Combined effects of microencapsulated essential oils and irradiation from gamma and X-ray sources on microbiological and physicochemical properties of dry fermented sausages during storage
Jiali Ji, Zahra Allahdad, Elham Sarmast, Stéphane Salmieri, Monique Lacroix
Abstract
Essential oils (EOs) or EOs encapsulated in alginate and alginate-cellulose nanocrystal combined with 1.5 kGy X-ray (0.76 kGy/h) or γ-ray (6.37 kGy/h) irradiation were applied on dry fermented sausages (DFS). Microbiological quality was tested in terms of the reduction of Escherichia coli O157:H7 cocktail, Listeria monocytogenes, molds and yeasts, lactic acid bacteria (LAB), and total mesophilic bacteria (TMF) during storage at room temperature (20 ± 1 °C) for 8 weeks. Physicochemical quality was tested by following the changes of texture and color of sausages. Synergistic effects were observed with combined treatments with γ-irradiation on inhibiting E. coli O157:H7 cocktail and LAB and with X-ray on inhibiting E. coli O157:H7 cocktail. Extensive inhibition of L. monocytogenes, molds and yeasts, and TMF was also noticed during storage. Antimicrobial formulations combined with γ-irradiation did not show adverse effects on texture and color of sausages while treatment with X-ray resulted in the reduction of redness and increase of hardness. However, the differences of texture were eliminated during storage.