Water activity reduction of intermediate moisture yellowstrip trevally (Selaroides leptolepis)

Water activity reduction of intermediate moisture yellowstrip trevally was studied. The optimal time (8, 12, 16, 20 hrs.) for curing marinade was investigated. The effects of different humectants (glycerol, sorbitol, lactitol, glucose syrup) at 50% w/w of curing ingredients were compared. Results showed that moisture content and water activity of cured yellowstrip trevally decreased as curing time increased (p<0.05). The curing time did not affect shear force, L a b value or acceptability scores, as evaluated by nine-point hedonic scale (p>0.05). However, the hardness of intermediate moisture Yellowstrip trevally, determined by texture analyzer, decreased. Hardness, shear force, L a b value of sample added with various humectants were lower than those of the control (p<0.05), whereas shear force of lactitol-added samples were not different from that of the control (p>0.05). The glycerol-added samples had the highest overall acceptability score and were higher than control, whereas the glucose syrup-added samples had the lowest score. Moisture content of the samples with the addition of various humectants was higher than that of the control (18.28 %). The samples added with glycerol retained the highest moisture (24.94%). The adsorption isotherm studies showed that the equilibrium moisture of sample added with glycerol was higher than that added with lactitol.