乙醇熏蒸处理对鲜切西兰花活性成分和抗氧化活性的影响

研究乙醇熏蒸处理对鲜切西兰花总酚、总黄酮、总硫代葡萄糖苷和萝卜硫素等活性成分含量及抗氧化活性的影响。先将花球在20 ℃条件下分别用体积分数为2%、5%、10%、20%乙醇溶液熏蒸处理6 h,再切割成小花并在10 ℃条件下贮藏。结果表明,10%乙醇溶液熏蒸处理可以显著延长鲜切西兰花的货架期、提高总酚和总黄酮含量、延缓总硫代葡萄糖苷和萝卜硫素含量下降,并可有效保持较高的DPPH（1,1-diphenyl-2-picrylhydrazyl）自由基清除能力和还原力,提高其清除超氧阴离子自由基和羟自由基能力,从而延缓西兰花采后衰老、保持较高的抗氧化活性。同时发现,总酚、总黄酮和萝卜硫素含量与DPPH自由基清除能力存在极显著的正相关性。这些结果表明乙醇熏蒸处理在鲜切西兰花保鲜中具有较好的应用前景。     

不同预处理和干燥方式下养心菜粉色泽、功能成分和抗氧化性水平 的比较

为了研究养心菜的加工适用性,拓展其利用途径,采用未预处理（Untreated,UT）、沸水漂烫（Boiling Water Blanching,BWB）、沸水+护色漂烫（COLOR Protection+Water Blanching,CPB）、蒸汽漂烫（Steam Blanching,SB）与冻融（Freeze-Thawing,FT）五种预处理方式处理后,分别进行热风干燥（Hot Air Drying,HA）、热泵干燥（Heat Pump Drying,HP）,得到UT HP、UT HA、BWB HP、BWB HA、CPB HP、CPB HA、SB HP、SB HA、FT HP及FT HA 10种养心菜粉,比较不同预处理方式和干燥方式下养心菜色泽、功能成分及抗氧化能力水平的变化。结果表明：UT HP没食子酸和山萘酚含量最高,但色泽差、叶绿素含量较低,干燥时间长;CPB HP的干燥时间短,Vc含量最高,具有较高的抗氧化水平,但没食子酸含量较低;SB HP总酚、总黄酮、槲皮素含量最高,其他品质指标介于中间;FT HP养心菜具有最好的色泽、最高的叶绿素、游离氨基酸含量,但总酚、总黄酮、槲皮素、山萘酚以及抗氧化水平低。从主成分分析来看,BWB HP、CPB HP、SB HP 和BWB HA、CPB HA、SB HA的养心菜品质分别具有一定的相似性,UT HP、FT HP、UT HA、UT HA和其有明显差异。该文综合比较了养心菜不同预处理及干燥方法的优劣,在养心菜下游的功能性食品的开发过程中,可以根据需求选择合适的干燥方法。     

Investigation on the Antioxidant Activity of Leaves, Peels, Stems Bark, and Kernel of Mango (Mangifera indica L.)

Bioactive polyphenols, cartenoids, and anthocyanins present in fruits and vegetables are receiving much attention because of their potential antioxidant activity. This study was conducted to determine antioxidant activity of leaves, peels, stem bark, and kernel of mango varieties langra and chonsa. Total phenolic (TPC) and total flavonoid contents (TFCs) in segments of langra ranged from 63.89 to 116.80 mg GAE/g DW and 45.56 to 90.89 mg CE/g DW, respectively, and that of chonsa were 69.24 to 122.60 mg GAE/g DW and 48.43 to 92.55 mg CE/g DW, respectively. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and linoleic inhibition capacity in segments of langra ranged from 53.30% to 61.10% and 40.0% to 47.20%, respectively, whereas for chonsa; 56.40% to 66.0% and 48.1% to 49.0%, respectively. The reducing potentials of different segments of langra and chonsa at concentration of 10 mg/mL were 0.512 to 0.850 and 0.595 to 0.665 mV, respectively. Comparison between both varieties showed chonsa exhibited better antioxidant activity. Data were analyzed by analysis of variance (ANOVA) using completely randomised design (CRD) under factorial.     

