Acrylamide formation and antioxidant level in biscuits related to recipe and baking

Heated plant foods may contain compounds with adverse health effects (e.g. acrylamide). On the other hand, health-promoting compounds (e.g. antioxidants) have also been identified in such foods. Therefore, a baking experiment with biscuits was carried out to study the potential impact of both acrylamide and antioxidants in that food. Two different wheat flour types – wholemeal (WMF) and white flour type 550 (T550; 0.55% mineral content) – as well as recipe (fat and leavening agent) and thermal input (temperature?×?time) were changed. Furthermore, the effect of an enzymatic asparagine hydrolysation was tested. Antioxidants were determined with two independent procedures ABTS – (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate)) and FRAP-assay (ferric reducing ability of plasma). WMF samples resulted in an unchanged acrylamide level, but in a significantly higher antioxidant concentration when compared with T550 samples (149 and 141?µg?kg^?1 acrylamide and 9.1 and 5.1?mmol?TE?kg^?1 FW ABTS for WMF and T550, respectively). A reduced fat content yielded in an increased volume. Raising agents had no effect on acrylamide levels, but antioxidants were higher in samples with sodium bicarbonate (SBC) than with ammonium bicarbonate (ABC). Thermal input (temperature?×?time; 150°C?×?25?min to 240°C?×?9?min) indicated an exponential acrylamide increase especially at higher temperatures (from 75 to 236?µg?kg^?1), whereas antioxidant increase was linear (from 7.0 to 7.7?mmol?TE?kg^?1 FW, ABTS). FRAP and ABTS values were correlated on a low level, whereas acrylamide content of biscuits was correlated with FRAP and lightness (R ^2?=?0.62 and 0.47, and 0.71 and 0.85 for WMF and T550, respectively). The enzyme asparaginase reduced acrylamide formation by about 50% for both raising agents (SBC and ABC, respectively), whereas antioxidant levels were not affected. An evaluation of recipe variants with low acrylamide and high antioxidants indicated the advantage of wholemeal biscuits.     

Antioxidant capacity, phenolic content and vitamin C in pulp, peel and seed from 24 exotic fruits from Colombia

Twenty-four exotic Colombian fruits were evaluated for antioxidant activity and total soluble phenolics (TP) (edible part, seed and peel) and ascorbic acid content (edible part). The antioxidant activities were evaluated by ABTS (free radical-scavenging capacity) and FRAP (ferric reducing antioxidant power) methods. The ABTS, FRAP, TP and ascorbic acid values in the edible part were 3.25 to 175 ??M Trolox equiv/g fresh weight (FW), 6.29 to 144 ??M Trolox equiv/g FW, 15.7 to 1018 mg gallic acid equiv/100 g FW, and 0.53 to 257 mg ascorbic acid/100 g FW respectively. There were positive correlations between antioxidant activity (assessed by both ABTS and FRAP) and TP and ascorbic acid with the FRAP and ABTS methods. The edible part of banana passion fruits (P. tarminiana and P. mollisima) exhibited the highest values of antioxidant activity and total phenolics, while the highest level of ascorbic acid was recorded in the edible part of guava apple and cashew. The seeds with the highest values of antioxidant activity and total phenols were cashew, algarrobo, arazá and coastal sapote, while the peel of coastal sapote and algarrobo had the highest values of antioxidant activity and total phenolics. To the best of our knowledge, this paper reports the first evaluation of pulp, seed and skin of Colombian tropical fruits with a view to their knowledge utilization for the development of novel functional food products.     

Determination of Anthocyanins, Total Phenolic Content, and Antioxidant Activity in Andes Berry (Rubus glaucus Benth)

ABSTRACT:  Anthocyanins, total phenolic content, ascorbic acid content, and the antioxidant activity were determined in extracts of Andes berry fruit ( Rubus glaucus Benth). Anthocyanis (ACNs) were isolated and characterized by means of high-performance liquid chromatography (HPLC) with photodiode array detection and electro spray ionization/mass spectrometry (PDA-ESI/MS/MS) analysis. The anthocyanin (ACN) content was 45 mg/100 g FW. The isolated anthocyanins were characterized as cyanidin 3-sambubioside, cyanidin 3-glucoside, cyanidin 3-xylorutinoside, cyanidin 3-rutinoside, pelargonidin 3-glucoside, and pelargonidin 3-rutinoside. The ascorbic acid content was 10.1 mg/100 g FW. The total phenolic content as determined by the Folin–Ciocalteau method was 294 mg GAE/100 g FW while the antioxidant activity as measured by ABTS ^{· +} radical scavenging capacity and ferric reducing antioxidant power (FRAP) was 2.01 and 4.50 mmol TE/100 g FW or 8.22 mmoles ferric iron reduced/100 g FW, respectively. The high phenolic content and antioxidant capacity of Andes berry suggest that this fruit could be a rich source of natural pigments, nutraceuticals, and natural antioxidants.     

