Ribeiro Gabriela, Piñero María-Ysabel, Parle Florencia, Blanco Belén, Roman Laura
CARTIF Technology Centre, Boecillo, 47151 Valladolid, Spain.
Food Technology Area, Department of Agricultural and Forestry Engineering, University of Valladolid, Av. Madrid, 50, 34004 Palencia, Spain.
Foods. 2024 Jun 2;13(11):1748. doi: 10.3390/foods13111748.
Soy remains the legume protein of excellence for plant-based meat alternatives due to its fiber-forming potential. In this study, protein-rich powders from soy protein isolate (SPI), concentrate (SPC), and their mixture (SPM) were thoroughly characterized for their proximate composition, nutritional quality, and physicochemical properties to understand their structuring behavior during high-moisture extrusion. SPI presented higher degrees of protein denaturation and aggregation, least gelation concentration and lower essential amino acid contents. Thus, an SPI:SPC combination (1:9 ratio, 70% protein) was extruded at three different screw speeds (300, 350, and 400 rpm) and two temperature profiles (120 and 140 °C maximum temperature). The effects of the processing parameters on the extrudates were evaluated for their appearance (fibrousness), texture (TPA, cutting force, and anisotropy), color, protein structure (FTIR), and trypsin inhibitors. Higher temperatures resulted in softer and darker extrudates, with increased visual and instrumental anisotropy. Increasing screw speeds led to softer and lighter extrudates, without a clear fibrousness effect. β-sheet structures decreased and intermolecular aggregates (A1) increased after extrusion, especially at 140 °C, together with the formation of intramolecular aggregates (A2). Extrusion also significantly decreased the amount of trypsin inhibitors (>90%). This study demonstrates that extrusion parameters need to be carefully selected to achieve meat analogs with optimal textural and nutritional characteristics.
由于大豆具有形成纤维的潜力，它仍然是植物性肉类替代品中优质的豆类蛋白质。在本研究中，对大豆分离蛋白（SPI）、浓缩蛋白（SPC）及其混合物（SPM）的富含蛋白质的粉末进行了全面表征，分析其近似组成、营养质量和理化性质，以了解它们在高水分挤压过程中的结构化行为。SPI表现出更高程度的蛋白质变性和聚集、最低的凝胶化浓度以及较低的必需氨基酸含量。因此，将SPI:SPC组合（1:9比例，70%蛋白质）在三种不同的螺杆转速（300、350和400转/分钟）和两种温度曲线（最高温度120和140°C）下进行挤压。评估了加工参数对挤出物外观（纤维性）、质地（TPA、切割力和各向异性）、颜色、蛋白质结构（FTIR）和胰蛋白酶抑制剂的影响。较高的温度导致挤出物更软、颜色更深，视觉和仪器各向异性增加。螺杆转速增加导致挤出物更软、颜色更浅，没有明显的纤维性影响。挤压后β-折叠结构减少，分子间聚集体（A1）增加，尤其是在140°C时，同时形成分子内聚集体（A2）。挤压还显著降低了胰蛋白酶抑制剂的含量（>90%）。本研究表明，需要仔细选择挤压参数，以获得具有最佳质地和营养特性的肉类模拟物。
