麦麸发酵前后不同存在形态酚类物质中酚酸含量的变化及其抗氧化活性分析

以小麦麦麸为培养基,采用三株泡盛曲霉进行固态发酵,分别提取并采用高效液相色谱法测定麦麸发酵前后不同存在形态(游离型、酯苷结合型、糖苷结合型、碱解束缚型和酸解束缚型)的酚类物质中酚酸的含量,并通过DPPH自由基清除试验、还原力试验以及抗脂质过氧化试验,研究这些酚类物质的抗氧化活性。结果表明:未经过发酵的麦麸,束缚型酚酸在总酚酸含量中约占总量的80%,其酚酸类成分主要包括对香豆酸、阿魏酸、丁香酸、对羟基苯甲酸、咖啡酸、绿原酸、没食子酸、香草酸和肉桂酸等。发酵后的麦麸,游离型酚类物质的含量显著提高。抗氧化试验的结果显示,麦麸中碱解束缚型的酚类物质和发酵后麦麸的游离型酚类物质的抗氧化性较强。试验结果说明泡盛曲霉能促使被束缚的阿魏酸游离出来,使游离型酚类物质的含量及抗氧化性显著提高;而且抗氧化活性与酚酸的种类及含量有关,咖啡酸、丁香酸和阿魏酸含量高的酚类物质,其抗氧化性也较强。     

Antioxidant activity of hard wheat flour, dough and bread prepared using various processes with the addition of different phenolic acids

BACKGROUND: The purpose of this study was to evaluate the effect of baking process on the antioxidant activity of different phenolic acids. Antioxidant potential was determined using the β‐carotene‐bleaching activity assay, and free phenolic acid levels were determined by high‐performance liquid chromatography. Four phenolic acids, caffeic acid, ferulic acid, syringic acid and gallic acid, were mixed with wheat flour at a concentration of 4.44 µmol/g of flour. RESULTS: Type of phenolic acid and processing affected antioxidant activity. Of the phenolic acids, caffeic acid had the most pronounced antioxidant effect. The ranking of phenolic acids in terms of their antioxidant activity in fermented dough and bread was similar to that before processing, i.e. syringic acid < gallic acid < ferulic acid < caffeic acid. The content of ferulic acid was greater than that of the other phenolic acids after baking. Antioxidant activity and free phenolic acid content were reduced by mixing but recovered after fermentation and baking. Phenolic acid recovery after baking was 74–80%. CONCLUSION: Phenolic acids retain their antioxidant activity after the baking process, which has potential health benefits for consumers. Elucidation of interactions between the baking process and phenolic acids is important for the development of functional foods. Copyright © 2010 Society of Chemical Industry     

Effect of phenolic acids on the rheological properties and proteins of hard wheat flour dough and bread

BACKGROUND: The effects of different phenolic acids on the rheological properties and gluten proteins of hard wheat flour dough and bread were investigated. Caffeic, ferulic, syringic and gallic acids were each blended with hard wheat flour at a concentration of 4.44 µmol L^?1 g^?1 flour. RESULTS: Mixing time and tolerance were reduced with the addition of phenolic acids. The phenolic acids reduced the maximum resistance to extension (R_max) and increased the extensibility of dough, with effects in the following order: gallic < syringic < ferulic < caffeic acid. The effect on R_max was more pronounced in overmixed dough. Loaf volume was most significantly decreased with the addition of caffeic acid. Extraction of sodium dodecyl sulfate‐soluble high‐molecular‐weight proteins was increased in both mixed and fermented doughs by the addition of ferulic and caffeic acids. The order of influence of the phenolic acids on the rheological properties and protein structure of dough and bread was consistent with that of their antioxidant activity. CONCLUSION: The addition of caffeic and ferulic acids reduced R_max and increased the extensibility of hard wheat flour dough by modifying the high‐molecular‐weight gluten, which resulted in decreased bread volume. Copyright © 2011 Society of Chemical Industry     

