Effect of Gelation Temperature during Water Bath Heating on Gel Performance of Bay Scallop (Argopecten Irradians) Adductor Surimi

To investigate the effect of heating on gel properties of scallop muscle, eight groups of heat-induced gels from bay scallop (Argopecten irradians) adductor were prepared by the conventional one-step (75, 85, 95, 115, 121 ℃) or two-step (35+95, 45+95, 55+95 ℃) water bath heating. Protein structure, texture and microstructural changes in the heat-induced gels were determined. And many exogenous additives were selected for texture modifications with the aims to create potential applications as dysphagia-friendly foods based on bay scallop adductor. The results showed that the total sulfhydryl content of the gel protein tended to decrease with the increase of one-stage heating induction temperature, while the 45+95 ℃ sample group was significantly (P<0.05) higher than the 95 ℃ sample group. Heat induced changes in protein secondary and tertiary structure. The α-helix and β-turn of protein decreased, β-sheet increased, and irregular curl change had on significantly after thermal induction. In the heat-induced gel samples, the highest surface hydrophobicity was found in the 95 ℃ sample group, whereas the lowest was found in the 45+95 ℃ sample group. The TPA, gel strength, whiteness and water holding capacity of heat-induced gels were significantly (P<0.05) different. The hardness, elasticity, chewiness, cohesion, gel strength and water holding capacity of heat-induced gel formed at 45+95 ℃ were the highest. The two-stage heating mode is more conducive to forming a dense and continuous network gel structure for bay scallop adductor surimi. Furthermore, the International Dysphagia Diet Standardization Initiative (IDDSI) framework indicated that the heat-induced gel formed at 45+95 ℃ could be categorized as Level 6 (soft and bite-sized). The water-holding capacity and cooking loss rate of gel with xanthan gum, carrageenan, TGase, konjac flour and egg white were significantly (P<0.05) improved. Meantime, the gel samples with 2.5% xanthan gum and 5% xanthan gum+2% carrageenan could be categorized as level 5 (crumbly and moist) of IDDSI, and gel samples with 2.5% xanthan gum+1.5% carrageenan as level 6 of IDDIS. In conclusion, heating treatment at the appropriate temperature (45+95 ℃) could promote the formation of gel network, resulting in a soft-textural property. This study may provide a theoretical foundation for the creation and design of new dysphagia nutritional food products based on bay scallop adductor added with carrageenan and/or xanthan gum.