Purpose: The main objective of this study was to evaluate the capabilities of Zataria multiflora essential oil (0-0.06%(W/W)), nisin (0-18mg/kg), and potassium sorbate (0-1000mg/kg) combinations on caviar processing.
Methods: Efficacy of the above hurdles was assessed using response surface methodology (RSM) and identification of caviar microbial flora.
Results: Results revealed that potassium sorbate, Zataria multiflora essential oil, and nisin were effective treatments for inhibiting the total count of caviar samples; although, the nisin was not as effective as potassium sorbate and Zataria multiflora essential oil. The RSM study indicated that the quadratic model for total count was sufficiently accurate to predict the corresponding response as a function of variable concentrations. Optimum concentration for caviar processing, with the least total count, was determined to be 1000 mg/kg potassium sorbate, 0.06% Zataria multiflora essential oil, and 6 mg/kg nisin. For identification of caviar microbial flora, one of the caviar colonies was isolated and a total of 1356 nucleotides from the 16S rDNA gene was sequenced.
Significance: Through performing BLAST, the sequence showed significant similarity (≥99%) to the 16S rDNA of known Rahnella aquatilis strains. The 16S rDNA gene sequence from the isolate was submitted to NCBI (accession number JQ968608).