Chemical composition, antioxidant activity and GC-MS analysis of juice and peel oil of grapefruit varieties cultivated in India

Citrus family especially Grapefruit,has attained considerable attention due to the presence of a number of essential components that have cardiovascular and anti-hypertensive properties.The juice and essential oil extracted from eight recently released grapefruit cultivars were used to study physicochemical and antioxidant properties.The total soluble solids(TSS),titratable acidity(TA) and pH of juice samples extracted from various grapefruit varieties differed significantly.The refractive index,specific gravity and optical rotation values for the oil varied from 1.473 to 1.396,0.863 to 0.847 and +93 to +86,respectively.The percent 2,2-diphenyl-1-picrylhydrazyl radical activity(% DPPH activity) and ferric reducing antioxidant power(FRAP) values for grapefruit juice and peel oil varied from 24.06 to 18.79,2.91 to 1.44 mmol g^–1 and 84.87 to 74.73,7.76 to 5.73 mmol g^-1,respectively.There were significant differences in physicochemical,antioxidant properties and volatile profiles of extracted juice and oil.The oil exhibited higher DPPH and FRAP values than the juice.Among different components identified which accounted for over 99% of the volatile fraction,limonene,myrcene,and benzopyran were major components in all oil samples.

Ameliorative effect of grapefruit juice on amiodarone-induced cytogenetic and testicular damage in albino rats

Objective:To evaluate the ameliorative role of grapefruit juice on the cytogenetic and testicular damage induced by the antiarrythmic drug amiodarone in albino rats.Methods:Animals were divided into four groups.Group I was considered as control.Group II was given grapefruit juice at a dose level of 27 mL/kg body weight.Group III was orally administered amiodarone(18 mg/kg body weight)daily for 5 weeks.Animals were sacrificed after 5 weeks of treatment.Bone marrow was collected from the femurs for analysis of chromosomal aberrations and mitotic indices.Testes were removed and stained with H&E for histological examination.Sperms were collected from epidedymis for detection of sperm head abnormalities.Comet assay was used to detect DNA damage.Results:Amiodarone treatment caused a significant increase in the percentage of chromosomal aberrations,decreased the mitotic index and increased DNA damage.The testis showed many histopathological alterations,inhibition of spermatogenesis and morphometric changes.The number of sperm head abnormalities was increased.Treating animals with amiodarone and grapefruit juice caused a reduction in chromosomal aberrations,mitotic index,DNA damage and testicular alterations caused by amiodarone.Conclusions:The results of this study indicated that grapefruit juice ameliorates the cytotoxicty and testicular alterations induced by amiodarone in albino rats and this is may be due to the potent antioxidant effects of its components.

Inquiry of Water-Soluble Polysaccharide Extraction Conditions from Grapefruit Skin

Water-soluble polysaccharide was isolated from grapefruit with the method of water-dissolving and ethanol-precipitating. By single factor test and orthogonal experimental method, the extraction conditions of the water-soluble polysaccharide were investigated, which contained liquid-solid ratio, temperature, time and pH. The results showed that pH was the most important factor of polysaccharide extraction, followed by temperature. The optimized extraction technology conditions were obtained. The liquid-solid ratio was 1:40, temperature was 90?C, time was 2.0 h, and pH was 2. The highest extraction rate of crude polysaccharide was 8.30%.

Effects of Bag Type on Fruit Quality of Red Massh Grapefruit

[Objectives]The effects of bag types on the appearance and internal quality of red Massh grapefruit were studied.[Methods]Outer-yellow inner-black double-layer pomelo special paper bags,white single-layer paper bags,yellow plastic film bags,and red plastic film bags were used to cover the fruit of red Massh grapefruit.With the fruit free of bagging as a control,the effects of fruit bags with different materials were compared.[Results]The four kinds of fruit bag treatments effectively reduced pests and diseases,and increased the good fruit rate,and the effects of paper bag treatments were better than those of film bags.The outer-yellow inner-black double-layer pomelo special paper bags had good air permeability and were easy to operate.The bagged fruit had a smooth and beautiful surface and showed a unique uniform pink color after removing the bags.The fruit had moderate sour and sweet flavor and good overall benefits.It is worthy of popularization and application.[Conclusions]Fruit bagging has good economic benefits,and it is recommended to use the outer-yellow inner-black double-layer pomelo special paper bags.

