超微粉碎对青稞麸皮粉多酚组成及抗氧化活性的影响

为评价超微粉碎对青稞麸皮多酚、体外抗氧化活性和淀粉消化酶抑制活性的影响。该研究制备了3种粒径分别为335.94、72.52、22.69μm的青稞麸皮粉体,对3种粉体的多酚、黄酮含量及其组成、体外抗氧化活性与淀粉消化酶活性抑制率进行测定。结果表明:与粗粉相比,2种微粉的多酚(游离酚、结合酚)、黄酮和总酚含量均显著高于粗粉(P0.05)且粒径越小,含量越高;青稞麸皮粉共检出19种酚酸,其中游离酚以阿魏酸和藜芦酸为主,结合酚以阿魏酸和苯甲酸为主;随着粒径的减小,粉体多酚提取物的抗氧化活性(DPPH·自由基清除能力、FRAP还原能力、ABTS~+·自由基清除能力)及对α-葡萄糖苷酶、α-淀粉酶抑制率均显著增强(P0.05);粉体多酚组成及含量与体外抗氧化活性及淀粉消化酶活性抑制率存在一定的相关性。相关分析结果表明:青稞麸皮游离酚提取物中2,4-二羟基苯甲酸、藜芦酸是清除DPPH·自由基、抑制α-葡萄糖苷酶活性的主要贡献物质,阿魏酸是抑制α-葡萄糖苷酶及α-淀粉酶活性的主要物质;结合酚提取物中2,4-二羟基苯甲酸是抑制α-淀粉酶活性的主要物质。该结果显示超微粉碎一定程度上可提高青稞麸皮中多酚含量、体外抗氧化活性及淀粉消化酶抑制率,可作为青稞麸皮食品的一种有效前处理加工手段。     

甘油水溶液提取米糠多酚绿色工艺优化及多酚种类鉴定

为探究甘油作为绿色溶剂提取米糠多酚的可行性,该文选取提取温度、甘油体积分数、液料比和提取时间4个因素,采用单因素结合响应面试验进行米糠多酚提取工艺优化。同时,分析了甘油提取液的黏度特性,并利用超高效液相色谱串联三重四级杆飞行时间质谱(UPLC-Triple-TOF/MS)方法进行多酚鉴定。结果表明,甘油提取米糠多酚最优条件为提取温度67℃,甘油体积分数19%,液料比33 mL/g,提取时间固定为80 min,获得的最大多酚得率为700.35 mg/(100 g)。甘油对米糠多酚的提取效率和甘油的黏度有显著的负相关性。此外,UPLC-Triple-TOF/MS分析表明,最优条件下甘油提取得到13种米糠多酚,其中酚酸质量分数如下:对羟基苯甲酸48.53μg/g,香草酸69.64μg/g,丁香酸33.63μg/g,4-香豆酸361.18μg/g,阿魏酸392.17μg/g,水杨酸34.67μg/g。研究结果表明,甘油可以作为从米糠中提取多酚的绿色溶剂。     

红松种子壳多酚物质的提取及抗氧化特性

该文选取超声波辅助提取法,采用单因素试验及响应面设计,研究了超声波提取时间、温度、乙醇浓度及料液比对红松种子壳中多酚类化合物提取的影响。并利用Fenton体系、1,1-二苯基-2-苦苯肼(DPPH·)体系及邻苯三酚体系测定其提取成分的抗氧化活性。结果表明,松壳中多酚成分提取的最佳工艺条件为:超声提取时间2.80h、料液比1∶26.36(g/mL)、乙醇浓度42.86%、提取温度80℃,多酚得率7.96mg/g。在此优化条件下,红松种子壳提取物对羟自由基(甲基紫法)、DPPH·自由基及超氧阴离子均具有较强清除作用,半数抑制浓度分别为6.67×10-4、2.34×10-2、3.97mg/mL。     

