高效液相色谱法测定大果山楂果实中6种三萜酸类成分的含量

建立同时测定大果山楂果实中蔷薇酸、2α,19α-二羟基-3-羰基-12-烯-28-乌苏酸、山楂酸、科罗索酸、齐墩果酸和熊果酸的高效液相色谱法（high performance liquid chromatography,HPLC）,并对这6种三萜酸在广西6个产地大果山楂果实中的分布及含量进行分析。采用Diamonsil C₁₈（2）色谱柱,以0.1%甲酸水溶液/甲醇（v/v）为流动相,梯度洗脱,流速0.8 mL/min,检测波长210 nm,柱温30 ℃。结果表明：6种三萜酸在线性范围内质量浓度与色谱峰峰面积具有良好的线性关系,相关系数均>0.9990,检出限0.46~2.00 μg/mL,定量下限1.53~6.67 μg/mL,变异系数均<5.0%,加标回收率99.2%~101.3%;6个产地的大果山楂果实中三萜酸含量丰富,均检出蔷薇酸、2α,19α-二羟基-3-羰基-12-烯-28-乌苏酸、山楂酸、科罗索酸、齐墩果酸和熊果酸6种三萜酸,均为五环三萜酸化合物,其中蔷薇酸、2α,19α-二羟基-3-羰基-12-烯-28-乌苏酸首次检出,以熊果酸、蔷薇酸、2α,19α-二羟基-3-羰基-12-烯-28-乌苏酸为主,三者含量之和占总三萜酸的71.82%~81.38%,总三萜酸含量在808.74~1090.75 μg/g FM之间,其中柳州柳江区和桂林平乐县的果实总三萜酸含量相对较高,分别达到1090.75 μg/g FM和1045.20 μg/g FM。本研究的HPLC法可作为大果山楂果实中三萜酸含量的检测方法,为大果山楂果原料和产品的品质评估提供科学参考。     

Determination of Chlorogenic Acids with Lactones in Roasted Coffee

An HPLC method has been developed which allowed the determination of mono- and dicaffeoylquinic acids (CQA and di-CQA), corresponding lactones (CQL) and feruloylquinic acids (FQA) in roasted coffee within one chromatographic run. The elution order was verified by isolation of the individual compounds by preparative HPLC, chromatography of the fractions on the analytical HPLC system, NMR spectroscopy and thermospray LC-MS. At least 15 additional minor compounds had the spectra of hydroxycinnamic acids, some of them only occurring in roasted coffee. Caffeoyltryptophan, which has been identified some time ago by another working group could also be separated with this system. The average contents in commercial roasted coffee samples (n=12) were: 3-CQA, 5·0 g kg⁻¹; 4-CQA, 6·2 g kg⁻¹; 5-CQA, 11·4 g kg⁻¹; 4-FQA, 0·7 g kg⁻¹; 5-FQA, 1·4 g kg⁻¹; 3-CQL, 2·1 g kg⁻¹; 4-CQL, 1·0 g kg⁻¹; 3,4-di-CQA, 0·7 g kg⁻¹; 3,5-di-CQA, 0·4 g kg⁻¹ and 4,5-di-CQA, 0·8 g kg⁻¹ dry matter. There were only small differences between the different brands. Two series of samples with different degrees of roast produced from the same green coffee have also been analysed. One series was steam treated before roasting (a process which is commercially used to improve digestibility). Only in the initial stages of roasting (light roast) could a difference in the contents of the acids between both series be observed. Keeping coffee brews at an elevated temperature (4 h at 80°C) reduced the amounts of CQL to 60% of the initial value. The contents of 3-CQA and 4-CQA increased, whilst that of 5-CQA decreased. The overall contents of CQA decreased.     