Effects of Hypobaric Treatments on the Quality,Bioactive Compounds,and Antioxidant Activity of Tomato

Hypobaric treatment is becoming a potential technology to protect fruits from postharvest decay. The objective of this study was to investigate the effects of hypobaric treatments on storage quality, bioactive compounds, and antioxidant activity of tomato fruit. In this study, green tomatoes (cv. “Fen guan”) were treated with hypobaric pressures (0.04 and 0.07 MPa) at ambient temperature (20 ℃) for 28 d. The results showed that under hypobaric storage, the respiration rates significantly declined and the respiratory peaks postponed 12 and 8 d by 0.04 and 0.07 MPa treatments, respectively, compared to control. Total soluble solid, titratable acidity, ascorbic acid, and lycopene were retained by hypobaric treatment. Moreover, ascorbic acid contents treated with 0.04 and 0.07 MPa were, respectively, 37% and 26% higher than control at day 24 and the contents of total polyphenols were, respectively, 1.28 and 1.11 times higher than control. Production and accumulation of toxic substances were significantly restrained. The ethanol content decreased, respectively, by 53% and 84% than control. At later storage period, the superoxide dismutase activity in treated fruits was about 0.58 U/(g·FW·min), whereas only 0.29 U/(g·FW·min) in control. Hypobaric treatment not only maintained a high activity of superoxide dismutase and peroxidase (POD), but also improved antioxidant capacity. All the results indicated that hypobaric treatment was a potential helpful method to protect the quality and nutrition of tomato and prolong ripening of tomato. Furthermore, the effect of 0.04 MPa hypobaric treatment was found better than 0.07 MPa.     

Effects of Electron Beam Irradiation on Physical, Textural, and Microstructural Properties of "Tommy Atkins" Mangoes (Mangifera indica L.)

This research focused on determining the dose levels suitable for electron beam irradiation of mangoes without detriment to the fruit's quality characteristics. Physicochemical, textural, respiration rates, microstructural, and sensory characteristics of “Tommy Atkins” mangoes irradiated at 1.0, 1.5, and 3.1 kGy using a 10 MeV (10 kW) linear accelerator with double‐beam fixture were determined. Fruits were stored at 12 °C and 62.7% RH for 21 d and evaluated at days 0, 5, 10, and 21. Nonirradiated mangoes served as controls. Irradiation did affect the textural characteristics of mangoes at doses higher than 1.0 kGy. Mangoes exposed to 1.5 and 3.1 kGy were softer and less stiff throughout storage. The radiation‐induced softening of the fruits may be associated with changes in the structural cell such as cracks and depressions on the surface and the breakdown of the cells and its components. Irradiation at 3.1 kGy affected the color of mangoes by the end of storage. Doses up to 1.5 kGy kept respiration rates at a normal level. Irradiation did not affect the specific gravity of mangoes, a parameter associated with fruit maturity levels. No effect of irradiation on pH, water activity, moisture content, acidity, and juiciness of mangoes was detected at the dose levels used in this study. Only fruits irradiated at 3.1 kGy were unacceptable to the sensory panelists in terms of overall quality, texture, and aroma. Electron beam irradiation of “Tommy Atkins” mangoes at 1.0 kGy is the recommended treatment to maintain the overall fruit quality attributes.     