An Updated Mini Review on Grapefruit: Interactions with Drugs, Obesity and Cardiovascular Risk Factors

The paper examines the effects of grapefruit consumption in relation to drugs, obesity and cardiovascular risk factors. The review includes the most updated studies found in Pub-Med. The grapefruit effect refers to the ability of grapefruit juice and supplements to interact with a wide variety of pharmaceuticals, either enhancing or limiting their systemic availability. Due to altering the active dosage of the pharmaceutical, Grapefruit juice is commonly not allowed to be used alongside with many drugs. Naringin is the most important one, which can inhibit absorption of some drugs but more commonly 6’7’-dihydroxybergamottin, which inhibits CYP3A4. Lately, grapefruit has been found both in rats and adults to reduce body weight, blood pressure, improve lipid and hepatic profile and decrease platelet aggregation. These promising results must be followed by additional studies in order to add to the importance of the role and effects of grapefruit as part of our diet.

Effect of Grapefruit Juice on Aluminum-Induced Hepatotoxicity in Albino Rats: Histological, Ultrastructural and Histochemical Assessment

The present work studied the effect of grapefruit juice (Citrus) on the hepatotoxicity of AlCl3. Four groups of adult male albino rats were used. Group I contained 10 rats and remained as a control group;Group II: 10 rats were included and orally administered with grapefruit juice at a dose level of 27 ml/kg of body weight per day for 6 weeks;Group III: 10 rats were included and AlCl3 was administered orally at a dose level of 100 mg/kg of body weight per day for 6 weeks;Group IV: animals of this group (10 rats) were given a combination of AlCl3 and grapefruit juice per day for 6 weeks. At the end of the sixth week, the liver was processed for histological and ultrastructure studies. In addition, ALT and AST were determined in blood sera. The results showed that AlCl3 induced several histological alterations in the liver, including congestion of blood vessels, leucocytic infiltration, cytoplasmic vacuolation of hepatocytes and fatty infiltrations. Ultrastructural changes include the degeneration of mitochondria, RER swelling and pyknosis of the nuclei with an increase in fat droplets and lysosomes. The biochemical results showed an increase in ALT and AST activities in the AlCl3 group. However, the group of rats treated with AlCl3 and grapefruit juice improved the histological and ultrastructural changes, while the levels of ALT and AST were reduced. It was concluded in the results that grapefruit juice has a protective effect against hepatotoxicity of AlCl3 that can be attributed to the antioxidant properties of its components.

Breeding and Analysis of Two New Grapefruit-Like Varieties with Low Furanocoumarin Content

Furanocoumarins (FCs) are a group of related plant defense metabolites occurring in several plant families, including some species in the genus citrus, such as grapefruit and pummelo. FCs function as toxins against pathogens, insects and other plant pests and some are toxic to humans at high levels. Although the levels of FCs in grapefruits are non-toxic to humans, they inhibit the intestinal enzyme CYP3A, thus preventing degradation of medicines, such as statins, and causing dangerous overdose effects. This overdosing can cause devastating side effects, ranging from stomach bleeding to kidney problems, muscle aches and irregular heartbeats. In the present study, we utilize LC/MS to characterize the levels of FCs pathway intermediates and end products in twelve citrus cultivars, including mandarin (Citrus reticulata), orange [Citrus sinensis (L.) Osbeck], Pummelo [Citrus maxima (Burm.) Merr.], grapefruit (Citrus paradisi Macf.), and two newly selected grapefruit like varieties [(Citrus reticulate) X [Citrus maxima (Burm.) Merr]. The orange and mandarin varieties do not contain FCs or FCs precursor compounds suggesting that this biosynthetic pathway is absent or inactive in mandarins and oranges and therefore a good genetic source for null alleles to FCs biosynthesis. We report the selection and characterization of two new low FCs and seedless grapefruit-like varieties, “Aliza” and “Coocki”, developed by a cross between pummelo and mandarin. Fruits of these varieties resemble grapefruit and contain high levels of the flavanone naringin, typical of grapefruit, but contain only trace amounts of FCs (based on LCMS analysis). Based on the variability of FCs content and inheritance in citrus species, the results suggest that future development of new low-FCs grapefruit varieties is an achievable objective.

