Kebede Yikeber Simachew, Teferra Tadesse Fikre
School of Nutrition, Food Science and Technology, Hawassa University College of Agriculture, Hawassa, Ethiopia.
Department of Food Science and Technology, Wachamo University, Hosaena, Ethiopia.
Heliyon. 2023 Feb 24;9(3):e14027. doi: 10.1016/j.heliyon.2023.e14027. eCollection 2023 Mar.
Pulses provide a significant nutritional potential for the large proportion of the population in developing countries. Lupine is among the underutilized legume crops for human food in Ethiopia and globally concomitant to its contents of bitter alkaloids. This research was initiated to investigate the effects of soaking lupine seeds of bitter and sweet varieties in water and 2% sodium carbonate (NaCO) solutions as grain softener on the protein extraction efficiency and its sensory acceptability. It was hypothesized that the soaking treatment results in the removal of characteristic bitterness when coupled with thermal treatment (roasting). The result showed that soaking in NaCO significantly increased the protein extraction efficiency (both protein yield and quality (purity)) in the two lupine cultivars. The roasting treatment did not help much. The bitter variety of lupine soaked in NaCO with no roasting treatment gave the highest protein yield (39.45%), while the sweet variety soaked in water followed by roasting exhibited the least protein yield (23.25%). The purity of the protein isolates from the lupine samples soaked in 2% NaCO followed by roasting was the highest (92.29%). The non-soaked samples of the sweet variety after roasting resulted in the lowest purity (75.05%). The water holding, and oil absorption capacity, as well as the emulsification activity and foaming capacity of the protein isolates were significantly varied for the lupine varieties, and by the soaking and roasting treatments. Higher (314.38%) WHC was recorded for the protein isolates from sweet variety soaked in NaCO, where the bitter variety, when soaked in 2% NaCO without roasting gave protein isolates of higher emulsion and foaming capacities. The research revealed also that soaking of lupine seeds in grain softeners shows a great potential as a pretreatment for enhanced protein extraction and functional desirability (in terms of emulsion and foaming capacities) as well as sensory acceptability and can be recommended for scaling up at industrial level.
豆类为发展中国家的大部分人口提供了巨大的营养潜力。在埃塞俄比亚乃至全球，羽扇豆作为人类食物的未充分利用豆类作物之一，其含有苦味生物碱。本研究旨在调查将苦、甜两种羽扇豆品种的种子分别浸泡在水和2%碳酸钠（NaCO）溶液（作为谷物软化剂）中对蛋白质提取效率及其感官可接受性的影响。研究假设浸泡处理与热处理（烘焙）相结合可去除羽扇豆特有的苦味。结果表明，浸泡在NaCO中显著提高了两个羽扇豆品种的蛋白质提取效率（包括蛋白质产量和质量（纯度））。烘焙处理的帮助不大。未经烘焙处理而浸泡在NaCO中的苦羽扇豆品种蛋白质产量最高（39.45%），而先浸泡在水中再烘焙的甜羽扇豆品种蛋白质产量最低（23.25%）。浸泡在2%NaCO中再烘焙的羽扇豆样品分离出的蛋白质纯度最高（92.29%）。烘焙后的甜羽扇豆未浸泡样品的纯度最低（75.05%）。羽扇豆品种以及浸泡和烘焙处理显著改变了蛋白质分离物的持水能力、吸油能力、乳化活性和起泡能力。浸泡在NaCO中的甜羽扇豆品种的蛋白质分离物记录到较高的持水能力（314.38%），而浸泡在2%NaCO中未经烘焙的苦羽扇豆品种的蛋白质分离物具有较高的乳化和起泡能力。研究还表明，将羽扇豆种子浸泡在谷物软化剂中作为预处理方法，在提高蛋白质提取率、功能特性（如乳化和起泡能力）以及感官可接受性方面具有巨大潜力，可推荐在工业规模上扩大应用。
