Stability of sunset yellow FCF and tartrazine in liquid model food systems

Effect of various preservatives, sugar, ascorbic acid and light on the stability of sunset yellow and tartrazine was studied. While sulphur dioxide enhanced the rate of degradation of sunset yellow, it stabilized tartrazine in aqueous model systems. At 30 and 45% sugar levels, the rate of degradation of both sunset yellow and tartrazine was practically same in the presence of benzoic acid and sorbic acid. At 15% sugar level, the rate of degradation of tartrazine was slightly higher in the presence of sorbic acid. Incorporation of ascorbic acid enhanced the degradation of both sunset yellow and tartrazine and its effect was considerably higher in the presence of light. Increase in sugar concentration enhanced the stability of both the dyes, but light enhanced their degradation.     

Determination of total non-sulphonated aromatic amines in tartrazine, sunset yellow FCF and allura red by reduction and derivatization followed by high-performance liquid chromatography.

Free and bound non-sulphonated aromatic amines (NSAA) are determined in the food colours tartrazine, sunset yellow FCF and allura red. After reduction of the bound amines with sodium dithionite, the NSAA are extracted into chloroform, then transferred to aqueous acid solution, diazotized with sodium nitrite and coupled with 2-naphthol-3,6-disulphonic acid, disodium salt (R-salt). Reversed-phase ion-pair liquid chromatography and an absorbance detector at 512 nm are used to analyse the coloured derivatives. Samples of dyes were spiked with known amounts of aniline, 1-naphthylamine, 2- and 4-aminobiphenyl, 4-aminoazobenzene, benzidine, p-cresidine or 4-nitro-p-cresidine bound to R-salt. Recoveries averaged 90% in tartrazine, 65% in sunset yellow FCF and 71% in allura red. Detection limits ranged between 2 and 32 ng/g. A survey of 24 commercial samples revealed levels up to 520 micrograms/g total NSAA. The majority of NSAA are bound to the coupling compound during the manufacturing process and less than 7% remain as free amines in the dye.     

高效液相色谱法同时测定熟肉制品中日落黄、 胭脂红和诱惑红

目的 建立对熟肉制品中日落黄、胭脂红和诱惑红三种合成色素同时测定的方法。方法 样品采用无水乙醇-氨水-水(7: 2: 1)提取, 加正己烷去除脂肪, 氮吹后定容, 用高效液相色谱法测定。经Symmetry Shield RP18柱分离, 甲醇-0.02 mol/L乙酸铵溶液梯度洗脱, 检测波长为508 nm。结果 本方法的相对标准偏差(n=6)在0.92%～3.2%之间, 平均回收率在86.4%～99.1%之间, 检出限在0.005～0.008 mg/kg之间。结论 本方法灵敏度高, 分离效果好, 结果稳定可靠, 适用于熟肉制品中日落黄、胭脂红和诱惑红的同时测定。     

聚甘氨酸修饰电极测定食品中的诱惑红

用循环伏安法制备了聚甘氨酸修饰电极,研究了诱惑红在聚甘氨酸修饰电极上的电化学行为,建立了测定诱惑红的新方法。结果表明:甘氨酸修饰的玻碳电极对诱惑红的电化学行为具有良好的催化性能,此电极可用于诱惑红的检测。在p H=3.0的Na2HPO4-柠檬酸缓冲溶液中,对诱惑红进行测定的线性范围为8.0×10-8⁶.0×10-6mol/L;检出限为2.0×10-8mol/L。干扰实验结果表明,一些常见的阳离子以及阴离子对诱惑红的检测无明显干扰。该修饰电极具有良好的灵敏度、选择性和稳定性,可用于食品中诱惑红的检测,结果满意。     

Determination of benzidine in the food colours tartrazine and sunset yellow FCF, by reduction and derivatization followed by high-performance liquid chromatography.

