African wild lettuce (Lactuca taraxacifolia Willd.) is an underutilised indigenous leafy vegetable containing essential nutrients and medicinal properties. Hence, this study aimed to determine the chemical composition, antioxidant activities, α-amylase, α-glucosidase and angiotensin converting enzyme inhibitory potentials of wild lettuce leaves powder samples. Freshly harvested Wild Lettuce leaves were processed into whole leafy powder (WLF), extracted powder (WLE), residue (WLR) and leaf protein isolate (WPI). Chemical composition, antioxidant activities, α-amylase, α-glucosidase and angiotensin-converting enzyme inhibitory potentials of the powder samples were determined. Crude protein of Wild Lettuce leaves ranged from 23.27 to 46.57 and crude fiber from 4.17–37.37 g/100 g. Phosphorous was the most abundant element, while zinc had the lowest concentration. The samples essential amino acids, protein efficiency ratio, essential amino acid index and biological values were 39.83–50.65 mg/100 g protein. 2.79–3.51, 77.03–92.36% and 72.26–88.97%, respectively. Saponin, tannin, oxalate, phytate, terpennoids, flavonoid and phenol in the leafy vegetable samples were within tolerable levels. The African wild lettuce leaf protein isolate (WPI) had higher DPPH antioxidant activity (91.88%), percentage inhibitory properties on α-amylase (26.11%), α-glucosidase (64.24%) and angiotensin-1-converting enzyme (97.53%) than WLF (18.28, 25.44, 55.41 and 67.56), WLE (70.85, 24.97, 62.53 and 93.27) and WLR (53.07, 24.68, 50.03 and 85.28) respectively. African wild lettuce leaf samples, particularly protein isolate, contain essential nutrients, antioxidant activities and ability to inhibit angiotensin-1-converting, α-amylase and α-glucosidase enzymes Therefore, the leafy vegetable samples, particularly WPI, may be suitable as antioxidant, antidiabetic and antihypertensive agent.

中文翻译：

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未充分利用的叶菜类蔬菜的营养，抗氧化剂，血管紧张素转化酶和碳水化合物水解酶的抑制作用：非洲野莴苣（Lactuca taraxacifolia Willd）

非洲野生生菜（Lactuca taraxacifolia Willd。）是一种利用不足的本土叶菜类蔬菜，含有重要的营养成分和药用特性。因此，本研究旨在确定野莴苣叶片粉末样品的化学成分，抗氧化活性，α-淀粉酶，α-葡萄糖苷酶和血管紧张素转化酶的抑制潜力。将新鲜收获的野莴苣叶加工成全叶粉（WLF），提取粉（WLE），残留物（WLR）和叶蛋白分离物（WPI）。测定了粉末样品的化学组成，抗氧化剂活性，α-淀粉酶，α-葡萄糖苷酶和血管紧张素转化酶抑制电位。莴苣叶片的粗蛋白范围为23.27至46.57，粗纤维含量为4.17–37.37 g / 100 g。磷是最丰富的元素，而锌的浓度最低。样品中必需氨基酸，蛋白质效率比，必需氨基酸指数和生物学值均为39.83–50.65 mg / 100 g蛋白。分别为2.79–3.51、77.03–92.36％和72.26–88.97％。多叶蔬菜样品中的皂素，单宁，草酸，肌醇六磷酸，萜类化合物，类黄酮和苯酚均在容许水平内。非洲野生生菜叶分离蛋白（WPI）具有较高的DPPH抗氧化活性（91.88％），对α-淀粉酶（26.11％），α-葡萄糖苷酶（64.24％）和血管紧张素1转化酶的抑制百分比（97.53％）比WLF（18.28、25.44、55.41和67.56），WLE（70.85、24.97、62.53和93.27）和WLR（53.07、24.68、50.03和85.28）分别高。非洲野生莴苣叶样品，尤其是蛋白质分离物，含有必需的营养素，