芝麻萌发工艺条件及抗氧化成分含量变化研究

以芝麻为原料,V_E、芝麻木酚素为评价指标,采用单因素实验、正交实验及相关性分析方法,对芝麻最佳萌发工艺条件及萌发过程中芝麻主要抗氧化成分含量变化进行研究。结果表明,芝麻最佳萌发工艺条件为芝麻∶水=50∶50 g/g、萌发温度35℃、萌发时间8 h。工艺优化后芝麻木酚素含量达到748.83 mg/100 g,较优化前提高了5.39%;芝麻木酚素和V_E含量呈正相关,工艺优化后V_E含量达到546.3 mg/kg,较优化前提高了4.50%。     

Evaluation of bioprocesses to improve the antioxidant properties of chickpeas

Chickpea seeds (Cicer arietinum cv. Blanco lechoso) were submitted to different bioprocesses; i) germination of seeds for 2 and 3 days, ii) natural fermentation of flour or cracked seeds, and iii) induced fermentation of flour or cracked seeds with Lactobacillus plantarum, in order to improve the antioxidant properties. Determination of vitamins C and E, reduced glutathione (GSH) and total phenolic compounds (TPC) were carried out. Antioxidant capacity was measured by SOD-like activity, peroxyl radical-trapping capacity (PRTC), lipid peroxidation inhibition (LPI) and trolox equivalent antioxidant capacity (TEAC). Vitamin C and E increased after germination, whilst fermentation caused a decrease in vitamin E. Both bioprocesses caused an increment in TPC content while GSH decreased. Germination increased SOD-like activity (47-41%), PRTC (16-55%) and TEAC (12-23%) and a slight inhibition of LPI was observed. After fermentation, SOD-like activity suffer a drastic reduction. The LPI decreased between 11.3 and 21.3%, while an increase of TEAC (29-57%) and PRTC (27-44%) was observed, except in flour natural fermented seeds where decreased the PRTC. TPC contributed highly to total antioxidant capacity (TEAC). Results indicated that with the bioprocesses studied the antioxidant properties of chickpea flours are enhanced and they can be used as desired ingredients for new functional food formulations.     

发芽燕麦不同溶剂提取液抗氧化活性的比较

将燕麦种子进行发芽,对未发芽原样、发芽6 d的籽粒、芽和根分别用体积分数80%的甲醇、乙醇和丙酮溶液提取其多酚,测定了不同溶剂提取液的总酚提取率、清除DPPH.自由基的能力、还原能力以及清除亚硝酸盐的能力,并对其差异性及相关性进行了分析。结果表明:发芽前后燕麦多酚均具有较强的清除DPPH.自由基的能力及较强的还原能力,对亚硝酸盐也具有一定的清除作用。不同溶剂提取液的抗氧化活性与其总酚种类和极性密切相关,发芽在一定程度上提高了燕麦的抗氧化活性。     

发芽对糜子酚类化合物及抗氧化活性的影响

探讨了发芽时间对糜子中酚类化合物含量、存在形式及抗氧化活性的影响。将经过表面灭菌的糜子种子放入25℃,相对湿度95%的人工气候箱中避光发芽6 d,每天取样,测定其中酚、黄酮含量及抗氧化指标（DPPH、ABTS、FRAP、ORAC）的变化。结果显示,从发芽2 d起,酚、黄酮含量及各项抗氧化指标明显增高。发芽6 d后,内糜8号总酚、总黄酮含量分别为发芽前的5.9和1.9倍,西农10-04号则分别为发芽前的4.6和1.9倍,抗氧化能力均显著增强（p<0.05）。此外,发芽4 d后芽中总酚、总黄酮含量及抗氧化能力显著高于（p<0.05）相应种子。总酚、总黄酮与抗氧化能力间均显示出极强的相关性,其中以总黄酮与FRAP相关性最高（r=0.985）。研究表明,发芽是一种有效提高糜子中酚类化合物含量及抗氧化活性的加工方式。      

