Antioxidant activity of extracts from Gevuina avellana and Rosa rubiginosa defatted seeds

Chilean hazelnuts (Gevuina avellana Mol) and mosqueta rose (Rosa aff. Rubiginosa L.) meals were extracted with methanol, ethanol, acidified water, acetone, butanol, diethyl ether and ethyl acetate. Ethanol and methanol extracted the highest amount of soluble substances from both seed meals. The highest concentration of total polyphenols was found in the ethanolic extracts, although that of acetone from R. rubiginosa presented similar values. The antioxidant activity of the extracts evaluated by the β-carotene assay and with as hydrogen radical scavenging ability showed that the activity of the butanol and methanol extracts from G. avellana was comparable to those of synthetic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The 2,2,-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging activity of the G. avellana methanol, ethanol and water extracts was 2–3 times lower than those of BHT and BHA, respectively. The activity of R. rubiginosa extracts ranged from that of BHT for the water extracts to 80% inhibition in respect to control achieved with the ethanol extracts.     

Stability of Metabolically Conjugated Precursors of Meat and Milk Flavor Compounds in Various Solvents

The stability of selected metabolic conjugates (phenylglucuronide, phenylphosphate, and naphthylsulfate) was determined in model systems composed of water and various ratios (3:1, 1:1, 1:3) of selected solvents (hexane, chloroform, ethyl acetate, diethyl ether, or methanol) held at either 22°C or 40°C for 30 min under various pH conditions (pH 1.5, 3.2, or 6.5). Notable hydrolysis occurred only for the more polar solvents held in contact with acidic aqueous phases. Conditions were identified for minimizing hydrolysis of conjugates during extraction of fat and free alkylphenols from milk and meat products with diethyl ether. They were pH near neutral, short exposure time, near ambient temperature, presence of excess water, and saturation of aqueous phase with sodium chloride.     

Drying ability of anhydrous sodium sulfate on wet organic solvents after liquid-liquid partition

Water concentration in organic solvents after liquid-liquid partition was determined by the Karl Fischer titration method. n-Hexane and petroleum ether showed quite low levels of water, such as 0.1 mg/mL. The water concentration in wet ethyl acetate was about 20-30 mg/mL and that in diethyl ether was about 8-10 mg/mL. Anhydrous sodium sulfate absorbed about 20-25% of the water after vigorous mixing with wet ethyl acetate or diethyl ether. Wet acetonitrile extract from wet food, which contained about 60 mg/mL water after salting out with sodium chloride, was not dried at all with anhyfrous sodium sulfate treatment. Spiking n-hexane into wet ethyl acetate or wet diethyl ether was effective to exclude water. Spiking toluene into salted acetonitrile drove out water and dissolved sodium chloride. It can be concluded that the drying ability of anhydrous sodium sulfate towards wet organic solvents is poor, but it is effective in removing suspended water in solvents.     

Gravimetric method for the determination of insoluble and soluble dietary fibres

The present paper describes a simple method for the determination of the insoluble and soluble dietary fibres in food. In a first step, starch and proteins are removed by enzyme treatment. The insoluble dietary fibres are determined gravimetrically after centrifugation and washing of the residue with water, ethanol, acetone and diethyl ether. The water-soluble dietary fibres are recovered from the supernatant liquid of the centrifugation by dialysis, freeze-drying, and subsequent weighing. The method has been used for the determination of dietary fibres in by-products from the industry.     

Solvent Extraction of Fatty Acids from Amylose Inclusion Complexes

The extractability of palmitic and other common fatty acids from inclusion complexes with potato amylose was studied using a wide range of common lipid solvents. At ambient temperature negligible yields were obtained with light petroleum or diethyl ether, and yields were low with most other solvents except those containing methanol or water. At 100°C, methanol, ethanol and propanol and all alcohol-water mixtures gave good yields. Complexes of amylose with 1-O-palmitoyllysophosphatidylcholine also gave good yields when extracted with propanol-water (3:1) at 100°C. Since more rigorous conditions are required for extraction of lipids from native cereal starch granules, it seems that the barrier to lipid extraction is the structure of the granule rather than the resistance to lipid extraction of any possible inclusion complexes in the granules.     