黑青稞麸皮结合态酚类物质大孔树脂分离纯化工艺优化

为了筛选对黑青稞麸皮结合酚类物质具有良好吸附、解吸性能的树脂,并建立其分离纯化工艺,评价其体外抗氧化活性,提高黑青稞麸皮的加工利用价值。本研究通过静态吸附和解吸试验比较了10种大孔树脂对黑青稞麸皮结合酚中总酚和总黄酮的分离纯化效果,筛选出AB-8为最佳吸附树脂类型,其静态吸附4 h可达到饱和;优化的吸附和解吸工艺参数为：黑青稞麸皮结合酚提取液pH值为3.0,上样质量浓度1.5 mg/mL,上样速度为1.5 mL/min,60%乙醇溶液作为洗脱剂进行动态洗脱,洗脱流速为1.5 mL/min;优化工艺条件下,经LC/MS检测,AB-8大孔树脂能显著提高71.43%以上不同种类单体酚的含量,且阿魏酸、丁香酸、苯甲酸、鞣花酸、杨梅素和芦丁是纯化后黑青稞麸皮结合酚中的主要酚类物质;体外抗氧化活性表明,黑青稞麸皮结合酚粗提物和纯化物均具有较强的体外抗氧化活性,纯化后的黑青稞麸皮结合酚溶液清除DPPH·、ABTS·+自由基及FRAP铁离子还原能力均显著增强。研究结果表明AB-8大孔树脂对黑青稞麸皮结合酚中总酚和总黄酮有较好的分离纯化效果,具有潜在的工业应用前景。     

欧李多酚提取纯化及抗氧化性研究

欧李富含钙素和多酚类物质，具有提高人体免疫力等保健功能，近年来在中国得到了大力发展。该研究欧李多酚提取、纯化及其抗氧化功能，为欧李开发利用提供理论依据。该研究采用单因素及响应面优化试验研究了欧李多酚超声辅助酶解提取工艺，采用大孔树脂纯化多酚粗提物，利用高效液相色谱法测定酚类物质的种类，利用分光光度法测定欧李多酚类物质总还原力和对自由基.OH、DPPH·、ABTS·的清除作用。试验得出欧李多酚提取最优工艺参数为：超声波功率105 W、酶解温度50 ℃、酶解时间80 min、液料比30∶1(mL/g），多酚提取量为42.63 mg/g。经大孔树脂纯化后纯化物中欧李总多酚含量为73.42 mg/g，从欧李果实中检测出6种多酚类物质，其含量顺序为绿原酸>没食子儿茶素没食子酸酯>咖啡因>对羟基苯甲酸>原儿茶酸>没食子酸。欧李多酚的总还原力与维生素C相当，对.OH、DPPH.、ABTS.等自由基清除作用显著。     

燕麦生物碱的提取及其抗氧化活性研究

采用正交试验设计对麸皮中燕麦生物碱(AV)的提取条件进行优化,提取物经大孔吸附树脂纯化,并利用活性氧和DPPH自由基的清除率研究其抗氧化活性.结果表明:最佳提取参数为温度60℃,提取时间2h,溶剂为乙醇/水/冰醋酸(80/19.9/0.1),料液比1:8,此条件下得率为5.29%,经树脂纯化后粗提物中生物碱纯度达19.2%,且纯化后的燕麦生物碱表现出较强的清除OH·,O2-·和有机自由基DPPH的体外抗氧化活性,其清除能力分别是α-生育酚的79.4%、82.2%和78.0%.     

苹果渣多酚提取工艺的优化

为优化苹果渣中多酚提取工艺,并得到提取工艺和多酚组成之间的关系,利用微波辅助提取法设计了由物料颗粒、液料比、乙醇浓度、微波功率和微波提取时间5个因素构成的多酚提取优化试验流程,构建了涵盖黄酮、原花青素2种典型多酚物质和抗氧化能力的提取工艺评价指标体系。采用证据理论对不同工艺在评价指标下的焦元进行识别,并基于信度函数和似真函数得到了不同提取工艺的效用区间和优化方案。优化结果为：物料颗粒60目,液料比30?mL/g,乙醇体积分数60%,微波功率600?W,提取时间70?s,此条件下苹果渣多酚的提取量为213.83?mg/100g,黄酮提取量为83.21?mg/100g,原花青素提取量为52.79?mg/100g,抗氧化的EC50值为3.71?mg/100mL,验证了采用证据理论进行苹果渣多酚提取工艺优化的有效性。     