Free and bound benzidine, a non-sulphonated aromatic amine (NSAA), were determined in the food colours tartrazine and sunset yellow FCF. Bound amines were released by reducing with sodium dithionite, then total NSAAs were extracted into chloroform, transferred to aqueous acid solution and diazotized with sodium nitrite before coupling with 2-naphthol-3,6-disulphonic acid, disodium salt (R-salt). Coloured benzidine and aniline derivatives (BZDRS and ANRS) were analysed using reversed-phase ion pair high-performance liquid chromatography (HPLC) and an absorbance detector set at 548 nm. Levels of total benzidine were similar to those reported in studies conducted in the USA, and ranged from < 5 to 270 ng/g. Total aniline was also determined (0.2-188 micrograms/g). Recoveries of benzidine with this method were found to be lower than expected (average ca 46%), but were reproducible. Detection limits were 15-20 ng BZDRS/g (3-4 ng benzidine/g). Mass spectrometry (LC-MS) was evaluated for identifying and determining purity of the standards, but difficulties were encountered when the methodology was applied to commercial samples.     

Structural determination of the subsidiary colors in food blue No. 1 (brilliant blue FCF) aluminum lake detected by paper chromatography

One of eight Food Blue No. 1 aluminum lakes (B-1Als) used in the official inspection of coal-tar colors in fiscal year 1999 had a violet sub-spot during paper chromatography and was rejected. To clarify the orgin of the sub-spot, the violet subsidiary color (Sub-V) was isolated from the sample. On the basis of NMR and MS analyses and ion chromatography, the structure of the subsidiary color was elucidated to be 2-[[4-[N-ethyl-N-(3- sulfophenylmethyl)amino]phenyl][4-hydroxyphenyl]methylio]benzenesulfonic acid. The relative content of Sub-V to that of m,m-B-1 in the rejected sample was determined to be 39.5% by HPLC. The relative contents in other submitted samples of B-1Al were in the range of 1.1-3.6%.     

Identification and determination of the isomer and subsidiary color in food blue no. 2 (indigo carmine) by LC/MS and HPLC

CFR and JECFA specify that the total color in FD&C Blue No. 2 (B2; Indigo Carmine, Indigotine, Food Blue No. 2) is not less than 85%, its isomer (B2iso) in B2 is not more than 18%, and its subsidiary color (B2sub) in B2 is not more than 2% (CFR) or 1% (JECFA). Japan's Specifications and Standards for Food Additives, 7th Edition, specifies that the total color in B2 is not less than 85.0% and other color materials in B2 are not detected by paper chromatography. LC/MS and HPLC were employed to identify and determine the main component (B2m) of B2, B2iso, and B2sub. The pseudo molecular ions (B2m and B2iso: [M-2Na+H]-, m/z=421; B2sub: [M-Na]-, m/z=341) of each color material were obtained and identified by LC/MS based on their absorptions and mass spectra. The contents of B2iso and B2sub in B2 samples (certified samples from fiscal year 1998 to fiscal year 2002) were determined by HPLC using calibration curves for the standards of B2m and B2iso. The contents of B2iso in most samples were less than 10%, and the contents of B2sub in all samples were not more than 1%. All of them were within the regulatory limits set by the CFR and JECFA.     

Determination of sunset yellow (E110) in foodstuffs and pharmaceuticals after separation and preconcentration via solid‐phase extraction method

The two novel preconcentration and separation methods based on adsorption onto Amberlite XAD‐1180 and Amberlite XAD‐16 polymeric resins for spectrophotometric determination of sunset yellow dye were developed. The parameters, affecting the quantitative recovery, including pH, sample and eluent flow rates, eluent type, sample volume, were investigated and optimised. The interference effects of some cations, anions and widely used dye were also studied. At the optimum conditions, detection limits of the methods were found as 2.0 and 1.6 μg L^?1 for Amberlite XAD‐1180 and Amberlite XAD‐16 resins, respectively. Linear dynamic ranges of the methods were obtained in the range of 0.2–50.0 and 0.2–20.0 μg mL^?1 for Amberlite XAD‐1180 and Amberlite XAD‐16 resins, respectively. The relative standard deviations were below than 7% and 5% for Amberlite XAD‐1180 and Amberlite XAD‐16 resins, respectively. The determination of dye was performed at 483.0 nm using spectrophotometry. Validations of the methods were performed comparatively with determination of the sunset yellow content of some foodstuffs and pharmaceuticals.     