Solvent type affects the number, distribution, and relative quantities of volatile compounds found in sweet whey powder

This study compares the performance of diethyl ether, methylene chloride, methyl formate, and pentane in the analysis of volatile flavor components in sweet whey powder. Extracts were prepared from sweet whey powder using each solvent. Volatile components were isolated by solvent extraction followed by solvent-assisted flavor evaporation. Gas chromatography-mass spectroscopy, coelution with known standards, and retention indices were used to identify the volatile compounds. Sixty total compounds were either positively or tentatively identified across all 4 solvents, but the number, distribution between the molecular classes, and relative quantities detected depended on solvent type. The highest number, widest distribution, and greatest relative quantities were found using methylene chloride and methyl formate, whereas diethyl ether and especially pentane were noticeably less effective. Results are characterized using molecular-based characteristics of solvents and solutes including dipole moment, dielectric constant, Log P (octanol-water partition coefficient), polarizability, water solubility, and Lewis acidity/basicity. Polarity and acidity/basicity were the primary factors that determined solvent performance. This work establishes a molecular-level basis for the selection of solvents in the analysis of sweet whey powder flavors.     

Effects of organic solvents on transesterification of phospholipids using phospholipase A2 and lipase

The transesterification abilities of phospholipase A₂ and Mucor javanicus lipase in various organic solvents were studied. Phosphatidylcholine and caprylic acid (molar ratio, 1:6) were transesterified by incubation at 40°C in three organic solvents using phospholipase A₂ and M. javanicus lipase. The fatty acid composition of the reaction product was measured using gas chromatography. Caprylic acid was incorporated into the sn-1 and -2 positions at a rate of 87.7% using phospholipase A₂ in hexane, and 36.7% using M. javanicus lipase in diethyl ether. Higher acyl migration into sn-2 was observed in diethyl ether than in hexane during transesterification using M. javanicus lipase, however, there was no substantial difference in the caprylic acid content at the sn-2 position. Acyl migration during transesterification in methanol was lower than in other organic solvents. Non-polar hexane and diethyl ether were more effective for transesterification than methanol.     

Wundreaktionen im Holzgewebe bei Birke,Buche und Linde

Following injury from an increment borer, birch exhibits discoloration up to 50 cm above and below the wound. The discoloration in beech and basswood was very small with beech having less. The reaction of the wood following wounding, particulary the discolored wood and the marginal zone, were characterized and compared using light-and electonmicroscopy. The results are in agreement with the Modified CODIT-Modell, proposing that trees respond to wounding by creating a marginal zone which acts to counter first the inflow of air and later the advance of fungi into the wood.     

石油醚与乙醚测定含糖类样品中脂肪含量的准确率比较

目的为了提高脂肪提取的准确度,采用石油醚及乙醚对含糖类样品进行提取并比对。方法采用GB/T 5009.6-2003《食品中脂肪测定》第二法对其进行提取。结果结果显示,含糖类样品中脂肪测定时,用乙醚提取后测定的结果比用石油醚提取后测定的结果高。由于水解后的物质,更易溶解在极性相对较高的乙醚中,却不会较好地溶解在石油醚中,因而,乙醚提取脂肪含量偏高,准确度下降。结论实验表明,含糖类样品脂肪测定时,用石油醚测定脂肪的准确度高。     

GC-MS分析中药白及中脂肪酸成分

目的气相色谱-质谱联用(GC-MS)分析中药材白及中脂肪酸成分。方法采用石油醚索氏抽提法提取白及中脂肪油,经三氟化硼乙醚甲醇溶液甲酯化处理,用GC-MS测定脂肪酸组成。结果共分离出13个峰,确定了12种脂肪酸成分,主要为亚油酸(9,12-十八碳二烯酸),棕榈酸(十六烷酸),山嵛酸(二十二烷酸),木蜡酸(二十四烷酸),肉豆蔻酸(十四烷酸)等。结论此法操作简单、迅速、灵敏、准确度高,可满足白及药材中脂肪酸成分的分析需要。     

Use of iron oxides to influence the weathering characteristics of wood surfaces: a systematic survey of particle size,crystal shape and concentration

Iron oxide pigments may be an alternative treatment for limiting weathering of wood surfaces instead of stains or clear coatings. An earlier study suggested the ability of iron oxides to protect against discoloration varied with particle size. In this study, iron oxides with different crystal shapes and particle sizes were investigated along with a carbon black pigment. Loblolly pine (Pinus taeda L.) samples were impregnated with water borne iron oxide dispersions, exposed to predetermined amounts of solar radiation in the high desert of Eastern Oregon, and then evaluated for discoloration, checking and changes in chemical composition. The results from this observational study suggest that much higher levels of iron oxide are required than previously thought to prevent discoloration and limit lignin degradation. Large particle sizes led to greater opacity and provided greater protection, but no iron oxide protected as well as carbon black. The findings also suggested that iron oxides had no effect on checking, indicating that the mechanisms of discoloration and checking were not directly related.     

