A Preliminary Study on Consumer Sensory Evaluation and Acceptance of Pomelo Peel Jelly

Pomelo peel is a by-product from pomelo consumption, but it is also rich in a variety of nutrients and functional substances. In order to solve the environmental problems caused by the large amount of discarded pomelo peels every year, in this study, we recycled pomelo peels to make pomelo yellow peel jelly (PYPJ) and pomelo white peel jelly (PWPJ) according to their different characteristics in pomelo peels. And the consumer sensory evaluation (n = 50) was carried out to explore the consumers’ evaluation and acceptance for these two innovative products. The results showed that both jellies received high mean scores for all sensory attributes expect PYPJ’ taste, and the consumer acceptances of PYPJ and PWPJ were 62% and 92%, respectively. These results displayed that there is a need to further improve PYPJ, and PWPJ is a product recognized by consumers. .

Removal of hexavalent chromium in aquatic solutions by pomelo peel

This study investigated the removal of hexavalent chromium(Cr(VI)) in aqueous solutions using pomelo peel(PP) and FeCl3-modified pomelo peel(FPP) as novel biomass adsorbents.Batch adsorption experiments were performed to evaluate the effects of pH,time,temperature,initial concentration,and adsorbent dose on Cr(VI) removal by PP and FPP.The results show that the maximum adsorption capacity of Cr(VI)was 21.55 mg/g for FPP and 0.57 mg/g for PP at a pH of 2.0 and a temperature of 40℃.The surface shape,microstructure,and chemical composition of FPP were analyzed with scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),and energy dispersive spectroscopy(EDS),and compared with those of PP.The results show that the adsorption performance of FPP was much better than that of PP,indicating that FPP can be an alternative high-efficiency adsorbent for Cr(VI) removal.

Efficacious anti-cancer property of flavonoids from citrus peels

Cancer is one of the two leading human fatal diseases.Drug development for cancer intervention has progressed well in past decades yet existing drugs face many limitations in applications and effectiveness and are often associated with serious of side effects,which can further deteriorate the patients’quality of life.Recent development of natural product based and therapeutically sound anti-cancer agents have gained popularity in the field of functional foods,in which a few have demonstrated efficacy and minimal toxicity toward the prevention and treatment of carcinogenesis.With multiple active molecular components,citrus peels and derived extracts have demonstrated potent efficacious properties against various cancers due in large part to the rich content of flavonoids present in citrus peels.This review summarizes the results of currently available data regarding the in vivo anti-cancer activity of citrus peel flavonoids,and identifies opportunities for subsequent human clinical trials to assess preventive and therapeutic effects in the near future.

Human plasma protein binding of water soluble flavonoids extracted from citrus peels

The human plasma protein binding of water soluble flavonoids in the peels of five spices of citrus fruits was studied by ultrafiltration combined with HPLC.The flavonoids were extracted separately by hot and cold water,and higher total flavonoid contents were detected in the former extracts than the latter ones.All the extracts show significant scavenging abilities to both ABTS and DPPH free radicals,which indicates the health benefits of the water extracts of citrus fruits peels.For DPPH radical,the IC50values of hot extract follow as Navel orange(NO)≈Mandarin orange(MO)< Lemon(LE)< Lo tangerine(LO)< Pomelo(PO),while the rank is NO< PO<LE≈MO<LO for ABTS radical.The HPLC results reveal that the kinds and contents of the flavonoids detected in the extracts are different among the species.MO extract has the most neohesperidin dihydrochalcone of 118.76 μmol/L and quercetrin of 211.81 μmol/L of which are much more than the rest extracts.Pomelo extract has the most plentiful flavonoids of naringin with a concentration of 303.28 μmol/L.The high contents of myricetrin and dihydromyricetin which both are potent free radical scavengers may explain the highest free radical scavenging activity of the NO extract.The plasma binding rates decrease with the increasing concentrations of flavonoids,and the flavonoids having plenty hydroxyl groups on both A ring and B ring of the molecular skeleton have relative higher plasma binding rates.In addition,the plasma binding rates of flavonoids with saturated C3-C4 bond decrease significantly with the increasing concentrations.

