Impact of ultra-high pressure processing on the texture and biochemical profiles of Chinses traditional smoked sausage

Ultra-high pressure (UHP) is an emerging food processing technology showing exciting advantages in meat processing. This work systematically investigated impacts of the UHP on the texture and biochemical profiles of Chinese traditional smoked sausage (CTSS). For this purpose, the CTSS sample filled in the vacuum package was conditioned by UHP for 15 min at different pressure (0, 200, 300, 400, 500 MPa). Remarkable improvements on the water-hold capacity, hardness, sheared force and appearance of the CTSS can be observed under 300 MPa UHP, accompanied with fast reducing of nitrate and microbial colony levels. However, moderate fat oxidation also occurred with increasing pressure. Besides, the flavor of the CTSS sample significantly responded to UHP conditions. Positive changes of flavor associated with the formation and accumulation of volatile sulfur-containing compounds and taste associated with reducing sour and astringent was both clearly recorded with the assistance of UHP. To further understand impacts of UHP on the myofibrils, changes of fragmentation index and functional groups (carboxyl, free Sulfhydryl and Surface hydrophobicity) of the extracted protein was accessed. It was revealed that UHP might be a ideal tool to modify the microstructure of CTSS in the molecular level, which was further evidenced by analyze its protein with differential interference microscopy and SDS-PAGE electrophoresis.超高压（Ultra-high pressure, UHP）是一种新兴食品加工技术，在肉类加工领域展现出极具潜力的应用优势。本研究系统探究了超高压对中式传统烟熏香肠（Chinese traditional smoked sausage, CTSS）的质构与生化特性的影响。为此，将装填于真空包装的中式传统烟熏香肠样品置于不同压力（0、200、300、400、500 MPa）的超高压环境中处理15分钟。实验结果显示，在300 MPa的超高压处理下，中式传统烟熏香肠的持水性、硬度、剪切力与外观均得到显著改善，同时硝酸盐含量与微生物菌落数快速降低。但随着压力升高，也会出现适度的脂肪氧化现象。此外，该香肠的风味对超高压处理条件存在显著响应：经超高压处理后，可清晰观测到两类积极变化——其一，风味层面，挥发性含硫化合物的生成与积累促成了正向风味改善；其二，口感层面，酸涩感得到有效缓解。为进一步明晰超高压对肌原纤维的影响，本研究对提取的蛋白质的碎裂指数以及羧基、游离巯基、表面疏水性等官能团的变化进行了检测分析。研究结果表明，超高压可作为一种理想工具在分子层面调控中式传统烟熏香肠的微观结构，这一结论通过差示干涉显微镜与十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE electrophoresis）对蛋白质的分析得到了进一步验证。