An active shrimp concentrate (SC), obtained from Litopenaeus vannamei cooking juice, was incorporated into a chitosan-gelatin matrix to develop edible packaging covers (coating and film). Both types of packaging, which showed antimicrobial activity against some fish spoilers and pathogenic organisms, were applied to preserve fish sausages during chilled storage. The storage trial showed that the coating increased the lag phase of total viable microorganisms and enterobacteria to 15 and 10 days, respectively, while the film drastically inhibited growth of these groups. No presence of Staphylococcus aureus or lactic acid bacteria was detected in any batches during storage. Total volatile bases and pH values also decreased during storage, the decrease being more pronounced in the film. With regard to physical-chemical properties, the coated sausages exhibited values for moisture, water holding capacity, and shear strength similar to those of the control sausages until about day 25. The coating was imperceptible and could be a promising way of improving the quality of sausages during storage since it delayed microbial growth. The sausages wrapped in the film showed a drop in pH and moisture, as well as texture hardening, and were described as resembling a pickled product. The sausages were stable for at least 42 days, which represents a shelf life increase of at least this time with respect to the control sausages (in commercial plastic casings). The coating and the film had different effects on the physicochemical and microbiological properties of the fish sausage, and therefore on the stability of the product. In addition, the film triggered modifications in the product that resulted in a product different from the original, offering an attractive alternative with regard to product design.

This research was financed by the Spanish Ministry of Economy and Competitiveness through projects AGL2011-27607, 201370E036, and AGL2014-528225. Ecuadorian government by scholarship SENESCYT.

Peer Reviewed