Interaction of different polysaccharides and protein on physicochemical and microstructural characteristics of fish emulsion sausages from threadfin bream surimi

Abstract The impacts of different types of polysaccharides: TS (tapioca starch), MTS (modified TS), TKP (native tamarind kernel powder, 20.17% xyloglucan) and HTKP (high-pressure modified TKP, 52.24% xyloglucan), on the physicochemical and microstructural properties of fish emulsion sausages from threadfin bream (Nemipterus hexodon) surimi were investigated. The physicochemical properties included colour value (L* a* b*), textural properties (TPA), cooking loss, total expressible fluid (TEF), and secondary structure. Microstructures were observed by scanning electron microscopy and confocal laser scanning microscopy. Sausages with HTKP exhibited the highest values of hardness and chewiness with superior emulsion stability. The sausages had similar secondary structures. Microstructural analysis revealed increased thickness of the protein network and a large number of evenly distributed tiny oil droplets. The addition of HTKP enhanced the properties of fish emulsion sausages, caused by interactions between myofibrillar proteins and tamarind seed proteins, while xyloglucan acted as a filler in the protein network.