Changes in sensory, physicochemical, and microbiological properties of fresh captured tropical pink shrimps (Penaeus duorarum notialis) inoculated with Lactobacillusplantarum Lp6SH, Lactobacillus rhamnosus Yoba, and their cell‐free culture supernatants during storage at 4°C

Abstract

AbstractThis study was conducted to evaluate the biopreservative potential of Lactobacillus plantarum Lp6SH (Lp6SH), Lactobacillus rhamnosus Yoba (LrYoba) and their cell‐free supernatants (CFS) on whole captured tropical pink shrimps (Penaeus duorarum notialis) during storage at 4°C for 8 days. Shrimps were inoculated with strains Lp6SH, LrYoba, their supernatants, sodium metabisulfite (2%) and stored at 4 ° C for 8 days. Sensory evaluation, physicochemical, and microbiological analyses were performed daily. Lp6SH, CFS of Lp6SH, and CFS of LrYoba were able to prolong the sensory shelf life up to 8 days. The total volatile basic nitrogen (TVBN) concentration was lower than the acceptable value at the end of the storage period. All the treatments reduced the number of total aerobic bacteria and fungi, and maintained the coliforms count for 2 days. Strain Lp6SH reduced the number of Staphylococci for 4 days. Based on the threshold values, the microbiological shelf life of shrimps was between 2 and 6 days at 4°C. L. plantarum Lp6SH and the CFS of L. rhamnosus Yoba could be used as natural preservatives to replace the use of sodium bisulfate in prolonging the microbiological and sensory shelf life of captured whole shrimps.Practical applicationsMicrobial spoilage of raw fresh shrimps and black spots formation constitute substantial economic losses as well as serious public health problem. Due to the harmful effects of chemical preservatives, attention is paid nowadays to the search for fresh shrimp preservation methods that could obviate the use of chemicals and prevent blackspot formation. In this respect, the results of this study supported that Lactobacillus plantarum Lp6SH strain and the cell‐free supernatant of Lactobacillus rhamnosus Yoba are suitable biopreservatives that could be used to increase the safety, prevent melanosis, and extend the sensory shelf life of captured whole shrimps stored under refrigeration. After studies for their application at large scale, the fishermen and food industries can use the bacterial suspension and the cell‐free supernatant as spray or immersion solutions for the treatment of shrimps (or other seafood) prior to freezing.