反相高效液相色谱法测定山楂中绿原酸的含量

本实验中运用反相高效液相色谱对山楂中的有效成分绿原酸进行了分离,并对其进行了含量测定,建立了反相HPLC测定山楂中绿原酸含量的方法。色谱柱:KromasilC18(250mm×4.6mm,5μm),流动相:乙腈-水-甲酸(9:91:0.1),流速:0.8ml/min,检测波长:327nm,柱温:35℃。加样回收率为98.2%,RSD为0.80%。     

热带水果多酚提取物的抗氧化和抗增殖活性研究

为明确12种热带水果多酚提取物的总酚含量、总抗氧化能力和抗肿瘤细胞增殖活性,分别采用Folin-Ciocalteu法确定了水果提取物的总酚含量,采用ORAC和FRAP的方法确定了其抗氧化能力,采用MTT的方法确定了其抗人肝癌细胞HepG2增殖的活性。结果显示,12种水果提取物的总酚含量为26.17-229.67 mg GAE/100g 鲜重,最高杨桃的总酚含量为最低鳄梨的8.78倍;ORAC和FRAP抗氧化值分别为607.05-2631.17 μmol TE/100g 鲜重和462.12-1067.92 μmol TE/100 g鲜重,杨桃具有最高的ORAC和FRAP抗氧化值,分别是最低木瓜的4.33倍和鳄梨的2.31倍;11种水果提取物抑制肿瘤细胞HepG2增殖的IC50值为31.79-66.93 mg/mL,抑制活性最弱木瓜的IC50值为最强杨桃的2.11倍。水果提取物的总酚含量与其ORAC抗氧化值（R2＝0.7839）、FRAP抗氧化值（R2＝0.7636）和抑制HepG2细胞增殖的IC50值（R2＝0.8847）之间具有显著的相关性。     

高效液相色谱法测定水果中吡虫啉农药残留量

建立高效液相色谱法测定水果中的吡虫啉残留量的检测方法。采用改进的QuEChERS方法,乙腈匀浆提取,提取液加C18和PSA填料净化,液相色谱法检测。结果表明：方法的定量检测限为0.05mg/kg,标准曲线线性相关系数0.9988;当添加水平在0.05～0.20mg/kg范围内时,回收率均可在92%～102%之间,相对标准偏差在5%～11%之间。本方法是一种快速、准确、灵敏度高的同时检测水果中吡虫啉残留的检测方法。     

高效液相色谱法测定南果梨中绿原酸的含量

目的建立测定南果梨中绿原酸含量的高效液相色谱法。方法C18色谱柱(250×4.6mm,5μm);流动相甲醇-0.4%磷酸溶液(2575);检测波长327nm。结果精密度试验RSD为1.9%,n=6;加样回收率98.5%～102.6%,RSD为1.6%～2.1%。结论南果梨果心、果肉、果皮中绿原酸的含量分别为1.785、0.271、0.714mg/g。     

Quality and biochemical changes of longan (Dimocarpus longan Lour cv. Daw) fruit under different controlled atmosphere conditions

Sulphur dioxide has been used to control pericarp browning in longan fruit. However, due to health and regulatory concerns, alternative treatments should be tested. The objective of this study was to find the tolerance levels of longan fruit to low O₂ (2%, 5%, 10% and 15%) and elevated CO₂ (5%, 10%, 15% and 20%) at 2 °C. According to the tolerance study, controlled atmospheres (CA) of 5% O₂ + 5% CO₂, 5% O₂ + 10% CO₂ and 5% O₂ + 15% CO₂ were compared with normal air (control) at 2 °C. Pericarp browning and decay incidence of longan were significantly (P ≤ 0.05) higher in control than all the CA treatments. CA storage reduced polyphenol oxidase (PPO) activity, maintained L* value and slowed down a decrease in total phenolic contents (TPC). Pericarp browning was highly correlated with PPO, L* and TPC.     

高效液相色谱法测定结石通胶囊中绿原酸含量

目的建立高效液相色谱法(HPLC)测定结石通胶囊中绿原酸含量的方法。方法采用C18柱(250 mm×4.6 mm,5μm),乙腈-0.5%磷酸溶液(7:93)为流动相,柱温35℃,流速1.0 mL/min,检测波长326 nm。结果绿原酸在0.020 42~1.0210μg范围内,峰面积与进样量线性关系良好,r=0.9999,平均回收率为99.00%,RSD 2.54%(n=9)。结论该方法重复性、准确性良好,可用于测定结石通胶囊中绿原酸含量。     

