Ngui Simon Pierre, Nyobe Carine Emilienne, Bakwo Bassogog Christian Bernard, Nchuaji Tang Erasmus, Minka Samuel René, Mune Mune Martin Alain
Department of Biochemistry, University of Yaoundé I, PO Box 812, Yaoundé, Cameroon.
Centre for Food and Nutrition Research, PO Box 6163, Yaoundé, Cameroon.
Heliyon. 2021 Aug 18;7(8):e07824. doi: 10.1016/j.heliyon.2021.e07824. eCollection 2021 Aug.
Bambara bean is a rich low-cost protein source and a functional ingredient in the food industry. We investigated the effects of temperature and different pH on the physicochemical and functional properties of Bambara bean protein isolate. Vicilin was the major protein of Bambara bean as revealed by SDS PAGE analysis. The emulsifying capacity of protein isolate was highest at 80 °C, pH 9 while emulsion stability was highest at pH 4. Generally, increase in temperature decreased protein solubility at pH 4 and 7, while increase was observed at pH 9 and 100 °C. The hydrophobicity of isolate was highest at pH 4 and lowest at pH 9, regardless of temperature. Protein isolate possessed highly compact β-sheet and α-helix secondary structures in proportions greater than 75% (at pH 9 and 50 °C). Increase in temperature generally promoted protein rearrangement and partial unfolding. Protein secondary structure and surface hydrophobicity can predict food functionality, directly affecting protein behavior during formulation and long-term storage. This study clearly demonstrated the potential of exploiting pulse protein isolates as nutritional and functional ingredients through temperature and pH control.
豇豆是一种丰富的低成本蛋白质来源，也是食品工业中的一种功能性成分。我们研究了温度和不同pH值对豇豆分离蛋白理化性质和功能特性的影响。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS PAGE）分析表明，豌豆球蛋白是豇豆的主要蛋白质。分离蛋白的乳化能力在80℃、pH 9时最高，而乳液稳定性在pH 4时最高。一般来说，温度升高会降低pH 4和7时的蛋白质溶解度，而在pH 9和100℃时则观察到溶解度增加。无论温度如何，分离蛋白的疏水性在pH 4时最高，在pH 9时最低。分离蛋白具有高度紧密的β-折叠和α-螺旋二级结构，比例大于75%（在pH 9和50℃时）。温度升高通常会促进蛋白质重排和部分展开。蛋白质二级结构和表面疏水性可以预测食品功能，直接影响蛋白质在配方和长期储存过程中的行为。本研究清楚地证明了通过温度和pH控制，将豆类分离蛋白开发为营养和功能成分的潜力。