响应面法优化花茶柚子瓤复合果酱研究

以玫瑰花、陈皮、柚子瓤、橙子等为原料制作复合果酱,通过单因素实验和响应面优化花茶柚子瓤复合果酱的配方,研究结果表明,花茶柚子瓤复合果酱的最优配方为:玫瑰花与陈皮的比例3∶1、柚子瓤橙子比例81.15 g/100g、黄原胶添加量0.63%、白砂糖添加量55.27%,制作出的复合果酱感官评分平均值为95.89分,可溶性固形物添加量符合国家标准.

羧甲基壳聚糖诱导罗伦隐球酵母对葡萄柚果实细胞壁代谢的影响

以‘里约红’葡萄柚为试材,对羧甲基壳聚糖(carboxymethyl chitosan,CMCS)、罗伦隐球酵母(Cryptococcus laurentii)以及CMCS-C.laurentii处理葡萄柚果实采后的硬度进行测定,结果显示:与对照组(无菌水处理)相比,CMCS-C.laurentii处理显著抑制了葡萄柚果实在整个贮藏期间内的果实硬度下降(P<0.05)。在此基础上,测定贮藏期间(75 d)葡萄柚果实质量损失率、细胞壁多糖物质含量和细胞壁水解酶活力并观察果实细胞壁微观结构。结果表明:CMCS-C.laurentii处理能有效维持果实内共价结合型果胶、紧密型半纤维素的含量,降低果实中水溶性果胶、离子型果胶以及松散型半纤维素的含量;并且相较于对照组,CMCS-C.laurentii处理组果实细胞壁水解酶(果胶甲酯酶、多聚半乳糖醛酸酶、纤维素酶、α-L-阿拉伯呋喃糖苷酶和β-葡萄糖苷酶)活性均受显著抑制;贮藏中后期,CMCS-C.laurentii处理的果实细胞壁结构更加稳定,胞内结构相对完整。综上所述,CMCS-C.laurentii处理能减缓采后葡萄柚果实细胞内部细胞器及细胞壁的降解,较好地维持细胞完整性,延缓果实软化。

响应面法优化超高压辅助柚子皮果胶提取工艺及理化特性分析

为实现柚子皮高值化利用,采用超高压辅助柠檬酸法提取柚子皮果胶(grapefruit peel pectin, GPP)。该研究以果胶得率为考察指标,以液料比、pH值、压力和保压时间为单因素,在单因素试验基础上,采用响应面法的Box-Behnken设计对提取工艺进行优化,并与工业上常见的酸法提取的柚子皮果胶(acid-extracted grapefruit peel pectin, AGPP)和商品柚子皮果胶(commercial grapefruit peel pectin, CGPP)进行比较,研究最优条件下提取果胶的特性。结果表明,GPP最佳的提取工艺参数为:液料比27∶1(mL∶g)、pH 1.9、压力324 MPa、保压时间5 min,在此条件下,果胶得率为21.56%。所得果胶水分9.49%、酸不溶灰分0.42%、半乳糖醛酸含量为80.06%,溶解度为81.25%,酯化度为58.84%,总酚含量为24.70 mg GAE/g果胶(GAE:没食子酸当量,gallic acid equivalent)。此外,与AGPP和CGPP相比,GPP具有更高的表观黏度和抗氧化性。该研究表明超高压提取的GPP具有良好的品质,可以作为食品原料在食品领域中加以利用。

