Effect of drying and frying conditions on physical and chemical characteristics of fish maw from swim bladder of seabass (Lates calcarifer).

BACKGROUND

Swim bladder is generated as a by-product during evisceration. It has been used for the production of fish maw, in which several processing parameters determine the characteristics or quality of the resulting fish maw. The present study aimed to investigate the characteristics of fish maws from seabass swim bladder as influenced by drying and frying conditions.

RESULTS

The expansion ratio and oil uptake content of fish maw increased as the moisture content of swim bladder increased (P < 0.05). Nevertheless, the expansion ratio of fish maw decreased when the moisture content was higher than 150 g kg(-1) . The L*-value decreased, whilst the a*- and b*-values of fish maw increased with increasing moisture content. When pre-frying and frying temperatures increased, the expansion ratio of fish maw increased (P < 0.05). However, the expansion ratio decreased when the frying was performed at a temperature higher than 200 °C. The oil uptake contents of fish maw with frying temperatures of 180 and 200 °C were in the range of 451.06-578.06 g kg(-1) , whereas the lower contents (378.60-417.17 g kg(-1) ) were found in those having frying temperatures of 220-240 °C. Hardness of fish maw decreased but no changes in fracturability were observed with increasing pre-frying temperature when subsequent frying was carried out 200 °C.

CONCLUSION

Drying temperatures, moisture content, pre-frying and frying temperatures were the factors influencing the characteristics and properties of fish maws from seabass swim bladder. Fish maw could be prepared by pre-frying swim bladder, dried at 60 °C to obtain 150 g kg(-1) moisture content, at 110 °C for 5 min, followed by frying at 200 °C for 20 s.