Determination of the effect on quality characteristics and practicability of freeze-drying technology on trout (Oncorhynchus mykiss, Walbaum 1792) mince

In this research was aimed to determination of process on stage quality characteristic and applicability of freeze dried technology on trout (Oncorhynchus mykiss Walbaum, 1792) mince. Sample groups were established as fresh trout mince, freeze dried trout mince and rehydrated trout mince after freeze dried. In the samples group were carried out protein%, fat%, moisture% and ash% analyses, Thiobarbituric acid (TBA), pH, rehydration ratio, water activity (aw), color and texture analyses, aminoacid, fatty acid, vitamin, mineral and sensory analyses. The protein, fat, moisture and ash values of the fresh trout mince, freeze dried trout mince and rehydrated trout mince were determined as 20.25±0.04%, 10.75±0.03%, 67.54±0.29% and 1.38±0.03%; 66.41±0.02%, 23.53±0.02%, 2.11±0.01% and 5.20±0.05%; 34.03±0.59%, 14.00±0.06%, 50.01±0.00% and 1.96±0.20% respectively (p<0.05). Water activity of the fresh trout mince, freeze dried and rehydrated trout mince were measured as 0.96±0.00 mg/kg, 0.19±0.02 mg/kg and 0.97±0.00 mg/kg, respectively (p<0.05). According to color analysis L values of fresh trout mince, freze dried trout mince and rehydrated trout mince were determined as 57.16±0.20, 77.34±0.72 and 74.00±1.41, respectively. While a* values in the same groups -0.46±0.23, 3.41±0.21 and 1.63±0.37; b* values were measured as 20.79±0.36, 27.79±0.68, 29.64±0.36, respectively (p<0.05). Texture Profile Analysis was investigated in terms of hardness, adhesiveness, resilience, fracturability, cohesiveness, springiness, gumminess and chewiness. In addition to TBA amount, rehydration ratio, aminoacid (p<0.05), fatty acid, vitamin (D, E, B1) (p<0.05), mineral (Mg, Na, P, Ca) (p<0.05), analyses and sensory analyses were carried out in the sample groups.