蜂胶中具有抗氧化活性的木脂素

利用柱层析方法从蜂胶中分离得到了4种呋喃骈呋喃类木脂素,利用波谱学方法鉴定为芝麻脂素（sesamin）、yangambin、（＋）－松脂素[( )-pinoresinol]和（＋）－丁香脂素[( )-syringaresinol],其中（＋）－松脂素和（＋）－丁香脂素为首次从蜂胶中得到。利用测定小鼠肝细胞微粒体脂质过氧化抑制作用的方法,检测了所得到的4种木脂素的抗氧化活性,其IC50值范围为9.0-14.0μg/ml。     

发芽对2种青稞营养成分及抗氧化活性的影响

以隆子黑青稞和藏青2000为原料,通过测定芽长、淀粉、蛋白质、脂肪、纤维、总酚、总黄酮和抗氧化活力,探讨萌发对2种青稞营养成分及抗氧化活性的影响.结果 表明:未发芽青稞中,除淀粉含量外,隆子黑青稞的蛋白质、脂肪、纤维、总酚、总黄酮含量与抗氧化活性均大于藏青2000.发茅处理降低了青稞的淀粉、蛋白质、总酚含量和铁离子还原...     

浸泡和发芽对杂豆酚类物质及其抗氧化性的影响

为了确定发芽过程中杂豆酚类物质的变化规律,研究了浸泡和发芽对六种杂豆中总酚、总黄酮、总花青素、总缩合单宁含量以及总抗氧化能力的影响。结果表明,浸泡处理可显著降低大部分杂豆酚类物质含量和总抗氧化能力,但浸泡后的绿豆中总酚、黑小豆中总黄酮、红芸豆中总花青素显著升高(P0.05)。发芽可显著提高黑大豆、黑小豆、绿豆和红芸豆酚类物质含量且在发4 d或5 d出现最大值,对红小豆和紫花芸豆的酚类物质无显著影响或使其显著降低(P0.05)。总抗氧化能力与总酚、总黄酮等指标呈极显著正相关(P0.01)。另外,发芽使杂豆中的花青素显著降低(P0.05),且花青素含量与其他指标无显著相关性(P0.05)。     

发芽对莜麦多酚及抗氧化活性生物可及性的影响

为了提高莜麦中多酚及抗氧化活性的生物可及性,采用体外模拟消化模型和结肠发酵模型,对比发芽和未发芽莜麦在不同消化阶段以及结肠发酵阶段总酚含量及抗氧化活性的变化。结果显示:体外模拟消化阶段,发芽莜麦中多酚生物可及性、DPPH自由基清除生物可及性、羟自由基清除生物可及性在小肠消化时最高,比未发芽莜麦分别高8.99%,47.75%, 9.57%,还原力生物可及性在胃消化时最高,此时,发芽莜麦比未发芽莜麦高39.82%。结肠发酵阶段,不同处理莜麦消化残渣中多酚含量及抗氧化活性在发酵24~30 h时最高。在结肠发酵30 h时,未发芽莜麦消化残渣多酚生物可及性比发芽莜麦消化残渣的高8.83%,DPPH自由基清除力生物可及性比发芽莜麦消化残渣的高8.16%。羟自由基清除生物可及性比发芽莜麦消化残渣的高16.68%。但与胃肠消化阶段的生物可及性几乎相当。结论:发芽不仅能显著提高莜麦多酚及抗氧化活性在胃肠消化道中的生物可及性,也能使多酚等抗氧化组分在结肠发酵中保持较高的生物可及性,这为谷物多酚在人体消化道内的生物利用度的提高提供新的研究思路。     

豌豆发芽过程中营养功能成分和抗氧化活性的变化

比较了豌豆原料、0.5 cm芽长、5 cm芽长和10 cm芽长4种豌豆形态下的营养功能物质含量及抗氧化活性。结果发现,发芽过程对豌豆各营养功能物质的含量和抗氧化活性均有影响。随着豌豆幼苗的增长,含水量呈不断上升趋势;可溶性糖含量先减少后增加;蛋白质和粗脂肪含量都呈先上升后下降的趋势,两者含量均在0.5 cm芽长时达到最大值;粗纤维和灰分含量都在发芽过程中持续下降;VC含量先上升后下降,在5 cm芽长时达到最大值;总酚含量、超氧化物歧化酶活力、过氧化物酶活力和总抗氧能力在发芽过程中均呈现上升趋势。结果表明发芽可以作为提升豌豆营养保健价值的重要手段。     

