Vegetable by-products, obtained from cauliflower (CA), broccoli (BRL), cabbage (CB) and beetroot (BR) can be a potentially good source of proteins. The proteins were obtained from leaves (LPs) of vegetables with alkaline extraction at pH 10, and their isoelectric precipitation at pH 4. Protein contents were in the range of 39.76 - 53.33%, and the molecular weights of fractions were mostly about 45, 25 and 14 kDa. Their solubility is higher in the alkaline environment, where they reach the highest solubility at pH 10 (9.7 mg/mL for CALP, 8.45 for BRLP, 5.35 mg/mL for CBLP, 5.5 mg/mL for BELP). Moreover, they showed favorable emulsifying abilities, water absorption capacities (0.62 to 1.61 g/g) and foaming capacity (86.3 to 92%) as well as stability (48.57 to 79.30%). Digestibility was studied using gastrointestinal proteases (pepsin and pancreatin), and all four LPs can easily be digested. The biologically active potential of the digests was evaluated measuring antioxidant capacity by two complementary methods – DPPH+ and ABTS+ radical cation scavenging activity. The values for DPPH+ and ABTS+ were in the range from 59 to 65.1% at 0.1 and 0.3 mg/ml to 0.22 mg/ml IC50 values, respectively. Therefore, it can be indicated from these results, that obtained LPs, owing to their good functional properties, may be considered as potential ingredients of health-promoting food and cosmetic products.

中文翻译：

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植物副产品作为功能性蛋白质的新来源

从花椰菜 (CA)、西兰花 (BRL)、卷心菜 (CB) 和甜菜根 (BR) 中提取的蔬菜副产品可能是蛋白质的潜在良好来源。蛋白质取自蔬菜叶片（LPs），pH 10 碱提，pH 4 等电沉淀。蛋白质含量范围为39.76 - 53.33%，馏分分子量大多在45、25左右和 14 kDa。它们在碱性环境中的溶解度更高，在 pH 10 时它们的溶解度最高（CALP 为 9.7 mg/mL，BRLP 为 8.45，CBLP 为 5.35 mg/mL，BELP 为 5.5 mg/mL）。此外，它们显示出良好的乳化能力、吸水能力（0.62 至 1.61 g/g）和发泡能力（86.3 至 92%）以及稳定性（48.57 至 79.30%）。使用胃肠蛋白酶（胃蛋白酶和胰酶）研究消化率，并且所有四个LP都可以轻松消化。通过两种互补的方法——DPPH+ 和 ABTS+ 自由基阳离子清除活性，测量抗氧化能力来评估消化物的生物活性潜力。DPPH+ 和 ABTS+ 的值分别在 0.1 和 0.3mg/ml 至 0.22mg/ml 的 IC50 值下在 59% 至 65.1% 的范围内。因此，从这些结果可以看出，获得的LPs由于其良好的功能特性，可以被认为是促进健康的食品和化妆品的潜在成分。分别为 3 mg/ml 至 0.22 mg/ml IC50 值。因此，从这些结果可以看出，获得的LPs由于其良好的功能特性，可以被认为是促进健康的食品和化妆品的潜在成分。分别为 3 mg/ml 至 0.22 mg/ml IC50 值。因此，从这些结果可以看出，获得的LPs由于其良好的功能特性，可以被认为是促进健康的食品和化妆品的潜在成分。