大孔树脂精制竹蔗烟熏液的工艺研究

对6种大孔树脂精制竹蔗烟熏液的效果进行比较,以烟熏液中的代表成分酚类物质和3,4-幕并芘为考察指标,对大孔树脂精制烟熏液的工艺进行筛选.结果表明:6种树脂对羰基化合物基本不吸附,静态吸附过程中,温度对树脂吸附酚类物质和3,4-幕并芘影响不大,烟熏液原液10mL,加入2g的树脂对3,4-苯并芘吸附效果最好,采用30mL体积分数95％乙醇进行解析,酚类物质和3,4-苯并芘的解析率最高,其中,XAD-4树脂精制烟熏液效果最佳.     

响应面法优化红柳枝烟熏液制备工艺及其理化特性分析

以红柳枝为实验材料,在高温下干馏（厌氧热解）得到烟熏液,通过单因素试验和响应面设计法,研究干馏温度、干馏时间和木材厚度对红柳枝烟熏液产率、酚含量、羰基化合物含量的影响,进而确定红柳枝烟熏液制备工艺参数的最优组合。在最佳制备工艺参数的基础上,探究干馏温度对红柳枝烟熏液色泽的影响和吸附精制处理对红柳枝烟熏液理化性质的影响。结果表明：最优参数组合为干馏温度402.22 ℃、干馏时间75.66 min、木材厚度0.627 cm,该条件下制备烟熏液的酚含量为10.066 mg/mL、羰基化合物含量为14.35 g/100 mL、烟熏液产率为33.082%;烟熏液的亮度值（L*）随干馏温度的增大而降低,黄度值（b*）、色度值和色调随干馏温度的增大变化趋势与L*相似,但红度值（a*）的变化趋势与L*相反（P＜0.05）,随干馏温度的升高,红柳枝烟熏液总色泽的变化趋势由淡黄色至棕褐色,当干馏温度为380 ℃时,总色差（ΔE）最小,红柳枝烟熏液的色泽鲜艳、与商业烟熏液最接近;大孔树脂与核桃壳吸附精制对烟熏液pH值没有影响,但降低苯并(a)芘含量、酚含量、羰基化合物含量和烟熏液产率（P＜0.05）,苯并(a)芘含量远低于国标限量（0.5 μg/kg）。     

液熏斑点叉尾鲴鱼肉中熏液渗透及苯并(a)芘检测

采用修正吉布斯法和盐酸羟胺法对液熏前后熏液中酚类物质和羰基化合物含量进行比较.采用高效液相色谱法对烟熏鱼和液熏鲴鱼中苯并(a)芘含量进行检测.结果表明,鱼肉液熏处理后,羰基化合物的渗透与鱼肉烟熏色泽之间具有显著相关性(P>0.9),酚类物质的渗透,对鱼肉具有很好的抗氧化作用.液熏细鱼时,取熏液质量浓度为3%,熏制2～6h为宜.液熏鮰鱼中苯并(a)芘含量为1.00μg/kg,符合国际食品卫生要求.     

不同部位“雪花”梨所酿梨酒中酚类物质的分析和抗氧化能力比较

以"雪花"梨为原料,分别采用全果(剔除种子)、皮肉和果肉榨取果汁接种市售酵母RC212后酿制梨酒。对梨汁和梨酒中所含的酚类物质分别采用高效液相色谱法(high performance liquid chromatograph,HPLC)进行分析。结果表明:果汁酿制成梨酒后,总酚含量下降,其中熊果苷、没食子酸、原儿茶酸、绿原酸和芦丁含量在不同梨酒中均呈下降趋势,其中绿原酸减少幅度最大;3,4-二羟基苯丙氨酸、儿茶素含量则显著增加;槲皮素增幅较小,而表儿茶素含量则在3种梨酒中呈现不同的变化趋势。熊果苷、儿茶素和3,4-二羟基苯丙氨酸是3种梨酒中含量最高的3种酚,其余酚类物质含量均较少,不足5μg/mL,咖啡酸含量甚至不足0.5μg/mL。DPPH自由基清除率与酚类物质含量呈正相关,但偏最小二乘分析(partial least squares,PLS)结果显示,任何一种酚类物质对DPPH自由基清除率均没有显著影响,说明清除DPPH自由基可能是各种酚类物质协同作用的结果。     

