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.

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。

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。

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。

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。

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)。

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。

柚子皮果酒发酵工艺的研究

本文以柚子皮、糯米为主要原料,通过单因素和正交试验确定柚子皮果酒的发酵工艺。结果表明,柚子皮果酒发酵的最佳工艺条件为柚皮浆5%、甜酒曲1.5%、果胶酶0.4%、纯净水15%、发酵温度30℃和发酵时间4 d。在该条件下,柚子皮果酒的可溶性固形物为20%,酒精度为12%,pH值为5。

葡萄柚柚皮苷提取工艺优化及抗氧化活性研究

以葡萄柚果皮为原料,研究优化果皮中柚皮苷的提取工艺条件及抗氧化活性。在单因素试验基础上,通过响应面法优化,得到最佳提取工艺条件为:超声功率590 W,乙醇体积分数49%,料液比1∶32(g/mL),在此工艺条件下,柚皮苷提取率为7.959%。柚皮苷自由基清除试验表明柚皮苷具有抗氧化活性,对DPPH自由基和羟自由基达到半抑制率(IC_(50))的柚皮苷浓度分别为0.511 mg/mL和0.241 mg/mL,本论文为葡萄柚果皮的高值化利用和天然抗氧化剂开发提供参考。

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.

柚子副产物主要活性成分及综合利用的研究进展

柚子是我国一种产量较大的特色水果,在加工过程中,通常剔除果籽和果皮,因此产生大量副产物而未得到有效利用。本文综述了国内柚子副产物综合利用的研究进展,论述了柚子副产物中功能性成分的提取方法及其生理特性和活性,以期为高值利用柚子加工副产物资源,不断开发柚子精深加工系列产品提供理论依据与技术指导,为柚子副产物资源综合利用提供参考。

响应面法优化超声波辅助提取柚子皮色素及其稳定性研究

采用超声波辅助提取法提取柚子皮中的天然色素,通过响应面法优化试验,确定柚子皮中天然色素的最佳提取条件,并对其稳定性进行研究。结果表明:柚子皮色素提取的最佳条件为乙醇体积分数63%、提取温度63℃、提取时间22 min。稳定性试验表明,柚子皮色素在低温、避光的情况下较为稳定,还原剂与甜味剂对其稳定性影响较为明显,Fe~(2+)、Cu~(2+)对柚子皮色素细胞具有破坏作用,抗坏血酸、柠檬酸、山梨酸钾和苯甲酸钠对色素稳定性的影响较小。

葡萄柚籽提取物及其纳米乳对大肠杆菌和金黄色葡萄球菌生物菌膜的抑制作用

目的:研究葡萄柚籽提取物(grapefruitseedextract,GSE)及其纳米乳(grapefruitseedextract nanoemulsion,GNE)对大肠杆菌和金黄色葡萄球菌生物菌膜的抑制作用。方法:分析菌膜黏附菌数变化、胞外聚合物(extracellular polymeric substances,EPS)含量并进行微观结构观察,比较GSE和GNE对两菌菌膜(单种菌膜和混合菌膜)形成的抑制作用和已形成菌膜的清除效果。结果:与对照组相比,1/2最小抑菌浓度(minimum inhibitory concentration,MIC)GSE和GNE可以抑制两菌单种菌膜形成时黏附菌和EPS产生,且对金黄色葡萄球菌的抑制作用更强。扫描电子显微镜(scanning electron microcopy,SEM)和共聚焦激光扫描显微镜(confocal laser scanning microscope,CLSM)所观察到的微观结构变化也显示出GSE和GNE对两菌菌膜形成具有抑制作用。GSE和GNE对已形成菌膜也有良好清除效果,且对金黄色葡萄球菌菌膜的清除作用更强,但混合菌膜的抗性强于单种菌膜。比较GSE和GNE发现,GNE的菌膜形成抑制及清除效果均强于GSE,1/2 MIC GNE作用120 h时两单菌菌膜形成量对数值均比GSE组少0.6(lg(CFU/cm^(2)))以上,质量分数1.8%GNE对菌膜的清除率比GSE高7.7%~27.2%。结论:GSE和GNE对大肠杆菌和金黄色葡萄球菌生物菌膜具有一定的抑制作用,研究可为GSE和GNE在生物菌膜控制方面的推广应用提供一定的科学依据。