番茄果胶和半纤维素抗氧化活性分析

为了探究番茄细胞壁中不同类型果胶和半纤维素的抗氧化活性,利用水、EDTA、Na₂CO₃、4% KOH和24% KOH溶液分步提取,得到水溶性果胶(WSP)、离子结合型果胶(CSP)、共价结合型果胶(SSP)、松散结合型半纤维素(LH)和紧密结合型半纤维素(TH)五种组分,对各组分进行了氧自由基吸收能力(ORAC)、DPPH自由基(DPPH·)清除能力、ABTS自由基(ABTS+·)清除能力和铁离子还原能力(FRAP)的分析。结果表明,番茄WSP含量显著高于CSP和SSP,为1.05 mg GalUA/g FW,TH含量显著高于LH(p<0.05),为0.09 mg Glu/g FW。番茄不同类型果胶和半纤维素均具有一定的抗氧化活性。其中,CSP的ORAC、DPPH·清除能力和ABTS+·清除能力较强,综合抗氧化活性较高。在5 mg/mL时,CSP的ORAC值相当于76.4 μmol/L Trolox,DPPH·和ABTS+·的清除率分别达到61.0%和99.8%。而SSP、LH和TH具有较强的FRAP。相关性分析表明各组分与抗氧化活性密切相关。研究结果为番茄的综合加工利用和作为功能性食品添加成分的开发提供了理论根据。     

蓝莓果浆不同形态多酚的酶法转化工艺优化及抗氧化活性分析

本研究以蓝莓果浆为材料,利用酶法转化促进结合态多酚释放为游离态多酚,并研究不同形态多酚抗氧化活性。利用不同酶制剂酶解,以游离态多酚转化率为指标,筛选最适复合酶组合,并采用单因素实验和Box-Behnken响应面试验确定最优酶解条件;以FRAP抗氧化能力和ABTS抗氧化能力进行抗氧化活性分析。结果表明最优酶解条件为:以果胶酶和纤维素酶作为复合酶(配比为4:6),复合酶用量2.8%、酶解温度50℃、酶解时间124 min。在此条件下,与对照组相比,酶解蓝莓果浆游离态多酚转化率可达83.47%,提高了9.96%;酶解蓝莓果浆游离态多酚含量(343.58 mg GAE/100 g FW)提高27.67%,结合态多酚含量(68.03 mg GAE/100 g FW)降低29.84%。体外抗氧化活性结果表明,酶解蓝莓果浆游离态多酚提取物的FRAP抗氧化能力和ABTS抗氧化能力分别提高了15.45%和27.25%,总酚提取物的FRAP抗氧化能力和ABTS抗氧化能力分别提高了6.81%和15.62%。本研究表明,酶解促进了蓝莓果浆游离态多酚的转化,并增强了蓝莓果浆的抗氧化能力,为蓝莓功能活性产品研发与...     

Comparison of the 2,2'-azinobis-3-ethylbenzotiazo-line-6-sulfonic acid (ABTS) and ferric reducing anti-oxidant power (FRAP) methods to asses the total antioxidant capacity in extracts of fruit and vegetables

