Comparative evaluation of the antioxidant capacity of smoke flavouring phenols by crocin bleaching inhibition, DPPH radical scavenging and oxidation potential

The antioxidant capacity of the main phenolic compounds present in wood smoke and smoke flavourings used in the food industry was investigated by three methods, based on a kinetic and thermodynamic approach: the bleaching of the carotenoid crocin, the scavenging of the DPPH radical, and the determination of the oxidation potential. The reaction with the DPPH radical was evaluated calculating the effective concentration (EC₅₀) and the antiradical efficiency (AE). The compounds tested were 2-methoxyphenols (guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-vinylguaiacol, 4-propylguaiacol, eugenol, isoeugenol, vanillin, acetovanillone, 2-propiovanillone), 2,6-dimethoxyphenols (syringol, 4-methylsyringol, 4-allylsyringol, syringaldehyde, acetosyringone) and dihydroxybenzenes (catechol, 3-methylcatechol, 4-methylcatechol, 3-methoxycatechol and hydroquinone). The trend in antioxidant capacity was similar in all the three methods, with dihydroxybenzenes > 2,6-dimethoxyphenols > 2-methoxyphenols, although some discrepancies in the ranking within the groups were present. Considering the overall ranking, isoeugenol was amongst the most active compound, like dihydroxybenzenes, evidencing the role of a conjugated double bond at para position for the stabilization of the phenoxyl radical in the radical scavenging process.     

PHENOL COMPOUNDS IDENTIFIED IN SELECTED LIQUID SMOKES

Liquid smokes including mesquite, hardwood blend, hickory (aqueous), and hickory-oil (oil-based) were subjected to direct ether extraction; phenolic components were separated and identified using gas chromatography/mass spectrometry (GC/MS). A solution containing 1,250 μg/ml each of phenol, isoeugenol, o -cresol, m -cresol, 4-allylsyringol, catechol, 4-methylcatechol, 2,6-dimethoxy-phenol, 2-methoxyphenol, 4-ethylphenol, and 2,3-dimethylphenol was injected directly or ether extracted prior to GC/MS separation for quantification of phenols in smokes and for recovery calculations. Phenol, guaiacol, syringol, and catechol in ether and ether extracted from oil were used as standards for oil-based smoke. The total amount of phenols in the smokes was similar but the proportions of individual phenols differed. Hickory smoke contained more syringol and its derivatives (4-allysyringol and 4-methylsyringol) than mesquite; mesquite contained more phenol, o-cresol, catechol and 4-methylcatechol than hickory.     

对国外一种新型烟熏液的初步剖析

运用GC/MS(气相色谱质谱联用法)对国外一种新型液体烟熏风味利(GLE1100)进行了初步剖析,总出色谱峰100多个,鉴定出了其中42个成分,初步剖析结果为:酚类15个;羰基化合物11个;酯类5个;酸类7个;其他化合物4个。列出了几个重要的具有明显的烟熏嗅与味的酚类化合物的质谱图。     

不同类型烟熏香精对西式培根风味的影响

为研究不同类型烟熏香精对西式培根风味的影响,本研究通过感官评价和电子鼻技术对添加不同类型烟熏香精制作的西式培根进行整体风味的分析,利用固相微萃取气相色谱-质谱联用技术研究不同类型烟熏香精对西式培根挥发性风味物质的影响。结果表明,不同类型烟熏香精制作的西式培根与传统西式培根在整体风味和主体风味化合物上进行比较,乐香水溶性烟熏香精（样品5）差异最小,其次为名花烟熏膏香精（样品1）和奇华顿油溶性烟熏香精（样品3）,再次为红箭油溶性烟熏香精（样品2）,而红箭水溶性烟熏香精（样品4）差异最大。乐香水溶性烟熏香精制作的西式培根与传统西式培根（对照样）的挥发性风味物质比较接近,有愈创木酚、4-甲基愈创木酚、苯酚和2,6-二甲基苯酚等35种共有成分。其中酚类物质的种类和传统西式培根相同,而含量是传统的1.22倍,从宏观和微观上都可以达到传统西式培根的风味。     

