อลิศรา ตลึงผล. ผลของทรานส์กลูตามิเนส โซเดียมแอสคอร์เบต บีฟพลาสมาโปรตีน และไข่ขาว ต่อคุณภาพของเจลซูริมิจากปลาทับทิม Oreochromis niloticus x O. placidus. ปริญญาโท(เทคโนโลยีทางอาหาร). จุฬาลงกรณ์มหาวิทยาลัย. สำนักงานวิทยทรัพยากร. : จุฬาลงกรณ์มหาวิทยาลัย, 2547.
ผลของทรานส์กลูตามิเนส โซเดียมแอสคอร์เบต บีฟพลาสมาโปรตีน และไข่ขาว ต่อคุณภาพของเจลซูริมิจากปลาทับทิม Oreochromis niloticus x O. placidus
Effects of transglutaminase, sodium ascorbate, beef plasma protein and egg white on ruby tilapia Oreochromis niloticus x O. placidus surimi gel quality
Abstract:
Suwari (gel setting) and modori (gel disintegration) phenomena of ruby tilapia surimi gel were studied. Food additives such as sodium ascorbate (SA), microbial transglutaminase (MTGase), beef plasma protein (BPP) and egg white (EW) were added to improve gel quality. Gel strength, folding test, color, expressible water and water-holding capacity were determined. Optimum temperature for suwari and modori were studied. The surimi gel was prepared using a 2-step heating process. The gel was first heated at various temperatures (35, 40, 45, 50, 55, 60 and 65 ℃) for 30 minutes followed by 90 ℃ for 20 minutes. The highest and lowest values of gel strength were obtained at 45 ℃ and 65 ℃, respectively. However, changes in folding test and whiteness were not significant (P>0.05). The effect of heating time on suwari (45 ℃) and modori (65 ℃) was investigated. It was found that setting time affected gel qualities (P<0.05). At 45 ℃, a setting time of 90 minutes resulted in a decrease in gel strength (P<0.05). While increasing time from 30 to 60 minutes, the difference in gel was not significant (P>0.05). At 65 ℃, the longer the setting time, the lower in gel strength value (P<0.05). A change in myosin heavy chain (MHC) band was observed by SDS-PAGE. Effects of food additives on gel qualities were studied. SA showed a significant effect on gel strength. The gel strength values significantly increased from 613.23 g.cm (control) to 898.44 g.cm (0.2% SA). Adding MTGase also enhanced gel strength. The highest value, significantly observed at 0.2% MTGase (1488.25 g.cm), increased 2.4-fold compared to that of the control (613.23 g.cm). Moreover, both SA and MTGase could improve whiteness and WHC (P>0.05). Adding BPP and EW at various concentrations (1.0, 2.0 and 3.0% w/w) significantly affected the texture of surimi gel compared with the control (P<0.05). Optimum concentration of BPP and EW were at 2.0% w/w. Although BPP could improve texture, higher level of addition significantly affected whiteness of gel (P<0.05). Comparing the qualities of gels containing each additive with the commercial sample, 0.2% MTGase gave higher values of gel strength, hardness, springiness and cohesiveness than other additives did (P<0.05). Similarly, sensory analysis (quantitative descriptive analysis) indicated that 0.2% MTGase gave the highest scores for hardness and elasticity than others additives did (P<0.05). However, the overall acceptance of 0.2% MTGase was lower than 0.2% SA.