Abstract：
BACKGROUND: High moisture meat analog (HMMA) products processed using extrusion have become increasingly popular in the last few years. Because the formation of disulfide bonds is believed to play a critical role in the texturization mechanism, this study aimed to understand how chemical compounds capable of reducing disulfide bonds, specifically cysteine, sodium metabisulfite, and glutathione, affect the texture and the chemical interactions between the proteins.
METHODS: Wheat protein blended with cysteine, sodium metabisulfite, or glutathione at levels of 0, 0.5, 1.0, 2.5, 5.0, and 7.5 g kg-1 was extruded at three different temperatures (115, 140, and 165 °C) using a co-rotating twin-screw extruder. The feed rate (85 g min-1), the moisture content (600 g kg-1), and the screw speed (300 rpm) were kept constant. Unextruded and extruded material was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, polymeric protein fractionation, and sulfhydryl group/disulfide bond analysis. Extruded samples were further analyzed for their hardness and their anisotropic index.
RESULTS: The inclusion of reductants significantly affected the structure of the obtained extrudates. Although reducing agents had a relatively small impact on the total amount of disulfide bonds, their action significantly enhanced crosslinking between the proteins. At select conditions, samples with high fibrousness were specifically obtained when cysteine or sodium metabisulfite was included at levels of 5.0 g kg-1.
CONCLUSIONS: In the presence of reducing agents, it is believed that disulfide bonds are split earlier during the process without binding to them, giving the protein strands more time to unravel and align, leading to a better flow behavior and more fibrous products. © 2024 Society of Chemical Industry.
METHODS: Wheat protein blended with cysteine, sodium metabisulfite, or glutathione at levels of 0, 0.5, 1.0, 2.5, 5.0, and 7.5 g kg-1 was extruded at three different temperatures (115, 140, and 165 °C) using a co-rotating twin-screw extruder. The feed rate (85 g min-1), the moisture content (600 g kg-1), and the screw speed (300 rpm) were kept constant. Unextruded and extruded material was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, polymeric protein fractionation, and sulfhydryl group/disulfide bond analysis. Extruded samples were further analyzed for their hardness and their anisotropic index.
RESULTS: The inclusion of reductants significantly affected the structure of the obtained extrudates. Although reducing agents had a relatively small impact on the total amount of disulfide bonds, their action significantly enhanced crosslinking between the proteins. At select conditions, samples with high fibrousness were specifically obtained when cysteine or sodium metabisulfite was included at levels of 5.0 g kg-1.
CONCLUSIONS: In the presence of reducing agents, it is believed that disulfide bonds are split earlier during the process without binding to them, giving the protein strands more time to unravel and align, leading to a better flow behavior and more fibrous products. © 2024 Society of Chemical Industry.
摘要：
背景：使用挤出加工的高水分肉类似物（HMMA）产品在过去几年中变得越来越流行。因为二硫键的形成被认为在质构机制中起关键作用，这项研究旨在了解能够还原二硫键的化合物，特别是半胱氨酸，焦亚硫酸钠，和谷胱甘肽,影响质地和蛋白质之间的化学相互作用。
方法：小麦蛋白与半胱氨酸混合，焦亚硫酸钠，使用同向旋转双螺杆挤出机在三个不同温度（115、140和165°C）下挤出0、0.5、1.0、2.5、5.0和7.5gkg-1水平的谷胱甘肽。进料速率(85gmin-1)，水分含量(600gkg-1)，并且螺杆速度(300rpm)保持恒定。对未挤出和挤出的材料进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳，聚合蛋白分级分离，和巯基/二硫键分析。进一步分析挤出样品的硬度和各向异性指数。
结果:还原剂的包含显著影响所得挤出物的结构。尽管还原剂对二硫键总量的影响相对较小，它们的作用显着增强了蛋白质之间的交联。在选定条件下，当半胱氨酸或焦亚硫酸钠的含量为5.0gkg-1时,特别获得了高纤维度样品.
结论：在存在还原剂的情况下，据信二硫键在此过程中更早地分裂而不与它们结合，给蛋白质链更多的时间来解开和对齐，导致更好的流动行为和更多的纤维产品。©2024化学工业学会。
方法：小麦蛋白与半胱氨酸混合，焦亚硫酸钠，使用同向旋转双螺杆挤出机在三个不同温度（115、140和165°C）下挤出0、0.5、1.0、2.5、5.0和7.5gkg-1水平的谷胱甘肽。进料速率(85gmin-1)，水分含量(600gkg-1)，并且螺杆速度(300rpm)保持恒定。对未挤出和挤出的材料进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳，聚合蛋白分级分离，和巯基/二硫键分析。进一步分析挤出样品的硬度和各向异性指数。
结果:还原剂的包含显著影响所得挤出物的结构。尽管还原剂对二硫键总量的影响相对较小，它们的作用显着增强了蛋白质之间的交联。在选定条件下，当半胱氨酸或焦亚硫酸钠的含量为5.0gkg-1时,特别获得了高纤维度样品.
结论：在存在还原剂的情况下，据信二硫键在此过程中更早地分裂而不与它们结合，给蛋白质链更多的时间来解开和对齐，导致更好的流动行为和更多的纤维产品。©2024化学工业学会。