高效液相色谱法测定糜子中酚酸类化合物

为探索糜子麸皮和糜米中酚酸类物质的成分和含量,采用福林-酚法和高效液相色谱法测定比较糜子麸皮 和糜米中自由酚含量和酚酸类物质的种类。结果表明：不同品种糜子麸皮之间自由酚含量差异不显著,糜米之间自 由酚法差异极其显著（P＜0.01）。同一品种糜子麸皮和糜米之间自由酚含量差异显著（P＜0.05）,糜子麸皮自由 酚含量远高于糜米。赤糜2号麸皮和糜米中自由酚含量最高,麸皮中为159.22 mg没食子酸/100 g,糜米中为47.98 mg 没食子酸/100 g。糜子中检测到的酚酸类物质有绿原酸、丁香酸、香草酸、p-香豆酸、阿魏酸。     

Color of whole-wheat foods prepared from a bright-white hard winter wheat and the phenolic acids in its coarse bran

Abstract: The color of wheat kernels often impacts the color and thereby the value of wheat‐based foods. A line of hard white winter wheat (B‐W HW) with bright appearing kernels has been developed at the Kansas State Agricultural Research Center. The objective of this study was to compare the color of several foods made from the B‐W HW wheat with those of 2 hard white wheat cultivars, Trego and Lakin. The B‐W HW kernels showed higher lightness (L*, 57.6) than Trego (55.5) and Lakin (56.8), and the increased lightness was carried over to its bran and whole‐wheat flour. Alkaline noodle and bread crumb made from the B‐W HW whole‐wheat flour showed slightly higher lightness (L*) than those made from Trego and Lakin. The sum of soluble and bound phenolics extracted from the 3 wheat brans, which had not been preextracted to remove lipids, was found to be 17.22 to 18.98 mg/g. The soluble phenolic acids in the brans were principally vanillic, ferulic, and syringic. The bound phenolic acids in the brans were dominated by ferulic, which accounted for 50.1% to 82.2% of total identified bound phenolic acids. Other bound phenolic acids were protocatechuic, caffeic, syringic, trans‐cinnamic, p‐hydroxybenzoic, p‐coumaric, and vanillic. The lightness (L*) values of coarse wheat brans correlated positively with their levels of bound protocatechuic (r = 0.72, P < 0.01) and p‐hydroxybenzoic acids (r = 0.75, P < 0.01).     

Influence of phenolic acids on morphological changes in roots of Pisum sativum

At relatively high concentrations (1 mM), ferulic, vanillic, p-coumaric, p-hydroxybenzoic, syringic and caffeic acids inhibited the growth of roots of Pisum sativum L cultured in a Hoagland nutrient solution under axenic conditions. These phenolic acids also profoundly affected root morphology in terms of extension growth of the main root and the number and size of the lateral roots. The precise growth effects depended on the phenolic acid. At concentrations that inhibited an increase in the length of the main root, the phenolic acids also inhibited cell division. To produce the maximum growth effect, the phenolic acids must be present continuously. Lower concentrations (1 μM)of the phenolic acids also affected root growth and morphology when the nitrogen content of the nutrient solution was limiting.     

The analysis of phenolic constituents in glabrous canaryseed groats

Nineteen glabrous canaryseed samples, comprising brown- and yellow-coloured seeds, were investigated to determine the nature of phenolic constituents present. Total phenolic content (TPC) was determined, using the Folin–Ciocalteau assay. Flavonoid and phenolic acid compositions were determined, using high performance liquid chromatographic and mass spectrometric (LC–MS/MS) techniques. TPC ranged from 174 to 209 mg/100 g for canaryseed wholemeal samples. The canaryseed bran contained twice as much TPC as the wholemeal. The brown- and yellow-coloured whole canaryseeds exhibited the same flavonoid profiles. LC–MS/MS analysis showed that the canaryseed acetone extract was rich in flavonoid glycosides, with the bran being mainly composed of O-pentosyl isovitexin and the flour having a compound at m/z 468. No proanthocyanidins were detected in the 19 samples. Ferulic acid was the dominant phenolic acid, followed by caffeic and p-coumaric acids. The wholemeal obtained from the brown-coloured group had significantly higher contents of ferulic (>196 mg/kg) and caffeic (>96 mg/kg) acids in comparison to the yellow-coloured canaryseed group. The latter had ferulic and caffeic acids at levels less than 165 and 78 mg/kg, respectively, with one exception which had relatively higher levels (190 and 94 mg/kg). Whilst canaryseed flour contained significantly very low levels of ferulic acid (22–34 mg/kg), the bran was enriched in ferulic (593–766 mg/kg), caffeic (304–452 mg/kg) and p-coumaric (119–142 mg/kg) acids.     

