Selected medium-chain dicarboxylic acid combinations: improving the shelf life and quality of salmon meat during refrigerated storage

Abstract Combining preservatives can increase their antimicrobial activities compared with using a single preservative. Three medium-chain dicarboxylic acids with previously validated antimicrobial activity, i.e., azelaic acid (AZA), succinic acid (SUA), and glutaric acid (GLA), were selected for this study to assess the potential for their development as novel combination preservatives. In the checkerboard assay, they exhibited high synergy in two-by-two combinations. However, they showed low antioxidant activity in antioxidant assays. Combining the two-part data (checkerboard and antioxidant synergistic assays), the most effective combinations of bacteriostatic and antioxidant were selected for the following application (i.e., GLA-AZA [2:1], GLA-SUA [1:1], and AZA-SUA [2:1]). Using two salmon models (sliced and minced samples), these combinations, especially AZA-SUA (2:1) at 2,000 μg/ml and 1,456 μg/g, shown synergistic effects on freshness during 12-day refrigerated storage. Expressly, AZA-SUA (2:1) preserved the quality of salmon slices for 9 days and minced salmon for 6 days in the best possible way, keeping the total viable count and Enterobacteriaceae count below the maximum limit, in contrast to the blank control group (3 days). The microbial counts in beef treated with AZA-SUA (2:1) were significantly lower (p < .05) than those in the positive control group on day 12 of refrigerated storage. In addition, the combination of selected medium-chain dicarboxylic acids effectively preserved salmon quality by maintaining colour, pH, and moisture and reducing spoilage indicators like TVB-N and other microbial counts. The findings suggest that these unique combinations have the potential to be alternatives to conventional preservatives for retaining the freshness of fish products during refrigerated storage.