四川安岳8个柠檬品种果实品质分析

以四川安岳柠檬高产优质示范资源圃内8年生的尤力克、阿伦、费米耐劳、斐诺、库托迪肯、蒙纳盖洛、维尔纳和维拉弗兰卡8个柠檬品种为材料,并将主栽品种尤力克柠檬设为对照,通过气相色谱-质谱联用(GC-MS)方法测定柠檬果实中糖酸代谢组分成分,测定柠檬果实果形指数、可溶性糖和总酸含量等品质研究。结果表明8个柠檬品种中共鉴定出糖酸代谢组分34种,其中糖及衍生物类23种、有机酸和氨基酸类11种。8个柠檬品种果实糖酸代谢组分中化合物种类及相对含量间存在差异,彼此间差异为0.05%~14.60%。8个柠檬品种的平均单果重和果形指数分别大于125 g和1.0,均达到优等果的标准。高可溶性固形物和高酸含量的品种均为斐诺、尤力克、维尔纳和维拉弗兰卡。斐诺和尤力克的TSS含量极显著高于其他6个品种,分别高达7.80%和7.71%。斐诺的总酸含量为6.89%,极显著高于尤力克和其他6个品种(p<0.01)。     

Purification and properties of the major pectinesterases in lemon fruits (Citrus limon)

Pectinesterase from lemon was separated into seven fractions by chromatography on CM-Sephadex C-50. Purification was hindered by the presence of pectin, for which the pectinesterase had a high affinity. Two major pectinesterases were purified: one was located solely in the peel and the other in the endocarp. They possessed similar molecular weights (35 kDa and 33 kDa, respectively) and high isoelectric points (> 11, and c 9). They required the presence of cations for optimal activity, the peel pectinesterase requiring a higher concentration of cations than the endocarp enzyme. Both enzymes were completely inactivated at temperatures above 88°C. Although neither enzyme destabilised the cloud of lemon juice or of comminuted lemon beverages, they caused cloud destabilisation of orange juice.     

薄荷醇的合成新工艺

以柠檬桉叶油为主要原料经环化、催化氢化二步反应得到薄荷醇。在环化反应中 ,考察了温度、环化剂、反应物浓度、反应器类型对反应的影响 ,得出反应产率达70 %～ 75 %。在氢化反应中 ,经过对反应时间、温度、压力、催化剂用量及催化剂套用等条件的探讨 ,将氢化压力由文献报道的 10 MPa降至 0 .3 MPa,产率近 10 0 %。实验表明此合成工艺简单 ,条件温和 ,易于工业化生产。     

测定柠檬黄的电位型漆酚树脂化学传感器研究

:报导了以湖北长阳县出产的山漆为原料合成漆酚树脂 ,以此漆酚树脂为载体 ,研制了测定合成食用色素柠檬黄的电位型化学传感器。此传感器对柠檬黄浓度在8.0× 1 0 -7～ 1 .0× 1 0 -3 mol/L间的响应符合 Nernst关系式 ,斜率为 2 1 .0 m V( 30°C,p H6.0 ) ,检测下限为 3.0× 1 0 -7mol/L。传感器的选择性、重现性和稳定性良好 ,对样品的测定结果与食用色素通用测试方法 ( OT- 1 5)基本一致。     

Contribution of soil compositions,harvested times and varieties on chemical fingerprint of Italian and Turkish citrus cultivars

This paper aims to define the stability over the time of chemical elemental patterns in some citrus varieties of PGI (Protected Geographical Indication) and not PGI Interdonato and Lunario cultivars coming from Italy and Turkey and to set up a range of markers useful to trace their geographical origin. During the 2015–2017 growing seasons, all fruits were collected and subjected to Inductively Coupled Mass spectrometry (ICP-MS) analysis, in order to determine the multielemental chemical profiles. The chemical variability was calculated for each element by Multi-way analysis of variance. The results highlighted how the measured Cr, Ni, Al, K, Fe and Zn levels mainly depend on the soil composition and the fingerprint allow to trace the geographical origins. Moreover, the stepwise linear discriminant analysis (SLDA) has allowed to correctly classify the 100% of lemon pulps provenances, based on Ni, Al, K, Ca and Na contents. Finally, our study demonstrates the role played by harvest years, variety and soils composition whose interaction contributed to define the chemical fingerprints.     

