Compositional and nutritional attributes of seeds from the multiple purpose tree Moringa oleifera Lamarck

Moringa oleifera Lam is a multipurpose tree cultivated to use as a vegetable, for spice, for cooking and cosmetic oil and as a medicinal plant. Owing to the use of its seeds as food and as a clarifying agent of turbid water some nutritional and antinutritional characteristics were studied. The mature seeds contained 332.5 g crude protein, 412.0 g crude fat, 211.2 g carbohydrate and 44.3 g ash per kg dry matter. The essential amino acid profile compared with the FAO/WHO/UNU scoring pattern requirements for different age groups showed deficiency of lysine, threonine and valine. The content of methionine + cysteine (43.6 g kg⁻¹ protein), however, was exceptionally higher and close to that of human milk, chicken egg and cow's milk. The seed extract agglutinated rabbit erythrocytes but did not show trypsin inhibitor and urease activities. Feeding rats with a diet containing the seed meal showed loss of appetite, impaired growth, lower NPU and enlargement of stomach, small intestine, caecum + colon, liver, pancreas, kidneys, heart and lungs and atrophy of thymus and spleen in comparison with rats fed on an egg‐white diet. The results indicated that consumption of M oleifera raw mature seeds should be viewed with some caution until suitable processing methods are developed to abolish the yet unknown adverse factors. © 1999 Society of Chemical Industry     

Influences of ultrasonic treatment on structure and functional properties of salt-soluble protein from Moringa oleifera seeds

Influences of ultrasonic treatment on structure and functional properties of salt-soluble protein from Moringa oleifera seeds (MOSSP) were explored. The results indicated that the ultrasonic treatment destroyed spherical structure of MOSSP and transformed the spherical structure into irregular fragments. The content of β-turn, α-helix and random coils in MOSSP significantly increased, but with extending the ultrasound time, the content of β-turn, α-helix and random coils had no significant change. SDS-PAGE results showed that sonication could stabilise the primary structure of MOSSP. The surface hydrophobicity and emulsification were significantly reduced, but sonication could improve the solubility and foaming properties of MOSSP within a certain range.     

Milk-clotting properties on bovine caseins of a novel cysteine peptidase from germinated Moringa oleifera seeds

A cysteine peptidase was previously identified from germinated Moringa oleifera seeds, but its milk-clotting properties on bovine caseins was still unclear. In this study, this novel cysteine peptidase (MoCP) showed preferential activity on κ-casein (κ-CN), with greater hydrolytic activity compared with calf rennet, whereas weak hydrolysis of α-casein and β-casein made MoCP suitable for application in cheesemaking and may yield various functional peptides. All 3 evaluated caseins were hydrolyzed to form relatively stable peptide bands within 3 h of proteolysis with MoCP. Cleavage sites were determined by gel electrophoresis, liquid chromatography mass spectrometry/mass spectrometry, and peptide sequencing, which revealed that cleavage of κ-CN by MoCP occurred at residue Ile129-Pro130 and generated a 14,895.37-Da peptide. The flocculation reaction between MoCP and κ-CN determined by 3-dimensional microscopy with super-depth of field revealed that the initial 30 min of reaction were key for milk coagulation, which may affect curd yield. Overall, the findings presented herein suggest that the cysteine peptidase from germinated M. oleifera seeds can be considered a promising plant-derived rennet alternative for use in cheese manufacture.     

辣木叶水溶性蛋白的超声-微波萃取及其性质研究

研究辣木叶中可溶性蛋白的提取工艺及其性质。采用超声-微波协同萃取方法提取辣木叶中可溶性蛋白,在单因素实验的基础上,通过Box-Behnken中心组合实验确定最佳工艺参数,并对蛋白质氨基酸组成进行分析。实验结果表明:当料液比1∶160（g/m L）,微波功率40 W,提取时间127 s,p H11,在此工艺条件下,辣木叶蛋白得率为40.11 mg/g。氨基酸分析表明,辣木叶可溶性蛋白中必需氨基酸含量为280.7 mg/g,含硫氨基酸含量较高,苏氨酸为第一限制性氨基酸。差示扫描量热仪（DSC）分析表明辣木叶可溶性蛋白的变性温度为113.7℃。      