中强度脉冲电场对娃娃菜活性物质含量及抗氧化能力的影响

为探明中强度脉冲电场（moderate intensity pulsed electric fields,MIPEF）诱导果蔬代谢的应激机制,同时确定最佳处理条件以获得高活性物质含量的娃娃菜,本实验研究不同电场强度（0.4～2.0 kV/cm）和占空比（0%～49.2%）的MIPEF处理对娃娃菜活性物质含量、抗氧化酶系（过氧化氢酶、过氧化物酶、抗坏血酸过氧化物酶、谷胱甘肽还原酶）活性以及抗氧化能力的影响。结果表明,MIPEF可刺激娃娃菜酚类物质、抗坏血酸、谷胱甘肽、总硫代葡萄糖苷和异硫氰酸酯的合成（2.76%～818.03%）,同时显著提升抗氧化酶系的活性（2.22%～42.00%）,从而提高1,1-二苯基-2-三硝基苯肼（1,1-dipenyl-2-pierylhydrazyl,DPPH）自由基、羟自由基（·OH）和超氧阴离子自由基（O2－·）清除率和总还原力（1.81%～202.11%）,以延缓娃娃菜衰老进程。通过拟合预测和验证实验,得出最优处理条件为电场强度1.1 kV/cm、占空比46.4%,此时活性物质含量为理论预测值的88.91%～103.40%。结论：MIPEF处理可显著提升娃娃菜活性物质含量和抗氧化能力,是一种极具潜力的果蔬非热预处理方式。     

气调贮藏对腐败菌引起的鲜切黄瓜品质、滋味和挥发性物质变化的影响

本研究采用电子舌、电子鼻和气相色谱-质谱等手段,探讨3％(体积分数,下同)O2+7％ CO2气调贮藏对变形假单胞菌导致的鲜切黄瓜营养品质、滋味和挥发性物质变化的影响.结果 表明,变形假单胞菌生长影响了鲜切黄瓜的营养品质,气调贮藏抑制了鲜切黄瓜的呼吸作用,延缓了丙二醛含量和相对电导率的增加,维持了可溶性固形物质量分数和色...     

Total Phenolics,Carotenoids, Ascorbic Acid,and Antioxidant Properties of Fresh‐cut Mango (Mangifera indica L., cv. Tommy Atkin) as Affected by Infrared Heat Treatment

Abstract: Mango (Mangifera indica L.) is a major tropical fruit that has not been exploited for fresh‐cut or minimally processed products on a scale similar to apples, pineapples, or melons. The objective of this study was to investigate the effect of infrared (IR) treatment on total phenolics, carotenoids, ascorbic acid, and antioxidant properties of fresh‐cut cubes from ‘Tommy Atkin’ mangoes. Mango cubes were IR treated (5, 10, 15 min) and evaluated at 4‐d intervals during 16‐d storage at 4 ± 1 °C. Total phenolics, carotenoids, and ascorbic acid content in fresh‐cut control mango cubes were 43.33, 1.37, and 15.97 mg/100 g FW, respectively. IR treatments increased total phenolics (59.23 to 71.16 mg/100 g FW) and decreased ascorbic acid (12.14 to 15.38 mg/100 g, FW). Total carotenoids showed a mixed trend (1.13 to 1.66 mg/100 g, FW). The IR treatment showed a significant positive impact on antioxidant properties (μM TE/100 g, FW) of mango cubes, as assayed by ABTS (261.5 compared with 338.0 to 416.4), DPPH (270.5 compared with 289.4 to 360.5), and ORAC (6686 compared with 8450 to 12230). Total phenolics, carotenoids, ascorbic acid, and antioxidant capacity decreased over 16‐d storage. However, IR treated samples had consistently higher ABTS, DPPH, and total phenolics during storage. It was demonstrated that IR treatment can be effectively used in improving antioxidant properties of fresh‐cut mangoes with minimal effect on the visual appearance. Practical Application: Various methods/treatments are in use for extending the quality of fresh‐cut fruits, including mild heat treatment. This study explored the application of infrared (IR) heat for processing fresh‐cut mango cubes and evaluated its effect on vitamin C and antioxidant capacity during 16‐d storage. This is the first study reporting on the use of IR heat in fresh‐cut fruits. IR treatment was shown to be effective in retaining antioxidant properties of fresh‐cut mango cubes with minimal effect on the visual appearance.     

