Identification of acid-stable carmine in imported apple syrup product

An unknown red pigment was purified from an apple syrup product imported from Canada, using a DIAION HP-20 column with methanol as the eluent. By spectroscopic means and chemical synthesis, the isolated pigment was identified as 4-aminocarminic acid, which is the major pigment of acid-stable carmine (a red colorant illegal in Japan). In addition, HPLC and TLC methods were proposed to detect this illegal colorant. While the color of carminic acid changed from yellow to red in the pH range of McIlvaine buffer (3.0-7.0), the color of 4-aminocarminic acid was always red, and also the ultraviolet/visible (UV/Vis) spectra did not change. These characteristics are useful to distinguish 4-aminocarminic acid from carminic acid.     

Detection of 4-aminocarminic acid in beverages and cake glaze from the German market: a food additive not approved in the EU

In the European Union, carminic acid and its ammonium, calcium, potassium or sodium salts and its aluminium lakes are approved as food additive E120. In beverages obtained from the German market 4-aminocarminic acid (“acid-stable carmine”) was detected by HPLC–PDA and LC–MS/MS. Isolation of the colorant from a liquid dye preparation used for the production of a beverage sample and subsequent NMR analysis confirmed the presence of 4-aminocarminic acid. Synthesis of ¹⁵N-4-aminocarminic acid clearly demonstrated that “acid-stable carmine” is not the ammonium salt of carminic acid, which is approved as food additive in the European Union. In fact, nitrogen in “acid-stable carmine” is covalently bound. The molecular structure of carminic acid is chemically modified and 4-aminocarminic acid does not comply with the specifications laid down for E120 in Commission Regulation (EU) No 231/2012. 4-Aminocarminic acid was also detected in the red-colored glaze of a raspberry cake and in the liquid dye preparation used for coloring this glaze.     

食用天然红色素胭脂虫红的性质研究

为保证胭脂虫红色素的品质,该文重点研究了pH值、日照、温度、储藏、部分金属离子和部分食品添加剂等对胭脂虫红色素稳定性的影响。结果表明：该色素适宜在弱酸性至中性环境中使用;其光稳定性较差,日照24h后色素保留率仅为18．4％;热稳定性和贮藏稳定性良好;对氧化性金属离子较敏感;常用食品添加剂对其稳定性影响微弱。     

蛋白酶法胭脂虫红色素的萃取及对柞蚕丝织物的染色

利用蛋白酶与水结合的方法对胭脂虫干体内的胭脂虫红色素进行萃取,并通过天然染料胭脂虫红色素对柞蚕丝织物进行染色。利用蛋白酶进行色素提取,过程具有温度低、萃取时间短、提取效果好等特点。通过对上染工艺中的胭脂虫红色素质量浓度、染色温度、染色时间、pH值等影响因素进行单因素试验分析,得到了最佳的染色工艺为:胭脂虫红质量浓度1.5 g/L,染色温度80℃,染色时间40 min,pH值为4,浴比1∶40。     

蛋白酶胭脂虫天然染料的提取及羊毛织物染色性能研究

利用蛋白酶对胭脂虫干体内的胭脂红酸进行萃取,通过天然染料胭脂虫色素对羊毛织物进行染色.利用蛋白酶进行色素提取,具有温度低、萃取时间短、提取效果好等特点.实验确定提取工艺为:蛋白酶浓度1％,50℃搅拌60 min,调pH值为4,升温至90℃,搅拌60 min.通过对上染工艺中的胭脂虫红色素浓度、染色温度、染色时间、pH值等影响因素进行单因素实验分析,得到了最佳的染色工艺:胭脂虫红色素浓度60％,pH值4,染色温度90℃,染色时间50 min,浴比1:40.     

