Changes in sensory and chemical quality in vacummed rainbow trout (Oncorhynchus mykiss walbaum,1792)when producing caviar and storageing

In this study, sensorial and chemical changes of caviars obtained from rainbow trouteggs were examined during storage time. For this purpose, the eggs were immersed from maturefemale fish and they were cleaned by washing with 5% NaCl solution. Then they were kept in25% NaCl solution at 40 ºC for brine. After strained, alcohol adding and dry salting, thesamples were vacuum- packaged in polyethylene bags and storaged in refrigerator (4±1 ºC) for84 days.Some chemical characteristics (moisture, lipid, protein, ash, salt, TVB-N and pH) ofcaviars were determined in 0, 7, 14, 21, 28, 42, 56, 70 and 84 days of preservation. In addition,the caviars were sensorialy tested in the same days of preservation above by a panelist groupconsisting of 10 people.While the value of moisture was 63.90% in untreated eggs, it was rapidly reduced to42.57% in the treated eggs. In day 7, it was slightly increased (49.17%) and then stayed stable indays 14-84 (48.75%-50.74%). While lipid and protein values were 11.07% and 23.23% in theuntreated eggs respectively, they reached 11.81% and 25.48% in the just treated eggs (in day 0).While ash ratio was 2.01% in untreated eggs, it increased to 12.47% in the treated eggs andstayed in the same value during preservation time. While salt value was 1.4.3% in the untreatedeggs, it was 14.03% in the eggs treated for caviars and this salt ratio did not change duringpreservation time. TVB-N value was found as 6.19mg/100g in the untreated eggs. Although itslightly increased to 6.19mg/100g in the treated eggs and stayed stable during the preservationtime, it reached to 6.99mg/100g in day 84. pH value was assessed as 7.77 in the untreated eggs.It reduced to 5.99 in day 0 and stayed stable in the following days, but pH value was measuredas 6.02 at the end of preservation time.The sensorial analysis showed that fried samples had higher point than uncookedsamples by panelists. In addition, the samples kept their eatable characteristics during thepreservation time.In conclusion, it was determined that treated and vacuumed caviars of rainbow trout canbe kept in refrigerator for nearly three mounts without spoilage.Key Words: Rainbow trout (Oncorhynchus mykiss W.), Caviar, Vacuuming, Chemicalquality, Sensorial quality.