高效液相色谱法同时测定果蔬中多种防腐剂

建立了高效液相色谱法同时测定水果及蔬菜中联苯、邻苯基苯酚、噻苯咪唑、抑霉唑、多菌灵、桂醛、乙萘酚、2, 4-二氯苯氧乙酸的方法。样品用碱性乙醚提取,浓缩后甲醇定容,经ODS-SP C18（4.6×150 mm,5 μm）柱分离,以甲醇-磷酸盐缓冲液（pH=6.8）为流动相,流速0.8 mL/min梯度洗脱,二极管阵列检测器（DAD）检测。此方法相关系数范围0.9991~0.9997,加标回收率范围88.0~97.4%,相对标准偏差0.53~3.9%。实验结果表明,该方法操作简单,结果灵敏准确,适用于水果及蔬菜中多种防腐剂的同时测定。     

RP-HPLC测定咽清颗粒中绿原酸含量

目的建立测定咽清颗粒中绿原酸含量的方法。方法以反相C18色谱柱为固定相(250mm×4.60mm,5μm),乙腈-0.4%磷酸溶液(12∶88)为流动相,流速1.0mL·min-1,检测波长327nm。结果绿原酸进样量10～60μg·mL-1范围内与峰面积积分值呈良好的线性关系(r=0.9999);平均回收率97.17%,RSD=1.73%(n=9)。结论本方法简便、可靠、准确,可用于测定咽清颗粒中绿原酸的含量。     

高效液相色谱法测定马铃薯块茎的绿原酸含量

目的:建立测定马铃薯块茎中绿原酸含量的高效液相色谱方法,并测定不同品质特点的马铃薯的绿原酸含量。方法:对甲醇浓度、固液比和超声提取时间三个试验因素进行正交试验设计:ZOBAX C18色谱柱,250mm×4．6mm 5μm;流动相:水-甲醇-冰醋酸（20∶80∶2;30∶70∶2;40∶60∶2）;甲醇-0．4%磷酸溶液（10∶90）:流速: 1．0ml/min;柱温:室温;进样体积:5μl;检测波长为327nm。结果:精密度:RSD为3．2%,n=6,加样回收率为97．5%,提取条件为:甲醇浓度70%,固液比1∶100,超声提取时间40min。确定水∶甲醇∶冰醋酸=30∶70∶2为流动相。     

代表性热带水果及其废弃物提取液的抑菌效果研究

目的研究热带水果(火龙果、杨桃、菠萝、芒果、荔枝、龙眼、绿橙和莲雾)以及水果废弃物(龙眼壳、荔枝壳、龙眼核、香蕉皮、火龙果皮、菠萝蜜芯和菠萝蜜仁)的乙醇、丙酮、乙酸乙酯和正己烷溶剂提取液对沙门氏菌、单增李斯特菌、金黄色葡萄球菌和大肠杆菌O157:H7的抑菌活性。方法采用平板打孔法测量抑菌圈的大小,以表示提取液的抑菌活性。通过测量菌株生长曲线,确定提取液对细菌的生长抑制率。结果乙醇、丙酮提取液的抑菌效果均较好。提取液对单增李斯特菌、金黄色葡萄球菌和大肠杆菌O157:H7抑菌效果最好。火龙果、芒果和菠萝提取液的抑菌效果最好。菠萝提取液的最小抑菌稀释比例为1/10,其他提取液为1/100。碱性条件下,龙眼壳提取液抑菌活性增强,其他提取液在酸性条件下抑菌活性较强。各类提取液具有较好的耐热性。火龙果、芒果、菠萝的乙醇提取液中金黄色葡萄球菌的生长明显受到抑制,提取液可改变该菌的细胞膜渗透性。结论芒果、菠萝、龙眼壳、火龙果、火龙果皮、莲雾、荔枝壳、龙眼核、菠萝蜜芯和菠萝蜜仁的提取液具有一定抑菌活性。火龙果、芒果、菠萝的乙醇提取液对金黄色葡萄球菌有明显抑制作用并可破坏细胞膜渗透性,为有效防控食源性致病菌提供了基础数据。     

Behaviour of aroma volatiles during the evaporative concentration of some tropical fruit juices and pulps