用化学发光法分析燕麦发芽前后酚类物质抗氧化活性

对燕麦种子进行发芽实验6 d,对原样、6 d籽粒、6 d芽和6 d根中的酚类物质进行提取纯化,采用化学发光法对不同部位纯化物清除活性氧自由基的能力进行测定。结果表明:原样、6 d籽粒、6 d芽和6 d根纯化物在不同体系中均表现出良好的抗氧化活性,其清除超氧阴离子的IC50值分别为0.952、0.702、3.248、1.060 mg/mL,清除羟基自由基的IC50值分别为8.80、3.31、13.69、11.68μg/mL,清除双氧水的IC50值分别为10.97、8.64、13.05、9.61μg/mL,可见发芽过程使燕麦籽粒在3个体系中的抗氧化活性均有所提高,而燕麦芽的抗氧化活性相对籽粒和根较差。     

Replacing ground corn with incremental amounts of liquid molasses does not change milk enterolactone but decreases production in dairy cows fed flaxseed meal

We investigated the effects of replacing ground corn (GRC) with incremental amounts of liquid molasses (LM) on milk enterolactone concentration, antioxidant enzymes activity in plasma, production, milk fatty acid (FA) profile, and nutrient utilization in Jersey cows fed flaxseed meal and low-starch diets. Sixteen multiparous organically certified Jersey cows averaging (mean ± standard deviation) 101 ± 45 d in milk, 462 ± 38 kg of body weight, and 19.8 ± 3.90 kg/d of milk in the beginning of the study were randomly assigned to treatment sequences in a replicated 4 × 4 Latin square design, with 14 d for diet adaptation and 7 d for data and sample collection. Diets were fed as total mixed rations consisting (dry matter basis) of 52% grass-legume baleage, 8% grass hay, 8.5% soyhulls, 2.5% roasted soybean, 15% flaxseed meal, and 2% minerals-vitamins premix. The GRC-to-LM dietary ratios (dry matter basis) were 12:0, 8:4, 4:8, and 0:12. Orthogonal polynomials were used to test linear, quadratic, and cubic effects using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). The milk concentration of enterolactone tended to respond cubically, thus suggesting that replacing GRC with LM did not affect this lignan in milk. The plasma activities of the antioxidant enzymes glutathione peroxidase and catalase did not differ, but superoxide dismutase activity tended to respond cubically with feeding increasing amounts of LM. Dry matter intake and yields of milk and milk fat, true protein, and lactose decreased linearly with substituting GRC for LM. Whereas the concentrations of milk fat and milk true protein did not differ across treatments, milk lactose content decreased linearly. Feeding incremental levels of LM reduced linearly the milk concentration of urea N and the amount of N excreted in urine, and tended to decrease linearly the concentration of plasma urea N. Apparent total-tract digestibilities of dry matter, organic matter, and neutral and acid detergent fiber did not differ across treatments, whereas digestibility of crude protein decreased linearly. Digestibility of starch responded linearly and quadratically, but the actual differences between treatments were too small to be biologically significant. Milk FA profile was substantially changed most notably by linear increases in cis-9,trans-11 18:2, cis-9,cis-12,cis-15 18:3, Σ odd-chain FA, and the trans-11-to-trans-10 ratio, and linear decreases in cis-9 18:1 and cis-9,cis-12 18:2 when replacing GRC by incremental amounts of LM.     

