Physicochemical Characterization,Antioxidant Capacity,and Sensory Properties of Murici (Byrsonima crassifolia (L.) Kunth) and Taperebá (Spondias mombin L.) Beverages

Amazonian fruits are excellent sources of bioactive compounds and can be used in beverages to improve the nutritional and sensorial characteristics. The present study aimed to develop a blend of murici (Byrsonima Crassifolia (L.) Kunth) and taperebá (Spondias Mombin L.) through experimental design and investigating the nutritional and sensorial characteristics of fruits and beverages. The murici was highlighted as higher vitamin C content (58.88 mg · 100 g⁻¹) compared to taperebá (25.93 mg · 100 g⁻¹). The murici and taperebá are good sources of total phenolic compounds (taperebá 1304.15 ± 19.14 mgGAE · 100 g⁻¹ and the murici of 307.52 ± 19.73 mg GAE · 100 g⁻¹) and flavonoids (174.87 ± 1.76 μgQE/g and 129.46 ± 10.68 μgQE/g, murici and taperebá, respectively), when compared to other Brazilian fruits. The antioxidant capacity in different methods revealed that the taperebá had a higher average in the results, only in the ORAC method and did not present a significant difference (p > 0.05) in relation to the murici. The beverage development was performed using experimental design 2³, showed through sensory analysis and surface response methodology that murici and high sugar content (between 12.5 and 14.2% of sugar) influenced in sensory acceptance. Our findings indicate that beverages with improved nutrition and a sensory acceptance can be prepared using taperebá and murici fruits.     

Determination of Iprodione,Vinclozolin, and Procymidone as the Heptafluorobutyramides of 3,5-Dichloroaniline

Abstract

A method was developed for the determination of three fungicides in foods based on alkaline degradation to 3,5-dichloroaniline, isolation of the latter by steam distillation and measurement of the heptafluorobutyrate by gas chromatography. Recoveries averaged 91% from several commodities spiked at from 10–80ppb. The minimum detectable limit of 2.6ppb was attainable in grape, with similar limits found in strawberry, tomato and beans. The method was capable of determining degradation products formed as a result of cooking.     

An analytical method for measuring α‐amylase activity in starch‐containing foods

The quality of starch‐containing foods may be significantly impaired by contamination with very small amounts of α‐amylase, which can enzymatically hydrolyze the starch and cause viscosity loss. Thus, for quality control, it is necessary to have an analytical method that can measure low amylase activity. We developed a sensitive analytical method for measuring the activity of α‐amylase (from Bacillus subtilis) in starch‐containing foods. The method consists of six steps: (1) crude extraction of α‐amylase by centrifugation and filtration; (2) α‐amylase purification by desalting and anion‐exchange chromatography; (3) reaction of the purified amylase with boron‐dipyrromethene (BODIPY)‐labeled substrate, which releases a fluorescent fragment upon digestion of the substrate, thus avoiding interference from starch derivatives in the sample; (4) stopping the reaction with acetonitrile; (5) reversed‐phase solid‐phase extraction of the fluorescent substrate to remove contaminating dye and impurities; and (6) separation and measurement of BODIPY fluorescence by HPLC. The proposed method could quantify α‐amylase activities as low as 10 mU/mL, which is enough to reduce the viscosity of starch‐containing foods. Copyright © 2012 John Wiley & Sons, Ltd.     

First report of the nutritional profile and antioxidant potential of Holothuria arguinensis,a new resource for aquaculture in Europe

This work reports for the first time the nutritional profile and antioxidant potential of the edible sea cucumber Holothuria arguinensis from the North-eastern Atlantic. H. arguinensis has high levels of protein, with the amino acids profile dominated by alanine, glycine and proline and low lysine/arginine ratios. Its carbohydrate and energetic contents are also low as well as the total lipid levels, although its lipid profile is rich in polyunsaturated fatty acids (PUFA), especially arachidonic, eicosapentaenoic and docosahexaenoic acids. In addition, H. arguinensis has high levels of calcium. The water and ethanol extracts show ability to scavenge free radicals and to chelate copper and iron ions. Our results indicate that H. arguinensis has a balanced nutritional quality suitable for human consumption. In addition, it contains compounds with antioxidant potential; thus its intake can contribute for a healthy and well-balanced diet.     

高效液相色谱法检测六种氟喹诺酮类兽药残留前处理的优化

建立了一个检测动物源性食品中6种氟喹诺酮类药物残留的高效液相色谱方法。不同基质的样品前处理对检测影响较大:鱼、肉及肝脏等样品需经过乙腈-0.1 mol/L KH2PO4缓冲液提取,乙腈饱和的正己烷洗涤去除油脂;蛋及乳制品样品用正己烷饱和的乙腈提取,乙腈饱和的正己烷去脂。目标化合物采用高效液相色谱-荧光检测器检测,外标法定量。对市售鸡肉、猪肉、鸡蛋进行检测,添加10、20、50、100μg/kg浓度水平时,回收率在82%~105%之间,相对标准偏差在4%~12%之间,方法的检出限诺氟沙星、环丙沙星、沙拉沙星及单诺沙星为5.0μg/Kg,恩诺沙星、达氟沙星为3.0μg/Kg。     

