Bio preservation Strategies: Evaluating the Efficacy of Lactic Acid cell-free Supernatants in Extending the Refrigerated Shelf Life of Shrimp

Enhancing the shelf life of shrimp poses a considerable challenge within the industry. This study examines the preservation of four groups of shrimps, each coated with a 1% tragacanth gel: control group, accompanied by 100 mg/L sodium metabisulfite (SMS), 25% (w/v) cell-free supernatant (CFS) of L. plantarum (TSP) , and 25% (w/v) CFS of L. rhamnosus (TSR) in triplicate over a 10-day refrigeration period. The TSP and TSR groups exhibited significantly lower microbial counts, particularly psychrophilics, Pseudomonas & H 2 S-producing bacteria (P < 0.05), lower melanosis, trimethylamine (TMA), thiobarbituric acid (TBA), and total volatile nitrogen (TVBN) compared to the control group (P < 0.05). Notably, the CFS from L. plantarum demonstrated greater effectiveness in reducing psychrophilis (1.53 log CFU/g), Pseudomonas (1.26 log CFU/g), H 2 S-producings (1.06 log CFU/g), TVBN (5 mg/100g), TMA (0.4 mg/100g), and TBA (0.01 mg MDA/kg) in comparison to L. rhamnosus. The phenolics, organic acids (lactic & acetic acid), H 2 O 2 , and peptide-based compounds are some antimicrobial agents present in this CFS.