Modified Atmosphere Packaging (MAP) for Control of Black Spot Formation in Chilled Prawns

Abstract

The marketing of organically labeled prawns is predominately in a cooked or raw frozen form to avoid the development of melanosis (black spot). Certification for organic status prohibits the use of any added chemicals. The application of 60% CO 2 /40%N 2 modified atmosphere to chilled (raw) prawns using two species of prawn was investigated for the ability to control black spot formation. Sensory assessment and microbiological counts were used to determine the end of product shelf life. Modified atmosphere packaged (MAP) prawns exhibited no melanosis for up to 16 days. The high quality life was retained for 12 days; shelf life of 16 days, according to standard microbiological criteria, was achieved, which is more than twice previously reported for non-MAP prawns. Results suggest MAP may be an effective method for the marketing of organically grown prawns as well as those produced by conventional prawn aquaculture without application of the normal chemicals used to prevent black spot.

Modified Atmosphere Systems and Shelf Life Extension of Fish and Fishery Products

“…For aquaculture products, more control exists on the elapsed time from harvest to processing but other pre-harvest variables also influence product quality such as crowding stress [ 24 ] and disease. For these reasons, it is not surprising that some studies report limited benefit to the quality and shelf life of fish and fishery products by the use of gases mixtures in MAP [ 25 , 26 , 27 , 28 ], while many others record significant extension in product shelf life [ 29 , 30 , 31 , 32 , 33 , 34 , 35 ].…”