Thermo-irreversible konjac glucomannan gels: Preparation, mechanism, and applications

The unique gelling properties of konjac glucomannan (KGM) have been utilized to produce a variety of gel products. However, KGM gels obtained from the existing preparation methods have several problems including sensory deterioration, instability during processing, and poor mechanical properties (especially insufficient gel strength), which make it difficult to meet the demand. The formation and number of cross-linking points are critical for the construction of the gel network and affect the mechanical properties of the gel. Based on this, an in-depth understanding of the formation process and related mechanisms is important for the quality improvement of KGM gel products. The present review discussion aims to elucidate the formation and related mechanisms of KGM gels, focusing on the alkali-induced thermo-irreversible KGM gels firstly. Then, this work systematically studies the development of alkali-induced thermo-irreversible gels in homogeneous and heterogeneous systems, from the swelling of KGM to the formation of gel network cross-linking points to the establishment of the gel network. Furthermore, it offers a review of post-gelation methods utilized to improve the mechanical properties of KGM gels. Finally, the potential applications of KGM gels are discussed. This study aims to advance innovation in polysaccharide-based gels creation.