柠檬香蜂草精油的气相色谱-质谱联用分析及抑菌活性研究

该文采用水蒸气蒸馏萃取法(steam distillation,SD)对柠檬香蜂草提取精油,气相色谱-质谱联用(gas chromatograph-mass spectrometry,GC-MS)分析精油成分,制备成不同体积分数稀释液,通过纸片扩散法(kirby-bauer,K-B)测定柠檬香蜂草精油对3种食源性致病菌...     

柠檬香蜂草精油化学成分的研究

分别采用微波水蒸气蒸馏法(MHD)和水蒸气蒸馏法(HD)提取得到了柠檬香蜂草精油,利用气相色谱-质谱(GC/MS)联用技术和保留指数比较法分析鉴定了该精油的化学成分.分析结果表明:两种方法所得精油的主要成分相同,均为柠檬醛,但是含量有所差异.从MHD法柠檬香蜂草精油中鉴定出28种成分,占精油总量的98.98％,主要成分为柠檬醛a(香叶醛)(50.42％)、柠檬醛b(橙花醛)(30.42％)、石竹烯氧化物(9.17％)和石竹烯(1.63％).从HD法柠檬香蜂草精油中鉴定出22种化学成分,占精油总量的93.68％,主要成分为柠檬醛a(香叶醛)(46.27％)、柠檬醛b(橙花醛)(28.21％)、石竹烯氧化物(5.97％)和石竹烯(3.28％).     

柠檬对诺丽果汁香气成分的改善效果

目的 采用柠檬汁来提高诺丽果汁的接受程度,为消费者提供一款风味独特的新型饮品。方法 采用正交试验优化,得到最佳配方,采用气相色谱?质谱法(GC?MS)探讨香气的成分变化,采用电子舌检测滋味的变化值。结果 采用正交试验优化得到的最佳配方(均用体积分数表示)为柠檬汁15%、蔗糖9%、复合酸0.3%,感官评价得分为96.58。通过GC?MS香气成分分析可知,添加柠檬后复合果汁的香气成分由20种上升到44种,其中增加得较多的是烯萜类(由8种上升到24种),相对含量从9.65%上升到61.86%;醇类由4种上升到10种,相对含量由19.01%上升到31.12%。复合果汁的香气成分主要为柠檬烯(34.03%)、γ?松油烯(10.37%)、α?松油醇(18.34%),它们对复合果汁香气的形成具有积极作用。诺丽果汁中的不良风味主要来源于辛酸,相对含量由原来的53.52%降低到0.65%。电子舌结果表明,复合果汁的甜度值由?3.21上升到8.57,酸度值由2.14上升到12.45,复合后改善了诺丽果汁的口感。结论 柠檬能增加复合果汁香味物质的种类,掩盖其辛酸的腐臭气味,改善果汁的风味和口感,为诺丽果的加工应用提供了一定的理论依据。     

衣康酰化降解壳聚糖在亚麻织物无甲醛防皱整理中的应用

自制衣康酸酐与降解壳聚糖合成了衣康酰化降解壳聚糖（IJCTA）,结构表征后应用于亚麻织物防皱整理研究中,通过单因素分析实验优选出最优合成条件及整理工艺。结果显示：酰化物合成最佳投料比为3﹕1,取代度为0.913～0.928;整理最佳工艺条件：浴比1﹕20,w（IJCTA）=0.8%,w（NaH2PO2）=5%,175℃下焙烘3 min。