, aroma compounds, superoxide radical (O2−), hydrogen peroxide (H2O2), and malondialdehyde (MDA), as well as the activities of enzymes, such as superoxide dismutase (SOD), peroxidase (POD), lipoxygenase (LOX), hydroperoxide lyase (HPL), alcohol dehydrogenase, and alcohol O-acyltransferase (AAT) activities, were investigated. The results revealed that MAP, especially for treatment II, could inhibit the loss of flavors such as sugars, acids, and aroma compounds; maintain higher SOD and POD activities; and inhibit the accumulation of O2−, H2O2, and MDA during shelf life after storage at low temperature for 30 days. It could also inhibit the LOX and HPL activities at low temperature, but maintain higher LOX and HPL activities during shelf life. These findings indicated that treatment II could prolong the storage time to 30 days and shelf life for 3 days; maintain the higher content of sugars, acids, and aroma compounds; protect the cell membrane from oxidative injury; and inhibit internal browning during cold storage and shelf life.

scholarly journals COMBINED TREATMENTS OF MODIFIED ATMOSPHERE PACKAGING WITH AMINOETHOXYVINYLGLYCINE MAINTAINED FRUIT QUALITY IN SWEET CHERRY THROUGHOUT COLD STORAGE AND SHELF LIFE

2019 ◽  
Vol 18 (5) ◽  
pp. 13-26 ◽  
Author(s):  
Saadet Koc Guler ◽  
Orhan Karakaya ◽  
Medeni Karakaya ◽  
Burhan Ozturk ◽  
Erdal Aglar ◽  
...  
Keyword(s):  
Weight Loss ◽  
Shelf Life ◽  
Cold Storage ◽  
Sweet Cherry ◽  
Modified Atmosphere Packaging ◽  
Storage Period ◽  
Titratable Acidity ◽  
Modified Atmosphere ◽  
Hue Angle

The effects of combined aminoethoxyvinylglycine (AVG) and modified atmosphere packaging (MAP) treatments on quality attributes of ‘0900 Ziraat’ sweet cherry fruit during the cold storage and shelf life were investigated in this study. Significantly lower weight loss and decay ratios were observed in all treatments throughout the cold storage period as compared to the control. A similar case was also observed referring to the shelf life. MAP treatments were found to be more effective in retarding the weight loss and decay ratio. Higher hue angle values were measured from AVG-treated fruit at harvest. Similarly, hue angle of AVG and MAP-treated fruit were also higher than for the control in all periods of cold storage and on the 7th and 21st day of shelf life. AVG-treated fruit had higher firmness values than the control at harvest. However, higher firmness values were measured from MAP-treated fruit during the cold storage and shelf life. At the end of cold storage, lower SSC and higher titratable acidity values were observed in AVG and MAP-treated fruit than in the control. AVG + MAP treatments yielded significantly higher vitamin C, total phenolics and antioxidant activity values than the control. Contrarily, the control fruit had significantly higher total monomeric anthocyanin than the other treatments. Based on current findings, it was concluded that combined AVG + MAP treatments could be used as a beneficial tool to maintain the quality of sweet cherry fruit throughout the cold storage and shelf life.

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