含硫吡咯基氨基酸化合物的合成表征及其与丙酮酸的反应

通过Paar-Knnor有机合成方法得到一种新的含硫吡咯基氨基酸化合物.此物质的结构类似于可能的大蒜绿变色素前体2-(3,4-dimethyl-1H-pyrrolyl)-3-methylbutanioc acid.(3,4-二甲基-1H-吡咯基)-3-甲基丁酸,简称为含硫吡咯基氨基酸,此物质与丙酮酸反应不能产生黄色素.丙酮酸是大蒜绿变过程中丙烯基半胱氨酸亚砜在蒜酶作用下的产物,先前合成的色素前体类似物与丙酮酸反应大多可以产生黄色素.研究表明,该中间体通过此途径与黄色素的产生无关.     

紫甘蓝色素的稳定性及抑菌性

从紫甘蓝叶片中提取分离紫甘蓝色素,研究紫甘蓝色素在不同条件下的稳定性及抑菌性。结果表明：紫甘蓝色素在pH 2 的酸性水溶液中呈现原植物具有的紫红色,稳定性较好;随着pH 值的增高,紫甘蓝色素发生向蓝色再到绿色的转变,且最大吸收波长发生红移。紫甘蓝色素自然光照射2d 后,色素的保存率在91% 以上,自然光照射6d 后,色素的保存率仍在79% 以上;紫甘蓝色素70℃以下加热2h,色素的保存率在97% 以上,90℃加热2h,色素的保存率仍在90% 以上,这说明紫甘蓝色素对光照和加热均有一定耐受性。紫甘蓝色素对钠、钾、钙、镁等金属离子和氧气均稳定,但铁离子会使其变质。在紫甘蓝色素溶液的质量浓度为10mg/100mL 时,对金黄色葡萄球菌和枯草芽孢杆菌的生长就具有极显著的抑制作用,随着色素质量浓度的提高,抑制作用愈来愈大,但未见紫甘蓝色素对大肠杆菌生长有抑制效果。     

Antioxidant Activity of Fungus Suihs bovinus (L: Fr.) O. Kuntze

Two major antioxidative compounds were isolated from wild mushrooms, Suillus bovinus (L: Fr.) O. Kuntze, and studied for antioxidative activity by comparison with other antioxidants, BHA and tocopherol. One compound was an orange pigment identified as variegatic acid (3,3′,4,4′-tetrahydroxy puluvinic acid) and the other was an orange-red pigment, possibly diboviquinone-4,4. The variegatic acid had strong antioxidative activity in an emulsion system as shown by peroxide value (POV) of linoleic acid and in an oil system as shown by the POV of methyl linoleate and weight gain of soybean oil. The second compound was active only in the emulsion system.     

改性磁性壳聚糖对胭脂红的吸附性能评价

以纳米Fe₃O₄、壳聚糖为材料,采用反相悬浮交联法,用三乙胺做改性剂制备改性磁性壳聚糖,研究其对胭脂红色素的吸附性能影响,考察时间、pH、温度及胭脂红的初始浓度等四个因素对改性磁性壳聚糖吸附胭脂红溶液吸附效果的影响,并对吸附动力学模型、吸附等温模型、吸附热力学和吸附再生性能进行初步探讨。结果表明,当pH=3,吸附时间为270 min,温度为50℃,初始浓度为100 mg/L时,改性磁性壳聚糖对胭脂红溶液的吸附率达到最高,为96.72%。改性磁性壳聚糖对胭脂红溶液的吸附动力学数据符合准二级动力学模型,吸附等温线数据符合Langmuir模型,热力学数据拟合得出ΔH>0,ΔS>0,ΔG<0,得出此反应是吸热反应。经过三次吸附-解析实验,吸附率和解析率仍在40%以上。     

Structure determination of minor red pigment in carthamus red colorant isolated by preparative LC/MS.

Carthamin is a well-known major pigment in carthamus red colourant. When analysed by HPLC on an ODS column, the colorant separated into two distinct reddish pigments, with both components having almost identical photodiode array spectra. LC/MS analysis suggested one of the compounds was carthamin, whilst the other was an unknown minor pigment. The minor pigment was purified and isolated from the colorant by preparative LC/MS collecting the faction based on monitoring the deprotonated molecule [M-H](-) m/z 953 in electrospray negative-ion mode. The structure was elucidated as a hydroxyethyl ether of carthamin, a novel compound, by means of NMR and HR-FAB-MS analyses.     