A comparison was made on the use of two spectrophotometric methods, the ferric reducing antioxidant power (FRAP) method and the 2,2'-azinobis-3-ethylbenzotiazoline-6-sulfonic acid (ABTS) method, for the measurement of the total antioxidant capacity (TAC) of plant foods. The correlations of TAC measured by the two methods were highly significant in both water-soluble (r2= 0.90) and water-insoluble extracts (r2= 0.98) from 13 strawberry samples. Also a corresponding comparison of TAC in extracts from 14 plant species showed high correlation coefficients, r2= 0.98 for water-soluble extracts and r2= 0.88 for water-insoluble extracts. The ratio of TAC values obtained with the two methods (ABTS/FRAP) varied between 0.7 and 3.3 for different plant extracts indicating that they contained antioxidants with varying reactivity in the two methods. TACs in six pure antioxidant substances were ranked in the following order by both methods: quercetin > ferulic acid > catechin > rutin > caffeic acid > Trolox = chlorogenic acid. The two methods showed similar TAC values for quercetin, rutin, caffeic acid and chlorogenic acid while ferulic acid and catechin gave higher results with the ABTS method than with the FRAP method, and such differences probably explain the varying ratios of ABTS/FRAP obtained in foods. Regarding storage TAC in water-soluble strawberry extracts stored at -20 or -80 degrees C was stable for at least five months while storage at 4 degrees C decreased the TAC value with 40% during five weeks of storage. The study showed that both the ABTS and FRAP methods can be used for convenient monitoring of the antioxidant capacities in fruit and vegetables, and that different antioxidants had varying reactivity in the two methods.     

Phenolic,apparent antioxidant and nutritional composition of quinoa (Chenopodium quinoa Willd.) seeds

Quinoa, a gluten-free pseudocereal, has a nutrient and phytochemical profile which may benefit health. Our aim was to investigate the variability in the phenolic and apparent antioxidant content of different quinoa varieties to identify a variety with a high phytochemical content to use in a quinoa-enriched bread. The results showed that free phenolics contributed most (50–83%) to total phenolic content compared with conjugated or bound forms. Apparent antioxidant activities measured by FRAP, ABTS+• and DPPH of free, conjugated and bound extracts were broadly similar, except for free antioxidants when determined by FRAP, which were higher. Phenolic content was positively correlated with FRAP and ABTS+• apparent antioxidant activity. Quinoa samples had a high protein content (13.5 g/100 g dry weight), with a well-balanced amino acid profile. Incorporation of quinoa into baked products such as bread is proposed as a way to deliver this healthy whole-grain cereal into the diet.     

Correlation of tocopherol,tocotrienol, γ-oryzanol and total polyphenol content in rice bran with different antioxidant capacity assays

The relationship between antioxidant capacity and levels of various antioxidants in rice bran and brown rice powder was evaluated. Three different varieties of Venezuelan rice, namely, Cimarrón, Zeta 15 and FONAIAP-1, were studied using ferric reducing antioxidant power (FRAP), 2,2′-azinobis-3-ethylbenzotiazoline-6-sulphonic acid (ABTS), and oxygen radical absorbance capacity (ORAC) to measure antioxidant capacity. The results showed that rice varieties contained different levels and combinations of total polyphenols, γ-oryzanol, α- and γ-tocopherols and α-, γ- and δ-tocotrienols. Compared to brown rice powder, rice bran contained most of the antioxidants and had correspondingly higher values of antioxidant capacity. Principal components analysis and multiple regression on the data indicate that FRAP was sensitive to polyphenols and total tocotrienols, while ORAC was sensitive to polyphenols and total tocopherols. ABTS was the least sensitive of all assays tested. Thus, results from antioxidant capacity assays must be interpreted with caution particularly in complex systems and that further study is necessary to define more precisely the nature of the relevant chemical reactions.     

刺葡萄皮醇提物和不同洗脱组分抗氧化成分及活性

以酸化甲醇为溶剂对刺葡萄皮进行超声波辅助提取,并用大孔树脂进行分离得到5 种不同洗脱组 分,研究刺葡萄皮醇提物和不同洗脱组分的活性成分及抗氧化能力。结果表明,刺葡萄皮含有较高含量的 多酚（1.836 mg/g mf）、黄酮（0.874 mg/ g mf）、VC（3.567 mg/g mf）、丹宁（3.578 mg/g mf）和花青素 （2.970 mg/g mf）,其1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力、 2,2’-二氮-双（3-乙基苯并噻唑-6-磺酸）二铵盐自由基（2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) radical, ABTS＋·）清除能力、铁离子还原能力（ferric reducing antioxidant power,FRAP）分别为22.325、17.595、 26.487 μmol TE/g mf。在5 种组分中以水解吸组分活性成分含量最高,其多酚、黄酮、VC、丹宁和花青素含量分别 为0.876、0.116、1.577、1.576 mg/g mf和1.330 mg/g mf,其DPPH自由基、ABTS＋·清除能力和FRAP分别为3.636、10.109、 13.415 μmol TE/g mf,相关性分析表明抗氧化活性与活性成分花青素、丹宁、VC含量呈强相关关系,表明抗氧化活性可 能主要由这3 种活性物质贡献。本研究结果表明,刺葡萄皮有潜力作为膳食补充抗氧化物质的主要来源。     