Preliminary Evaluation for Comparative Antioxidant Activity in the Water and Ethanol Extracts of Dried Citrus Fruit (<i>Citrus unshiu</i>) Peel Using Chemical and Biochemical <i>in Vitro</i>Assays

Comparative antioxidant activities of the water and ethanol extracts obtained from dried citrus fruit (Citrus unshiu) peel were determined using chemical and biochemical in vitro assays. Chemical assays were used for evaluation of 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, hydrogen peroxide scavenging, and reducing power of both extracts and their total phenolic, flavonoid and tannin contents and antioxidant activities were investigated. Biochemical assays were performed to evaluate the inhibition activities of AAPH-induced rat RBC hemolysis and Fe2+-induced lipid peroxidation using rat brain tissue cells. Linear correlation between the antioxidant activities of both extracts were determined by chemical assays, and total phenolic, flavonoid and tannin contents was observed in concentration-dependent mode. Both extracts showed >95% DPPH radical scavenging and >85% hydrogen peroxide scavenging, and higher reducing capacity at the same level of 3200 ppm. In the inhibition activity of AAPH-induced hemolysis, water extracts showed a strong activity in concentration-dependent mode up to 1600 ppm with no statistical difference found between 1600 and 3200 ppm (P > 0.05). In the inhibition activity of Fe2+-induced lipid peroxidation, ethanol extracts showed the higher inhibition percentage of lipid peroxidation than those of water extracts at the same concentration with no significant difference (P > 0.05) found in the range of 800 to 3200 ppm. The extracts of dried Citrus unshiu peel may be considered as potential antioxidant ingredients of functional food depending on the conditions at which reactive oxygen species are implicated.

Quantification of Flavonoids in Brazilian Orange Peels and Industrial Orange Juice Processing Wastes

The flavonoid content in orange peels of different Brazilian citrus varieties such as bahia, lima, lima-of-persian, morcote, pera, ponkan, seleta, cravo, kinkan and pomelo was assessed. Industry processing juice wastes such as bagasse, bagasse residues, animal feeding bagasse, pulp WEUE and CORE-wash were also analyzed. The HPLC analysis indicates that the most abundant flavonoids found in these Brazilian citrus peels are hesperidin and naringin. The solvents used are selective for flavonoid extraction, and depending on their polarity, glycoside or aglycone flavonoids are extracted. The use of multivariate analysis shows that DMSO is the best solvent to extract glycosides flavanones while hexane displays high selectivity in the extraction of polymethoxylated flavones. The flavonoids present in the orange wastes, obtained at different stages of the industrial processing, are qualitative and quantitatively different. The identification and quantification of the flavonoid composition in each Brazilian citrus variety were evaluated and allowed the selection of the best solvent for the extraction of each specific class of flavonoids. These compounds were found to be more abundant in the fruit peels than in their juices, revealing their great industrial potential. The residual portion of the processing juices is also rich in flavonoids, depending on the processing step.

In situ synthesis of biomass-derived Ni/C catalyst by self-reduction for the hydrogenation of levulinic acid to γ-valerolactone

Herein,we reported in situ synthesis of biomass-derived Ni/C catalyst by self-reduction with pomelo peel.Compared with the conventional method, which includes carbonization, activation, impregnation and reduction, the entire preparation process was simplified to two steps, which was more straightforward. This synthesis method was green as Ni/C can be prepared without any additional chemical and the self-reduction process was realized in N2, which can avoid using H2 thus averting some problems such as storage, transportation and safety of H2. Meanwhile, the size and dispersion of Ni particles can be controlled by changing carbonization temperature.The synthesis mechanism of Ni/C catalyst with selfreduction was investigated, which was mainly attributed to the carbon and reducing gas produced during the carbonization process.For the catalytic performance of GVL synthesis, a high yield (94.5%) can be obtained and it exhibited good stability up to 5 cycles without obvious loss of catalytic activity.