表面增强拉曼光谱对纺织品文物中茜素和茜紫素的快速检测

为快速检测古代纺织品文物中的天然色素并达到无损分析的目的,采用表面增强拉曼光谱技术(SERS)对纺织品文物中天然染料茜素和茜紫素进行鉴定。以纳米银溶胶为SERS基底检测茜素和茜紫素的标准品,利用密度泛函理论计算结果对茜素和茜紫素分子的SERS光谱进行确认,分析得到茜素和茜紫素的SERS光谱在3种激发波长下的差异,并找出判断茜素和茜紫素存在的特征峰。在此基础上,从纺织品文物中提取1根长度约为2 mm的纤维,采用原位非萃取水解方法对其进行预处理,并进行SERS检测。结果表明,出土于新疆营盘的纺织品文物中红色染料成分是茜素和茜紫素。     

酸性α-淀粉酶基因在枯草芽孢杆菌中的高效表达

酸性α-淀粉酶是发酵行业用量最大的酶类,为了实现酸性α-淀粉酶基因的高效表达,将本实验室已经克隆得到的去信号肽的酸性α-淀粉酶基因在枯草芽孢杆菌WB600宿主中进行表达,成功的构建了表达菌株pHT43-amy/WB600。在初始菌浓度OD600为0.8时加入终浓度为0.9 mmol/L的IPTG,诱导6 h的条件下测得酶活力为1 230 U/mL,又由于宿主菌WB600外分泌蛋白较少,因此具有明显的生产优势。     

红曲橙色素的提取及其稳定性研究

以固态发酵生产的红曲色素为材料,从色素的提取方法、稳定性测试及与氨基酸反应3方面进行研究。结果表明,用板层析方法可分离、制备较纯的橙色素。该色素的热稳定性良好,光稳定性差;酸性条件下较稳定,pH>5.7时色素可能发生变化,导致吸光值下降,最大吸收峰对应波长发生位移;Na2SO3与H2O2对橙色素有一定的破坏作用,NaCl与蔗糖没有太大影响;不同氨基酸与橙色素会发生不同程度的反应,文中对谷氨酸和橙色素反应生成的衍生物进行了分析,确定出其分子量和结构。     

天然色素稳定性研究及其新的类型划分

本工作对16种不同类型的天然色素分子结构与其稳定性的关系进行了研究，并系统地考查了光照、氧化、温度、金属离子、介质极性、pH值等条件对其稳定性的影响。发现天然色素的脂肪族与芳香族化合物色泽不稳定的行为、褪色（变色）机理、主要影响因素等均有本质上的差异，并且这两类色素还具有诸多互补特性，同时还发现色素的光稳定性与理论计算生成热之间存在良好的线性关系。基于上述结论，提出了天然色素“二分法”的概念。这’新的天然色素类型划分方法，为预测、提高和改善天然色素色泽稳定性具有一定的指导意义，并为天然色素替代有毒副作用的人工合成色素的进程将起到积极的促进作用。     

1株产蓝色素真菌F10的ITS序列及其色素性质分析

从赣南野生松木上分离到1株产蓝色素真菌F10,该菌经鉴定为葡萄糖座科Pseudofusicoccum属。为研究F10产生的蓝色素的性质,实验采用不同pH值、温度、光照、金属离子、氧化剂和还原剂处理蓝色素,结果表明,该蓝色素对光照、温度、氧化剂都不敏感,对pH值、金属离子、还原剂敏感,推测这几种因素可能改变了色素的化学结构。为确定该蓝色素的结构成分,采用高效液相色谱串联质谱、红外光谱法对其进行鉴定,结果表明该色素为芳香族羧酸类化合物。     

