Growth, fatty acid profile in major lipid classes and lipid fluidity of Aurantiochytrium mangrovei Sk-02 as a function of growth temperature

Aurantiochytrium mangrovei Sk-02 was grown in a medium containing glucose (40 g/l), yeast extract (10 g/L) and sea salts (15 g/L) at temperatures ranging from 12 to 35°C. The fastest growth (µmax= 0.15 h-1) and highest fatty acid content of 415 mg/g-dry cell weight were found in the cells grown at 30°C. However, the cells grown at 12°C showed the highest percentage of polyunsaturated fatty acid (PUFA) (48.6% of total fatty acid). The percentage of docosahexaenoic acid (DHA) and pentadecanoic acid (C15:0) decreased with an increase in the growth temperature, whereas, palmitic acid (C16:0), stearic acid (C18:0) and DPA (C22:5n6) increased with an increase in the growth temperature. The composition of the major lipid class (%w/w) was slightly affected by the growth temperature. The fluidity of the organelle membrane or intracellular lipid (by DPH measurement) decreased with an increase in the growth temperatures, while the plasma membrane fluidity (by TMA-DPH measurement) could still maintain its fluidity in a wide range of temperatures (15 - 37°C). Furthermore, the distribution of DHA was found to be higher (36 - 54%) in phospholipid (PL) as compared to neutral lipid (NL) (20 - 41%).

Quantitative analysis of limonin in grapefruit juice using an enzyme-linked immunoassay: interlaboratory study.

Eleven laboratories participated in an interlaboratory study of an enzyme-linked immunoassay for limonin in grapefruit juice. Participating laboratories received training and practice samples until familiar with the procedure. Laboratories then received 8 sample pairs of grapefruit juice as blind duplicates. Samples were refrigerated and analyzed within 4 days of receipt. Results from 1 laboratory and 6 individual samples were excluded from the statistical analysis. Method performance was measured by the one-way component of variance analysis. Repeatability relative standard deviations (RSDr) ranged from 7.0 to 15.6%. Reproducibility relative standard deviations (RSDR) ranged from 12.9 to 29.4%.

Olfactory bulb transection alters fetal behavior after chemosensory but not tactile stimulation.

Rat fetuses respond to an intraoral infusion of lemon extract with an increase in overall activity and facial-wiping behavior. Other studies have suggested a role for olfaction in mediating fetal responses to chemosensory stimuli. In the present study, a micro-knife was used to surgically isolate the main and accessory olfactory bulbs from more caudal structures in the fetal brain. Fetuses that received this transection procedure or a sham treatment showed normal levels of non-evoked motor activity during the period prior to chemosensory infusion. Surgical isolation of the olfactory bulbs had no effect on fetal response to perioral tactile stimulation. Behavioral responses to infusion were diminished but not eliminated in fetuses with olfactory bulb transections. The olfactory bulb, which is functional in spite of its anatomical immaturity, plays a role in the control of fetal behavior.

Determination of biphenyl residues in citrus fruit by derivative infrared spectrophotometry.

A method for determination of biphenyl residues in whole citrus fruit is described. The mascerated fruit was distilled in an acid medium, the distillate was extracted with cyclohexane, and biphenyl was determined in the extract using various measures obtained by first and second derivative infrared (IR) spectrophotometry. Calculations were performed by PE680 and SNGLE programs on data obtained using a Perkin-Elmer Model 3600 data station. The relative precision of the determinations at 70 ppm was 1.8 to 2.0%; the detection limit was 5 ppm in all measurements, and recovery of spiking concentrations of 20 to 80 ppm ranged from 90.2 +/- 5.5% (for the amplitude of the 739 cm-1 peak of the first derivative) to 97.5 +/- 2.0% (for the trough-to-peak difference from the 737 cm-1 minimum to the 743 cm-1 maximum of the second derivative.

[Effect of disintegrating method on quantity extracted and constituents of essential oil in fructus Aurantii].

The quantity extracted, constituents and their contents in essential oil from Fructus Aurantii were obviously influenced by the method of disintegration. Among stamp breaking in water, crusher-run and miling, stamp breaking in water is the best method. The advantage of this method lies in higher percentage recovery of the oil and smaller loss in volatilization.

Aldicarb residues in citrus soil, leaves and fruits.

Aldicarb was applied to the soil of Late Valencia orange field plots. A comparative study between four analytical methods is reported, the NPD-gas chromatography method being the best choice. The work also reports the study of accumulation and persistence of aldicarb and its biologically active metabolites in the soil, leaves and fruits (rind and pulp, separately). Residue content, at the ppb level, was found in the order leaves much greater than rind greater than pulp. Carbamate was found to accumulate mainly in its oxidized forms. Residues had reached a maximum level in about 90 days after application.

[Studies on the preparation and evaluation of Kijitsu, the immature citrus fruits. III. Relation between diameter of Kijitsu and synephrine content].