微型DPPH、ABTS和FRAP法动态监测从红酒中分离得到的不同种类多酚化合物的抗氧化活性

本文确定了微型1,1-二苯基-2-三硝基苯肼自由基清除能力测定法(2,2-Diphenyl-1-picrylhydrazyl,DPPH)、2,2-联氮基双(3-乙基-苯并噻唑啉-6-磺酸)二铵盐总抗氧化能力测定法(2,20-Azino-bis(3-ethylben zothiazoline-6-sulfonic acid)diammonium salt,ABTS)和铁离子还原/抗氧化力测定法(ferric reduction ability plasma assay,FRAP)测定从红酒中分离得到的不同种类多酚化合物抗氧化活性的最佳反应时间以及抗氧化活性的大小。以抗氧化剂Trolox和Vc为对照,动态监测红酒中不同种类多酚化合物在三种体系中的反应过程,计算不同浓度下红酒多酚类化合物的抗氧化活性。结果表明,三种反应体系的最佳反应时间分别是100 min、240 min和370 min。不同种类的红酒多酚类化合物与抗氧化剂一样,其样品浓度与抗氧化活性呈明显的量效关系。从相关性分析得出,表儿茶素、多聚体、低聚体、花色苷是影响葡萄酒抗氧化活性的主要成分,可以将其确定为葡萄酒质量控制的指标。本文建立的微型DPPH、ABTS和FRAP法操作简单,重复性好,样品消耗少。     

五倍子制备没食子酸丙酯的抗氧化活性研究

对天然植物五倍子浸提物没食子酸（GA）进行改性,得到没食子酸丙酯（PG）,并采用亚铁还原能力法（FRAP）、1,1-二苯基-2-三硝基苯肼（DPPH）自由基法、2-联氨-双-3-乙基苯并噻唑啉-6-磺酸（ABTS）自由基法对其抗氧化活性进行评价。结果显示,FRAP值由大到小排序为：PG（FRAP值0.506）＞TBHQ（FRAP值0.412）＞BHA（FRAP值0.409）＞BHT（FRAP值0.067）;DPPH自由基清除能力由强到弱的顺序为：PG（IC50值4.2 μmol/L）＞BHT（IC50值53 μmol/L）＞TBHQ（IC50值87 μmol/L）＞BHA（IC50值816 μmol/L）;ABTS自由基清除能力由强到弱的顺序为：PG（IC50值 4.2 μmol/L）＞BHA（IC50值44 μmol/L）＞BHAT（IC50值45 μmol/L）＞TBHQ（IC50为50 μmol/L）。结果表明,PG的抗氧化活性均强于其他三种抗氧化剂,可作为新兴食品抗氧化剂应用。     

Dietary acrylamide exposure among Finnish adults and children: the potential effect of reduction measures

A deterministic exposure assessment using the Nusser method that adjusts for within-subject variation and for nuisance effects among Finnish children and adults was carried out. The food consumption data covered 2038 adults (25-74 years old) and 1514 children of 1, 3 and 6 years of age, with the data on foods' acrylamide content obtained from published Finnish studies. We found that acrylamide exposure was highest among the 3-year-old children (median = 1.01 μg kg(-1) bw day(-1), 97.5th percentile = 1.95 μg kg(-1) bw day(-1)) and lowest among 65-74-year-old women (median = 0.31 μg kg(-1) bw day(-1), 97.5th percentile = 0.69 μg kg(-1) bw day(-1)). Among adults, the most important source of acrylamide exposure was coffee, followed by casseroles rich in starch, then rye bread. Among children, the most important sources were casseroles rich in starch and then biscuits and, finally, chips and other fried potatoes. Replacing lightly roasted coffee with dark-roasted, swapping sweet wheat buns for biscuits, and decreasing the acrylamide content of starch-based casseroles and rye bread by 50% would result in a 50% decrease in acrylamide exposure in adults. Among children, substituting boiled potatoes for chips and other friend potatoes and replacing biscuits with sweet wheat buns while lowering the acrylamide content of starch-based casseroles by 50% would lead to acrylamide exposure that is only half of the original exposure. In conclusions, dietary modifications could have a large impact in decreasing acrylamide exposure.     