超声辅助法提取柚子皮多酚的工艺优化

为优化超声辅助法提取柚子皮多酚的工艺条件,为工业化提取柚子皮多酚提供数据支持,本文通过单因素和响应面实验探究超声时间、提取温度、料液比等因素对柚子皮多酚提取量的影响。结果表明,柚子皮多酚最佳提取条件为提取时间33 min、提取温度40℃、料液比1∶55(g:m L)、乙醇浓度60%、提取功率560 W,该条件下柚子皮多酚提取量为7.589 mg·g^(-1)。

大孔柚子型微结构光纤探针的表面增强拉曼散射性能研究

随着光纤制备工艺以及纳米材料制备技术的发展,光纤探针已成为一种新型的表面增强拉曼散射(SERS)基底,通过在普通单模光纤或多模光纤上制备不同的结构并修饰相应的纳米材料,可以得到多种类型的光纤表面增强拉曼散射探针,并实现较好的检测效果。但受限于光纤本身的结构,普通光纤仅能利用端面或侧表面提供拉曼检测的“热点”区域,限制了其SERS性能的进一步提高。因此制备了大孔柚子型微结构光纤(MSF)表面增强拉曼散射(SERS)探针,其中大孔柚子型MSF SERS探针结构通过一段阶跃多模光纤与柚子型微结构光纤熔接制得。实验分别对自制的纳米银溶胶基底以及大孔柚子型MSF SERS探针的SERS性能进行检测。采用溶胶自组装法制备负载银纳米颗粒的MSF SERS探针,通过控制自组装时间制备不同光纤SERS探针(Ag/MSF-x,其中x为自组装时间,分别为15、30、45、60 min)。采用溶液检测方法,利用Ag/MSF-x探针对10^(-3) mol·L^(-1)的亚甲基蓝(MB)探针分子进行检测,通过比较相同条件下的增强效果筛选得到Ag/MSF-45探针。为进一步检测Ag/MSF-45探针的SERS性能,制备不同浓度的MB溶液,分别利用纳米银溶胶基底和Ag/MSF-45探针对其进行检测。实验结果表明,纳米银溶胶基底对MB的检测限(LOD)为10^(-6) mol·L^(-1),Ag/MSF-45探针对MB的检测限(LOD)为10^(-7) mol·L^(-1);拉曼信号的再现性结果表明纳米银溶胶基底以及Ag/MSF-45探针在各个特征峰处的RSD值均在合理范围内;在1619 cm^(-1)拉曼位移处对纳米银溶胶基底以及Ag/MSF-45探针检测MB的拉曼强度和浓度进行对数转换拟合,纳米银溶胶基底的拟合优度R2达0.91628,Ag/MSF-45探针的拟合优度R2达0.98848;纳米银溶胶基底和Ag/MSF-45探针的再现性结果表明,其在各个特征峰处的RSD值均处于合理范围,但Ag/MSF-45探针的各特征峰RSD值均小于纳米银溶胶基底,最大为13.89%;利用10^(-6) mol·L^(-1)的MB对Ag/MSF-45探针的增强因子(AEF)进行计算,Ag/MSF-45探针的AEF达到6.09×10^(6),表现出良好的增强效果。因此,基于大孔柚子型MSF SERS探针凭借独特的空气孔结构使其具有较高的灵敏度以及良好的再现性,且其SERS性能均优于纳米银溶胶基底,在农业、化学分析、生物检测等领域及大分子物质检测等方面应用前景广泛。

植物乳杆菌1-1-2发酵去除葡萄柚果汁苦味物质及其抗氧化活性

通过筛选功能性寡糖代谢较强的菌株发酵葡萄柚汁有潜力对其中的柚皮苷进行水解,从而去除苦味。结果显示,通过植物乳杆菌1-1-2发酵后果汁中柚皮苷含量降低,同时,柚皮素含量显著提高,总酚含量和1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率也显著提高。DPPH自由基清除活性与总酚含量和柚皮素含量呈正相关。植物乳杆菌1-1-2可将柚皮苷进行水解,转化为没有苦味的柚皮素,而柚皮素的抗氧化活性显著高于柚皮苷。发酵后的葡萄柚汁感官评价得分高于未发酵葡萄柚汁。本研究可为改善葡萄柚口感、开发活性更强的功能性益生菌发酵产品提供理论依据。