Polyphenolic content and antioxidant properties of Moringa oleifera leaf extracts and enzymatic activity of liver from goats supplemented with Moringa oleifera leaves/sunflower seed cake

The study investigated antioxidant potency of Moringa oleifera leaves in different in vitro systems using standard phytochemical methods. The antioxidative effect on the activities of superoxide dismutase (SOD), catalase (CAT), lipid peroxidation (LPO) and reduced glutathione (GSH) were investigated in goats supplemented with M. oleifera (MOL) or sunflower seed cake (SC). The acetone extract had higher concentrations of total flavonoids (295.01 ± 1.89 QE/g) followed by flavonols (132.74 ± 0.83 QE/g), phenolics (120.33 ± 0.76 TE/g) and then proanthocyanidins (32.59 ± 0.50 CE/g) than the aqueous extract. The reducing power of both solvent extracts showed strong antioxidant activity in a concentration dependent manner. The acetone extract depicted higher percentage inhibition against DPPH, ABTS and nitric oxide radicals which were comparable with reference standard antioxidants (vitamin C and BHT). MOL increased the antioxidant activity of GSH (186%), SOD (97.8%) and catalase (0.177%). Lipid peroxidation was significantly reduced by MOL. The present study suggests that M. oleifera could be a potential source of compounds with strong antioxidant potential.     

辣木籽粗多糖的分级提取及抗氧化活性

为了更好地开发与利用辣木籽,以辣木籽为原料,研究了不同体积分数乙醇（20%、40%、60%、80%）分级醇沉得到的辣木籽粗多糖（P20、P40、P60、P80）的单糖组成差异以及抗氧化活性,并采用紫外可见光谱（UV-Vis）和傅里叶红外光谱（FT-IR）对纯化后的辣木籽多糖结构进行表征。结果表明：4种辣木籽粗多糖的主要成分均为鼠李糖（Rha）、半乳糖（Gal）和葡萄糖（Glc）,其中粗多糖P80中单糖总含量最高（84.09 μg/mg）;在4种辣木籽粗多糖中,P20（1 mg/mL）对DPPH自由基和超氧阴离子自由基清除率均最高,分别为50.24%、34.54%,P40（1 mg/mL）对羟自由基清除率最高,为76.92%,P80的总还原力最强;通过UV-Vis和FT-IR表征可知,不同体积分数乙醇能够对辣木籽粗多糖进行分级醇沉。综上,采用不同体积分数乙醇进行醇沉的辣木籽粗多糖有不同的抗氧化活性,需要根据具体应用有针对性地提取。     

多油辣木不同部位营养成分分析及评价

以北方辣木叶为对照,分析了多油辣木不同部位的常规营养成分、氨基酸含量与组成、维生素与矿物质。结果表明:在多油辣木不同部位中,叶中蛋白质、维生素E、维生素C、维生素B6、β-胡萝卜素、Mg、Ca与P含量最高,分别为7.00 g/100 g、4.15 mgα-TE/100 g、188.20 mg/100 g、1.53 mg/100 g、0.10 g/kg、35.32 mg/100 g、69.72 mg/100 g与63.94 mg/100 g。茎中膳食纤维、Cu、Zn与Mn含量最高,分别为15.50 g/100 g、0.22 mg/100 g、0.89 mg/100 g与1.82 mg/100 g。果中叶酸、K与Na含量最高,分别为46.76μg/100 g、120.68 mg/100 g与49.46 mg/100 g。根中碳水化合物与Fe含量最高,分别为5.56 g/100 g与4.65 mg/100 g。与北方辣木叶相比,多油辣木叶中的水分、脂肪、蛋白质、烟酸、维生素B6、Mg、Fe、Zn、Na、Mn与P含量较高。多油辣木叶与果中均含有17种氨基酸,以谷氨酸与天冬氨酸含量居多。多油辣木叶中必需氨基酸与总氨基酸总量较高,分别为2.32 g/100 g与5.95 g/100 g,氨基酸比值系数分为69.71,属于优质蛋白质。在各种必需氨基酸中,多油辣木叶的第一限制氨基酸均为蛋氨酸+胱氨酸,多油辣木茎与根的为异亮氨酸,多油辣木果的为赖氨酸。      