For the purpose of evaluating Kijitsu, the content of synephrine in dried unripe citrus fruits was analyzed by high performance liquid chromatography after cleaning up the MeOH extract with an ion exchange cellulose column. Among them, Citrus unshiu had the highest amount of synephrine. No difference was found between C. hassaku and C. aurantium. The synephrine content decreased corresponding with an increase in diameter of Kijitsu.

Induction of anti-orange antibodies in rabbits.

The capacity of certain foods to cause allergic reactions is well known. The four types of mechanisms that Gell and Coombs described in 1968, are involved in these reactions, although the reaginic antibodies retain the paramount attention of the immunologists. The physiochemical composition of the allergen molecule is the goal of investigators with the purpose to clarify the intrinsic kinetics of antibody synthesis. This paper contributes to the conflicting data about orange allergens especially those obtained from Citrus Aurantium Sinensis and Citrus Silension (CAS and CS, respectively). Glycoproteins were separated by gel filtration through a Sephadex G-50 column. A definite protein peak was obtained meanwhile several hexoses appeared throughout the fractionation procedure. These molecules have adequate physiochemical properties that make them able to trigger the immunological response (molecular weight, definite chemical composition and glycoprotein content). Although CAS and CS have a similar chemical composition a slight inverse proportion of proteins and hexoses was demonstrated between the two classes. Molecular weights were different for CAS (51.500) and for CS (37.000) in comparison with well established protein makers. Ouchterlony revealed two precipitin lines in the CAS-anti-CAS system but none in the CS-anti-CS one. The Boyden technique showed a titre of 1/256 in the first case and only of 1/64 in the second of specific anti-orange antibodies. All the eluted fractions gave negative results although they were concentrated ten times by pre-evaporation. This animal model reinforced the statement that after a long and continuous exposure to orange antigens it was possible to develop specific antibodies. It is assumed that this phenomenon happens in atopic children with it's diagnostic and therapeutic importance.

[Pharmacognostic studies on the peel of Citrus reticulata Blanco cv. zhangshuensis and Citrus reticulata Blanco Var. kinokuni (Tanaka) H. H. Hu produced in Jiangxi].

Pharmacognostical studies on the peel of Citrus reticulata cv. zhangshuensis and Citrus reticulata var. kinokuni have been carried out in comparison with four crude drugs of Chenpi. Information on the research of resources of these two drugs is provided.

[A study on the quality of fruits of Citrus aurantium L. (zhishi and Zhiqiao) produced in Jiangxi].

Through a study on the quality of different commercial fruits of Citrus aurantium (Zhishi and Zhiqiao) produced in Jiangxi, it has been found that the quality of Eyan Zhishi is good and Jiang Zhishi and Jiang Zhiqiao are the best varieties.

[Studies on the preparation and evaluation of Kijitsu, the immature citrus fruits. II. Analysis of factors which affect the flavonoid contents].

Factors which affect the content of flavonoids in Kijitsu were studied. Flavonoids in immature citrus fruit decomposed gradually by standing after divided horizontally in two parts. About 90% of flavonoids were retained by use of hot air drying of fresh samples. The content of flavonoids in Kijitsu decreased to about 60% by standing one year. Flavonoid contents decreased corresponding with an increase in diameter of Kijitsu. There is no wide difference between Hassaku and other Citrus fruits in their essential oils determined by gas chromatography-mass spectrometry. It was concluded that C. hassaku might be used for the material for Kijitsu.

[Studies on quantitative determination of total flavonoid in qingpi, zhiqiao and zhishi by TLC-densitometric methods].

A method for the determination of total flavonoid contents in Pericarpium Citri Reticulatae Viride (Qingpi), Fructus Aurantii (Zhiqiao) and Fructus Aurantii Immaturus (Zhishi) was established by the use of TLC-densitometry. The results show that the total flavonoid contents in Qingpi and Zhishi are higher than in Zhiqiao. The content in Zhiqiao is 9.81%-15.85%.

Determination of limonin in grapefruit juice and other citrus juices by high-performance liquid chromatography.

A method has been developed for the quantitation of the bitter component limonin in grapefruit juice and other citrus juices. The sample clean-up consisted of centrifugation, filtration and a selective, rapid and reproducible purification with a C2 solid-phase extraction column. The limonin concentration was determined by high-performance liquid chromatography on a C18 column with UV detection at 210 nm. A linear response was obtained from 0.0 to 45 ppm limonin. The minimum detectable amount was 2 ng. The minimum concentration which was detected without concentration with good precision was 0.1 ppm. The method was also used for the determination of limonin in different types of oranges, including navel oranges, mandarins, lemons, limes, pomelos and uglis.

[Quantitative analysis of methoxylated flavonoids in iyo (Citrus iyo) peels by high-performance liquid chromatography].