Copper ion/gallic acid MOFs-laden adhesive pomelo peel sponge effectively treats biofilm-infected skin wounds and improves healing quality

Bacterial infection and scar formation remain primary challenges in wound healing.To address these issues,we developed a decellularized pomelo peel(DPP)functionalized with an adhesive PVA-TSPBA hydrogel and antibacterial gallic acid/copper MOFs.The hybrid wound dressing demonstrates favorable biocompatibility.It does not impede the proliferation of fibroblasts or immune cells and can stimulate fibroblast migration,endothelial angiogenesis,and M2 macrophage polarization.Additionally,the dressing can scavenge reactive oxygen species(ROS)and provide antioxidant effects.Furthermore,DPP+MOF@Gel effectively inhibits the viability of S.aureus and E.coli in vitro and in vivo.The histological observations revealed enhanced granulation tissue formation,re-epithelialization,and angiogenesis in the DPP+MOF@Gel group compared to other groups.The local immune response also shifted from a pro-inflammatory to a pro-regenerative status with DPP+MOF@Gel treatment.The skin incision stitching experiment further exhibits DPP+MOF@Gel could reduce scar formation during wound healing.Taken together,the hybrid DPP+MOF@Gel holds great promise for treating bacteria-infected skin wounds and inhibiting scar formation during wound healing.

Optimization of Extraction and Characterization of Pectin from Grapefruit Peels

In this study, pectin was extracted from grapefruit peels with hydrochloric acid and precipitated with 95% ethanol solution and 5% tartaric acid. The physical and chemical properties of pectin obtained were analyzed, including color, texture, degree of esterification, and water solubility. The effects of peel to sol- vent ratio, pH of the solvent, extraction temperature and extraction duration on pectin extraction rate were investigated. On the basis of single-factor experiments, an L9 （34） orthogonal experiment was performed to screen the optimal extraction conditions. According to the results, the optimal combination of technical parame- ters was A1B3 C1 D3, i. e. , solid to liquid ratio 1：40 （g： ml）, pH 2.0, extraction duration 70 rain, extraction temperature 90 ℃. The average pectin extraction rate was 68.60% ; the color of pectin extracted under the optimal conditions varied from milky white to light yellow; the degree of esterification of pectin extracts was 65. 71% ; the extracted pectin exhibited good water solubility. Key words Pomelo peel; Pectin extraction; Optimum conditions; Esterification degree; Water solubility

羧基化柚子皮吸附Cd^(2+)的性能与机制

为探索利用食品加工废弃物柚子皮制备一种重金属离子吸附材料的可行性,通过NaOH将柚子皮中甲酯化的羧基水解成羧酸,再利用TEMPO/次氯酸钠/溴化钠体系将柚子皮中C-6位伯羟基氧化成羧酸,制备出一种羧基化柚子皮吸附材料,同时采用FTIR、SEM-EDS和XPS对柚子皮和吸附Cd^(2+)前后的羧基化柚子皮进行表征,研究其吸附机制。结果表明羧基化柚子皮中羧基含量为2.34 mmol/g,是改性前的10.64倍,且可以有效地去除水溶液中Cd^(2+)。羧基化柚子皮吸附Cd^(2+)更符合Langmuir和伪二阶动力学模型,属于单层化学吸附,对Cd^(2+)的最大吸附量为76.16 mg/g,是改性前的5.81倍。羧基化柚子皮中羧基(-COO^(-))是吸附Cd^(2+)的功能性基团,吸附后形成羧酸镉,其中镉以Cd^(2+)的形式存在,与-COO^(-)的配位方式主要是双齿桥式,该吸附过程是一个阳离子(Na^(+)和Cd^(2+))交换的过程。

