DETERMINATION OF GLASS TRANSITION TEMPERATURE OF RAINBOW TROUT (ONCORHYNCHUS MYKISS) AND EFFECTS OF VARIOUS CRYOPROTECTIVE BIOPOLYMER BLENDS ON SOME CHEMICAL CHANGES

Sucrose + sorbitol + gum arabic (2 + 2 + 0.15%), sucrose + sorbitol + carrageenan (2% + 2% + 0.15%), sucrose + mannitol + gum arabic (2% + 2% + 0.15%), sucrose + mannitol + carrageenan (2% + 2% + 0.15%), sorbitol + mannitol + gum arabic (2% + 2% + 0.15%) and sorbitol + mannitol + carrageenan (2% + 2% + 0.15%) were blended with ground rainbow trout and stored at glass transition temperature (T-g) of rainbow trout (-13C), determined by differential scanning calorimetry at -9 and -18C for 6 months. Total volatile basic nitrogen (TVB-N) and thiobarbituric acid-reactive substances (TBARS) were determined at 1st, 3rd and 6th months of storage periods. Biopolymer blends and storage period had a significant effect (P < 0.05) on the TVB-N and TBARS values. T-g and -18C showed same effect on TVB-N and TBARS values but -9C has statistically different effect on them.