Effect of selected phenolic compounds on the membrane-bound adenosine triphosphatase of Staphylococcus aureus

The effect of selected phenolic compounds on the membrane-bound ATPase activity of two strains of Staphylococcus aureus was studied. These phenolic compounds were: butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary butylhydroquinone (TBHQ), propyl gallate (PG), p-coumaric, ferulic, caffeic acids, methyl paraben and propyl paraben. Cytoplasmic membrane-bound ATPase activity was measured in the presence of 0, 150, 300, 600 and 1200 μg ml⁻¹ of each phenolic compound. Among all the compounds studied, only BHA was found to significantly stimulate the activity of the enzyme. In contrast, some of the compounds were found to significantly inhibit the activity of the enzyme as was the case of TBHQ, PG, p-coumaric acid, ferulic acid and caffeic acid. The remaining compounds did not influence the activity of the ATPase at any of the concentrations tested. Strain LP ATPase as stimulated less by BHA and inhibited to a greater extent by TBHQ and PG than was the enzyme from strain A100. In contrast, LP ATPase was less inhibited by p-coumaric acid and not affected by either ferulic or caffeic acid.     

黑小麦麸皮酚酸物质的定性分析与阿魏酸含量测定

对黑小麦麸皮中的主要酚酸物质进行制备和定性分析,并测定阿魏酸含量。采用乙醇和氢氧化钠溶液处理黑小麦麸皮,提取样品中的游离态酚酸(free phenolic acids,FPA)和结合态酚酸(conjugated phenolic acids,CPA)。通过液质联用(LC/MS)和紫外光谱(UV)等方法对提取的酚酸物质进行定性分析。紫外光谱显示,游离态和结合态酚酸具有与阿魏酸相似的分子结构。LC/MS检测结果显示,游离态和结合态酚酸的相对分子质量分别为224和194。由此判断黑小麦麸皮中的游离态酚酸FPA主要为芥子酸,结合态酚酸CPA主要为阿魏酸。采用高效液相色谱(HPLC)对黑小麦麸皮中的结合态阿魏酸含量进行测定。结果表明,紫粒黑小麦麸皮的阿魏酸含量为2.07 mg/g,与蓝粒黑小麦麸皮的阿魏酸含量(2.12 mg/g)相近,其含量高于当地种植的普通小麦麸皮的阿魏酸含量(1.17 mg/g)。     

桑葚、甘蔗糖蜜多酚的成分鉴定及其复配物的抗氧化活性

为探索酚类提取物及其复配物的协同增效作用,以桑葚和甘蔗糖蜜多酚作为研究对象,分别测定其总酚、黄酮含量及酚类组成,基于单一提取物的总酚含量按一定配比制得复配物,评价抗氧化活性。结果表明,桑葚游离多酚（MFP）占桑葚总酚含量的90.3%,为677.62 mg没食子酸当量（Gallic Acid Equivalent,GAE）/100 g,黄酮含量为736.65 mg芦丁当量（Rutinum Equivalent,RE）/100 g,共检测出原儿茶酸、3,4-二羟基苯丙酸、咖啡酸、丁香酸、对香豆酸、阿魏酸、矢车菊素3-O-葡萄糖苷和芦丁8种多酚物质,其中矢车菊素3-O-葡萄糖苷含量占92.6%。甘蔗糖蜜多酚（SMP）总酚含量为339.69 mg GAE/100 g,总黄酮含量为314.61 mg RE/100 g,主要单体包括没食子酸、原儿茶酸、绿原酸、咖啡酸、丁香酸、对香豆酸、阿魏酸、芦丁和表儿茶素9种多酚物质。在0~10 mg/mL的浓度范围内SMP、MFP及其复配物具有良好的抗氧化活性且呈现量效关系。同时,两种复配物的抗氧化活性优于SMP和MFP,其中中效原理计算复配物DPPH自由基清除能力的0.25 IC50、0.5 IC50、0.75 IC50、1 IC50、1.25 IC50、1.5 IC50的联合作用指数CI分别为0.73、0.85、0.94、0.91、0.89和0.90,均小于1,表明桑葚和甘蔗糖蜜多酚复配物具有协同抗氧化作用。     