菜籽蛋白加工废液中多酚和多糖同步提取工艺优化

为开发利用菜籽蛋白加工废液中的生理活性物质,该研究在单因素试验基础上,采用Box-Behnken响应面试验设计法,对菜籽蛋白加工废液中多酚和多糖提取工艺条件进行优化,同时探究两种物质的体外抗氧化活性。结果表明,影响菜籽蛋白加工废液中多酚和多糖得率的因素大小顺序为:乙醇体积分数浸提温度浸提时间,最佳提取工艺为:浸提温度60℃、乙醇体积分数65%、浸提时间31 min,在此条件下多酚得率为2.19%,多糖得率为8.14%;多酚提取物对DPPH·具有较强清除能力,其半抑制质量浓度为0.20 mg/mL,多糖提取物对DPPH·和·OH均具有较强的清除能力,其半抑制质量浓度分别为1.45、2.38 mg/mL;高效液相色谱法初步检测表明,菜籽蛋白加工废液中含有香豆酸、丁香酸、对香豆酸、芥子酸和苯甲酸。研究结果为菜籽蛋白加工废液的再利用提供参考。     

黑莓原花青素超声波辅助提取优化及抗氧化性研究

论文采用响应曲面法研究了超声波辅助提取时温度、时间、料液比、超声波功率及其交互作用对黑莓原花青素提取效果的影响,同时研究了黑莓原花青素对二苯代苦味酰自由基(DPPH)、·OH及·O2-的清除效果.用SAS软件确定了黑莓原花青素超声波提取的工艺参数为:提取温度为70.9℃,料液比为1∶9.14,时间为30.5 min,超声波功率为526.9 W.黑莓原花青素对DPPH、·O2-及·OH 3种自由基具有显著的清除效果,且明显优于茶多酚,当浓度为3.0 μg/mL时,对DPPH、·O2-及·OH 3种自由基的最大清除率分别可达到82.54%、79.90%和65.90%,且黑莓原花青素对3种自由基的清除效果与其浓度之间存在明显的量效关系.     

大孔树脂分离纯化玫瑰果多酚及其抗氧化性

为了研究大孔树脂对玫瑰果多酚的纯化效果,该试验以玫瑰果多酚粗提液为原料,利用大孔树脂吸附法对其进行纯化,并对其体外抗氧化活性进行了研究。结果表明,大孔吸附树脂纯化较佳工艺为:在20℃条件下,用质量浓度为0.80 mg/m L的玫瑰果多酚粗提液(p H值5.8)以1 m L/min的流速上样200 m L;吸附平衡后用少量蒸馏水洗至洗脱液无色,后用70 m L体积分数为70%的乙醇溶液,以1.5 m L/min的流速进行动态洗脱,洗脱峰相对集中、对称,无拖尾。纯化后,总酚质量分数由纯化前的122.90 mg/g提高到399.42 mg/g。体外抗氧化活性的研究表明:清除1,1-二苯基-2-苦基肼自由基的作用效果顺序为维生素C纯化多酚2,6-二叔丁基-4-甲基苯酚(Butylated hydroxytoluene,BHT)粗多酚;清除超氧阴离子自由基的作用效果顺序为维生素CBHT纯化多酚粗多酚;清除羟基自由基的作用效果顺序为维生素C纯化多酚BHT粗多酚。研究结果为玫瑰果多酚的进一步利用提供依据。     