Evaluation of antioxidant activity and total phenolics of selected Czech honeys

Honey serves as a good source of natural antioxidants, which are effective in reducing the risk occurrence of heart disease, cancer, cataracts, different inflammatory processes and immune-system decline. In the fresh selected Czech honey samples originated mainly from the region North Moravia antioxidant activity and total polyphenol content were determined. A total of 40 honey samples (multifloral, lime, rape, raspberry, mixture and honeydew honeys) native to different stations gained in the period from May by August year 2006 were analysed. Total phenolics (TP) content was determined by the modified Folin-Ciocalteau method [TP was expressed as mg of gallic acid equivalent (GA eq.) per kg of honey]. For evaluation of the antioxidant activity (AOA) three different methods were used, the ferric reducing antioxidant power (FRAP) assay, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and the 2,2′-azinobis(3-ethylbenzothiazolin)-6-sulfphonate (ABTS) assay. AOA was expressed in mg ascorbic acid equivalent (AA eq.) per kg of honey. The results indicated that TP and AOA in Czech honey varied greatly between the honey kinds, location and time of the harvest. Average TP ranged from 89.9 mg GA eq. kg^-1 in lime honey to 215.2 mg GA eq. kg⁻¹ in honeydew honey. Antioxidant activity determined by the DPPH, ABTS and FRAP methods was lowest in floral honeys. The highest values were obtained for honeydew and mixture honeys. ABTS and FRAP assays have been shown to be the optimal methods for AOA determination in honey. A positive linear correlation between AOA and TP was observed (in FRAP assay R² = 0.852). It indicates that phenolics are one of the main components responsible for antioxidant behaviour of honey. The obtained results support and extend complete knowledge about the content of bioactive phenolics and antioxidant activity in the Czech honeys.     

Study on Mitigation of Acrylamide Formation in Cookies by 5 Antioxidants

Abstract: This study investigated the capacity of various antioxidants in reducing the formation of acrylamide during cookie processing. Five antioxidants, antioxidants of bamboo leaves (AOB), sodium erythorbate (SE), tea polyphenols (TP), vitamin E (VE), and tert‐butyl hydroquinone (TBHQ), were individually added into cookie formulas, and acrylamide content was determined by liquid chromatography tandem mass spectrometry (LC‐MS/MS). Cookie quality indexes, including flavor, brittleness, and water activity, were also evaluated. Results showed that the maximum inhibitory rate of acrylamide by AOB was achieved with addition of 0.2 g/kg AOB. Addition of AOB (0.2 g/kg), TP (0.1 g/kg), VE (0.1 g/kg), SE (0.1 g/kg), and TBHQ (0.2 g/kg) mitigated the formation of acrylamide by 63.9%, 43.0%, 71.2%, 49.6%, and 54.1%, respectively. Sensory evaluation showed that the color, texture, and flavor of cookies processed with either AOB (0.2 g/kg) or VE (0.1 g/kg) had no significant difference compared to control cookies (P > 0.05). The present study indicated that AOB (0.2 g/kg) and VE (0.1 g/kg) could not only effectively mitigate the formation of acrylamide, but also retain acceptable sensory attributes of cookies. This work shows the potential effectiveness of antioxidants in food processing to decrease acrylamide formation. Practical Application: There is an urgent need for reducing the level of acrylamide produced during food processing. This study found that certain antioxidants (antioxidant of bamboo leaves and vitamin E) could effectively inhibit acrylamide formation in cookie processing without affecting sensory properties. The results suggested that the application of antioxidants could be an effective method to decrease acrylamide formation.     

