Chemical and microbiological changes of salted Caspian Kutum (Rutilus frisii kutum) roe

Abstract

Salted Kutum roe was prepared by soaking in brine to a traditional procedure. Proximate composition (moisture, protein, lipid, pH, ash and salt content), total volatile basic nitrogen (TVB-N), fatty acid profiles and microbiological characteristics of raw and salted roe of Caspian white fish (Rutilus frisii kutum) were determined. The results indicated that protein and moisture contents were significantly higher in raw roe compared to salted one (28.81 and 61.07% to 23.99 and 51.57%, respectively). Significant differences in ash and salt contents were obtained among different treatments. TVB-N in all samples was less than 25mg/100g. The gas chromatography (GC) analysis showed that the major saturated fatty, monounsaturated fatty acids and poly unsaturated fatty acids were 16:0, 18:1n-9, and 22:6n-3, respectively. Aerobic plate count (APC) and Total Coliform Count (TC) in all samples were significantly higher (p < 0.05) in raw roe (5.33 logCFU/g and 210 MPN/g) compared to salted roe (1.23 log CFU/g and 1.2 MPN/g). None of the samples contained Escherichia coli, Salmonella, Clostridium perfringens or yeast.