青海黑青稞营养及活性成分分析与评价

为明确青海不同品种黑青稞的营养及化学成分含量,筛选优异种质资源,本研究开展了12种黑青稞营养及化学成分分析与评价。结果表明,参试黑青稞蛋白、总淀粉、直链淀粉、粗脂肪、粗纤维、灰分、β-葡聚糖含量在部分品种间存在显著差异(P<0.05),黑青稞具有较高含量的蛋白质(12.19%~14.07%)、纤维(2.13%~3.64%)、直链淀粉(18.96%~25.94%)和β-葡聚糖(3.91%~7.50%);参试黑青稞中Ca、K、Zn含量存在品种间显著差异(P<0.05),其余测定的矿物质含量存在部分品种间显著差异(P<0.05),其中K(581.42 mg·100g^-1)、Mg(171.90 mg·100g^-1)、Ca(90.28 mg·100g^-1)、Na(17.33 mg·100g^-1)含量较高;参试黑青稞蛋白中总必需氨基酸含量平均值为319.90 mg·g^-1(接近WHO/FAO推荐值360 mg·g^-1),第一限制性氨基酸为赖氨酸,第二限制性氨基酸为甲硫氨酸和胱氨酸,第三限制性氨基酸为苏氨酸;参试部分黑青稞品种的总酚、游离酚、结合酚、总黄酮、游离黄酮、结合黄酮及花色苷含量存在显著差异(P<0.05);主成分筛选出950、Z536、Z533黑青稞综合品质较优,聚类分析将12个黑青稞品种分为4类,第1类蛋白质、多酚、黄酮、β-葡聚糖含量较高;第2类花色苷、氨基酸含量较高;第3类纤维含量较高;第4类淀粉含量较高。本研究结果为黑青稞营养功能品质评价及加工利用奠定了基础,也为特异青稞资源的筛选提供了参考。     

Analysis of phenolic acids in barley by high-performance liquid chromatography

Phenolic acids from 30 barley varieties (combination of hulled/hulless/two-row/six-row/regular/waxy) were investigated by HPLC following four different sample treatments: (a) simple hot water extraction, (b) extraction after acid hydrolysis, (c) acid plus alpha-amylase hydrolysis, and (d) acid plus alpha-amylase plus cellulase hydrolysis treatments. The benzoic acid (p-hydroxybenzoic, vanillic, and protocatechuic acids) and cinnamic acid derivatives (coumaric, caffeic, ferulic, and chlorogenic acids) were identified, and some of the phenolic acids were quantified after each above-mentioned treatment. The data indicated that a combination of sequential acid, alpha-amylase, and cellulase hydrolysis treatments might be applicable for release of more phenolic acids from barley.     

Antioxidant phenols in barley (Hordeum vulgare L.) flour: comparative spectrophotometric study among extraction methods of free and bound phenolic compounds

Phenolic compounds are found in both free and bound forms in cereals. The majority is in the insoluble bound form, that is, bound to cell wall material, such as ferulic acid and its derivatives. The antioxidant properties of the phenolic compounds in grains are associated with the health benefits of grains and grain products. The extraction capacity of several solvent mixtures, for extracting free phenols from barley flours, and the possibility of employing a rapid automated solvent extraction method were studied. The extraction yield of each method was evaluated by correlating several spectrophotometric indices (absorption at 280, 320, and 370 nm and total phenolic compounds by the Folin-Ciocalteu method) with the antioxidant activities of the barley extracts (scavenging activity by the 2,2-diphenyl-1-picrylhydrazyl method). Interesting results were obtained when ethanol and acetone-based extraction mixtures were employed to extract free phenols. A comparison was made between alkaline and acid hydrolysis. The extraction yield of bound phenolic compounds increased when the digestion time for alkaline hydrolysis was prolonged.     

Phenolic compounds of barley grain and their implication in food product discoloration

Barley grains contain significant amounts of phenolic compounds that may play a major role in the discoloration of food products. Phenolic acid and proanthocyanidin (PA) composition of 11 barley genotypes were determined, using high-performance liquid chromatography and liquid chromatography-mass spectrometry, and their significance on food discoloration was evaluated. Abraded grains contained 146-410 microg/g of phenolic acids (caffeic, p-coumaric, and ferulic) in hulled barley and 182-282 microg/g in hulless barley. Hulled PA-containing and PA-free genotypes had comparable phenolic acid contents. Catechin and six major barley PAs, including dimeric prodelphinidin B3 and procyandin B3, and four trimers were quantified. PAs were quantified as catechin equivalents (CE). The catechin content was higher in hulless (48-71 microg/g) than in hulled (32-37 microg/g) genotypes. The total PA content of abraded barley grains ranged from 169 to 395microg CE/g in PA-containing hulled and hulless genotypes. Major PAs were prodelphinidin B3 (39-109 microg CE/g) and procyanidin B3 (40-99 microg CE/g). The contents of trimeric PAs including procyanidin C2 ranged from 53 to 151 g CE/g. Discoloration of barley flour dough correlated with the catechin content of abraded grains (r = -0.932, P < 0.001), but not with the content of individual phenolic acids and PAs. Discoloration of barley flour dough was, however, intensified when total PA extracts and catechin or dimeric PA fractions were added into PA-free barley flour. The brightness of dough also decreased when the total PA extract or trimeric PA fraction was added into heat-treated PA-free barley flour. Despite its low concentration, catechin appears to exert the largest influence on the discoloration of barley flour dough among phenolic compounds.     