光照区域对近红外光谱在线检测柚子糖度的影响

[目的]提高近红外光谱技术在线检测柚子糖度的精度。[方法]采用自主研发的柚子在线无损检测设备采集3种光照区域的柚子的漫透射光谱数据,在650~950 nm的波长范围内采用标准正交变量变换(SNV)、多元散射校正(MSC)、归一化(normalize)、SG一阶求导(savitzky-golay first order derivative,SG-1st)对原始数据进行预处理,使用自适应性加权算法(CARS)筛选反映柚子糖度的光谱特征,建立了偏最小二乘回归(PLSR)模型。使用未参与到建模的30个柚子样本进行在线验证。[结果]光照区域C结合SNV-CARS-PLSR方法的建模效果最优。其预测集的决定系数为0.95,均方根误差为0.30°Brix。在线验证时决定系数为0.90,均方根误差为0.58°Brix。模型对于柚子糖度具有较强的在线检测能力。[结论]在光斑直径为70 mm且位于柚子赤道上方20 mm的光照区域C的条件下采集的柚子光谱数据所建立的预测模型能更有效地实现柚子糖度的在线预测。

石墨烯改性柚子皮活性炭复合材料的制备及其电化学性能研究

以柚子皮为原料、采用水热浸渍法在氢氧化钾活化作用下制备得到柚子皮基生物质活性多孔炭材料。然后以乙醇和水作为溶剂,采用水热法将柚子皮基活性炭与氧化石墨烯进行复合,通过红外、扫描电镜、热重分析等方法表征了复合活性炭的化学结构和微观形貌,最后采用恒电流充放电、循环伏安和交流阻抗测试等方法对柚子皮基复合活性炭电极的电化学性能进行了比较。结果表明:800℃活化1h和1.0A/g的条件下得到活性炭电极材料比电容可达218.6F/g,说明该活性炭材料具有优异的电化学性能,有望应用于超级电容器领域。

橘皮对黄瓜苗期枯萎病的防效

采用体外抑菌试验与盆钵培养试验相结合的方法,探究了橘皮与柚皮浸提液对尖孢镰刀菌生长及橘皮对黄瓜苗期枯萎病的防效,结果表明,橘皮浸提液对尖孢镰刀菌黄瓜专化型病原菌表现出较显著的抑制作用,且抑制作用与提取液浓度成正比。在PDA上接种病原菌后的第2天与第6天,对照的菌落直径分别为全浓度橘皮浸提液处理的1.58与1.54倍。橘皮的总黄酮含量是柚皮的1.14倍;此外,土壤强还原灭菌时添加0.25%橘皮可有效降低黄瓜苗期枯萎病,接种病原菌条件下,添加橘皮的幼苗地上部生物量较对照增加了15.49%,根系可溶性糖含量是对照的1.12倍。表明利用橘皮防治黄瓜苗期枯萎病有极大的应用潜力。

GEO与氯己定联合应用治疗牙周炎的作用及机制

目的 探讨葡萄柚精油与氯己定联合应用治疗牙周炎的作用机制。方法 将60只大鼠随机分为5组:对照组(C组)、牙周炎组(P组)、GEO组(G组)、氯己定组(CH组)、GEO联合氯己定组(U组)。P组、CH组、G组和U组采用结扎丝结扎右侧上颌第一磨牙,建模后给药15 d。建模前与治疗中记录体重并比较;治疗15d后检查5组大鼠的牙龈指数(GI)、附着丧失水平(AL)及龈沟出血指数(SBI)。处死大鼠,ELISA检测龈沟液TNF-α、IL-1β、IL-6浓度;HE染色观察牙周组织改变;菌斑指示液比较牙菌斑显示情况。结果 氯己定和GEO都能降低TNF-α、IL-1β、IL-6;GI、AL、SBI和PLI下降;HE染色显示炎细胞浸润程度降低,但与CH组治疗相比,U组治疗作用更加显著(P <0.05)。结论 GEO联合氯己定治疗牙周炎能进一步增强抗菌、抗氧化及伤口愈合能力,从而减轻牙周炎症。