Phospholipase D of cereals (author's transl)]

Phospholipase D containing water insoluble fraction was isolated from mature barley; the enzym preparation only had weak phospholipase B activity. The phospholipase D of barley was activated by Ca2+, diethyl ether and sodium dodecyl sulphate (SDS); EDTA inhibited the enzyme to an extent of 10% of the original activity. Diethyl ether and SDS showed and additive effect. Phospholipase D activated by CaC12, diethyl ether and SDS exhibited a sharp optimum at pH 6.6. Lysophosphatidylcholine was hydrolysed much slower than phosphatidylcholine. Diethyl ether and SDS also increased the breakdown of the lysophosphatidylcholine.     

On the contamination of milk and milk products with chlorinated hydrocarbons. I. Methods]

A method of gaschromatographic determination of chlorinated insecticides in milk and butter in the presence of PCB's is described. The fatty components were extracted from milk after adding sodium oxalate and ethanol with diethyl ether and petrol ether. The clean up of the extracts was carried out according to a modification of the method of Hadorn and Zürcher with propylene carbonate as a selective solvent.     

气相色谱法测定膨化食品中氯丙醇类化合物

本文建立了检测膨化食品中3-氯-1,2-丙二醇和1,3-二氯-2-丙醇含量的方法。采用乙醚索氏提取、甲醇净化,再经N,O-双(三甲基硅烷)三氟乙酰胺(BSTFA)衍生,毛细管气相色谱法分离,FID作检测器。方法检出限为0.01mg/kg,回收率85%～5%。     

Solid State and Solution Properties of Octyl D-Glucopyranosides

The physical properties of the surfactants octyl α- and β-D-glucopyranoside show some remarkable differences. At 25°C, the β-anomer is much more soluble in water or diethyl ether than the α-anomer, but only a slight difference in solubility is observed in 1-octanol. The α-anomer, which shows a Krafft-point at ∼40°C, forms (above this temperature) micelles at half the concentration required for the β-anomer. Comparison of the transition to the liquid crystal by DSC indicates that the β-anomer will have a crystal packing which is much less ideal than the crystal packings observed for the α-anomer.     

槟榔提取物对小白鼠体内抗氧化作用的研究

以海南产槟榔鲜果为原料,制备槟榔提取物,研究槟榔提取物对小白鼠体内的抗氧化作用,通过体外实验筛选出来活性较好的提取物,将其作为受试物,以血清SOD及血清MDA水平为评价指标,进行小白鼠体内抗氧化作用研究。结果表明,槟榔粗提取物、乙酸乙酯萃取物和水溶出物三种组分对羟自由基(·OH)具有良好的清除作用,清除率均在53%以上。三种受试物的各个剂量均能显著提高小白鼠的血清SOD水平(p＜0.05);而除乙酸乙酯萃取物高剂量作用效果不显著外(p＞0.05),其他各受试物的各个剂量均能显著降低实验动物的血清MDA浓度(p＜0.05)。槟榔提取物在小白鼠体内具有良好的抗氧化活性作用。     

Antioxidant and antimicrobial activities of essential oil and various oleoresins of Elettaria cardamomum (seeds and pods)

