Effect of Artemisia sphaerocephala Krasch gum on the gel properties of myofibrillar protein and its application in cooked sheep sausage

Abstract

Artemisia is widely distributed in desert areas northern China. Its seeds are rich in water-insoluble gelatin Artemisia sphaerocephala Krasch gum (ASKG) and frequently utilized for various types of pasta making. This study aims at wider utilization of the ASKG in food industry and to improve the gel properties of the myofibrillar protein-based food system containing starch. Firstly, the influence of ASKG on pasting and retrogradation of potato starch (PS) was discussed. Also, the rheological properties, emulsification properties, microstructure, protein conformation, and textural properties of sheep meat myofibrillar protein (SMP)/ASKG and SMP-potato starch (PS)/ASKG composites were investigated. Besides, the sensory quality and texture of cooked sheep sausage were evaluated to explore the application of ASKG in real complex food system. The stronger hydrophobic interaction of protein and H-bonding formed between components, which may be attributed to transition of α-helix to β-conformation of the protein. The ASKG additive promoted the formation of a more compact and uniform gel network of composites, leading an increase of the water holding capacity (WHC), gel strength and springiness and emulsion stability of SMP composites. The SMP-PS/ASKG-0.5% composites kept the highest WHC about 66.5%, gel strength about 70.57 g, springiness about 0.73 g. Furthermore, ASKG has a retardation effect on the retrogradation of PS. ASKG could delay the water loss and the increase of hardness of sausage during five-day storage, suggesting a visible satisfactory capability of the ASKG to improve the gel texture and storage quality of cooked sheep sausage.