不同果锈程度的阳光玫瑰葡萄果皮的代谢组学分析

【目的】探明阳光玫瑰葡萄果锈形成的机制,为其有效防治提供科学的指导建议。【方法】以6年生阳光玫瑰葡萄植株为试材,在果实进入软化期后,采集有果锈和无果锈的果粒样品,按照果锈发生程度分成无果锈、轻度果锈和重度果锈3个等级,研究不同果锈等级的果皮相关物质含量、酶活性及代谢组的变化。【结果】随着果锈程度的增加,阳光玫瑰葡萄果皮的叶绿素、纤维素、半纤维素和总果胶含量逐渐降低,木质素、总黄酮和总酚含量逐渐升高;果皮中过氧化物酶、多酚氧化酶、苯丙氨酸解氨酶、肉桂醇脱氢酶和4-香豆酸:辅酶A连接酶的活性逐渐升高,过氧化氢酶活性先升高后降低,肉桂酸-4-羟基化酶活性先降低后升高。不同果锈程度的果皮中共鉴定到1372种代谢物,差异代谢物有485种,3组果锈等级的果皮之间共有的差异代谢物有110种,其中,有105种差异代谢物在3组中均上调表达,占所有差异代谢物的95.45%,包括37种酚酸类、31种黄酮、17种芪类和5种醌类等;2种差异代谢物在3组中均下调表达,包括1种脂质和1种核苷酸及其衍生物。上述差异代谢物质主要分布在17条代谢途径中,包括山柰酚苷元Ⅱ的生物合成、山柰酚苷元Ⅰ的生物合成和次生代谢物的生物合成等。【结论】酚酸类和黄酮类物质对阳光玫瑰葡萄果锈的发生影响最大,且山柰酚苷元Ⅱ的生物合成途径可能在果锈的形成中发挥重要作用。

柚子皮不溶性膳食纤维的提取工艺优化及特性分析

为获得复合酶法制备柚子皮不溶性膳食纤维的制备工艺及其吸附特性,实验以柚子皮为原料,采用正交试验优化提取柚子皮不溶性膳食纤维(IDF),并对其特性进行研究。结果表明,料液比1:40 g/mL、淀粉酶的添加量0.6%、淀粉酶的酶解时间90 min、木瓜蛋白酶的添加量0.2%、木瓜蛋白酶的酶解时间30 min为最佳提取条件,该条件下柚子皮IDF得率为55.07%。柚子皮IDF的膨胀力、持水力、持油力和阳离子交换能力分别为2.84±0.09 mL/g、12.54±0.11 g/g、1.54±0.02 g/g和0.36±0.04 mmol/g。此外,体外吸附研究表明,柚子皮IDF对葡萄糖、胆固醇、胆酸钠的吸附能力分别为0.13±0.003 mmol/g、12.27±0.020 mg/g和53.25±0.100 mg/g。FT-IR分析表明,柚子皮IDF具有纤维素类多糖的特征吸收峰,符合膳食纤维的结构。综上,优化工艺后提取的柚子皮IDF具有较好的特性,这为进一步开发利用柚子皮IDF提供了理论依据。

离子液体辅助微波法提取橘皮中黄酮成分

优化离子液体辅助微波法提取橘皮中的黄酮工艺,为进一步提取橘皮中的黄酮类化合物提供依据。将离子液体加入提取溶剂中辅助微波法提取橘皮中的黄酮,依次改变离子液体的种类、浓度、提取溶剂总体积、药材质量比、微波时间、微波温度。以总黄酮提取率为指标,在确定单因素最佳条件基础上结合响应曲面设计优化最佳提取工艺。用HPLC法测定柚皮甙、橙皮苷、新橙皮苷等成分的含量,探究不同提取方法提取橘皮中黄酮的变化规律。最优提取条件为微波功率400 W,m(原料)∶V(提取液)=20 g/mL,V(乙醇)∶V(离子液体)=12,t=50℃,提取橘皮黄酮的提取率预测值为0.196 501%。比较传统方法和离子液体法黄酮中主要成分含量,后者提取率较高。