Identification of migrants from nitrile-butadiene rubber gloves

Polyvinyl chloride gloves containing di(2-ethylhexyl) phthalate are restricted for food contact use. In their place, disposable gloves made from nitrile-butadiene rubber (NBR) are used in contact with foodstuffs. Some unknown substances were found to migrate into n-heptane from NBR gloves. By GC/MS, HR-MS and NMR, their chemical structures were confirmed to be 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (used as a plasticizer), 4,4'-butylidenedi(6-tert-butyl-m-cresol), a mixture of styrenated phenols consisting of 2-(alpha-methylbenzyl)phenol, 4-(alpha-methylbenzyl)phenol, 2,6-di(alpha-methylbenzyl)phenol, 2,4-di(alpha-methylbenzyl)phenol and 2,4,6-tri(alpha-methylbenzyl)phenol (used as antioxidants), and 2,4-di-tert-butylphenol, which seems to a degradation product of antioxidant. Migration levels of these compounds were 1.68 micrograms/cm2 of 2,4-di-tert-butylphenol, 2.80 micrograms/cm2 of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, 46.08 micrograms/cm2 of styrenated phenols and 4.22 micrograms/cm2 of 4,4'-butylidenedi(6-tert-butyl-m-cresol) into n-heptane, respectively. The content of total styrenated phenols was 6,900 micrograms/g in NBR gloves.     

Automated determination of seven phenolic compounds in mainstream tobacco smoke

Exposure to hydroxyl-substituted arenes, commonly referred to as phenols or phenolic compounds, can have serious health consequences. Select phenols present in tobacco smoke are cardiovascular toxins, act as tumor co-promoters and show genotoxic activity. To examine the mainstream smoke levels of these compounds, we developed and applied a method for quantitative analysis of seven phenols (phenol, o-cresol, m-cresol, p-cresol, catechol, resorcinol, and hydroquinone) in mainstream smoke. Total mainstream smoke particulate matter was collected on a Cambridge filter pad and spiked with an isotopically labeled internal standard solution. This pad underwent an automated phenol derivatization procedure to increase analyte volatility and enhance detection. Following the derivatization step, phenols from the particulate matter were sampled using solid-phase microextraction with subsequent gas chromatography/mass spectrometric detection. Sensitivity, selectivity, accuracy, and reproducibility were more than adequate for routine detection of phenols in mainstream smoke. Detection limits ranged from 0.04-0.57 microg, with a quantification range of 0.1-710 microg. Higher sensitivity and sample throughput were achieved compared with previously described methods. Mainstream smoke from 28 brands of domestic commercial cigarettes was evaluated to assess typical levels, and reference cigarettes containing single tobacco blends were examined to ascertain the phenolic profile from different types of tobaccos. As expected under machine smoking conditions using the Federal Trade Commission parameters, full-flavored cigarettes deliver more phenols than the light varieties, followed by the ultra light varieties. Differences were seen in relative levels of phenolic compounds in the mainstream smoke from unfiltered cigarettes made with a single type of tobacco.     

抗氧化剂对川式腊肉低温冷藏中挥发性风味物质的影响

了解低温贮藏与川式腊肉风味品质的关系以指导合理贮藏。采用同时蒸馏萃取-气相色谱-质谱联用法分析抗氧化剂对川式腊肉低温贮藏中挥发性风味物质的影响。结果显示,处理A(直接真空包装)、处理B(添加0.4g/kg茶多酚后真空包装)、处理C(添加0.5g/kg异抗坏血酸钠后真空包装)的腊肉挥发性成分从原料的67种分别变化至贮藏结束(120d)时的75、64、63种;处理A、B、C的酚类、碳氢化合物及羰基化合物种类从初始的56种分别变化至结束时的55、45、44种,相对含量从初始的69.44%分别变化至结束时的59.30%、60.51%、61.87%;主体风味物质酚类相对含量从初始的34.43%分别降至结束时的24.26%、28.06%、33.41%;处理B、C的苯酚、愈创木酚、5-甲基愈创木酚、壬醛、乙酰呋喃、3-呋喃甲醇和苯甲醛相对含量高于处理A。表明添加抗氧化剂可减缓腊肉特征风味物质在冷藏中下降的趋势。     