混菌发酵黑青稞甜醅工艺优化及品质特性研究

为改善单一菌株发酵制备青稞甜醅的风味与口感,提高其质量品质,本试验采用米根霉和酵母菌为发酵菌株,以氨基酸态氮含量及感官评分为指标,确定混菌发酵黑青稞甜醅的最佳工艺条件,并比较单一菌株发酵黑青稞制品与混菌发酵黑青稞制品中酚类物质含量、抗氧化活性及风味物质组成的差异。结果表明,混菌发酵黑青稞制品最佳发酵条件为:发酵温度33℃,发酵时间48 h,菌种比例(酵母菌J7∶米根霉)1∶1.20,接种量6.81%,在此条件下混菌发酵黑青稞制品的氨基酸态氮含量为9.32 mg·100 g^-1,感官评分为95.48分。与单一菌株发酵黑青稞制品相比,混菌发酵黑青稞的黄酮含量(32.22 mg·100 g^-1)、 多酚含量(230.68 mg·100 g^-1)及DPPH自由基清除能力(95.03 μmol·L^-1)显著提高。气相色谱-质谱(GC-MS)分析结果表明,酵母菌单独发酵的黑青稞中共检出33种挥发性风味物质,米根霉单独发酵的黑青稞中共检出41种挥发性风味物质,混菌发酵的黑青稞中共检出46种挥发性风味物质,其中酯类和醇类是3种发酵方式黑青稞制品的主要风味组分。混菌发酵黑青稞的醇类、酯类和酸类种类及含量均显著高于其余两种发酵方式,其相对含量分别达到59.09%、29.44%和6.46%,风味更丰富。综上分析,混菌发酵使黑青稞制品在功能及风味方面具有一定的优势。本研究结果为混菌发酵黑青稞制品的开发和应用奠定了基础。     

Nitrogen effects on yield,beta‐glucan content,and other quality factors of oat and waxy hulless barley

Abstract

Oat (Avena sativa L.) and waxy hulless barley (Hordeum vulgare L.) are important sources of water soluble plant fiber (ß‐glucan) needed in human diets to lower serum cholesterol. Recent studies have shown grain ß‐glucan content is influenced by soil type and environment, however, nitrogen (N) response data for oat and waxy hulless barley are lacking. In this study, we evaluated N effects on grain ß‐glucan content and yield; grain yield, protein content, and test weight; and total dry matter production and N utilization of oat and waxy hulless barley. Rates of applied N were 0, 34, 67, and 101 kg N/ha at three field environments in central Montana during 1989 and 1990. Nitrogen increased all variables except test weight and ß‐glucan content. Waxy hulless barley grain yields fluctuated from 0.82 to 4.11 Mg/ha, ß‐glucan content from 62 to 76 g/kg, and ß‐glucan yields from 51 to 354 kg/ha. Oat yields ranged from 0.85 to 3.83 Mg/ha, ß‐glucan content from 37 to 51 g/kg, and ß‐glucan yields from 35 to 178 kg/ha. Oat ß‐glucan content was positively related to grain protein content, and waxy hulless barley ß‐glucan content was positively related to test weight. ß‐glucan content appeared more related to environmental factors other than N.     