不同配比陈皮-蜜橘皮茶汤品质分析

为了解陈皮、蜜橘皮以及两者不同配比合煎所得茶汤的汤色、风味感官以及活性成分等品质变化规律,以10年新会陈皮、温州蜜橘皮为研究对象,采用高效液相色谱法测定茶汤中的主要黄酮类化合物,顶空固相微萃取结合气相色谱-质谱联用技术测定其挥发性成分。结果表明,陈皮茶汤的感官评价综合得分、总黄酮、川陈皮素、橘皮素、总酚含量和抗氧化能力(DPPH法、ABTS法、FRAP法)均显著高于蜜橘皮茶汤,而蜜橘皮茶汤的橙皮苷和香蜂草苷含量显著高于陈皮茶汤;陈皮茶汤的主要挥发性成分是2-(甲氨基)苯甲酸甲酯、(-)-4-萜品醇、百里醌等,蜜橘皮茶汤的主要挥发性成分是(1 R,5 R)-rel-香芹醇、4-乙烯基-2-甲氧基苯酚、芳樟醇等;陈皮-蜜橘皮的不同质量比(5∶5、3∶7、2∶8、1∶9)茶汤中,随着陈皮比例的下降,除橙皮苷和香蜂草苷含量之外,其余相应的活性成分含量和抗氧化能力均随之降低,其中5∶5能够全面地凸显两者的优点。该研究明确了新会陈皮、温州蜜橘皮以及两者不同配比茶汤的品质变化规律,为陈皮、蜜橘皮的综合利用及精深加工提供理论基础。

不同提取方法对井冈蜜柚皮精油组成与性质的影响

以井冈蜜柚皮精油(Jinggang pomelo peel essential oil,JPPEO)为研究对象,采用水蒸气蒸馏法、低温连续相变法两种方法进行提取,以精油得率为主要指标,研究了萃取温度、压力、时间等因素对井冈蜜柚皮精油得率的影响,并通过正交法进行低温连续相变法提取工艺优化,同时对精油的理化性质及化学组成进行分析。研究表明,低温连续相变提取井冈蜜柚皮精油(Low-temperature continuous phase transition extraction essential oil,L-JPPEO)的最佳工艺为:颗粒度30目,萃取温度55℃,萃取压力0.6 MPa,萃取时间60 min,解析温度70℃,此时精油得率为10.99‰,比水蒸气蒸馏法提取的精油(Hydro distillation essential oil,H-JPPEO)得率高出了2.88倍;理化性质实验结果表明,低温连续相变萃取的井冈蜜柚皮精油的不饱和脂肪酸含量较高,游离脂肪酸含量较低,酯类成分含量较低;傅里叶衰减全反射中红外光谱法(Fourier transform infrared spectroscopy,FTIR)鉴定出L-JPPEO和H-JPPEO含萜烯类化合物、醇类、酚类、醛类以及含羰基化合物。气相色谱-质谱联用法(Gas chromatography-mass spectrometry,GC-MS)从H-JPPEO、L-JPPEO样品中分别鉴定出23和32种化合物,其中两种精油都检测出的有15种物质,D-柠檬烯相对含量均最高,L-JPPEO中相对含量为4.75±0.16μg/mL,H-JPPEO中相对含量为640.93±44.47μg/mL;顶空气相色谱-离子迁移谱法(Headspace-gas chromatography-ion mobility spectrometry,HS-GC-IMS)从两种提取方法的精油均鉴定出71种化合物,与水蒸气蒸馏相比,低温连续相变萃取技术提取出较多的萜烯类(45.75%)、酮类(7.68%)及酯类(15.85%)、酸类(5.62%)成分。

