Departamento de Engenharia e Tecnologia de Alimentos, Faculdade de Engenharia de Alimentos, Universidade Estadual de Campinas (UNICAMP), Monteiro Lobato, 80, 13083-862 Campinas, SP, Brazil.
Departamento de Ciência de Alimentos e Nutrição, Faculdade de Engenharia de Alimentos, Universidade Estadual de Campinas (UNICAMP), Monteiro Lobato, 80, 13083-862 Campinas, SP, Brazil.
Food Res Int. 2024 May;183:114212. doi: 10.1016/j.foodres.2024.114212. Epub 2024 Mar 12.
This study evaluated the effect of ultrasound treatment combined or not with heat treatment applied to lentil protein isolate (LPI) aiming to enhance its ability to stabilize high internal phase emulsions (HIPE). LPI dispersion (2%, w/w) was ultrasound-treated at 60% (UA) and 70% (UB) amplitude for 7 min; these samples were subjected to and then heat treatments at 70 °C (UAT70 and UBT70, respectively) or 80 °C (UAT80 and UBT80, respectively) for 20 min. HIPEs were produced with 25% untreated and treated LPI dispersions and 75% soybean oil using a rotor-stator (15,500 rpm/1 min). The LPI dispersions were evaluated for particle size, solubility, differential scanning calorimetry, electrophoresis, secondary structure estimation (circular dichroism and FT-IR), intrinsic fluorescence, surface hydrophobicity, and free sulfhydryl groups content. The HIPEs were evaluated for droplet size, morphology, rheology, centrifugal stability, and the Turbiscan test. Ultrasound treatment decreased LPI dispersions' particle size (∼80%) and increased solubility (∼90%). Intrinsic fluorescence and surface hydrophobicity confirmed LPI modification due to the exposure to hydrophobic patches. The combination of ultrasound and heat treatments resulted in a reduction in the free sulfhydryl group content of LPI. HIPEs produced with ultrasound-heat-treated LPI had a lower droplet size distribution mode, greater oil retention values in the HIPE structure (> 98%), lower Turbiscan stability index (< 2), and a firmer and more homogeneous appearance compared to HIPE produced with untreated LPI, indicating higher stability for the HIPEs stabilized by treated LPI. Therefore, combining ultrasound and heat treatments could be an effective method for the functional modification of lentil proteins, allowing their application as HIPE emulsifiers.
本研究评估了超声处理与热处理联合应用于菜豆分离蛋白（LPI）以增强其稳定高内相比乳液（HIPE）能力的效果。将 LPI 分散体（2%，w/w）在 60%（UA）和 70%（UB）振幅下超声处理 7 分钟；这些样品分别经受和随后在 70°C（UAT70 和 UBT70，分别）或 80°C（UAT80 和 UBT80，分别）下热处理 20 分钟。使用转子-定子（15,500 rpm/1 min）制备 25%未经处理和处理的 LPI 分散体和 75%大豆油的 HIPE。评估 LPI 分散体的粒径、溶解度、差示扫描量热法、电泳、二级结构估计（圆二色性和 FT-IR）、固有荧光、表面疏水性和游离巯基含量。评估 HIPE 的粒径、形态、流变学、离心稳定性和 Turbiscan 试验。超声处理降低了 LPI 分散体的粒径（80%）并提高了溶解度（90%）。固有荧光和表面疏水性证实了 LPI 的修饰，因为它暴露于疏水性斑块。超声和热处理的联合处理导致 LPI 的游离巯基含量降低。与用未经处理的 LPI 制备的 HIPE 相比，用超声-热处理处理的 LPI 制备的 HIPE 的粒径分布模式更低，HIPE 结构中的油保留值更高（>98%），Turbiscan 稳定性指数更低（<2），外观更坚固、更均匀，表明用处理过的 LPI 稳定的 HIPE 具有更高的稳定性。因此，超声和热处理的联合处理可能是菜豆蛋白功能改性的有效方法，允许其作为 HIPE 乳化剂应用。