裸燕麦米和燕麦粉加工所得麸皮中β-葡聚糖和酚酸的分布

选取具有代表性的裸燕麦品种,分析燕麦麸皮和胚乳所占的比例和微观结构特征;同时分析β-葡聚糖和酚酸在燕麦麸皮（果皮、种皮＋糊粉层）和胚乳中的分布,并验证了现有燕麦米和燕麦粉主流加工方式的适宜程度。结果表明,在所选裸燕麦品种中,β-葡聚糖均富集在麸皮中,质量分数达8.57%,约是胚乳中含量的4.5?倍;麸皮中p-香豆酸和阿魏酸的含量分别达0.099?mg/g和1.00?mg/g,分别是胚乳中相应含量的24?倍和48?倍;在麸皮中,果皮中p-香豆酸和阿魏酸含量分别约为种皮＋糊粉层中的13?倍和2.7?倍。研磨制燕麦米所得第2道麸皮中,β-葡聚糖质量分数平均为1.7%,远小于麸皮中的平均含量,加工程度适宜;而燕麦制粉所得第4道和第5道麸皮,β-葡聚糖质量分数达6.73%和7.80%,接近糊粉层中β-葡聚糖含量,加工过度。综上可知,利用分析燕麦加工所得麸皮中葡聚糖和酚酸含量,可初步判定燕麦米和燕麦粉的加工程度,为其加工提供技术支撑。     

荞麦蜜酚酸含量的高效液相色谱测定及其抗氧化作用的研究

以中国产荞麦蜜为原料,采用高效液相色谱-电化学检测法(HPLC-ECD)测定其中的原儿茶酸、没食子酸、咖啡酸、丁香酸、p-香豆酸、绿原酸、阿魏酸和鞣花酸等8种酚酸的含量。结果表明,中国荞麦蜜中含有原儿茶酸、没食子酸、咖啡酸、p-香豆酸、阿魏酸等五种酚酸,其含量分别为没食子酸为461μg/100g蜂蜜,p-香豆酸为150μg/100g蜂蜜,咖啡酸为79μg/100g蜂蜜,原儿茶酸为30μg/100g蜂蜜,阿魏酸为39μg/100g蜂蜜。本文还对荞麦蜜酚酸提取物的抗氧化作用进行了研究,结果显示荞麦蜜酚酸提取物对超氧阴离子自由基、羟基自由基、DPPH自由基和脂质过氧化均有抑制作用。     

Phenolic acid composition of sprouted wheats by ultra-performance liquid chromatography (UPLC) and their antioxidant activities

The phenolic acid profiles of flours from two Canadian wheat classes, Canadian Western Red Spring (CWRS) and Canadian Western Amber Durum (CWAD), were investigated using two different extraction mediums and analysed on an ultra-performance liquid chromatography (UPLC) system at different degrees of sprout damage. A sound (non-sprouted) control sample as well as two different sprouted sub-samples, derived from different germination protocols of the control, were prepared for both the CWAD and CWRS. Free phenolic acids were extracted from the ground whole wheat meal using three repetitive 80% ethanol extractions. Bound phenolic compounds were subsequently released from the residue by alkaline hydrolysis followed by triplicate extraction with diethyl ether:ethyl acetate (1:1, v/v). Twelve phenolic acid standards were clearly resolved and quantified using a short 5 min elution gradient. Seven phenolic acids (4-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic and sinapic) were detected in the CWRS and CWAD alcoholic and alkaline extracts. Syringic acid was the main compound in the free phenolic alcoholic extracts of the wheat meal representing 77.0% and 75.3% of the total amount of detected free phenolic compounds for CWRS and CWAD, respectively. However, the major released phenolic compound detected in the alkaline hydrolysed extracts was ferulic acid accounting for 72.3% and 71.0% for CWRS and CWAD respectively total bound phenolics. During germination, syringic acid levels rose as the length of germination time increased, resulting in the increase in total phenolic compound and antioxidant activity of the sprouted wheat flours. There was an increase in total phenolic compounds and the antioxidant activity of the alcoholic extracts from the CWRS and CWAD wheat flours as the germination time was extended. As a result, the sprouted wheats exhibits better nutritional properties than un-germinated wheat and could be used to improve the nutrition value in food products.     

