Shelf life extension of minimally processed vegetables using combinations of bacterial bioprotection and modified atmosphere packaging
Peter the Great St. Petersburg Polytechnic University, Graduate School of Biotechnology and Food Science, Polytechnicheskaya, 29, RU195251 St. Petersburg, Russia
Abstract:
The objective of the work: to study the effect of combination of bacterial bioprotective cultures and modified atmosphere packaging for prolonging the refrigerated storage period of minimally processed vegetables. Sweet pepper, zucchini, eggplant, celery stalks were used for preparation of minimally processed vegetables. SafePro® bio-products from Chr. Hansen (Denmark) containing strains of Lactobacillus sakei, Pediococcus acidilactici, Lactobacillus сurvatus, Leuconostoc carnosum were used as bioconservatives. For packaging minimally processed vegetables, the bags made of flat multilayer PA/adhesive/PE films and composite PET/A1/PE film material were used. The bags were filled with gas mixtures including nitrogen and carbon dioxide. Storage of packaged minimally processed vegetables was carried out in a refrigerator at a temperature of 4 ± 2 °C for 16 days. The viability of cultures Lactobacillus sakei, Pediococcus acidilactici, Lactobacillus curvatus, Leuconostoc carnosum in modified atmosphere packaging was studied. It was revealed that the gas mixture of 60% nitrogen and 40% carbon dioxide and the culture of Lactobacillus sakei contribute to the preservation of the quality of fresh-cut sweet pepper, eggplant and zucchini, and Leuconostoc carnosum is the more effective for celery storing. In the process of refrigerated storage for 14 days, the solids content in the experimental samples increased 1.3–2.1 times, the loss of organic substances was 26–50%, depending on the type of vegetables. The developed technology for the refrigeration preservation of minimally processed vegetables using bio-products treatment and in modified atmosphere packaging made it possible to increase the shelf life of fresh-cut vegetables by 2 times.
Key words:
bacterial bioprotection, Lactobacillus sakei, minimally processed vegetables, modified atmosphere packaging, refrigerated storage, shelf life extension, vegetable microbiota