RESUMEN
The levels of copper (Cu), zinc (Zn), cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg) in eight types of honey collected in China were determined. The average concentrations of the six heavy metals in the honey samples were 46.18, 1329.5, 1.34, 33.98, 13.44, and 1.65 µg kg(-1), respectively. All these values were below the maximum allowable contaminant levels in foods (GB2762-2005) and honey (GB14963-2011) in China. The hazard quotients of individual heavy metals and the hazard index of all six heavy metals were far below one, indicating no chronic-toxic risk from these metals for the inhabitants of Zhejiang under the current consumption rates of honey. However, the carcinogenic risk of As for the female inhabitants in Zhejiang exceeded the acceptable level of 10(-4). Therefore, As is the most concerning heavy metal in honey.
Asunto(s)
Contaminación de Alimentos/análisis , Miel/análisis , Metales Pesados/análisis , Adulto , Arsénico/análisis , Cadmio/análisis , China , Cobre/análisis , Femenino , Humanos , Plomo/análisis , Masculino , Mercurio/análisis , Control de Calidad , Medición de Riesgo , Encuestas y Cuestionarios , Zinc/análisisRESUMEN
Supercritical carbon dioxide (SC-CO(2)) extraction of flavonoids from pomelo (Citrus grandis (L.) Osbeck) peel and their antioxidant activity were investigated. Box-Behnken design combined with response surface methodology was employed to maximize the extraction yield of flavonoids. Correlation analysis of the mathematical-regression model indicated that a quadratic polynomial model could be used to optimize the SC-CO(2) extraction of flavonoids. The optimal conditions for obtaining the highest extraction yield of flavonoids from pomelo peel were a temperature of 80 °C, a pressure of 39 MPa and a static extraction time of 49 min in the presence of 85% ethanol as modifier. Under these conditions, the experimental yield was 2.37%, which matched positively with the value predicted by the model. Furthermore, flavonoids obtained by SC-CO(2) extraction showed a higher scavenging activity on hydroxyl, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals than those obtained by conventional solvent extraction (CSE). Therefore, SC-CO(2) extraction can be considered as a suitable technique for the obtainment of flavonoids from pomelo peel.
Asunto(s)
Antioxidantes/química , Dióxido de Carbono/química , Citrus/química , Flavonoides/química , Análisis de Varianza , Cromatografía con Fluido Supercrítico , Citrus/metabolismo , Etanol/química , Oxidación-Reducción , Extractos Vegetales/química , Presión , TemperaturaRESUMEN
Four crude water soluble polysaccharides, CABP, CAAP, CFVP and CLDP, were isolated from common edible mushrooms, including Agaricus bisporus, Auricularia auricula, Flammulina velutipes and Lentinus edodes, and their chemical characteristics and antioxidant properties were determined. Fourier Transform-infrared analysis showed that the four crude polysaccharides were all composed of ß-glycoside linkages. The major monosaccharide compositions were D-galactose, D-glucose and D-mannose for CABP, CAAP and CLDP, while CFVP was found to consist of L-arabinose, D-galactose, D-glucose and D-mannose. The main molecular weight distributions of CABP and the other three polysaccharides were <5.1 × 10(4) Da and >66.0 × 10(4) Da, respectively. Antioxidant properties of the four polysaccharides were evaluated in in vitro systems and CABP showed the best antioxidant properties. The studied mushroom species could potentially be used in part of well-balanced diets and as a source of antioxidant compounds.
Asunto(s)
Agaricales/química , Antioxidantes/química , Antioxidantes/farmacología , Polisacáridos/química , Polisacáridos/farmacología , Agua/química , Peso Molecular , Monosacáridos/análisis , Monosacáridos/química , Oxidación-Reducción/efectos de los fármacos , Extractos Vegetales/química , Extractos Vegetales/farmacología , SolubilidadRESUMEN
Infrared spectroscopy and dual-indicator sequence were used to study their IR characteristic peaks of Ganoderma lucidums from different places and species. The experimental results showed that the majority of Ganoderma lucidum from different places and species had the similar characteristic peaks of infrared spectra, Their common peak ratio could reach more than 91.67%, but the common peak ratio of mycelium was 52.94%-58.82%, and variant peak ratio was 29.41%-66.67%. The main variation peak was in the fingerprint regions 1 460.9-1 423.7 cm(-1) with ladder peaks. The IR characteristic peaks of Ganoderma lucidum obviously appear as the main characteristic peaks with the type of polysaccharide and protein bands. There was obviously a wide and strong absorption peak in 3 377.8-3 396.5 cm(-1), a small acromion in 2 924.2-2 925.1 cm(-1), a medium intensity absorption peak in 1 635.8-1 650.3 and 1 372.5-1 375.2 cm(-1), a strong absorption bifurcate peak in 1 074.8-1 075.3 and 1 043.2-1 045.2 cm(-1), a obvious weak peak in fingerprint regions 891.0-894.8 cm(-1), and a medium intensity absorption peak in 563.10-574.7 cm(-1).
