Abstract: The objective of this study was to investigate the effect of camellia tea oil on gel strength, water distribution, lipid and protein structure of surimi gels. The results showed that added oil resulted in a significant increase in gel strength, emulsion stability and water-holding capacity of surimi gels (P < 0.05), and when the oil concentration was increased to 8%, these parameters basically kept stable. Under this condition, the gel strength was 225.1 g·cm and the percentage of total expressible fluid (TEF) was 2.60%. Raman spectroscopy analysis revealed that the addition of camellia tea oil changed the structure of lipid and protein in surimi gels, as indicted mainly by the increased width of C?H band, the decreased intensity of O?H band and the increased contents of β-sheet, β-turn and random coil accompanied by the decreased content of α-helix in surimi protein. Meanwhile, with increasing added oil, the water was distributed in a much smaller state in surimi. These findings may further explain the mechanism for the effect of exogenous oil on gel strength, emulsion stability and water-holding capacity of surimi gels.

Key words: surimi gel, gel strength, emulsion stability, water distribution, protein structure, Raman spectroscopy