响应面法优化葡萄柚桂花蜜复合果冻配方

以葡萄柚为主要原料,辅以桂花蜜、脱苦剂、复合凝胶剂和甜味剂制备复合型果冻。以感官评价得分为响应值,结合单因素试验和响应面试验优化葡萄柚桂花果冻配方。结果表明,桂花蜜添加量为1.6%、复合凝胶添加量为1.5%、白砂糖添加量为20%,此时果冻的感官评价得分最高,产品色泽鲜艳,外形整齐,酸甜可口有层次,口感细腻无杂质。本结果可为葡萄柚及果冻相关的新型食品研发提供一定的参考。

柚子皮活性碳制备及吸附性能探究

利用柚子皮制备出IR-750、IR-850和IR-950三种吸附碳,并对吸附碳进行红外吸收光谱表征,探究了样品在不同的pH、吸附时间、吸附剂量单因素条件下对Cu^(2+)、Cr^(6+)、Ag^(+)和Zn^(2+)四种离子的吸附性能。通过单因素实验探究后选取了对Cu2+离子综合吸附性能正交试验进行研究。结果表明三种吸附碳中都有-C=O、-OH、-C-O特征官能团,在吸附性试验中,得出了不同因素对吸附性能的影响效果。根据单因素结果选择了样品IR-850进行正交试验探究,结果表明吸附时间对IR-850样品吸附性能影响最大,其最优化吸附条件为吸附反应时间240分钟,pH为5,加入吸附剂100mg,此时测得对400mg/L的Cu^(2+)溶液吸附率最高,达88.73%。本研究发现柚子皮碳化制备生物碳样品对环境中金属离子有一定的吸附效果,是一种可开发的吸附碳材料。

Effects of fruit bagging on the physiochemical changes of grapefruit(Citrus paradisi)

Fruit bagging is a commonly used cultivation measure to protect citrus fruit from insects and adverse environments.The present study aimed to comprehensively investigate the effects of bagging on the physiochemical characteristics of grapefruit.The grapefruit were bagged at approximately 110–120 d after anthesis with a one-layer kraft paper bag with black coating inside(SL),a double-layer kraft paper bag with one black paper as the inner layer(DL),and a three-layer kraft paper bag with two black papers as inner layers(TL),respectively.Ultra performance liquid chromatography-high resolution mass spectrometry(UPLC-HRMS)technique was used to identify a total of 19 flavonoids,2 phenylpropanoids,9 coumarins,and 5 limonoids.By using UPLC,50 carotenoids were identified.Gas chromatography–mass spectrometry was used to identify 3 soluble sugars,3 organic acids,and 11 amino acids.In the quantitated components in the peel(albedo and flavedo),the chlorophylls and the carotenoids components(such as luteoxanthin,violaxanthin,9-cis-violaxanthin,xanthophyll,zeaxanthin andβ-carotene)were significantly downregulated by bagging,causing the surface color of bagged fruit to turn yellow earlier but paler than that of the unbagged control,particularly in the three-layer kraft bag treatment.Unlike the peel,the color and the carotenoid content of the juice sacs were less affected.The physiochem-ical compounds other than pigments,including soluble sugars,organic acids,amino acids,flavonoids,coumarins and limonoids,were minimally affected by bagging treatments.Our results indicated that bagging at approximately 110–120 d after anthesis exerted influence mainly on peel color,but less on sugars,acids,amino acids,flavonoids,limonoids and coumarins of grapefruit.