天然琼脂和双螺杆加工琼脂的胶体特性(RR)分析.doc

Title: Physicochemical properties of native and twin-screw extruded agar gels Author names and affiliations Keyu Wan1, Yulu Chen1, Chun Li1,3, Chao Zhang1, Ning Liu1,2,3 1 Key Laboratory of Dairy Science, Ministry of Education; College of Food Science, Northeast Agricultural University, Harbin 150030, China; 2 National Dairy Engineering Research Center, Harbin 150030, China; 3 Synergetic Innovation Center of Food Safety and Nutrition, Harbin 150028, China Corresponding author Ning Liu Tel. +86-451 fax +86-451E-mail: ningliuneau@ Present/permanent address College of Food Science, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin 150030, China ABSTRACT 天然琼脂(NA)和双螺杆挤压琼脂(TEA)都是属于江蓠属的亲水性胶体，可以广泛的应用到食品、医疗和生物技术等行业中。将NA和TEA制备成浓度为1%的胶溶液，通过NMR研究NA和TEA的结构差异，发现NA的4连接的3,6-脱水-L-半乳糖(3,6-anhydro-α-L-galactose, LA)’’)更强。这与对NA和TEA两种凝胶在线性粘弹区内进行的流变学分析结果一致。同时FTIR研究表明TEA的羟基基团比NA的含量高,表现为TEA比NA的亲水性更强，保水能力高，这与扫描电子显微镜(SEM)的分析结果一致。本研究的结果表明，NA具有更高的凝胶强度和粘弹性，TEA具有更好的保水性能，可以利用不同的特性应用到具体的生产中，开发新产品，提高生产效率。 Keywords: Native agar; Twin-screw extruded agar; Rheology; Hydrocolloid; Physicochemical properties 1. Introduction 天然琼脂又称为琼胶，是特定海洋红藻主要江蓠和石花菜属中发现的水溶性的和形成凝胶的多糖混合物。琼脂是非常有用的质地改性剂，在食品工业生产中用作纹理设计(Nakauma, Ishihara, Funami, Yamamoto, Higashimori, 2014; Nishinari, 2009; Wang, Yang, Brenner, Kikuzaki, Nishinari, 2014)。在非常低的浓度条件下，仍然具有显著的胶凝能力，这种胶凝能力受到琼脂的种类、形状、取代程度和分子量影响由于琼脂的热滞后性形成热可逆的物理凝胶(M. Lahaye and C. Rochas, 1991; K. T. Nijenhuis, 1991; S. Boral, A. Saxena and H. B. Bohidar, 2008)，使其广泛的应用于食品、医疗、生物技术以及生物医药等行业( D. J. McHugh, 2003; F. Pereira-Pacheco, D. Robledo, L. Rodriguez-Carvajal and Y. Freile-Pelegrin, 2007; J. B. Romero, R. D. Villanueva and M. N. E. Montano, 2008; Z. Cao, R. J. Gilbert and W. He, 2009; N. Benmouhoub, N. Simmonet, N. Agoudjil and T. Coradin, 2008; T. Singh, T. J. Trivedi and A. Kumar, 2010; V. T. Nayar, J. D. Weiland, C. S. Nelson and A. M. Hodge, 2012; V. Kumar and R. Fotedar, 2009; P.-L. Lam, K.