Free and Bound Phenolic Acids and Total Phenolics in Black,Blue, and Yellow Barley and Their Contribution to Free Radical Scavenging Capacity

Barley is considered a healthy food because of its high content of β‐glucan and phenolic antioxidants. In the current study, 28 black, blue, and yellow barleys were investigated in terms of their composition of free and bound phenolic acids and 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging capacity. Free phenolics were based on aqueous methanol extraction, whereas bound phenolics were extracted following alkaline hydrolysis. Phenolics were then separated and quantified by liquid chromatography and the Folin–Ciocalteu method. Significant differences were observed between the three barley color groups, and within each color group a wide range of phenolics concentrations existed. Ferulic acid was the predominant phenolic acid in free and bound extracts, followed by p‐coumaric acid in all the barleys investigated. Total phenols content and individual phenolic acids strongly correlated with free radical scavenging capacity of barley. Black and blue barley were found to be related and distinct from yellow barley. The results showed significant variations in phenolics among barleys, with a potential for the development of barley grains with high content of phenolic compounds as antioxidant potential.     

适度水分亏缺管理提高青稞营养品质和环境效益

【目的】 针对青藏高原水资源短缺会降低青稞产量,但对产量构成和籽粒品质特性的影响尚不明确的问题,研究不同水分供应对青稞籽粒产量构成以及营养品质的影响,为青稞合理高效栽培管理提供理论依据。 【方法】 以昆仑14号为供试品种,进行了随机区组田间试验。设计灌溉至田间持水量的75% (充分灌溉处理)、50% (水分轻度亏缺处理) 和25% (水分重度亏缺处理) 3个水平。调查了青稞根系、产量和籽粒NPK、蛋白质和氨基酸含量。 【结果】 水分亏缺显著降低青稞公顷穗数、穗长、穗粒数、产量、分蘖数、株高,且降幅随水分亏缺程度的加剧而增大。水分亏缺致使青稞产量显著降低,但不同亏缺程度对产量三因素的影响存在一定差异。水分轻度亏缺使公顷穗数和穗粒数显著降低,重度亏缺使产量三因素均显著降低。水分亏缺下青稞籽粒中氮、钾、蛋白质和总氨基酸的含量均呈升高趋势,且随着水分亏缺程度的加剧而进一步增加。重度亏缺处理青稞籽粒中磷含量、必需和非必需氨基酸含量均比充分灌溉显著升高。 【结论】 水分轻度亏缺有助于促进青稞根系生长,重度亏缺则会严重抑制根系生长。水分亏缺不利于青稞穗部的生长发育,导致其产量显著降低,却有利于籽粒中蛋白质及其组分含量的提高。适度亏缺灌溉不仅能节约水资源和降低农业成本,且该灌溉方式下青稞产量和籽粒中养分、蛋白质及其组分的含量均较高,为较佳的灌溉制度。      

氮素对大麦籽粒中酚酸和蛋白质含量的影响

采用穗培养技术在7个氮素(NH4NO3为氮源)浓度水平(N1:0mg/L;N2:412.5 mg/L;N3:825.0mg/L;N4:1237.5mg/L;N5:1650.0ms/L;N6:3300.0mg/L;N7:4950.0mg/L)下研究了氮素对2个大麦品种籽粒中酚酸和蛋白质含量的影响.结果表明,在高氮水平(N...     

Indigenous knowledge and traditional conservation of hulless barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis>) germplasm resources in the Tibetan communities of Shangri-la,Yunnan, SW China

Hulless barley (Hordeum vulgare L. s. l.) is the staple food crop of Tibetan communities in the Qinghai-Tibet Plateau, covering Tibet, Qinghai, Gansu, Sichuan and Yunnan provinces in China. Participatory Rural Appraisal methodolgies were employed in twenty-seven villages that were randomly selected in Shangri-la region, or Diqing Prefecture of Yunnan Province to document the ethnobotanical and indigenous knowledge related to the production, diversity, use and conservation of hulless barley. For Tibetans in Shangri-la, the crop has a high socio-cultural value. The genetic diversity of landraces managed by the farmers in Shangri-la is an extremely important germplasm resource. We recorded a total of 54 landraces that are primarily described by farmers based on their cooking quality, growth cycle, color and size of the grains. The ethnobotanical and indigenous knowledge recorded in this study contributes to the understanding of the genetic diversity of hulless barley in Shangri-la and even in the Qinghai-Tibet Plateau, and in defining appropriate strategies for its conservation on farm.