Sensory Characteristics and Microbiological Quality Changes of Nile Tilapia Fillet Processed by Various Sous-vide Conditions During Chilled Storage

Sensory characteristics and microbiological quality of Nile tilapia cooked with various sous-vide (SV) conditions including 50 and 60°C, for 30, 45 and 60 min (S5-30, S5-45, S5-60, S6-30, S6-45 and S6-60) and their changes during storage (4°C) were investigated, compared with control (cooking with boiling water). The result found that increasing temperature and time of SV accelerated protein degradation, both myofibrillar protein and connective tissue. This affected to the lower water-holding capacity (WHC) and shear force of samples treated with severe SV conditions (S6-45 and S6-60) (P<0.05). SV technique may less contribution to the flavor formation, particularly lipid oxidation products, since there were no differences in total volatile base nitrogen (TVB-N) content and thiobarbituric acid reactive substances (TBARS) value among all samples (P>0.05). However, SV cooked samples had higher sensory scores than control, both at day 0 (before storage) or throughout the storage time. This suggested the potential to improve consumer acceptability by this technique. In this study, SV at 60°C, 60 min seem to be the optimal condition for tilapia fillet, which can preserve at 4℃ for at least 6 weeks without any spoilage.