Influence of Aging Process on the Bioactive Components and Antioxidant Activity of Ginseng (Panax ginseng L.)

The effects of aging process on the ginsenosides and antioxidant activity of ginseng was investigated. Fresh ginseng roots were aged in oven at 70 or 80 °C for 7, 14, 21, or 28 d. Their ginsenosides, phenolics, and antioxidant activity were analyzed. Ginseng aged at 80 °C for 14 d exhibited the highest amounts of total saponins and phenolics. It also showed markedly higher free radical scavenging activity, reducing power, and ferrous ion chelating ability than the other aged ginsengs. The ginsenosides Rb₁, Rb₃, Rg₃, Re, Rg₁, and Rg₂ were generated during aging. The Rg₂ was the most abundant ginsenoside in aged ginseng, with samples treated at 80 °C for 14 d having the highest amount. These findings provide the first evidence that aging, particularly at 80 °C for 14 d, could increase the bioactive compounds, indicating that this heating process may be useful in enhancing the biological activity of ginseng.     

马兰提取物抗氧化性研究

目的：考查马兰中水提取物和乙醇提取物抗氧化活性。方法：分别以水和乙醇为提取液,探讨马兰中水提取物和乙醇提取物的抗氧化活性,包括还原能力以及清除DPPH自由基、羟自由基、超氧阴离子自由基和H2O2的能力。 结果：提取物主要成分为黄酮类化合物。马兰水提取物的抗氧化活性为：超氧阴离子自由基(IC50 2.2μg/mL)＞H2O2(IC50 2.8μg/mL)＞羟自由基(IC50 5.6μg/mL)＞DPPH自由基(IC50 8.5μg/mL) ＞金属螯合性(IC50 28.0μg/mL)。而马兰乙醇提取物的抗氧化活性为：H2O2(IC50 2.0μg/mL) ＞超氧阴离子自由基(IC50 2.1μg/mL)>羟自由基(IC50 2.5μg/mL)> DPPH自由基(IC50 5.6μg/mL) ＞金属螯合性(IC50 51.2μg/mL)。结论：马兰提取物具有较强的抗氧化活性。     

四棱豆总黄酮抗氧化和抗肝损伤作用研究

目的：探讨四棱豆总黄酮体外和体内抗氧化能力以及对CCl4诱导小鼠肝损伤的修复效果。方法：利用超声波辅助提取四棱豆种子总黄酮,以1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基、2,2’-联氮-二（3-乙基-苯并噻唑-6-磺酸）二铵盐（2,2’-azinobis-（3-ethylbenzothiazoline-6-sulphonate）,ABTS）自由基、羟自由基的清除率和还原力表征四棱豆总黄酮的抗氧化活性。利用CCl4诱导昆明小鼠肝损伤,以不同剂量的四棱豆总黄酮灌胃7 d,测定血清中谷草转氨酶、碱性磷酸酶、谷丙转氨酶、γ-谷氨酰转肽酶活性和总胆红素含量,测定肝、肾组织中的超氧化物歧化酶、过氧化氢酶活性及谷胱甘肽、丙二醛含量,免疫组化法观察肝细胞中肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）表达水平,苏木精-伊红染色观察肝脏组织病理学变化。结果：体外抗氧化实验表明四棱豆总黄酮具有较强的抗氧化效果,四棱豆总黄酮各剂量组均能降低CCl4致小鼠急性肝损伤血清谷草转氨酶、碱性磷酸酶、谷丙转氨酶、谷氨酰转肽酶活性和总胆红素含量升高,降低肝、肾组织中丙二醛含量,增强超氧化物歧化酶、过氧化氢酶活性和谷胱甘肽含量,抑制肝细胞中TNF-α表达,减轻CCl4对肝组织的损伤。结论：四棱豆总黄酮对CCl4致小鼠急性肝损伤具有一定的保护作用,其保护机制可能与清除自由基、抑制脂质过氧化、抑制TNF-α表达有关。     