贡柑皮多甲氧基黄酮的提取优化及其油脂抗氧化稳定性研究

目的 优化德庆贡柑皮多甲氧基黄酮的提取,并探究其对油脂抗氧化稳定性的影响。方法 在单因素实验基础上,根据Box-Benhnken的中心组合设计实验,采用响应面法对贡柑皮中多甲氧基黄酮(polymethoxy flavonoids,PMFs)的提取工艺进行优化;采用高效液相色谱-串联质谱法(high performance liquid chromatography-tandem mass spectrometry, HPLC-MS/MS)分析贡柑皮中PMFs组分。结果 提取的最佳工艺参数为:料液比1:3.23 (g:mL)、乙醇浓度87%、超声提取时间46 min,提取率为6.87%;贡柑皮中含有6种PMFs,分别为橘皮素、川陈皮素、5-羟基-2’,4’,7,8-四甲氧基黄酮、黄芩黄酮Ⅱ、栀子黄素B、5-去甲基川陈皮素,相对质量浓度分别为10494.1、8428.4、826.3、678.4、141.3、12.0μg/mL;贡柑皮PMFs提取物对1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)和2,2’-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonicacid)ammoniumsalt,ABTS]+自由基具有清除作用,当提取物质量浓度达到2.00 mg/mL时,对DPPH自由基清除率为83.44%,对ABTS+自由基清除率为77.56%;贡柑皮PMFs提取物对油炸油饼中的油脂氧化具有一定的抑制作用,在油炸时间5 h内,添加1.00%贡柑皮PMFs提取物的样品显著降低了油脂的过氧化值和酸价,而添加0.50%贡柑皮PMFs提取物的样品茴香胺值显著降低。结论 优化后的PMFs提取率为6.87%,贡柑皮种含有6种PMFs,对自由基有清除作用且对油脂氧化有抑制作用。

超高压处理对柚皮海绵层不溶性膳食纤维理化性质、结构和抗氧化活性的影响

该研究解析了超高压处理(600 MPa, 15 min)对3种柚皮海绵层不溶性膳食纤维(insoluble dietary fiber, IDF)理化性质、结构以及抗氧化活性的影响规律。结果表明,超高压处理显著提高了3种柚皮海绵层IDF的溶胀力,其中琯溪蜜柚柚皮海绵层IDF的溶胀力(78.03 mL/g)最高。然而过高的压力会严重破坏膳食纤维的内部结构,导致柚皮海绵层IDF持水力和持油力下降。超高压处理后柚皮海绵层IDF微观结构更加疏松,并显著提高了柚皮海绵层IDF葡萄糖、木糖、阿拉伯糖和半乳糖的含量。通过X-射线衍射发现超高压处理后柚皮海绵层IDF的结晶度降低;傅里叶变换红外光谱显示,超高压处理对柚皮海绵层IDF活性基团种类影响较小,但对其特征峰的吸收强度影响较大。此外,柚皮海绵层IDF经超高压处理后ABTS阳离子自由基和DPPH自由基清除率均有所下降,表明其抗氧化活性降低。以上研究结果表明,超高压处理可改变柚皮海绵层IDF的理化性质、结构和抗氧化活性。该研究为柚皮海绵层IDF的多元化利用提供理论和技术支撑。