Antioxidant capacity of bovine milk as assayed by spectrophotometric and amperometric methods

The total antioxidant capacity (TAC) of bovine milk, whey, and low-molecular-weight (LMW) fractions of whey was investigated using spectrophotometric methods including an ABTS-based method (reduction of the cation radical of 2,2′-azinobis(3-ethylenebenzothiazoline-6-sulfonic acid)) and a FRAP method (reduction of Fe³⁺). Significant antioxidant capacity in milk and whey was demonstrated by the ABTS method (TAC(ABTS)), and it apparently increased with increasing pH. TAC (ABTS) was several-fold higher in milk than in whey, which had a slightly higher TAC than a LMW fraction prepared from it. Also the FRAP method could be used to demonstrate TAC in whey, although the low pH necessary for this method led to some protein precipitation. Most of the ferric-reducing activity of whey was found in the LMW fraction. The TAC values obtained using these methods were also compared to those obtained using a newly developed flow-injection amperometric (FIAmp) procedure for LMW fractions. High correlations were found for the TAC values of LMW samples obtained by the ABTS, FRAP and FIAmp methods (R²>0.8, P<0.001). Furthermore, to identify the major antioxidants in the LMW fraction, it was treated by uricase. Since most of the TAC (using ABTS, FRAP and FIAmp methods) was removed by uricase treatment, it could be concluded that urate is the major antioxidant in the LMW fraction. Also the effect of heat treatment on TAC in milk and whey was monitored. After heating of whey at 63°C for 1 h, TAC(ABTS) tended to increase by at least 20%, while TAC(FRAP) was not significantly changed. In milk, TAC(ABTS) remained constant during the same heat treatment. It is concluded that the methods tested gave the most reliable results for the LMW fraction of whey and that the use of several methods is necessary to characterise the antioxidant capacity of milk.     

Antioxidant capacities and total polyphenol contents of hydro-ethanolic extract of phytococktail from trans-Himalaya

The aim of this study was to evaluate the in vitro antioxidant potential of hydro-ethanolic extract of a novel phytococktail comprising of sea buckthorn, apricot, and Rhodiola (SAR) from trans-Himalaya. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) activity of the extract increased in a dose-dependent manner (upto 0.1 mg/mL), and was found to be about 38% of that of ascorbic acid at 0.1 mg/mL. The hydro-ethanolic extract of SAR also scavenged the ABTS(.+) radical generated by ABTS/potassium persulfate (PPS) system and was found to be about 62% of that of ascorbic acid at 0.1 mg/ mL. The total antioxidant power of the extract was determined by ferric reducing antioxidant power (FRAP) assay. Total phenolic content was found to be 1.28016 × 10(-3) mol gallic acid equivalent (GAE)/g extract. Total flavonoid and flavonol contents were estimated to be 2.5970 × 10(-4) mol and 4.87 × 10(-4) mol quercetin equivalent/g extract, respectively. The hydro-ethanolic extract of this phytococktail indicated presence of essential phytoconstituents of polyphenols, flavonoids, flavonols, and ascorbic acid, which contributed significantly to its antioxidant capacity. The combination of the 3 plants may well support their use in traditional medicine to combat oxidative stress and high-altitude sickness.     

青海藜麦资源酚类物质及其抗氧化活性分析

为了明确青海藜麦资源酚类物质含量及其抗氧化活性的差异,筛选出酚类物质和抗氧化活性高的藜麦资源,采用化学法分析了90份藜麦资源中游离酚类、结合酚类含量,通过DPPH·、ABTS+·清除力及FRAP铁还原力指标评价各组分的体外抗氧化活性。结果表明:不同藜麦酚类物质含量均存在较大差异,且结合酚类物质含量差异较大,游离酚类物质含量相对较小,游离酚类和结合酚类物质在清除DPPH·、ABTS+·、FRAP方面存在明显差异,其中结合酚类具有较强的清除DPPH·、ABTS+·能力,分别达4732.56、3371.97 μmol Trolox Eq/100 g DW;游离酚类的FRAP还原能力相对较强,达1408.64 μmol Trolox Eq/100 g DW。白色、黄色藜麦的结合酚类物质清除DPPH·、ABTS+·能力显著高于红色藜麦,分别达4657.41、5065.66 μmol Trolox Eq/100 g DW,3532.37、3350.72 μmol Trolox Eq/100 g DW;红色藜麦的酚类物质FRAP铁还原力最强(3264.42 μmol Trolox Eq/100 g DW)。聚类分析表明,参试的大部分青海藜麦资源结合酚类物质含量较低,DPPH·、ABTS+·清除力较弱,但FRAP铁还原力较强,其中有6个藜麦资源的结合酚类物质含量最高,5个藜麦资源的抗氧化活性最强。此结果为功能性藜麦新品种的选育提供了优质资源和指导意义。     