真空液熏泥鳅加工工艺研究

以泥鳅为原料,通过分析感官评价和酚类物质浓度,在单因素试验基础上结合正交试验对真空液熏泥鳅的工艺条件进行优化。结果显示,真空液熏泥鳅的最佳工艺参数为:在熏液浓度为5.0%,真空度为0.08 MPa的条件下熏制4.5 h。在此工艺条件下熏制的泥鳅色泽金黄,烟熏味浓郁,其蛋白质含量、脂肪含量、pH值都较熏制前增加,水分含量下降,亮度降低,苯并芘含量为0.76 μg/kg。     

苹果木烟熏液的品质特性

以苹果木烟熏液为研究对象,从感官品质、pH值、羰基化合物、酚类化合物、苯并（a）芘的含量、挥发性风味物质的组成和电子鼻分析等角度研究苹果木烟熏液的性质,并与目前市场上烟熏液产品进行比较。结果表明,苹果木烟熏液pH值为2.31,酚类化合物、羰基类化合物的含量分别达到9.94 mg/mL和7.91 g/100 mL,挥发性风味物质以酚类物质和醛类为主,相对含量分别为36.15%和17.58%,通过电子鼻主成分分析发现,苹果木烟熏液与其他几种烟熏液之间主成分有显著性差异,与市场其他烟熏液相比,在核心成分和特征性风味物质均有明显的优势,同时无苯并（a）芘检出,表明苹果木烟熏液具有良好的应用前景。     

响应面优化溶剂法提取马铃薯皮酚类物质的工艺

响应面优化溶剂法提取马铃薯皮酚类物质的工艺条件。采用单因素实验和响应面设计,研究溶剂法提取时间、提取温度、料液比对马铃薯皮中酚类物质提取的影响。研究结果表明:马铃薯皮酚类物质提取的最佳工艺条件:料液比1∶15 (g/mL)、提取时间59 min、提取温度62 ℃,马铃薯皮总酚含量可达0.620 mg/g。研究结果对马铃薯皮多酚物质的进一步开发利用提供一定的理论基础。     

荸荠皮酚类物质超声波辅助提取工艺优化

采用超声波辅助提取荸荠皮中的酚类物质,考察溶剂种类、料液比、提取温度、超声功率及超声时间对酚类物质提取率的影响。在单因素试验的基础上,确定最佳提取溶剂,并利用响应面法优化工艺条件。结果表明,荸荠皮总酚的最佳提取工艺条件为:甲醇提取,料液比1:15 (g/mL),提取温度55℃,超声功率270 W,超声时间55 min,该条件下总酚含量的最大响应值为4. 42 mg/g;荸荠皮总黄酮最佳提取工艺条件为:甲醇提取,料液比1:20 (g/mL),提取温度60℃,超声功率240 W,超声时间55 min,该条件下总黄酮含量的最大响应值为15. 20 mg/g。     

干馏温度对龙眼木精制烟熏液挥发性成分的影响

以岭南特色果木-龙眼木为材料,采用气相色谱-质谱联用仪(GC-MS)检测技术,研究不同干馏温度对龙眼木烟熏液挥发性成分的影响。结果表明,在200℃,300℃和400℃干馏温度下制备的精制龙眼木烟熏液分别鉴定出20种,19种和23种挥发性成分,分别占烟熏液中化合物的相对含量95%,93.17%和95.25%。龙眼木精制烟熏液的挥发性成分主要是酚类化合物、酮类化合物、醛类化合物等,其中酚类化合物相对含量最高,在400℃干馏温度区间制备的烟熏液中挥发性酚类化合物含量为72.6%。经过低温净化处理的龙眼木烟熏液及挥发性成分中未检出苯并芘类化合物。     

基于UPLC-QTOF-MS和HPLC-QQQ-MS技术的鹰嘴豆酚类化合物定性、定量分析及其抗氧化能力研究

鹰嘴豆为一种高营养豆类植物。为深入了解其营养价值,用80%甲醇溶液提取酚类物质,对提取物中不同存在形态的酚类化合物及其抗氧化活性进行测定,并对其提取物进行酚类的定性及定量分析。结果表明,酚酸含量最高部分为糖苷键合态酚类物质(0.81 mg/g),黄酮含量最高部分为游离态酚类物质(0.26 mg/g),不同存在形式酚类物质含量及抗氧化能力不同;80%甲醇提取物通过UPLC-QTOF-MS定性分析,对其24种化合物进行鉴定,包括12种黄酮、4种酚酸;HPLC-QQQ-MS定量分析表明:对羟基苯甲酸、香豆酸、原儿茶酸类化合物含量丰富。     