超声波协同萌发处理富集黑青稞多酚的工艺优化及其酚酸组成分析

研究以黑青稞为原料，采用单因素实验及Box-Behnken响应曲面法优化超声波协同萌发处理富集黑青稞多酚的最佳工艺参数，并在此基础上比较超声波协同萌发处理前后黑青稞的酚酸组成差异。结果表明，超声协同萌发富集黑青稞多酚的最佳工艺为：超声预处理功率350 W、超声处理温度30℃、超声处理时间25 min、萌发时间64 h，在此条件下黑青稞的总酚含量（688.84±5.30 mg/100 g DW）最高。酚酸物质结果表明，萌发处理显著提高了主要酚酸物质中原儿茶酸（游离和结合）、对羟基苯甲酸（游离）、香草酸（游离）、咖啡酸（游离）、丁香酸（游离）、对香豆酸（游离）的含量，分别提高为未处理组的14.49、1.54、4.73、1.67、1.46、3.73、11.49倍；而超声波协同萌发处理显著增加了尿黑酸（结合）、咖啡酸（结合）、对香豆酸（结合）、阿魏酸（结合）的含量，分别提高为未处理组的39.24、1.09、1.60、1.13倍。抗氧活性结果表明，经萌发处理及超声波协同萌发处理的黑青稞其DPPH·清除能力均显著增加，分别提高为未处理组的11.66%、21.55%。综上分析，萌发处理及超声协同萌发...     

Phenolic acid profiles and antioxidant activities of wheat bran extracts and the effect of hydrolysis conditions

Four different types of wheat bran were extracted and analyzed for phenolic acids using the Folin–Ciocalteu method and HPLC. The extracts and their hydrolysis products were also evaluated for their antioxidant activities. The total phenolic content of the red wheat bran was higher than that of the white wheat. We found that the majority of the phenolic acids existed in a bound form in wheat bran. These phenolic acids can be released by hydrolyzing the bran under alkaline or acidic conditions; however, the former was more efficient in the release of free phenolic acids than the latter. Ferulic, vanillic, and syringic acids were the major individual phenolic acids in the studied wheat bran. The main portion of the total ferulic acid was from alkaline hydrolysis. The alkaline hydrolysable fractions had greater antioxidant activities, while the acid hydrolysable fractions showed lower activities in both the red and white bran. The antioxidant activity of bran extract was stronger than that of free phenolic acids.     

POLYPHENOLIC SUBSTRATES OF CATIONIC AND NEUTRAL/ANIONIC PEROXIDASES FROM BARLEY AND MALT USING A CHRONOMETRIC METHOD FOR THE DETERMINATION OF POD ACTIVITY

4-methylcatechol, phenolic acids from the benzoic and cinnamic series, flavan 3-ols and L-tyrosine were tested to determine the catalytic behavior of barley peroxidases (POD) at the expense of hydrogen peroxide. A chronometric assay using L-ascorbic acid was described for determining the peroxidatic activity of basic and neutral/anionic enzymatic fractions. The effects of hydrogen donors H₂O₂, and Ca⁺⁺ ion concentrations and pH were studied to set maximal conditions for POD measurement. The sensitivity to endogenous phenolic compounds (ferulic and p-coumaric acids, (+) catechin) along with caffeic acid for POD fractions was investigated and compared with their response versus guaiacol. Under the conditions tested, syringic and sinapinic acids as well as L-tyrosine were very weakly oxidized by POD from barley, whereas ferulic and caffeic acids were rapidly transformed. Levels of POD activity extracted from barley, green malt and kilned malt crude extracts were thereafter compared.     