BACKGROUND: This paper describes the chemical analysis of the essential oil and various oleoresins of Elettaria cardamomum (seeds and pods) by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) techniques. It also compares the effects of the different extraction solvents used (chloroform, methanol, ethanol and diethyl ether) on the antioxidant and antimicrobial activities of the essential oil and oleoresins. RESULTS: The essential oil was found to contain 71 compounds. The major components were α‐terpinyl acetate (44.3%), 1,8‐cineole (10.7%), α‐terpineol (9.8%) and linalool (8.6%). The chloroform and methanol oleoresins both contained α‐terpinyl acetate (21.8 and 25.9% respectively) as the main component, while 5‐hydroxymethylfurfural (28.9%) was the most abundant compound in the ethanol oleoresin. However, very few components (total 0.61%) were found in the diethyl ether oleoresin. The antioxidant activities of the essential oil and oleoresins, studied in mustard oil by monitoring the peroxide value of the oil substrate, were comparable to those of the synthetic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) at 0.02% concentration. The essential oil exhibited strong antibacterial activity against the micro‐organisms Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella typhi at 3000 ppm by the agar well diffusion method. Antifungal activity was tested against the food‐borne fungi Aspergillus terreus, Penicillium purpurogenum, Fusarium graminearum and Penicillium madriti. The methanol and ethanol oleoresins gave the best results against A. terreus at 3000 ppm by the poison food method. CONCLUSION: This study provides important information about the chemistry and antioxidant and antimicrobial properties of E. cardamomum. Copyright © 2007 Society of Chemical Industry     

一种测定红花籽粕中5-羟色胺衍生物总量的方法

建立了一种以5-羟色胺硫酸肌酐为标准样品快速简便地测定红花籽粕5-羟色胺衍生物总量的方法。测定过程包括无水乙醚去油、甲醇回流提取5-羟色胺衍生物,再经过乙酸乙酯萃取,得到乙酸乙酯萃取物。根据5-羟色胺硫酸肌酐和Ehrlich试剂的反应来测定5-羟色胺衍生物的总量。得出的回归方程为y=0.0085 0.2213x。应用该法测定了4个样品,平均回收率为99.6%。实验表明该反应的选择性、重现性和对照性均好,操作方便,适用于5-羟色胺衍生物提取过程中的常规检测。     

Methods to purify and determine rubratoxins

Rubratoxin were recovered from cultures of Penicillium rubrum after the mold grew in natural substrates, a semi-synthetic medium, and a glucosemineral salts broth. Substrates that contained rubratoxins were extracted with: diethyl ether, ethyl acetate-benzene, ethanol (100%), ethanol-acetone, acetonitrile, or diethyl ether with refluxing at 45 degrees C. Extracts were screened for rubratoxins by thin-layer chromatography. Some extracts were partially purified with a column of silicic acid using acetone as the eluant. Other extracts were purified (primarily removal of pigments) using columns of silica gel plus Celite and gradient solvent elution. Most rubratoxin B (1.9 mg/g or 0.77 mg/ml) was recovered when corn, rice, or glucose-salts broth were extracted successively with diethyl ether, ethyl acetate-benzene, and diethyl ether or when samples were adjusted to pH 1.5 before refluxing with diethyl ether at 45 degrees C for 1--4h. Most rubratoxin A (0.1--0.15 mg/ml or 1.0 mg/g) was obtained from samples of corn extracted twice each with ethyl alcohol, acetone, and ethyl acetate; from glucose-mineral salts broth extracted with diethyl ether; or from yeast extract sucrose broth extracted with diethyl ether and refluxed for 4 h at 45 degrees C. Large amounts of fairly pure rubratoxin A (up to 400 mg) and rubratoxin B (greater than lg) were obtained with a combination of preparative thin-layer and column chromatography.     

Production of Blue-Fluorescent Pyrazines by A. parasiticus

Aspergillus parasiticus NRRL 2999 did not produce aflatoxins on peptone-mineral salts medium, but did accumulate blue-fluorescent material having R_f's on thin-layer chromatographic plates similar to aflatoxins B₁ and B₂. The blue-fluorescent material was ultimately resolved into nine compounds. The four major compounds were tentatively identified by mass spectrometry as deoxyaspergillic acid, flavocol, deoxydehydroxymutaaspergillic acid, and 2-hydroxy-3,6-di-sec-butylpyrazine, blue-fluorescent pyrazines that have previously been isolated from other aspergilli. Evaluation of AOAC- recommended solvent systems for aflatoxin analyses indicated that diethyl ether/methanol/water (98:1:1) was the best TLC solvent system for separating aflatoxins from interferring fluorescent material. Pyrazine production was inversely related to carbohydrate content of the medium. Care should be taken in evaluating aflatoxin analyses of material with high protein and low carbohydrate levels.