Laboratory of Bioactives, Food and Nutrition Graduate Program, Federal University of State of Rio de Janeiro, UNIRIO, Brazil; Center of Innovation in Mass Spectrometry, Laboratory of Protein Biochemistry, UNIRIO, Brazil.
INRAE, Université de Montpellier, Montpellier SupAgro, CIRAD, UMR 1208 IATE, Montpellier, France.
Food Res Int. 2021 Nov;149:110663. doi: 10.1016/j.foodres.2021.110663. Epub 2021 Aug 25.
Sorghum is a potential substitute for corn/wheat in cereal-based extruded products. Despite agronomic advantages and its rich diversity of phenolic compounds, sorghum kafirins group together and form complex with tannins, leading to a low digestibility. Phenolic content/profile by UPLC-ESI-QTOF-MS and kafirins polymerization by SE-HPLC were evaluated in wholemeal sorghum extrudates; tannin-rich (#SC319) and tannin-free (#BRS330) genotypes with/without turmeric powder. Total phenolic, proantocyanidin and flavonoid contents were strongly correlated with antioxidant capacity (r > 0.9, p < 0.05). Extrusion increased free (+60%) and decreased bound phenolics (-40%) in #SC319, but reduced both (-40%; -90%, respectively) in #BRS330, which presented lower abundance after extrusion. Turmeric addition did not significantly impact antioxidant activity, phenolic content and profile and kafirins profile. Tannins presence/absence impacted phenolic profiles and polymerization of kafirins which appears related to the thermoplastic process. The extrusion improved proteins solubility and can positively enhance their digestibility (phenolic compounds-proteins interactions), making more accessible to proteolysis in sorghum extrudates.
高粱是谷物挤压产品中玉米/小麦的潜在替代品。尽管高粱具有农业优势和丰富的酚类化合物多样性，但高粱醇溶蛋白会与单宁形成复合物，导致其消化率较低。本文通过 UPLC-ESI-QTOF-MS 评估了全谷物高粱挤压物中的总酚、原花青素和类黄酮含量及其多酚谱；通过 SE-HPLC 评估了高粱醇溶蛋白的聚合情况；并研究了富含单宁（#SC319）和不含单宁（#BRS330）的基因型，以及添加和不添加姜黄粉的情况。总酚、原花青素和类黄酮含量与抗氧化能力呈强相关性（r>0.9，p<0.05）。挤压处理增加了 #SC319 中的游离酚（增加了 60%），减少了结合酚（减少了 40%），但在 #BRS330 中则减少了两者（分别减少了 40%和 90%），且挤压后其含量更低。添加姜黄粉对抗氧化活性、酚类含量和谱以及醇溶蛋白谱没有显著影响。单宁的存在/不存在会影响酚类谱和醇溶蛋白的聚合，这似乎与热塑性加工过程有关。挤压处理提高了蛋白质的溶解度，并能促进其消化率（酚类化合物-蛋白质相互作用），使高粱挤压物中的蛋白质更易被水解。