响应曲面法优化大蒜中总酚提取工艺及其抗氧化活性测定

采用响应曲面法对料液比、提取时间、不同体积分数酸化甲醇提取剂3个因素进行优化,以料液比、提取时间、不同体积分数酸化甲醇提取剂为自变量,总酚提取量为响应值,利用Box-Behnken设计原理和响应曲面法,研究各自变量及其交互作用对总酚提取的影响,模拟求得二次多项回归方程的预测模型,并确定料液比1:14(g/mL)、提取时间31min、80%酸化甲醇为提取剂是最佳的提取条件。在此条件下,总酚提取量为0.67mg GAE/g,模型预测值偏差为6.9%,证明所选工艺条件为最佳工艺条件。同时,用5种方法对其抗氧化活性进行测定,结果表明大蒜具有良好的抗氧化活性。     

Extraction for profiling free and bound phenolic compounds in tea seed oil by deep eutectic solvents

Bound phenolic compounds have rarely been reported in vegetable oils and this may be due to little research about the extraction. Deep eutectic solvents (DESs), recently applied in the extraction of phenolic compounds as alternatives to organic solvents, were adopted in the extraction of free and bound phenolic compounds from tea seed oil in this work. First, the phenolic compounds were analyzed by ultra-high-performance liquid chromatography with quadrupole-time-of-flight and triple-quadrupole tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) for characterization and UHPLC-QqQ-MS/MS for quantification and 25 phenolic compounds were found to exist in both free and bound forms. Then, DESs were screened for extraction of free and bound phenolic compounds from tea seed oil as the pretreatment for analysis and the results showed that hydrogen bond donors (HBDs) and temperature significantly affected the extraction efficiency of DESs. Finally, free phenolic compounds (83.91 µg/g) and bound phenolic compounds (25.71 µg/g), extracted by the DES with glycerol as HBD at 50 °C, were 51.0% and 93.2% higher than those extracted by methanol/water (60%, v/v), respectively. This work not only advanced the basic data of phenolic compounds in tea seed oil but also explored an efficient extraction method for scientific analysis of free and bound phenolic compounds.     

反相高效液相色谱法同时测定马铃薯块茎中酚酸类物质

目的：运用反相高效液相色谱法同时测定马铃薯中的绿原酸、咖啡酸、对香豆酸和阿魏酸。方法：色谱柱为YMC-C18(250mm×4.6mm,5μm),流动相为甲醇-水-冰醋酸(30:70:1,V/V)等度洗脱,柱温25℃,检测波长327nm。结果：绿原酸、咖啡酸、对香豆酸和阿魏酸在进样质量浓度分别为7.80～1000、0.78～100、0.312～40、0.078～10μg/mL范围内线性关系良好(r值范围0.9968～0.9999),平均回收率为92.38%～101.73%。结论：本法分析快速准确、灵敏度高、重现性好,江西、北京和新疆3个地域的环境条件对马铃薯的酚酸含量有一定的影响。     

桂圆酵素的发酵工艺优化及其酚类化合物生物转化分析

以桂圆水提液为原料,总酚含量为评价指标,采用单因素及正交试验优化桂圆酵素的发酵工艺,并用高效液相色谱（HPLC）分析桂圆酵素中酚类化合物的生物转化。结果表明,最优桂圆酵素发酵工艺为菌株组合酿酒酵母＋醋酸杆菌＋植物乳酸杆菌1∶1∶1、接种量10%、发酵温度30 ℃、发酵时间36 h。在此优化工艺条件下,桂圆酵素的总酚含量达（46.05±0.76） μg/mL,是桂圆水提液总酚含量（9.12±0.26） μg/mL的5.05倍。HPLC分析表明,桂圆水提液中10多种酚类化合物,除了绿原酸及其它4种酚类化合物外,其余酚类化合物经发酵后均被完全转化。桂圆酵素中至少含有20余种酚类化合物,至少有16种为新生成,其中1种可以确定为柚皮苷,含量达3.32 μg/mL。     

Microwave-assisted extraction of phenolic compounds from wine lees and spray-drying of the extract