The dynamic changes of ascorbic acid,tocopherols and antioxidant activity during germination of soya bean (Glycine max)

The objective of this investigation was to study the dynamic changes of ascorbic acid, tocopherols and their antioxidant activity of soya bean sprouts during germination. Results showed that the expression levels of genes related to biosynthesis of ascorbic acid and tocopherols dramatically increased during germination. The expression levels of most genes were up to the peak at day 3 and kept constantly until the end of germination. The contents of ascorbic acid, α‐tocopherol, γ‐tocopherol, δ‐tocopherol and total tocopherols increased during soya bean sprouts germination and reached peak levels on day 5, of 74.42 ± 1.64 mg/100 g DW, 7.64 ± 0.13 mg/100 g DW, 15.84 ± 1.85 mg/100 g DW, 12.37 ± 1.06 mg/100 g DW, 35.85 ± 2.81 mg/100 g DW, respectively. The antioxidant activity of soya bean sprouts increased during germination and reached peak level on day 5 to 311.01 ± 49.01 μmol ASA equiv./100 g DW. Therefore, germination significantly increased the biosynthesis of ascorbic acid, tocopherols and antioxidant activity of soya bean sprouts.     

萌发菌HL-003胞内多糖的提取及抗氧化性研究

采用乙醇沉淀法提取多糖,在单因素试验基础上进行正交试验,探讨萌发菌HL-003胞内多糖提取的最佳条件;分别采用Fe2+/H2O2体系和邻苯三酚自氧化法探讨多糖清除羟基自由基和氧自由基的能力。结果表明,最佳提取条件为液料比20∶1（mL∶g）、提取时间1.5 h、提取温度70 ℃、乙醇体积分数80%,其最佳提取率为7.63%;萌发菌HL-003胞内多糖对羟自由基和氧自由基清除作用明显,是一种良好的天然抗氧化剂。     

藜麦富硒萌发工艺优化及抗氧化活性研究

[目的]提高藜麦种子有机硒含量,开发优质富硒藜麦食品原料。[方法]以青白藜1号为原料,亚硒酸钠为硒源,通过单因素试验结合正交试验对藜麦富硒萌发工艺条件进行优化,进一步对富硒藜麦可溶性蛋白、多酚含量及抗氧化能力进行分析。[结果]藜麦富硒萌发最佳工艺条件为亚硒酸钠溶液质量浓度20 mg/L、浸泡温度25 ℃、浸泡时间6 h、浸泡液pH 7.0、萌发时间48 h、萌发温度20 ℃。该条件下,富硒萌发藜麦有机硒含量为349.52 μg/kg。富硒萌发藜麦游离酚（236.35 mg/100 g）、结合酚（198.31 mg/100 g）含量最高,普通去离子水萌发藜麦可溶性蛋白（22.18%）含量最高。富硒萌发藜麦可溶性蛋白、游离酚和结合酚的抗氧化活性均最强,其次为普通去离子水萌发藜麦,未处理藜麦相对最低。[结论]富硒萌发能够显著提升藜麦有机硒、可溶性蛋白和多酚含量,并增强其抗氧化能力。     

大麦发芽过程中不同存在形式的酚类物质及其抗氧化活性变化

以甘啤4号为原料,研究发芽过程中4类多酚物质提取物的含量及其抗氧化活性的变化,采用的评价指标为DPPH自由基清除活性、ABTS自由基清除活性和铁还原力,同时利用HPLC法依次检测4类粗多酚中9种单体酚酸的含量及其变化。试验结果表明:发芽显著影响大麦粗多酚、单体酚酸的种类和含量及其抗氧化活性。游离粗多酚在原麦和萌发过程中始终占总粗多酚含量的最大比例,并且其综合抗氧化活力也显著高于其它3类粗多酚提取物。4类粗多酚提取物和各单体酚酸的总含量及抗氧活性总是原麦高于各萌发时期,在浸泡阶段统一显著下降,萌发后期又有显著升高。相关性分析表明,4类粗多酚的铁还原能力、清除DPPH和ABTS自由基的能力均与其含量密切相关,与粗多酚显著相关的单体酚酸,同样显著影响着其抗氧化活性。阿魏酸、儿茶素、对香豆酸是主要的活性酚酸。