一种被毛孢中天然色素的提取分离和结构鉴定

利用二氯甲烷和乙酸乙酯混合物(体积比1:1)提取出了一种被毛孢RCEF0851菌丝体中的色素,用高效液相色谱方法从提取物中分离纯化出一种橘黄色纯化合物Hh-2。该色素用显色反应、质谱、紫外和核磁共振谱等方法鉴定为醌茜素(skyrin)。虽然该化合物是一已知化合物,但是该物质在虫生真菌中发现尚属首次。     

辣椒的分析与综合利用

论述了辣椒碱的结构、生理作用及其提取方法；论述了辣椒色素、辣椒油的组成及应用，辣椒色素及其油的提取方法等，使辣椒制品可广泛用于医药、食品、化妆品、保健油品、天然抗氧化剂等方面。     

Purification and characterization of pedioxanthin (carotenoid pigment) produced by Pediococcus pentosaceus N33 strain isolated from pickles

Forty-two lactic acid bacteria were isolated from 28 pickles and yoghurt samples, and screened for their antimicrobial efficacy against certain multidrug resistant (MDR) bacteria using well diffusion method. A strain Pediococcus pentosaceus N33 (MF062087) showed the best inhibitory effects against both Brevibacillus brevis H18 (MG637284) and Lysinibacillus fusiformis R29 (MG637285). Pediococcus pentosaceus N33 strain produced high thermostable antimicrobial compound as indicated by heat treatment between 60 and 100°C for 20 min as well as at 121°C for 15 min. It is a proteinaceous compound highly active at acidic pH (2–6). The antimicrobial compound was extracted and precipitated by 70% ammonium sulfate and finally fractionated using Sephadex G₅₀ column. The molecular weight of pure compound was 10 kDa using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The spectroscopic analysis based on UV, IR, NMR and MS analyses were used to characterize and identify the pure antimicrobial compound. From the characterization and identification of this inhibitory compound, it was observed that the target compound contains carotenoid pigment in addition to protein. This carotenoid pigment was identified as pedioxanthin which is the first observed from this strain. Our results evaluated the potential activity of Pediococcus pentosaceus N33 strain as a probiotic agent and its potential contribution for food industry and pharmaceutical applications.     

Susceptibility of strawberry varieties to breakdown in sulphite by endopolygalacturonase from zygomycete spoilage fungi

Differences were observed in the texture and susceptibility to enzymic breakdown of sulphited fruit of eight strawberry varieties. Cambridge Favourite was the softest variety in sulphite and was also the most susceptible to breakdown by pectolytic enzymes of Rhizopus and Mucor spp. Endopolygalacturonases (endo-PG) from these species were more rapidly inactivated in sulphite liquor in the presence of fruit of the variety Harvester, which consequently showed the greatest resistance to breakdown. Isoelectric focusing indicated that a single major isoenzyme from each strain of R. sexualis, R. stolonifer and M. piriformis persisted in sulphite liquor and was, therefore, responsible for breakdown, although the major form of M. piriformis was less acid-stable than those of the Rhizopus spp. Other minor isoenzymes produced by the fungi were inactivated within 24 h of sulphiting. Each species produced its major acid-stable endo-PG in the three varieties tested; thus varietal differences in susceptibility to breakdown may be related to the occurrence of natural enzyme inhibitors and/or fruit structure.     

Anthocyanin Pigments of Sweet Potatoes–Ipomoea batatas

The anthocyanin pigments of red sweet potato roots (Impomoea batatas) were isolated, purified and identified by HPLC and conventional paper chromatographic, spectral and chemical methods. Two major pigments and two minor pigments were present in fresh tissue slices extracted with boiling 1% HAc methanol. Tissues extracted cold yielded 11 or more pigments probably from degradation of the two major pigments. One major pigment was identified as peonidin-3-diglucoside-5-glucoside with three molecules of ferulic acid and one molecule of caffeic acid. The other major pigment was peonidin-3-diglucoside-5-glucoside with two molecules of ferulic acid and one caffeic acid.