Combined Effect of Modified Atmosphere Package and Short-Wave Ultraviolet Does Not Affect <i>Proteus </i><i>m</i><i>irabilis</i> Growth on Rainbow Trout Fillets (<i>Oncorhynchus m</i><i>ykiss</i>)

Abstract

The current study investigated the effectiveness of short-wave ultraviolet (UV-C) radiation on rainbow trout fillets inoculated with Proteus mirabilis when combined with Modified Atmosphere Packaging technology (MAP). Rainbow trout were inoculated, packaged under different ratios of CO 2 and N 2 gases and subjected to UV-C radiation. Our study model demonstrated that at least 0.1001 J/cm 2 is necessary to significantly reduce Proteus mirabilis loads (reduction of 1.8 log CFU.g -1 ) in trout fillet packaged without CO 2 gas barrier. The rainbow trout fillet packaged with CO 2 gas barrier had significantly reduced Proteus mirabilis load but not when associated with UV-C radiation exposure. The combined effect of UV-C and MAP at different radiation doses and ratios of CO 2 and N 2 gas did not contribute to Proteus mirabilis growth reduction. Overall, the use of MAP significantly reduces the penetration and effect of UV-C radiation when compared to the unpackaged control. The combination of these two technologies of food preservation does not seem to be a suitable model to extend the shelf life of packaged fish fillet.

Combined Effect of Modified Atmosphere Packaging and UV-C Radiation on Pathogens Reduction, Biogenic Amines, and Shelf Life of Refrigerated Tilapia (Oreochromis niloticus) Fillets

“…MAP/UV was ineffective against the growth of both evaluated pathogens, and it was better observed for Escherichia coli O157:H7. These findings may be explained because MAP can impair the penetration power of the UV-C radiation at 0.30 J/cm 2 as well as to the higher ability of adaptation of E. coli compared to S. enterica [ 20 , 39 , 40 ]. Rodrigues et al [ 20 ] observed that MAP (50% CO 2 /50% N 2 ) was a barrier to penetration of UV-C radiation in rainbow trout fillets.…”

“…and E. coli in meat. However, Rodrigues et al [ 20 ] reported that combined MAP (30% CO 2 /70% N 2, 50% CO 2 /50% N 2 , and 70% CO 2 /30% N 2 ) and UV-C radiation (0.04, 0.06, and 0.10 J/cm 2 ) were ineffective on the reduction of Proteus mirabilis in rainbow trout fillets. It is worth highlighting that Proteus mirabilis is a Gram-negative and facultative anaerobic bacteria, as well as S. typhimurium and E. coli O157:H7 [ 23 ].…”

“…At the present moment, there are only two studies related to the combined effect of the CO 2 /N 2 MAP and UV-C. However, they investigated this effect on the reduction of pathogen or shelf life using a combination of a different gas mixture of MAP and UV-C dose, different pathogen, and different fish species [ 2 , 20 ] when compared to the present study. Moreover, these studies did not include protein oxidation, instrumental color, and texture parameters, which are relevant fish freshness indicators.…”

“…The effect of both MAP and UV-C depends on dose or gas ratios used, food composition, load, and type of microorganisms, which have different adaptation mechanisms [ 2 , 3 , 10 , 16 , 20 , 21 ]. At the present moment, there are only two studies related to the combined effect of the CO 2 /N 2 MAP and UV-C.…”

“…Regarding packaging, some authors have focused on evaluating different packaging materials to improve the shelf life of foods [ 18 , 19 ]. Modified atmosphere packaging (MAP) is a well-known technology for inhibiting the bacterial growth in fish at a low cost, ease implementation, and overall quality maintenance depending on food composition, choice, and ratio of gases used [ 2 , 20 , 21 ]. MAP replaces the atmosphere air composition inside the package with a gas mixture, mainly carbon dioxide (CO 2 ), nitrogen (N 2 ), and oxygen (O 2 ).…”