Abstract:To develop a novel fat substitute，this study constructed a ternary composite system （OPTK） using oat protein （OP），tea polyphenols （TP），and konjac glucomannan （KGM） to prepare high internal phase emulsions （HIPEs） with different oil phase volume fractions （φ=74%-86%），and investigated the effects of substituting pork back fat with HIPEs on the quality of emulsified sausages. The results showed that when φ=82%，the emulsion exhibited the smallest droplet size （25.69 μm） and the most uniform distribution. Substitution with HIPEs significantly reduced cooking loss，water loss，and fat loss. At substitution levels of25% and 50%，the hardness and chewiness were improved compared with the control group，with the 50% substitution group showing the best springiness. Scanning electron microscopy revealed that this group had the most compact and uniform gel network. Sensory evaluation indicated that the 50% substitution group achieved the highest overall acceptability score （8.27）. Oxidative stability analysis demonstrated that HIPEs substitution effectively inhibited lipid oxidation. Considering all indicators，the OPTK-stabilized HIPEs with an oil phase volume fraction of 82% achieved the best overall quality of emulsified sausages when substituting 50% of pork back fat. This study provides a theoretical basis for the development of low-fat meat products.