辣木籽凝乳酶的提取分离条件优化

为给辣木籽凝乳酶的开发利用提供理论依据,以脱脂辣木籽粉为原料,采用盐法提取、硫酸铵(AS)分级沉淀和离子交换色谱法提取分离凝乳酶。通过单因素试验和正交试验对辣木籽凝乳酶的盐法提取条件进行优化,采用单因素试验对离子交换色谱法分离纯化条件进行优化,并采用SDS-PAGE和RP-HPLC对分离得到的辣木籽凝乳酶的分子质量和纯度进行分析。结果表明：盐法提取的最佳条件为料液比1∶10、提取温度30℃、pH 7.15、NaCl浓度0.3 mol/L、提取时间0.5 h;在20%～40%AS饱和度下的沉淀蛋白凝乳活性最好且蛋白质总占有率达61.71%;离子交换色谱法的最佳分离条件为进样质量浓度30 mg/mL、流动相pH 5.15、流速1.68 mL/min、流动相组成为0.05 mol/L醋酸钠+0.05 mol/L氯化钠,在此条件下辣木籽凝乳酶的凝乳比活力值达到24 SU/mg;该凝乳酶的分子质量主要分布在35～45 kDa,纯度达到90%以上。采用该方法能有效提取分离辣木籽凝乳酶,且能很好地保持其凝乳活性。     

辣木叶总黄酮的提取及其降血糖作用

采用乙醇回流法从辣木叶中提取黄酮类化合物,经AB-8型大孔吸附树脂柱纯化获得辣木叶总黄酮（TFM）;以四氧嘧啶糖尿病小鼠为动物模型,以中成药消渴丸为对照,进行TFM的降血糖动物试验研究。结果表明TFM能明显降低糖尿病模型小鼠的血糖,同时能提高血清SOD活力,降低血清MDA含量,但TFM对正常小鼠的血糖水平无影响。     

辣木叶多糖的分离纯化及其体外降糖活性研究

目的研究辣木叶多糖的制备、单糖组成以及体外降糖活性。方法采用水提醇沉、Sevage法、大孔树脂-阴阳离子交换树脂联用技术得到较高纯度辣木叶粗多糖,再进一步通过二乙氨基乙基纤维素和葡聚糖凝胶柱层析分离得到2个主要多糖组分(MOs-2-a、MOs-2-b),并通过水解衍生化对其单糖组成进行分析。此外,采用HepG2细胞建立胰岛素抵抗模型,以细胞葡萄糖消耗量为指标,考察辣木叶多糖的降糖作用。结果本文采用的制备工艺可以得到较高纯度的辣木叶粗多糖(纯度为73.10%),辣木叶多糖主要由甘露糖、鼠李糖、葡萄糖及半乳糖组成,其中各单糖摩尔比为0.49:3.65:0.63:1.27。与模型组相比,辣木叶多糖组分MOs-2-a、MOs-2-b均能显著增加胰岛素抵抗HepG2细胞的葡萄糖消耗量(P0.05)。结论辣木叶多糖MOs-2-a、MOs-2-b具有良好的降糖效果,本文可以为辣木叶多糖作为功能食品发展的提供科学依据。     

辣木叶抗氧化活性研究及活性成分含量测定

目的:确定辣木叶抗氧化有效部位,建立HPLC测定辣木叶中新绿原酸和异槲皮苷含量的方法。方法:采用体外方法评价辣木叶提取物四个部位石油醚萃取物、乙酸乙酯萃取物、总奎宁酸和总黄酮的抗氧化活性;采用HPLC,选择Sepax Sapphire C₁8（250 mm×4.6 mm,5μm）色谱柱,流动相为乙腈-0.05%磷酸溶液梯度洗脱,流速为1 mL/min,检测波长330 nm,柱温30℃。结果:以异槲皮苷为代表的黄酮类成分和新绿原酸等奎宁酸类成分清除能力最强,二者浓度大于800μg/m L时,对DPPH清除率达80%以上,且对DPPH和羟自由基清除率均高于石油醚和乙酸乙酯萃取物;新绿原酸和异槲皮苷在检测范围内线性关系良好,平均加样回收率分别为98.84%、98.70%,RSD均小于3.0%。结论:辣木叶抗氧化有效部位为总奎宁酸和总黄酮;该方法简便可靠,可作为辣木叶中新绿原酸和异槲皮苷的定量分析方法。