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。     

Cross-coupling of sulfonamide antimicrobial agents with model humic constituents

The oxidative cross-coupling of sulfonamide antimicrobials to constituents of natural organic matter was investigated. Sulfonamide antimicrobials were incubated with surrogate humic constituents in the absence and presence of phenoloxidases (viz., peroxidase, laccase, and tyrosinase) or acid birnessite. Substituted phenols were chosen as simple model constituents to determine the structures in humic substances important for cross-coupling reactions. The extent of sulfonamide transformation was evaluated by the disappearance of the parent compound from solution. Incubation with phenoloxidases in the absence of substituted phenols resulted in little or no sulfonamide transformation. In contrast to this, direct oxidation of sulfonamides by acid birnessite was significant. Inclusion of o-diphenols and 2,6-dimethoxyphenols in reaction mixtures resulted in significant phenoloxidase-mediated transformation of sulfonamides and enhanced antimicrobial transformation in the presence of acid birnessite. Phenolic compounds with other substitution patterns were less effective in promoting sulfonamide transformation. Nuclear magnetic resonance spectroscopy experiments provided direct evidence of peroxidase-mediated covalent cross-coupling of sulfamethazine with syringic and protocatechuic acids. Our results indicate that sulfonamide antimicrobials may be chemically incorporated into humic substances. This may result in their diminished mobility, bioavailability, and biological activity.     

国内外混合型卷烟主流烟气中酚类物质的分析

对 10种国内外混合型卷烟主流烟气中酚类物质进行了分离鉴定。方法包括酚类物质的萃取分离、硅醚化和毛细管气相色谱分析。测定了 17种酚类物质的含量 ,结果表明 :①国内外卷烟烟气中的主要酚类如苯酚、对苯二酚和邻苯二酚相同 ;②在焦油量接近的情况下 ,国外混合型卷烟主要酚类含量明显低于国内混合型卷烟 ,其次为甲基酚、二甲基酚、甲氧基酚和间苯二酚。     

Extraction of phenolic compounds from red grape marc for use as food lipid antioxidants

Grape marc resulting from red winemaking was extracted with a mixture of ethyl acetate and water in order to obtain its phenolic compounds with a view to their use as food lipid antioxidants. Crushed and uncrushed marcs were extracted for 5, 10, 20 and 30 min in order to determine the minimum time required for ensuring maximal extraction of phenols. The results reveal a higher extraction of these compounds by the ethyl acetate acting on crushed marc, so the cost of this last operation can be largely compensated. The antioxidant lipid activity of the phenolic compounds of this extract was determined by using the Rancimat method on refined olive oil, and compared with the induction periods of BHT, BHA, propyl gallate and pure standards of those phenols identified in the above mentioned organic extract. In this test, the phenols of the extract show a lower antioxidant activity than the synthetic food antioxidants, although close to that of BHT, mostly as a result of its catechin content. ©     

Oxidative stability, volatile components and polycyclic aromatic hydrocarbons of cold-smoked sardine (Sardina pilchardus) and dolphinfish (Coryphaena hippurus)