核桃(Juglandaceae)种仁、叶、花粉抗氧化活性及成分鉴定

为综合开发核桃生物资源,研究了7种不同溶剂提取的不同种类核桃种仁、叶及其花粉提取物的抗氧化活性,并鉴定其抗氧化成分。采用DPPH和ABTS⁺自由基清除能力以及FRAP还原能力评价其抗氧化活性,并测定总酚、总黄酮含量,采用高分辨质谱仪鉴定样品抗氧化活性成分。结果表明,供试7种溶剂中60%丙酮提取物抗氧化活性较高。山核桃叶的DPPH(IC₅₀=0.156 mg/mL)和ABTS⁺(IC₅₀=0.131 mg/mL)自由基清除能力及还原能力(62.17 mg V_C/g)较其他品种核桃叶强。‘西林3号’核桃不同部位抗氧化活性测定显示,DPPH和ABTS⁺自由基清除力及FRAP还原力顺序从强到弱为:内种皮 > 叶 > 花粉 > 带皮种仁 > 去皮种仁。利用LC-MS从‘西林3号’内种皮及其核桃叶、KT-J02核桃叶、山核桃叶等4个供试样品的60%丙酮提取物中共鉴定出17种抗氧化活性成分,其中酚类9种,黄酮类8种,槲皮素和汉黄芩素为4种供试样品共有成分。山核桃叶中鉴定出13种成分,其中4种仅存在与山核桃中,即没食子酸、3-咖啡酰奎宁酸、表儿茶素没食子酸酯和对香豆酸;‘西林3号’和KT-J02核桃叶分别有1种成分仅存在于其中,为没食子酸-4-O-β-D-吡喃葡萄糖和儿茶素。内种皮中鉴定出6种成分,鞣花酸仅存在于内种皮中。     

乳酸菌发酵对山楂汁理化性质、酚类化合物、抗氧化性及风味的影响

选用6 种商品乳酸菌植物乳杆菌90（Lactobacillus plantarum 90,Lp）、干酪乳杆菌37（Lactobacillus casei 37,Lc）、副干酪乳杆菌01（Lactobacillus paracasei 01,Lpc）、嗜酸乳杆菌85（Lactobacillus acidophilus 85,La）、双歧乳杆菌80（Bifidobacterium lactis 80,Bla）、瑞士乳杆菌76（Lactobacillus helveticus 76,Lh）,分别对山楂汁进行发酵,比较不同乳酸菌发酵对山楂汁理化性质（pH值、可溶性固形物、总可滴定酸）、酚类物质、体外抗氧化性、色值和风味物质的影响,并进行感官评价。结果表明：6 种乳酸菌在调酸后的山楂汁中（pH 4.70）表现出良好的生长状况且无显著差异,发酵结束时活菌数高于8.5（lg（CFU/mL））,同时表现出良好的发酵性能,乳酸产量超过2.6 mg/mL。Bla和Lh发酵显著提高了总酚含量,但对总黄酮无显著影响,而La、Lc和Lpc发酵显著降低了总黄酮含量,对总酚无显著影响。此外,Lpc、Bla和Lh发酵山楂汁的抗氧化活性有所增强（P＜0.05）,表现出较强的2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除活性（约49.0%）和Fe3＋还原能力（约25.0 mmol/L,以Trolox计）。相关性分析结果表明,抗氧化活性与对香豆酸、绿原酸、槲皮素和表儿茶素的含量呈负相关。乳酸菌发酵使山楂汁挥发性成分种类及总量增加,形成了17 种新的醇和17 种新的酯,并降低了醛含量。感官评价结果表明,乳酸菌发酵改善了山楂汁的香气和滋味,Bla发酵山楂汁的总体感官品质最好,Lh次之。与其他乳酸菌相比,Bla发酵山楂汁具有较高的抗氧化性、丰富的香气物质和良好的感官品质,具有更大的研究和开发价值。     