Asunto(s)
Reishi/química , Espectrofotometría InfrarrojaRESUMEN
Ganoderma lucidum polysaccharides were extracted by boiling water from the fruiting bodies of red ganoderma lucidum, then protein was removed by Sevage reagent, with ethanol precipitation, run water dialysis, centrifugation and freeing-drying. Monosaccharides were acetylated and quantified by external standard, and the polysaccharides the amount of total carbohydrates was determined by phenol-sulfuric acid method. The monosaccharide constituents, structure and Mw distribution were analyzed by UV-Vis, IR, GC, GC-MS and HPSEC with ELSD. The results demonstrated that ganoderma lucidum polysaccharides were beige, the yield was about 2%, and the content > or = 43%. IR spectrometry showed that the structure of ganoderma lucidum polysaccharide was pyranoid glucan with beta-glycosidic bond. The quantitative result of external standards indicated that the monosaccharide constituents were mainly composed of glucose, at about 89% percent, and contained a small amount of D-arabinose, D-xylose, D-mannose and D-galactose. It was a homogeneous polysaccharide with the amorphous structure, attributed to biological macromolecules, its Mw distribution was at 80-2000 Kda, and a primary Mw at 2000 Kda.
Asunto(s)
Polisacáridos/química , Reishi/química , Estructura MolecularRESUMEN
Twenty trace elements, Al, As, Ca, Cd, Co, Cr, Cu, Fe, Ge, Hg, K, Mg, Mn, Na, Ni, P, Pb, S, Se and Zn were determined by ICP--AES with wet digestion from two kinds of different ling zhi fruitbody materials (Zhongzhi and Xianyuan), Ling Zhi root, ling zhi mixture, unbroken and broken ling zhi spore powder. The common feature about the element content showed that there were rich trace elements in different Ling Zhi materials, and the concentrations of K, Ca, Mg, Fe, Zn, P and S in all kinds of ling zhi samples were relatively high. Besides, there were trace elements, Cu, Co, Grand Ni, and potentially physiologically toxic elements, Al, As, Hg, Pb and Cd, in all samples. Elements Se and Ge with anticancer efficacy were not found in ling zhi samples. The concentrations of heavy metal elements were lower in spore powders than in other ling zhi samples. Trace element contents in the broken and unbroken spore powders showed minor difference, The concentrations of Fe and Se in ling zhi mixtures were obviously higher than in other kinds of Ling Zhi samples, due to factitious addition of these elements to Ling Zhi mixture sample. There was some difference between two kinds of Ling Zhi fruitbody from deferent plant places, which may have some relations with the soil and environment. The concentrations of Ca, Cu and Zn in ling zhi root were higher than in other ling zhi materials. According to the analyses, these elements in ling zhi were helpful to improving cardiovascular function.
Asunto(s)
Medicamentos Herbarios Chinos/química , Espectrofotometría Atómica , Oligoelementos/análisis , Límite de Detección , Raíces de Plantas/química , Polvos , ReishiRESUMEN
Twelve kinds of fish tissues were wetly decomposed and the harmful elements of Cd, As, Pb and Hg were determined by ICP-AES method in the present paper. The techniques for operating ICP instrument were optimized, spectral interference for elements in special wavelength range was studied, and the correction factor of IECs model was established. The results indicated that the signal to noise ratio and detection limit for elements with higher ionization potential energy may be improved by increasing the radio generator power properly and reducing the nebulizer pressure. There were Cr, Cu, As, Sn and Na elements that mainly disturbed the determined elements such as As (189.042 nm), Pb (220.353 nm), Cd (228.802 nm) and Hg (184.950 nm). The primary contaminating elements in tissues of freshwater fish and seawater fish were Pb and As respectively.
Asunto(s)
Peces/metabolismo , Agua Dulce/análisis , Espectrofotometría Atómica/métodos , Contaminantes Químicos del Agua/análisis , Animales , Arsénico/análisis , Cadmio/análisis , Peces/clasificación , Análisis de los Alimentos/métodos , Agua Dulce/química , Plomo/análisis , Mercurio/análisis , Especificidad de la Especie , Contaminantes Químicos del Agua/metabolismoRESUMEN
Shellfish samples were prepared by microwave, and 27 microelements including Ca, Mg, K, Na, P, S, Zn, Mn, Fe, Cu, Cr, Co, Se, Sn, Ni, Al, Ti, V, Mo, Ba, Ge, Si, Cd, I, Pb, As and Hg were determined by ICP-AES. It was showed that ICP-AES had an obvious advantage in the determination of microelements, and shellfishes contained upwards of 20 kinds of microelements. Calcium in fresh water was higher than that in seawater, and As and Pb were the major pollutants.