Analysis of raw materials, intermediates and subsidiary colours in Food Yellow No. 5 (Sunset Yellow FCF) by LC/MS

Raw materials, intermediates and subsidiary colours in Food Yellow No. 5 (Sunset Yellow FCF) were determined using liquid chromatography/mass spectrometry (LC/MS) with electrospray ionization. A gradient consisting of acetonitrile and 0.04% aqueous ammonium carbonate solution was used for the HPL C mobile phase. Quasi-molecular ions of impurities were used as monitor ions. It was necessary to use fragment ions of the sodium salts of 6-hydroxy-5-phenylazo-2-naphthalenesulphonic acid (SS-AN) and 4-(2- hydroxy-1- naphthylazo) benzenesulphonic acid (2N-SA) as monitor ions because the compounds are not resolved by chromatography and have the same molecular weight. Fifteen samples of commercial Sunset Yellow FCF were examined. The results obtained by UV-Vis spectroscopy were in good agreement with the results of LC/MS analyses. The detection limits of the impurities in Sunset Yellow FCF ranged from 0.01 to 0.1%.     

高效液相色谱法测定食品中糖精钠和天冬糖

利用高效液相色谱测定食品和复合甜味剂蛋白糖中人工合成甜味剂-糖精钠和天冬糖,采用国产C     

Comparative analysis of the chemical composition and antioxidant activity of red (Psidium cattleianum) and yellow (Psidium cattleianum var. lucidum) strawberry guava fruit

Abstract: Strawberry guava (Psidium cattleianum Sabine) is a native fruit of Brazil widely consumed fresh and used in the food industry. In this context, the present study deals with the chemical characterization and the antioxidant activity of the red (Psidium cattleianum) and yellow (P. cattleianum var. lucidum Hort.) strawberry guava fruits, cultivars Irapuã and Ya‐Cy, respectively. Knowledge of chemical composition is fundamental to human nutrition, contributing to the quality of foods. Phenolic compounds in both fruits were analyzed by HPLC–DAD and the total flavonoid content was determined by the Folin–Ciocalteu assay. The antioxidant activity was evaluated by the total reactive antioxidant (TRAP) method. Psidium cattleianum presented a higher content of polyphenolic compounds than P. cattleianum var. lucidum (501.33 and 292.03 mg/100 g, respectively), with hyperoside being one of the major flavonoids identified for both cultivars. In addition to flavonoids, P. cattleianum presented an anthocyanin, identified as cyanidin. The antioxidant activity varied in a concentration‐dependent manner for both strawberry guava species. The volatile oils in fruits and fatty acids in seeds were quantified by GC‐EM. The analysis of the essential oil of yellow strawberry guava was compared with a previous study on the red cultivar, revealing β‐caryophyllene as the main component in both oils. The fatty acid composition was also quite similar and was especially characterized by the presence of unsaturated fatty acids (86.25% and 76%, respectively), among which linoleic acid as the most abundant. Practical Application: In this study, the chemical characterization and the antioxidant activity of the red (Psidium cattleianum) and yellow (P. cattleianum var. lucidum Hort.) strawberry guava fruits were investigated. This is important for potential application of strawberry guava as functional food. Moreover, it may be the experimental basis for further development and use in food industry.     

5L立瓶发酵制备益生菌直投式发酵剂及应用试验

对长双歧杆菌、保加利亚乳杆菌、嗜热乳酸链球菌在5 L立瓶中分别进行培养,确定了各自的发酵最适收获期,菌体收集后经制备所获得冷冻浓缩直投式发酵剂活菌数大于1010mL-1,冷冻干燥直投式发酵剂活菌数大于1011g-1。以制备的冷冻浓缩、冷冻干燥直投式发酵剂,进行牛乳发酵应用试验,生产的益生菌酸奶风味纯正、品质良好。     

乳粉中克罗诺杆菌属阪崎肠杆菌能力验证样品制备及应用

目的 制备均匀性及稳定性均满足要求的克罗诺杆菌属(阪崎肠杆菌)检验能力验证样品,用于组织能力验证考核.方法 通过生化及基质辅助激光解吸电离飞行时间质谱方法鉴定背景菌株及所使用的克罗诺杆菌属(阪崎肠杆菌)菌株.采用冷冻干燥技术制备均匀性及稳定性均满足要求且各种菌含量为104 CFU/瓶的能力验证菌球.依据CNAS-GL0...     