Degradation of cereal bran polysaccharide-phenolic acid complexes by Aspergillus niger CFR 1105

Cereal brans such as wheat and rice are abundant sources for obtaining bioactive phenolic compounds such as ferulic and coumaric acids, in turn these can be bio-transformed into high value flavour compounds such as vanillin. Aspergillus niger CFR 1105, found to induce greater amounts of cell wall degrading enzymes, was inoculated into wheat and rice brans, and grown for 24, 48, 72 and 96 h to understand the degradation pattern of non-starch polysaccharides and phenolic acid complexes. Native wheat bran polysaccharides mainly consisted of arabinose, xylose, galactose, and glucose, in % of 27:39:2:30, with traces of mannose, whereas rice bran consisted of arabinose, xylose, galactose, and glucose in % of 9:27:31:32, respectively. Both the cereal bran arabinoxylans were degraded extensively by A. niger at 96 h, whereas the degradation of 1,3/1,4-β-d-glucans and cellulose was negligible. Bound phenolic acids of rice and wheat brans identified by HPLC were found to be mainly ferulic, coumaric, syringic acids in % of 93.6:6.3:0 (wheat), 34.7:55.8:9.5 (rice) and were drastically degraded/utilized at 96 h. The above results have indicated preferential degradation of arabinoxylans of wheat bran by A. niger, which can be exploited to obtain bioactive compounds such as ferulic acid.     

Phenolic Antioxidants of Soy Protein Hydrolyzates

Soy protein hydrolyzate (SPH) was investigated to identify the phenolic compounds responsible for antioxidant activity. Three isoflavones–genistein, daidzein, and glycitein–were found in SPH. These are the same isoflavones that have been identified in raw soybeans. No isoflavone glycosides were found in SPH. The phenolic acids found in SPH were caffeic, ferulic, p-coumaric, syringic, vanillic, gentisic, and p-hydroxybenzoic acids. The compounds were identified by TLC, GLC and UV spectra. The isoflavones were confirmed by their mass spectra.     

Phenolic Profile and Antioxidant Activity of Extracts Prepared from Fermented Heat‐Stabilized Defatted Rice Bran

Heat‐stabilized, defatted rice bran (HDRB) serves as a potential source of phenolic compounds which have numerous purported health benefits. An estimated 70% of phenolics present in rice bran are esterified to the arabinoxylan residues of the cell walls. Release of such compounds could provide a value‐added application for HDRB. The objective of this study was to extract and quantify phenolics from HDRB using fermentation technology. Out of 8 organisms selected for rice bran fermentation, Bacillus subtilis subspecies subtilis had the maximum phenolic release of 26.8 mg ferulic acid equivalents (FAE) per gram HDRB. Response surface methodology was used to further optimize the release of rice bran phenolics. An optimum of 28.6 mg FAE/g rice bran was predicted at 168 h, 0.01% inoculation level, and 100 mg HDRB/mL. Fermentation of HDRB for 96 h with B. subtilis subspecies subtilis resulted in a significant increase in phenolic yield, phenolic concentration, and radical scavenging capacity. Fermented rice bran had 4.86 mg gentistic acid, 1.38 mg caffeic acid, 6.03 mg syringic acid, 19.02 mg (‐)‐epicatechin, 4.08 mg p‐courmaric acid, 4.64 mg ferulic acid, 10.04 mg sinapic acid, and 17.59 mg benzoic acid per 100 g fermented extract compared to 0.65 mg p‐courmaric acid and 0.36 mg ferulic acid per 100 g nonfermented extract. The high phenolic content and antioxidant activity of fermented HDRB extract indicates that rice bran fermentation under optimized condition is a potential means of meeting the demand for an effective and affordable antioxidant.     

小麦麸皮中酚酸提取方法的研究

研究了酸种类、酸碱浓度、水解时间、水解顺序对小麦麸皮中束缚型酚酸释放量的影响。结果表明,酚酸在小麦麸皮中主要以束缚型形式存在,且肉桂酸类酚酸含量明显高于苯甲酸类酚酸,其中以阿魏酸的含量最高。水解方法对酚酸释放量的影响存在显著差异。采用超声波辅助有机溶剂（甲醇：丙酮：水=7：7：6）提取,酚酸释放量最高的水解条件为：先用2mol／L氢氧化钠室温水解4h,再用2mol／L盐酸于85℃下水解1h,束缚型酚酸总释放量达4719μg／g麸皮。