The Phenolic Compounds,Metabolites, and Antioxidant Activity of Propolis Extracted by Ultrasound‐Assisted Method

The influences of ultrasound‐assisted, pharmacopeia, and supercritical fluid extraction methods on bioactive compounds and biological activities of propolis were evaluated. Results showed that propolis extracted by ultrasound‐assisted method contained more phenolic compounds, and showed the highest total phenolic content (245.84 ± 6.41 mg GAE/g DW), total flavonoids content (198.82 ± 5.74 mg RE/g DW), and stronger in vitro antioxidant activity (DPPH·: 1.03 ± 0.04 mmol Trolox/g DW, ABTS+·: 2.19 ± 0.05 mmol Trolox/g DW, and FRAP: 1.48 ± 0.12 mmol FeSO₄/g DW) than those of pharmacopoeia and supercritical fluid methods. A total of 36 phenolic compounds were identified in propolis. Among them, quercetin, quercetin‐3‐methyl‐ether, kaempferol, isorhamnetin, luteolin‐methyl‐ether, and quercetin‐7‐methyl‐ether could only be found in ultrasound‐assisted and pharmacopoeia methods. Moreover, the phenolic compounds had the similar metabolic pathways in rats and were mainly metabolized by sulfation and glucuronidation pathways. Additionally, ultrasonic‐treated propolis have good in vivo antioxidant activity and could repair D‐galactose‐induced oxidative damage in rats. Therefore, ultrasound‐assisted method could replace pharmacopeia method to be considered as bioactive compounds extraction from propolis, taking into consideration of yield, short extraction time, and high antioxidant activity.     

HPLC-DAD-Q-TOF-MS在线筛选鉴定牛蒡中的抗氧化成分

建立高效液相色谱-飞行时间质谱联用在线筛选并鉴定牛蒡提取物中抗氧化活性成分的方法。样品经在线色谱柱分离后进行分流,一路与稳定的1,1-二苯基-2-三硝基苯肼-甲醇溶液混合,实现在线筛选自由基清除剂;另一路进入二极管阵列检测器-串联三重四极杆飞行时间质谱,用于化合物的快速鉴别。负离子模式下,通过高分辨率质谱获得的相对分子质量结合化合物的紫外吸收特征,参考相关文献和部分对照品验证,从牛蒡乙酸乙酯相中筛选并鉴定出咖啡酸及衍生物19 种。本方法可实现快速定向筛选和鉴定食品及中药等复杂体系中的抗氧化活性成分。     

Physicochemical Characteristics,Antioxidant Activity,Organic Acid and Sugar Contents of 12 Sweet Cherry (Prunus Avium L.) Cultivars Grown in Turkey

Physical characteristics, antioxidant activity and chemical constituents of 12 cultivars (Prunus avium L.) of sweet cherry (Belge, Bing, Dalbasti, Durona di Cesena, Lambert, Merton Late, Starks Gold, Summit, Sweetheart, Van, Vista, and 0–900 Ziraat) were investigated. Significant differences (P < 0.05) were observed among tested cultivars for pH, total soluble solid, hardness, color parameters, antioxidant activities and pomological measurements (P < 0.05). The color parameters were important tools for the determination of fruit maturity and anthocyanin contents. Belge cultivar showed the highest levels of total phenolic and anthocyanin, while Starks Gold contained the lowest level of anthocyanins. The darker cultivars, measured by ABTS^+?, DPPH^? and FRAP, exhibited higher antioxidant activities than the lighter ones. Bing (42.78 g/kg) and Sweetheart (40.53 g/kg) cultivars contained higher levels of malic acid, which was the most intense organic acid in sweet cherries. Four different sugars were observed in the samples and their concentrations ordered as glucose > fructose >> sucrose > xylose. Sugar alcohol in the cherries was represented by sorbitol (more than 90%) and its concentration varied between 13.93 and 27.12 g/kg. As a result significant differences were observed among the physical properties and chemical constituents of the cherry cultivars.