Riaz Tahreem, Iqbal Muhammad Waheed, Jiang Bo, Chen Jingjing
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu 214122, China.
School of Food and Biological Engineering, Jiangsu University, Zhenjiang, China.
Int J Biol Macromol. 2021 Sep 1;186:472-489. doi: 10.1016/j.ijbiomac.2021.06.196. Epub 2021 Jul 2.
Xanthan gum (XG), a bacterial polysaccharide has numerous valuable characteristics in the food, biomedical, pharmaceuticals, and agriculture sector. However, XG has also its particular limitations such as its vulnerability to microbial contamination, inadequate mechanical and thermal stability, unusable viscosity, and poor water solubility. Therefore, XG's structure and conformation need to be modified enzymatically, chemically, or physically to improve its optimistic features and decrease the formation of crystals, increase antioxidant ability, and radical scavenging activity. We have found out different means to modify XG and elaborate the importance and significance of the modified structure of XG. In this review, different enzymes are reviewed for XG degradation, which modifies their structure from different points (main chain or side chain). This article also reviews various physical methods (ultrasound, shear, pressure, sonication, annealing, and heat treatments) based on prevailing publications to alter XG conformation and produce low molecular weight (LMW) and less viscous end-product. Moreover, some chemical means are also discussed that result in modified XG through crosslinking, grafting, acetylation, pyruvation, as well as by applying different chemical agents. Overall, the current progress on XG degradation is very auspicious to develop a new molecule with considerable uses, in various industries with future assessments.
黄原胶（XG）是一种细菌多糖，在食品、生物医学、制药和农业领域具有许多宝贵特性。然而，XG也有其特殊局限性，比如易受微生物污染、机械和热稳定性不足、粘度不合适以及水溶性差。因此，需要通过酶法、化学法或物理法对XG的结构和构象进行修饰，以改善其优良特性，减少晶体形成，提高抗氧化能力和自由基清除活性。我们已经找到了不同的方法来修饰XG，并阐述了XG修饰结构的重要性和意义。在这篇综述中，我们对用于XG降解的不同酶进行了综述，这些酶从不同角度（主链或侧链）修饰其结构。本文还基于现有文献综述了各种物理方法（超声、剪切、压力、超声处理、退火和热处理），以改变XG的构象并产生低分子量（LMW）和低粘度的终产物。此外，还讨论了一些化学方法，这些方法通过交联、接枝、乙酰化、丙酮酸化以及应用不同化学试剂来实现对XG的修饰。总体而言，目前XG降解方面的进展对于开发一种在各个行业具有广泛用途且有待未来评估的新分子非常有利。