Isolation, identification and determination of a magenta subsidiary colour in Food Blue No. 1 (Brilliant Blue FCF)

A magenta subsidiary colour was isolated from commercial Food Blue No. 1 (B-1; Brilliant Blue FCF). The absorption maximum for this subsidiary colour at 580nm is outside of the range of 614-628nm found for other subsidiary colours and m,m -B-1. On the basis of MS and NMR analyses, the structure of the subsidiary colour was elucidated as the disodium salt of 2-[[4-[Nethyl-N-(3-sulphophenylmethyl)amino]phenyl][4-oxo2,5-cyclohexadienylide acid. HPL C analyses revealed that 24 batches of commercial Food Blue No. 1 (three manufacturers) contain 0.1- 0.8% (average: 0.5% ) of the magenta subsidiary colour.     

Application of a simplified HPLC assay for the determination of phylloquinone (vitamin K1) in animal and plant food items

The lack of precise data in food composition tables demands intensive investigation of phylloquinone content in human food, for the purpose of nutritional intake assessment and support of anticoagulant drug therapy. The determination of small phylloquinone amounts requires sensitive and selective detection methods. Based on a RP-HPLC assay using post-column derivatization and fluorescence detection, and combined with a liquid-liquid sample clean-up, a rapid and routinely usable assay is presented. The application to foods is shown in the items of milk (0.36 ± 0.07 μg/100 g), other dairy products (yoghurt, 0.34 ± 0.04 μg/100 g), eggs (1.85 ± 0.99 μg/100 g), edible oils (from 0.97 to 112 μg/100 g), oatmeal (4.07 ± 0.35 μg/100 g), broccoli (195 ± 40 μg/100 g), cauliflower (12.0 ± 6.1 μg/100 g), carrots (5.94 ± 3.39 μg/100 g) and potatoes (1.62 ± 1.21 μg/100 g). The samples cover a range of foods, from those of fairly low to those of high phylloquinone content. High precision and wide application range both offer valuable instruments for food analysis and construction of current food composition and nutrition tables in the future.     

In vitro evaluation of red and green lettuce (Lactuca sativa) for functional food properties

Lettuce (Lactuca sativa) is an important leafy vegetable consumed fresh or in salad mixes. We have compared the functional food properties of selected commercial red and green lettuce varieties grown under field conditions. Both lettuce cultivars were extracted with water at biological (38 °C) and room temperatures (22 °C) at pH 2. The residues from each extraction were further extracted, sequentially with methanol and ethyl acetate. The extracts were evaluated for their in vitro lipid peroxidation (LPO) and cyclooxygenase enzyme (COX) inhibitory activities. Amongst the extracts tested, all three extracts of red lettuce showed higher LPO and COX-1 and -2 enzyme inhibitory activities than did the green lettuce extracts. Red lettuce contained a single anthocyanin, cyanidin-3-O-(6″-malonyl-β-glucopyranoside) (1), which immediately converted to cyanidin-3-O-(6″-malonyl-β-glucopyranoside methyl ester) (2) and cyanidin-3-O-β-glucopyranoside (3) under laboratory conditions. Anthocyanins 1 and 2 inhibited LPO by 88% and 91.5%, respectively, at 0.25 μM concentration. Also, they inhibited COX-2 enzyme by 78.9% and 84.3% and COX-1 by 64% and 65.8%, respectively, at 5 μM. The chicoric acid (4), amongst other phenolics, such as quercetin glucoside, ferulic and caffeic acids, isolated from both green and red lettuce, showed 85.6%, 45.6% and 94% of LPO, COX-1 and -2 enzyme inhibitions at 50 μM, respectively. This is the first report of the LPO, COX-1 and -2 enzyme inhibitory activities of compounds 1, 2 and 4. The variation of phenolics in the red and green lettuces, and specifically the lack of anthocyanins in green lettuce, might account for the higher biological activity obtained with the red variety in our study.