The dynamics of aroma separation from some tropical fruit juices and pulps was studied using a thin film evaporator. In the case of mango (Mangifera indica Linn, Alphonso and Totapuri varieties) and guava (Psidium guajava Linn) pulps, 90% of each of the volatile fraction, esters, carbonyls and alcohols, was removed at 30–35% evaporation of the water in a single pass. In the case of pineapple (Ananas sativa Schult F) juice, 90% separation of esters and carbonyls required about 80% and 47% evaporation, respectively. However, the behaviour of alcohols in pineapple juice was found to be similar to that of mango and guava. Mango pulp from Alphonso and Totapuri varieties on 60% evaporation showed a loss in oxygenated terpenes of 80% and 63%, respectively, while guava pulp lost about 58% oxygenated terpenes on 60% concentration. The dynamics of the total aroma volatiles separation from the fruit juices and pulps showed that, in a single pass evaporation, 85–90% volatiles were removed at a juice evaporation degree of 60% water, while the same extent of aroma removal occurred at 32–35% total evaporation by multiple pass.     

绿原酸影响氨基酸消减丙烯酰胺的研究

绿原酸是马铃薯中的主要酚酸。试验将丙烯酰胺分别与7种氨基酸进行高温加工处理,研究添加绿原酸对体系中丙烯酰胺消减的影响。结果表明,绿原酸促进丙烯酰胺的消减。加入绿原酸在160℃反应30 min后,丙烯酰胺消减率显著提高,为9.58%(天冬酰胺)～33.46%(半胱氨酸)。采用甘氨酸/丙烯酰胺体系,进一步研究绿原酸添加量、加热温度和时间对丙烯酰胺消减的影响,发现丙烯酰胺消减率随绿原酸添加量、加热温度的增加和时间的延长而提高。绿原酸与丙烯酰胺物质的量比25∶1,180℃反应60 min后,丙烯酰胺消减率达到66.9%。     

以绿原酸为目标物优化杜仲叶发酵醋的工艺研究

以绿原酸作为评价指标,以杜仲叶辅以麸皮和葡萄糖为原料进行发酵醋工艺研究。首先杜仲叶按料液比1∶10并添加叶干重质量0.8%的纤维素酶45℃预处理2h,获得绿原酸含量为592.1μg/mL的酶解液。然后添加与酶解液中叶干重相同的麸皮,调节杜仲叶-麸皮与水的质量体积比为1∶7,加入占发酵液体积10%的葡萄糖、占杜仲叶-麸皮质量1%的醋前发酵剂进行酒精发酵。最后接入占发酵液体积14%的醋酸菌进行醋酸发酵。按此工艺条件,得到的杜仲叶发酵醋中绿原酸含量为131.1μg/mL,总酸（以醋酸计）含量为4.9g/100mL,发酵醋色泽澄清,具备醋特有的香气,口感柔和,符合国家酿造食醋感官特性要求,DPPH自由基清除率达到97.3%,有较好的体外抗氧化效果。本实验为杜仲叶资源的开发提供了一种新思路,同时为杜仲发酵醋饮的酿造提供了技术依据。      

QuEChERS-HPLC测定柚类果实中柠檬苦素类化合物

建立了柠檬苦素类化合物的QuEChERS-HPLC检测方法,同时测定了不同品种柚类果实中柠檬苦素、诺米林、黄柏酮3种柠檬苦素类化合物含量。样品经乙腈均质超声提取,离心后取上清液,用QuEChERS净化管净化,通过CAPCELL PAK C₁₈ MG色谱柱(250 mm×4.6 mm, 5μm)梯度洗脱分离,检测波长为210 nm,二极管阵列检测器。结果表明,方法在0.10～200μg/mL线性良好,相关系数大于0.999,平均回收率为99.0%～100.3%,相对标准偏差为1.0%～2.1%。柚类果实不同品种以及不同果实组织部位中3种柠檬苦素类化合物含量差异显著。该研究可为柠檬苦素类化合物在食品和医药等领域的利用研究提供参考。     

杜仲雄花及花茶中绿原酸含量分析

用高效液相色谱法测定杜仲雄花茶加工前后绿原酸的含量变化。色谱条件Kromasil-C18色谱柱(4.6mm×250mm,5.0μm);流动相乙腈-0.4%磷酸(8∶92);检测波长327nm;流速1.0mL·min-1;柱温25℃。绿原酸对照品在0.05～0.55μg范围内有良好的线性关系,平均回收率为98.95%,RSD为1.61%,提取方法为50%甲醇加热回流30min。该方法准确、简捷,可用于杜仲雄花茶加工过程中绿原酸的含量控制。