Efficacy of natural antimicrobials to prolong the shelf-life of minimally processed apples packaged in modified atmosphere

The first goal of this study was to determine the packaging film O2 permeability required to maintain a steady-state O2 concentration of 3% in modified-atmosphere packaging (MAP) of minimally processed romaine lettuce (Lactuca sativa L.). The second goal of the study was to determine the extent to which MAP could preserve lettuce quality and consequently extend product shelf life. Oxygen consumption rates of commercially prepared lettuce samples were determined in a closed system for each of three atmospheres (3% O2 combined with either 6%, 10%, or 14% CO2). Enzymatic, quadratic, and linear mathematical models were compared to determine which best described the respiratory data. The linear model was the most suitable and was used to predict the O2 consumption rate of the minimally processed romaine lettuce under the desired package headspace gas concentrations. The predicted O2 consumption rate was used to calculate the necessary O2 permeability for the packaging film. Packages (21.6 × 25.4 cm) were constructed from a polypropylene-polyethylene-laminate film with the appropriate O2 permeability. Packaged samples were stored under three modified atmospheres (MAs) (3% O2 combined with either 6%, 10%, or 14% CO2) for 20 days, and headspace gas concentrations, lettuce appearance, and color were evaluated every other day. Growth of pectinolytic and lactic acid bacteria was also studied. The O2 consumption rate of the lettuce decreased with increasing CO2 levels. The O2 levels in the MA packages equilibrated at 7% to 11%. Compared to a control atmosphere of air, MAP delayed the development of tissue discoloration. Preliminary results indicated no effect of MAP on microbial growth. Of the three CO2 levels, 10% was slightly more effective than 6% and 14%. Critical choice of packaging permeabilities combined with MAP maintained the quality of minimally processed romaine lettuce and thereby increased shelf life by about 50%.

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

Journal of Food Protection ◽

10.4315/0362-028x.jfp-16-289 ◽

2017 ◽

Vol 80 (5) ◽

pp. 740-749 ◽

Cited By ~ 2

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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Biopolymer Coatings as Alternative to Modified Atmosphere Packaging for Shelf Life Extension of Minimally Processed Apples

Coatings ◽

10.3390/coatings9090569 ◽

2019 ◽

Vol 9 (9) ◽

pp. 569 ◽

Cited By ~ 2

Author(s):

Stefania Volpe ◽

Silvana Cavella ◽

Elena Torrieri

Keyword(s):

Antioxidant Capacity ◽

Shelf Life ◽

Respiration Rate ◽

Modified Atmosphere Packaging ◽

Life Extension ◽

Second Phase ◽

Modified Atmosphere ◽

Gas Composition ◽

Minimally Processed ◽

Life Study

The effect of caseinate/chitosan blend on the shelf life of minimally processed apples was studied. In the first phase of the work, the effect of the biopolymer coating on the respiration rate of the minimally processed apples was studied as function of gas composition (5%, 10%, 21% of O2 with N2 as balance at 5 °C) and temperature (5 °C, 10 °C at 5% of O2 with N2 as balance). In the second phase, the shelf life of the packed product was studied during storage at 5 °C. The gas composition (O2%-CO2%) in the package headspace, relative humidity, pH, hardness, color and antioxidant capacity of the product were monitored after 0, 1, 4, 7, 11, and 14 days. The coating effectively reduced respiration rate of the product when oxygen was over 10%. In the presence of the coating, the reduction of oxygen did not affect the respiration rate. At 5% of O2, the respiration rate decreased by 50% by changing the temperature from 10 °C to 5 °C. Shelf life study showed that the chitosan—caseinate coating was able to preserve the mechanical properties and the antioxidant capacity of the product during storage by increasing the shelf life by 7 days to 11 days at 5 °C.

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