The new gastronomic product: dried and vacuumed rainbow trout roe

Abstract

In this study, it was aimed to investigate that the effect of drying process on rainbow trout (Oncorhynchus mykiss Walbaum, 1792) roes in terms of the proximate composition, aw, pH, TVB-N, TBARs, microbiological counts and color parameters. Drying was lasted 42 hours including, 18 hours at 30oC and 24 hours at 45oC. The dried fish roes were vacuum-packed (vacuum degree 0.02MPa) and stored at 4oC for 90th days. The crude lipid, crude protein, crude ash and moisture contents of fresh fish roe was 6.67%, 18.51%, 2,67%, and 71.99%, respectively. No change detected in terms of aw value in vacuum packed dried eggs between the first and 90 days (p>0.05). While the pH value of the fresh roe decreased with pretreatments and drying, TVB-N and TBARs value increased. At the end of the storage period, TVB-N value reached to 42.57mgN / 100g. The total mesophilic aerobe bacteria count of dried roes did not exceed the limit value at the end of the storage period. Total anaerobe mesophilic bacteria, Total Coliform, E. coli, H2S producing bacteria (including S. putrefaciens) and Lactic acid bacteria counts of fresh and vacuumed dried roes were below detectable limit values (<0.30 LogCFU/g). In conclusion, it has been determined that vacuum-packed dried rainbow trout roes can be safely consumed for 60 days at ±4oC.