The quantitative analysis of eight kinds of methoxylated flavonoids in Citrus iyo Hort. ex Tanaka (Rutaceae) was examined by high-performance liquid chromatography. These compounds could be determined within 50 min on C-18 reversed-phase column. Elution system was carried out with a mixture of 1,4-dioxane-water-acetic acid in ratios of 2:7:1 and 7:2:1 in the form of a gradient from 8:2 to 2:8 for 60 min.

Salmonella e escherichia coli em sucos de frutas e outros substratos ácidos: uma revisäo sobre injúria bacteriana / Salmonella and escherichia coli in fruit juices and other acid substrates: a review on bacterial injury

Apesar do efeito limitante do pH de sucos de frutas e outros substratos ácidos, constatou-se a presença de Salmonella e Escherichia coli nesse tipo de alimento, com envolvimento da primeira em surtos toxinfecciosos. Os microorganismos injuriados pelas condiçöes ácidas, ou por outras, de caráter adversas, apresentam lesöes a nível celular que os diferenciam das células normais. Nesta revisäo, o fenômeno da injúria será conceituado e caracterizado. Metodologias adequadas de reparo, evolvendo condiçöes especiais de cultivo e maiores requerimentos nutricionais seräo mostrados, evidenciando-se os reflexos práticos da injúria celular na microbiologia de alimentos e possível comprometimento da saúde pública.

Simultaneous determination of the nine food additives using high-performance liquid chromatography.

A technique for the simultaneous determination of sorbic acid, benzoic acid, dehydroacetic acid, p-hydroxybenzoic acid esters (ethyl, isopropyl, n-propyl, isobutyl and n-butyl p-hydroxybenzoate) and saccharin sodium using ion-pair reversed-phase high-performance liquid chromatography is described. The nine food additives were separated on a Nucleosil 3C18 (3 microns) column (75 x 4.6 mm I.D.) using methanol-acetonitrile-0.05 M aqueous acetonic acid solution (pH 4.5) (1.5:1:3.1) containing 2.5 mM cetyltrimethylammonium chloride as the mobile phase at a flow-rate of 1.0 ml/min, and detected at 233 nm. The food additives were separated within 18 min and their calibration graphs were linear between 2 and 200 ng.

Determination of arsenic and selenium in environmental and agricultural samples by hydride generation atomic absorption spectrometry.

Agricultural and environmental samples are digested with acid, and arsenic and selenium are determined using hydride generation atomic absorption spectrometry. Interelement interferences are eliminated by high acid concentrations or cation-exchange resins. Agreement with standard reference material is excellent. The technique is also applied to actual samples.

C18 solid-phase isolation and high-performance liquid chromatography/ultraviolet diode array determination of fully methoxylated flavones in citrus juices.

A new analytical methodology for the determination of fully methoxylated flavones (FMFs) in citrus juices is described. Isolation of the FMFs is carried out by percolation of 30 mL of clarified citrus juice (to which tetramethyl-o-kaempferol is previously added as internal standard) through a C18 Sep-Pak cartridge, washing with 3 mL of water followed by 5 mL of water/acetonitrile (3:1), and selective elution of the retained FMFs with 5 mL of water/acetonitrile (9:11). Determination of the isolated FMFs is carried out by reversed-phase high-performance liquid chromatography (HPLC) and UV diode array detection (DAD). Signals at wavelengths 320, 335, and 345 nm (bandwidth 4 nm) are simultaneously acquired, stored, plotted, and integrated. The column used is a microbore (200 x 2.1-mm) Hypersil ODS 5 microns. Elution is in gradient mode, using a ternary mobile phase (water/acetonitrile/tetrahydrofuran). Column temperature is 40 degrees C. Recovery yields are nearly 100% for all the FMFs detected and identified: isosinensetin, hexamethyl-o-gossypetin, sinensetin, tetramethyl-o-isoscutellarein, hexamethyl-o-quercetagetin, nobiletin, tetramethyl-o-scutellarein, heptamethoxyflavone, and tangeretin. Chromatographic separation of the FMFs is extremely dependent upon the minor changes of the mobile phase composition and percentages, gradient rate, and temperature. The UV spectra (230 to 400 nm) of the FMFs obtained under chromatographic conditions are given. The FMFs relative response factors at 320, 335, and 345 nm and their concentrations in hand-squeezed and commercial concentrated orange and mandarin juices are tabulated. The FMF concentration differences found among samples are discussed.

Quantitative determination of limonin in citrus juices by HPLC using computerized solvent optimization.

The commercially available computer program, Drylab, for optimization of separations by high-performance liquid chromatography (HPLC) using binary solvent mixtures is used to improve an HPLC method for separation of the bitter principle, limonin, in grapefruit and navel orange juices. Best conditions for separation of limonin in a reasonable time are 30 to 32% acetonitrile in water at 0.9 mL/min using a 5-micron C18 column 10 cm long. These conditions are used to analyze grapefruit and navel orange juice samples, and these HPLC results are compared with values determined by enzyme immunoassay or thin-layer chromatography (TLC) on the same samples.