5 种梅干菜的酚类化合物及抗氧化能力比较分析

以市售5 种梅干菜为研究对象,测定梅干菜酚类化合物的含量,用高效液相色谱-串联质谱（high performance liquid chromatography-tandem mass spectrometry,HPLC-MS/MS）法鉴定梅干菜酚类化合物的种类,并用4 种抗氧化能力评价方法评价梅干菜。结果表明,市售5?种梅干菜所含的酚类化合物含量和各酚类化合物所占的比例及其抗氧化能力差异显著。其中咕咕鲜牌梅干菜（GGX）的总酚含量为14.18?mg?GAE/g,总黄酮含量为7.10?mg?RE/g,2,2’-联氮-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐（2,2’-azino-bis(3-ethylbenzthiazoline-6-sulphonate),ABTS）法、铁离子还原（ferric reducing antioxidant power,FRAP）法、1,1-二苯基-2-三硝基苯肼法和氧自由基吸收能力（oxygen radical absorbance capacity,ORAC）法测得的抗氧化能力分别为28.09、32.88、31.72?μmol?TE/g和445.55?μmol?TE/g,显著高于其他4?种梅干菜。其次,利用HPLC-MS/MS法分析鉴定出梅干菜中共含有17?种酚类化合物,包括9?种类黄酮和8?种酚酸。其中,梅干菜中的类黄酮主要有野漆树苷、山柰酚、异鼠李素、柚皮素等;酚酸主要有阿魏酸、香豆酸和肉桂酸等。此外,4?种抗氧化能力评价方法中,ABTS与FRAP相关性最高,相关系数为0.967;ORAC法测得的梅干菜抗氧化能力显著高于其他3?种方法;而ABTS法与梅干菜的抗氧化剂相关性最高,最适合评价梅干菜的总抗氧化能力。综上所述,不同种类市售梅干菜的酚类化合物含量和抗氧化能力均不同,其中,GGX总酚含量最高、抗氧化能力最强。     

Antioxidant activity of cookies and its relationship with heat-processing contaminants: a risk/benefit approach

Formation of both health promoting and potential harmful substances (acrylamide and hydroxymethylfurfural) has been associated to the extent of the Maillard reaction. The effects of recipe compositions in terms of leavening agent (ammonium and sodium bicarbonates) and sugars (sucrose and glucose), and baking conditions (temperature and time) on the antioxidant activity (AOA) in cookies were studied. The cookies were baked at different temperatures (180–220 °C) for different times (10–25 min). AOA was measured by the ferric reducing power (FRAP), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2,-diphenyl-1-picrylhydrazyl (DPPH) coloured radicals, and oxygen radical absorbance capacity (ORAC-fluorescein) in automated plate-reader assays. Net AOA varied regarding the assay applied, whereas higher AOA was always obtained for the ABTS assay and lower for DPPH assay, and ranging from 2 to 200 μmol Trolox/g sample. At higher temperature and baking times, higher AOA in cookies regardless of the formulation was recorded. Glucose enhances formation of compounds with higher AOA compounds as compared with sucrose recipes. Ammonium bicarbonate clearly promotes the formation of AOA for sucrose recipes but this effect is not observed in glucose recipes and varied with the AOA procedure applied. A risk/benefit index, based on the concomitant formation of neo-formed contaminants and substances with AOA (potentially health-promoting substances) is presented, and its application for recipe comparison is discussed. Risk/benefit index rapidly increased with increased temperature and time of baking.     

Antioxidative effect of lotus seed and seedpod extracts

The antioxidative activity of 6 kinds of extracts including 80% ethanol, hexane, chloroform, ethyl acetate, butanol, and water from seeds and seedpods of lotus (Nelumbo nucifera Gaertner) were evaluated by determining DPPH and ABTS radical scavenging activities as well as ferric reducing ability of plasma (FRAP). DPPH and ABTS scavenging capacities of the ethyl acetate fraction of lotus seed (LS) were 94.6 and 91.9% and those of the water fraction of lotus seedpod (LSP) were 94.5 and 95.2% at 0.8 mg/mL. The ethyl acetate fraction of LS and the water fraction of LSP also showed high FRAP. The high antioxidant capacities of LS and LSP may be due to their flavonoid and proanthocyanidin contents. The evaluation of antioxidant effect in LS and LSP is a valuable purpose, particularly for finding an inexpensive source for natural antioxidants and functional food. The high antioxidant capacity of LSP water fraction could be available as natural additive in food.