高效液相色谱-串联质谱法同时测定食品中五种黄色化工染料

采用高效液相色谱-串联质谱法(HPLC-MS/MS)建立了食品中非法添加的碱性橙、碱性嫩黄、酸性橙I、酸性橙II和酸性黄36这5种黄色工业染料的定量定性分析方法。使用Agilent ODS C18分离柱(50 mm×2.0 mm, 1.8 μm),以5 mmol/L乙酸铵水溶液(0.1%甲酸)-乙腈(3:2, v/v)为流动相,流速为0.3 mL/min。采用电喷雾离子化源,以多反应监测(MRM)方式分别在正、负离子模式下进行检测。在最佳检测条件下,得到了较宽的线性范围和较低的定量检出限。碱性橙和碱性嫩黄的线性范围均为5.0～80.0 mg/L;酸性橙I、酸性橙II及酸性黄36的线性范围均为10.0～160.0 μg/L。食品中碱性橙、碱性嫩黄、酸性橙I、酸性橙II及酸性黄36的定量限分别为20、20、40、40、40 ng/g。该方法重现性较好,保留时间和峰面积的相对标准偏差分别不大于0.50%和2.14%。本研究还测定了鸡肉、豆制品和黄鱼中添加的5种化工染料,回收率在79.8%~95.2%之间,结果令人满意。     

Vortex‐assisted surfactant‐enhanced‐emulsification liquid–liquid microextraction of biogenic amines in fermented foods before their simultaneous analysis by high‐performance liquid chromatography

A simple, rapid, sensitive, and environmentally friendly method, based on modified dispersive liquid–liquid microextraction coupled with high‐performance liquid chromatography was developed for the simultaneous determination of five biogenic amines in fermented food samples. Biogenic amines were derivatized with 9‐fluorenylmethyl chloroformate, extracted by vortex‐assisted surfactant‐enhanced emulsification liquid–liquid microextraction, and then analyzed by high‐performance liquid chromatography. Five biogenic amine compounds were separated within 30 min using a C₁₈ column and gradient elution with acetonitrile and 1% acetic acid. Factors influencing the derivatization and extraction efficiency such as type and volume of extraction solvent, type, and concentration of surfactant, pH, salt addition, and vortex time were optimized. Under the optimum conditions, the method provided the enrichment factors in the range of 161–553. Good linearity was obtained from 0.002–0.5 mg/L for cadaverine and tyramine, 0.003–1 mg/L for tryptamine and histamine, and 0.005–1 mg/L for spermidine with coefficient of determination (R²) > 0.992. The limits of detection ranged from 0.0010 to 0.0026 mg/L. The proposed method was successfully applied to analysis of biogenic amines in fermented foods such as fermented fish (plaa‐som), wine and beer where good recoveries were obtained in the range of 83.2–112.5%     

前体离子扫描法在快速筛查中药及保健食品中非法添加的5型磷酸二酯酶抑制剂及其未知衍生物中的应用

改造有明确疗效的药物,合成新的衍生物以避开法定检验方法是目前化学药物非法添加的趋势之一。本文提出将液相色谱-三重四极杆质谱联用仪的质谱前体离子扫描模式应用于中药及保健食品等复杂体系中非法添加药物衍生物的快速筛查策略,以5型磷酸二酯酶抑制剂为实验对象,通过分析该类化合物的结构和质谱特点将其分类,筛选各类共有的子离子碎片,优化质谱参数,建立了前体离子扫描模式的LC-MS筛查方法,讨论了质谱参数和碎片离子的选择对筛选结果的影响,并应用于实际样品的测定。结果表明,该方法既可以满足已知化合物的测定需要,又可以对复杂体系中未知的同类衍生物进行快速筛查,防止未知衍生物的漏检。该方法灵敏、专属、高效,值得进一步研究。     

Ionic liquids as mobile phase additives in high-performance liquid chromatography with electrochemical detection: Application to the determination of heterocyclic aromatic amines in meat-based infant foods

The beneficial effects of several ionic liquids (ILs) as mobile phase additives in high-performance liquid chromatography with electrochemical detection for the determination of six heterocyclic aromatic amines (HAs) have been evaluated for first-time. The studied ionic liquids were 1-butyl-3-methylimidazolium tetrafluoroborate (BMIm-BF₄), 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIm-BF₄) and 1-methyl-3-octylimidazolium tetrafluoroborate (MOIm-BF₄). Several chromatographic parameters have been evaluated in the presence or absence of ILs, or using ammonium acetate as the most common mobile phase additive, with three different C18 stationary phases. The effect of the acetonitrile content was also addressed. In general, best resolution, lower peak-widths (up to 72.1% lower) and lower retention factors are obtained when using ILs rather than ammonium acetate as mobile phase additives. The main improvement was obtained in the baseline noise, being 360% less noisy for BMIm-BF₄, 310% for HMIm-BF₄, and 227% for MOIm-BF₄, when compared to ammonium acetate at +1000 mV. Different chromatographic methods using the best conditions for each IL were also evaluated and compared. Finally, the best chromatographic conditions using 1 mM of BMIm-BF₄ as mobile phase additive, the Nova-Pak^® C18 column, 19% (v/v) of acetonitrile content in the mobile phase, and +1000 mV in the ECD, have been applied for the chromatographic analysis of six HAs contained in meat-based infant foods. The whole extraction method of meat-based infant foods using focused microwave-assisted extraction and solid-phase extraction has also been optimized. Extraction efficiencies up to 89% and detection limits ranged between 9.30 and 0.165 ng g⁻¹ have been obtained under optimized conditions.     

动物源性食品中四环素类残留分析研究进展

综述了检测动物源性食品中四环素类残留的前处理方法,包括固相萃取、固相微萃取、基质分散技术、分子印迹技术、限进介质材料;对高效液相色谱、毛细管电泳、微生物法和酶联免疫分析等在四环素类药物中的检测应用进行了综述,比较了各种方法的优缺点。