Although a wide variety of compounds are deposited during the smoking process, much more attention has been given to phenols and polycyclic aromatic hydrocarbons (PAHs). However, even though phenols have an important role to play as food antioxidants, some PAHs have cytotoxic and mutagenic effects. In the present work, two fish species differing in composition (dolphinfish (Coryphaena hippurus) and sardine (Sardina pilchardus)) were salted and cold-smoked. Two different smoking treatments were selected in order to compare phenol content and muscle antioxidant activity employing the ferric reducing power (FRAP) method. Both smoking treatments increased fish lipid oxidation stability compared with the salted muscle. The characterization of the volatile components of the headspace of the more intensely processed smoked products was carried out by SPME/GC/MS, which revealed the presence of typical phenol and carbonyl derivatives, as well as some oxidation products and PAHs of low molecular weight. PAH composition was further investigated by extracting and identifying the PAHs by GC/MS. Neither benzo(a)pyerene nor other high molecular weight PAHs were detected, naphthalene and its derivatives being the most abundant compounds in the smoked products.     

Antioxidant capacity in cultivated and wild Solanum species: the effect of wound stress

Wild potatoes are of increasing interest as a gene pool in breeding. In this study, 23 genotypes of two cultivated (S. tuberosum subsp. andigena, S. phureja) and two wild Solanum species (S. chacoense, S. pinnatisectum) were evaluated for contents of soluble phenols and soluble proteins as well as their antioxidant capacity measured as ascorbic acid and trolox equivalent. Amounts of phenols present in tuber tissue ranged from 0.25 to 2.84 mg kg(-1) fw. On average, S. pinnatisectum (pnt) exhibited 3.9-fold greater quantities of phenols in its tuber tissue than the other Solanum species. In pnt tissue, high phenol content coincided with high levels of soluble proteins and antioxidants. It is concluded that an involvement of individual accessions of pnt in breeding could be profitable for the antioxidant potential and thus for the nutritional value of new potato cultivars. The results also revealed that soluble phenols as well as proteins present in tuber tissue substantially contributed to the total antioxidant capacity of potatoes. Moreover, it was found that quantities of soluble phenols, proteins and antioxidants increased notably upon wounding the tubers, a fact which underlines the role of all these components in wound stress responses of potatoes.     

醋纤和改性丙纤滤嘴过滤卷烟烟气有害成分效果比较

选用由醋酸纤维丝束和改性聚丙烯纤维丝束两种不同材料滤嘴卷制成的同一牌号卷烟,研究了两种不同材料滤嘴对卷烟烟气中特有亚硝胺、芳香胺、酚类、多环芳烃、氨以及挥发性羰基化合物等有害成分的过滤效果。结果表明:对多环芳烃,改性丙纤滤嘴的过滤效率高于醋纤滤嘴;对芳香胺、烟草特有亚硝胺、挥发性羰基化合物和酚类化合物,两种滤嘴的过滤效率接近,醋纤滤嘴的过滤效率略高于改性丙纤滤嘴;对烟气中的氨,醋纤滤嘴的过滤效率高于改性丙纤滤嘴。     

Preventive effect of adding antioxidants on mutagenic compound formation in fumes of cooking oil

The preventive effect of various antioxidants on the formation of mutagenic compounds such as trans,trans‐2,4‐decadienal in degummed peanut oil (DPO) fumes was investigated. The mutagenicity of the DPO fumes was significantly reduced by antioxidants added before heating. The addition of antioxidants increased the smoke point and oxidative stability of DPO and decreased the yield of oil fumes and the amount of mutagens. Butylated hydroxyanisole and butylated hydroxytoluene were more effective than natural antioxidants in reducing the amount of four enal compounds in fumes from DPO. Thus edible cooking oil with a high smoke point, less fume and lower mutagenicity might be developed with an appropriate antioxidant. Copyright © 2004 Society of Chemical Industry     

传统豆酱挥发性风味化合物的研究

采用顶空固相微萃取(HS-SPME)和气质联用(GC-MS)方法,共分离鉴定出传统豆酱中的挥发性风味化合物136种,其中酯22种,醇13种,醛12种,酸15种,酮15种,呋喃化合物16种,含硫化合物4种,吡嗪等含N化合物14种,酚5种,及其他少量烃类、酰胺类化合物等。其中2-甲基丁醛、安息香醛、乙酸乙酯、乙酸异烯酯、乙酸甲酯、糠醛、二氢-2(3H)-呋喃酮、3-辛酮、甲基硫丙醇、2,6-二甲基吡嗪等是除醇、酸外含量较高的化合物,占挥发性风味化合物总量的33.23%,对豆酱的风味起着重要作用。     

