Chemical quality and microbiological content of Kutum (Rutilus frisii kutum) roe processed in different brine concentration during storage

Abstract

Caviars represent the best-known form of fish roe products. The conventional method of roe processing includes saturated brine salting. However, despite the importance of these products, there is relatively little technical information available about their chemical composition, product quality and food safety attributes. Three experimental treatments were provided with kutum roe brined in 10, 18 and 24% sodium chloride solutions for 14 days (24°C). Then, the brined-roes were removed from the solution and stored at 4°C for 90 days in refrigerator. The contents of proximate compositions, salt, volatile base nitrogen (VBN), total psychrotrophic bacteria and histamine forming bacteria, color were measured. Sampling was carried out at the first and at the end of days 30, 60 and 90 of storage period. The samples brined in 10% solution putrefied during the brining and removed from study. The moisture and total volatile nitrogen content of 24% brined roes were lower than 18% treatment. The pH and histamine forming bacteria number at the end of storage and total psychrotrophic bacteria number after 60 days of storage were higher. The increase of L* value and the decrease of a* value in samples of brine 18% were observed on days 60 and 90 of storage, but this increase was induced only on the day 90 for samples of brine 24%. 18%brined roe showed acceptable chemical and microbial results in refrigerated condition, and 24% brine roe appeared optimal during storage period.

Keywords

• kutum
• roe
• shelf life
• brine concentration