基于靶向代谢组学的山楂黄色和红色果皮呈色物质差异分析

【目的】探究黄色山楂和红色山楂成熟过程中果皮类黄酮和类胡萝卜素的积累模式,增加对山楂果皮呈色机理的认识,为果皮色泽定向遗传育种提供参考。【方法】以黄山楂‘金如意’(Crataegus pinnatifida Jinruyi)和红山楂‘软籽’(Crataegus pinnatifida Ruanzi)的果皮为试材,利用靶向代谢组学对2个品种5个生长时期果皮中的类黄酮和类胡萝卜素组分及含量进行定性定量研究,通过正交偏最小二乘分析(OPLS-DA)对不同果色品种果皮中积累的类黄酮和类胡萝卜素代谢物进行差异分析。【结果】两个山楂品种果皮中共检测出130种类黄酮代谢物和49种类胡萝卜素代谢物,这些物质在不同品种、不同生长时期内的山楂果皮中存在显著的种类及含量差异。‘软籽’山楂果皮中花青素含量远高于‘金如意’山楂果皮,成熟期(S5)花青素化合物在红色山楂和黄色山楂果皮中的总含量分别为930.04和2.32μg·g^(-1),两个品种山楂果皮中花青素含量相差约400倍。矢车菊素-3-O-半乳糖苷是最主要的花青素成分,其在花青素代谢物总含量中占比高达95%以上。类胡萝卜素代谢分析显示,‘软籽’和‘金如意’S1—S3时期果皮总类胡萝卜素含量无显著差异,主要积累的类胡萝卜素成分均为叶黄素。S4—S5时期,两种山楂果皮中类胡萝卜素含量差异逐渐扩大,β-胡萝卜素、β-隐黄质、新黄质、α-胡萝卜素和玉米黄质在‘金如意’果皮中大量积累,其含量高于‘软籽’山楂。【结论】花青素积累是导致‘软籽’山楂果皮在成熟期呈现红色的主要原因,类胡萝卜素的积累是‘金如意’山楂发育后期黄色加深的主要原因,花青素和类胡萝卜素的差异性积累是造成山楂果皮颜色差异的关键因素。

MgFe-LDH@柚子皮生物炭复合材料吸附Gd(Ⅲ)的性能研究

该研究以柚子皮生物质为原材料制备生物炭,采用共沉淀法将镁铁型层状双氢氧化物(MgFe-LDH)负载于其表面制备复合材料(HBC),探究其吸附水中Gd(Ⅲ)的性能。通过批量吸附实验考察应用环境条件对吸附效果的影响,采用吸附理论模型拟合分析结合SEM-EDS、FT-IR、XPS表征分析,探究吸附作用机理。结果表明:在35℃、pH=7的条件下以0.60 g/L的吸附剂投加量对20 mg/L的Gd(Ⅲ)吸附处理10 h后,HBC对其去除率达到95.65%;吸附过程符合拟二级动力学模型、Weber-Morris粒子内扩散模型、Boyd’s液膜扩散模型,吸附速率受到颗粒内扩散和颗粒外扩散共同控制;吸附平衡符合Langmuir模型、D-R模型和Temkin模型,由Langmuir模型计算所得的最大吸附量为42.07 mg/g,吸附过程结合能分布均匀,为单分子层吸附;热力学结果表明HBC对Gd(Ⅲ)的吸附过程是一个自发的吸热过程;HBC对Gd(Ⅲ)的吸附以化学吸附和静电吸附为主,吸附机理包括离子交换作用、表面沉淀作用、表面物理吸附作用、静电吸附作用、氢键吸附作用和表面络合作用等。

不同品种柚子皮精油成分及抗氧化与抑菌能力对比研究

柚子皮是一种富含精油的具有药用价值的生物质资源,但其精油成分与生物活性尚未深入研究。本文首先通过水蒸汽蒸馏法提取了12个不同品种的柚子皮精油,接着用气相色谱质谱联用仪(GC-MS)对精油成分与相对含量进行了测定,然后采用DPPH自由基清除法、滤纸片法对不同品种柚子皮精油的抗氧化和抑菌能力进行比较,最后对不同品种柚子皮精油GC-MS分析数据进行主成分分析和聚类分析,结合抗氧化和抑菌实验结果,着力于理清柚子皮精油成分与抗氧化、抑菌能力的关系。实验结果表明:柚子皮精油的提取率为0.22%~1.52%;GC-MS法从不同品种柚子皮精油中鉴定出D-柠檬烯、β-月桂烯、α-蒎烯、α-水芹烯、芳樟醇等35种化学成分;DPPH自由基清除实验表明柚子皮精油的抗氧化能力与精油浓度呈正相关性;滤纸片法抑菌实验表明柚子皮精油有一定的抑菌效果,且对特定的菌种抑菌效果更明显。主成分分析和聚类分析结果表明,抗氧化和抑菌效果显著的成分有D-柠檬烯、柠檬醛、芳樟醇,而石竹烯、香叶烯醇、α-水芹烯也具有一定的抗氧化和抑菌能力。