Heat-treatment with the vacuum-press dewatering method: chemical properties of the manufactured wood and the condensation water

Certain properties of wood can be improved with thermal modification, allowing its application fields to be considerably extended without the use of any chemical additives. This study focuses on the chemical investigation of hardwood (oak, beech, ash) products heat-treated with an industrial scale vacuum-press dewatering method (Vacu³) as well as on the evaluation of the parameters of the condensation water exhausted during the treatment. Wood modification was carried out at 195 and 210 °C. The pH value, loss of VOCs and total phenols were determined from the samples. Waste waters collected after the treatment cycles were investigated for pH, conductivity, COD, VOCs, total phenols and also for possible utilizable compounds. Release of VOCs from wood can be a health concern. Results show that the losses of the measured components were quite low. The composition of the highly acidic waste waters also depends on wood species, containing mostly phenolic compounds, aldehydes and acids. Possible ways for the utilization of these components need to be worked out in the future.     

加热烟草制品(HTPs)气溶胶成分的MD-GC/MS分析

  目的  了解加热烟草制品（HTPs）气溶胶成分特点。  方法  采用中心切割二维气相色谱-质谱法,对17个典型的HTPs气溶胶成分进行了分析。  结果  （1）HTPs气溶胶的主要成分与普通卷烟烟气相近,但释放量较低,其中66.7%的成分种类在HTPs气溶胶中的每口释放量小于卷烟烟气释放量的10%;（2）HTPs气溶胶中占比最高的成分为甘油（35.8%）,烟碱（25.7%）,1, 2-丙二醇（10.8%）,乙酸（3.1%）,糠醛（3.1%）等;苯甲醇、苯乙醇、茄酮、新植二烯等成分释放量与卷烟烟气较为接近;（3）不同种类HTPs气溶胶主要成分基本一致,但含氧裂解产物和酚类物质的释放量差别较大。      

皮蛋风味物质的测定

采用固相微萃取法,结合气相色谱-质谱（GC-MS）技术对减压法制作的皮蛋挥发性风味物质进行了分析检测,并与市售皮蛋的风味物质进行了对比研究。减压法皮蛋的加工条件为：温度23℃,真空度-0.06 MPa,抽空时间10 h。结果表明：在检出的48种减压法皮蛋的挥发性风味物质中,有贡献的主要挥发性物质为2-甲基环戊醇、1-辛烯-3-醇、苯甲醛、1-甲基环庚醇、2,6-二叔丁基对甲基苯酚等;而检出的28种市售皮蛋的挥发性风味物质中,有贡献的主要挥发性物质为1,2,5-三甲基吡咯、2-甲基环戊醇、4-氨基吡啶、1-辛烯-3-醇、2-乙基-6-甲基吡嗪等;减压法皮蛋与市售皮蛋相比,在挥发性风味物质组成及其相对含量上均存在着明显差异,不但证实了减压法加工皮蛋的可行性,且发现减压法皮蛋风味比市售皮蛋要好,醇香味更浓厚,这与嗅觉判断和品尝评定的结果相符。     

Volatile Compounds in Processed Duck Fillet

Volatile components of smoked and dry-cured, smoked, brined or raw duck fillets were fractionated by simultaneous distillation-extraction before GUMS. Volatile compounds (62) identified were phenols, alcohols, ethers, aldehydes, ketones, hydrocarbons, acids, esters, terpenes and N-and S-compounds. Some compounds (34) were related to the smoke process. Most of these flavor compounds had been identified in smoked meat products and 7 are reported for the first time. The formation of aldehydes and alcohols mainly results from oxidative decomposition of membrane polyunsaturated fatty acids.