Most research on extraction of phenol compounds from wine by-products and commercial exploitation of extracts use grape seeds and/or skins as raw materials. Looking for alternative antioxidants sources, obtaining antioxidant extracts from wine lees (also known as dregs), a sub-exploited by-product of winemaking process, is here presented. Microwave-assisted extraction (MAE) of phenolic compounds from wine lees has been optimized using the total phenols index, the ORAC values and yield of the extraction as response variables. Under the optimal working conditions, the proposed MAE method provides better extraction efficiency in a much shorter time (17 min) than the conventional extraction method for phenolic compounds (24 h). The liquid extract obtained by MAE was spray-dried. The type and amount of excipients used, as well as the spray-drying temperature, were optimized in order to minimize the oxidation of phenolic compounds and maximize the yield of the spray-drying process. The total phenols index in the dried extract thus obtained was 36.8% (expressed as gallic acid), showing an ORAC value of 3930 μmol TE/g. Additionally, Mv3G, Cm-Mv3G, myricetin, quercetin, quercetin-3-β-glucoside, caffeic acid and p-coumaric acid were quantified in the dry extract by HPLC–DAD. The results indicate that wine lees antioxidant extracts can be a suitable and cheap alternative to those obtained from grape seeds or skins.     

Isolation and Identification of Phenolic Antioxidants in Black Rice Bran

Black rice bran contains phenolic compounds of a high antioxidant activity. In this study, the 40% acetone extract of black rice bran was sequentially fractionated to obtain 5 fractions. Out of the 5 fractions, ethyl acetate fraction was subfractionated using the Sephadex LH‐20 chromatography. The antioxidant activity of phenolic compounds in the extracts was investigated by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical assay, 2,2‐azino‐bis‐(3‐ethylenebenzothiozoline‐6‐sulfonic acid) (ABTS) radical cation assay, reducing power. The subfraction 2 from ethyl acetate fraction had the highest total phenolic contents (TPC) (816.0 μg/mg) and the lowest EC₅₀ values (47.8 μg/mL for DPPH radical assay, 112.8 μg/mL for ABTS radical cation assay, and 49.2 μg/mL for reducing power). These results were 3.1, 1.3, and 2.6 times lower than those of butylated hydroxytoluene (BHT), respectively. At a concentration of 100 μg/mL, the antioxidant activity and TPC of various extracts was closely correlated, with correlation coefficients (R²) higher than 0.86. The major phenolic acid in subfraction 2 was identified as ferulic acid (178.3 μg/mg) by HPLC and LC‐ESI/MS/MS analyses. Our finding identified ferulic acid as a major phenolic compound in black rice bran, and supports the potential use of black rice bran as a natural source of antioxidant.     

2种艾叶酚类化合物与挥发油成分比较

为研究艾叶化学成分与其产地之间关系,分别以产自河南南阳和新疆的艾叶为实验材料,对比研究其酚类化合物和挥发油的组成。以体积分数60%乙醇溶液为溶剂超声提取酚类化合物,高效液相色谱法结合标样检测其组成;同时蒸馏萃取结合气相色谱-质谱联用检测挥发油的化学成分。结果表明,河南南阳和新疆艾叶挥发油得率分别为2.644%、0.805%;河南南阳、新疆艾叶分别检测出标准品中的19种和14种酚类化合物,总含量达13.43 mg/g和9.75 mg/g;挥发油中分别鉴定出29种和12种化合物,占挥发油总量的80.24%和71.22%。河南南阳艾叶比新疆艾叶含有更加丰富的酚类化合物和挥发油。     

Assessment of phenolic profile of Turkish honeys

In this study, phenolic profile and antioxidant activity of 60 Turkish honey samples of nineteen different floral origins were evaluated by ultra-performance liquid chromatography with electrospray ionization coupled to tandem mass spectrometry, providing the identification of 32 phenolic compounds. Thyme (1051.58 mg/kg), pine (994.18 mg/kg), carob (935.03 mg/kg), eucalyptus (814.46 mg/kg), rhododendron (680.71 mg/kg), heather (562.59 mg/kg), cedar (561.83 mg/kg), and euphorbia (501.64 mg/kg) present significantly high phenolic content. Moreover ferulic, homogentisic, gentisic, syringic, 3,4-dihydroxybenzoic, caffeic, vanillic, p-coumaric, 4-hydroxy benzoic, and trans-2-hydroxy cinnamic acids were the most abundant of the determined compounds. The antioxidant activities of the honeys were evaluated by β-carotene-linoleic acid inhibition, DPPH free radical scavenging activity and ABTS⁺ cation radical scavenging activity which were measured as IC₅₀: 10.87 – 48.23 µg/mL, SC₅₀: 54.33 – 99.40 µg/mL and SC₅₀: 10.33 – 41.20 µg/mL, respectively. Phenolic compounds are considered antioxidant constituents, and they could be stated as components that account for antioxidant activity in Turkish honeys.