Abstract:
The main purpose of this study was to investigate the effects of supplementary mineral content in feed(0,1 and 36%) and salinity levels of water (10,20and 30ppt.) on chemical properties and sensory attributes of frozen black tiger prawn. Control group was prawns raised under optimum level of salinity (20 ppt.) and fed with normal diet (0%mineral). All prawns (9 treatment groups) were kept at -20๐c for 7 months prior to analysis. Based on approximate analysis, there was no significant difference in moisture content (78.21-82.29%), protein content (13.81-18.61%)and lipid content (0.22-0.73%) of prawns raised in different cultivation conditions. Texture Data (TA-XT2) revealed that salinity of water of water statistically affected on firmness (Compression force, Flat cylinder P/6) of prawns (p<0.05). Prawns raised at 30 ppt. of salinity were firmer than those raised at lower salinity (10 ppt.) Nonetheless, no difference was found in toughness (Shear force, Warner-Bratzler blade). After cooking in boiling water for 45 seconds, all cooked prawns lost their weight about 7-19%. In addition, it was found that there was an interaction between supplementary mineral content in feed and salinity of water on cooking loss (p<0.05). Without mineral supplementary mineral content in feed and salinity of water on cooking loss (p<0.05). Without mineral supplemented diet, prawns raised at 30 ppt. possessed higher cooking loss than those raised at 10 ppt(p<0.05). However, at lowest salinity (10 ppt), the increase of mineral content in diet caused higher cooking loss of prawns. According to texture profile analysis(TA-XT2,Flat cylinder P/50) , no difference was found in hardness (96-129N), factorability (83-108 N), and chewiness (43-61 N) among cooked prawns. Trained panelists (n=8) performed descriptive test (Quantitative Descriptive Analysis, 15 attributes) and preference test (9-point Hedonic scale test ) on cooked prawns. The panel concluded that all cooked black Tiger prawns possessed similar sensory profiles such as redness, odor, taste, flavor and texture. Furthermore, the panelists had no difference on overall liking on cooked prawns.