Simple validated method for simultaneous determination of deoxynivalenol,nivalenol, and their 3-β-D-glucosides in baby formula and Korean rice wine via HPLC-UV with immunoaffinity cleanup

A simple and reliable method for the simultaneous determination of major type B trichothecene mycotoxins, deoxynivalenol (DON) and nivalenol (NIV), along with their 3-β-d-glucosides (DON-3-glucoside (DON3G) and NIV-3-glucoside (NIV3G)) in baby formula and Korean rice wine was validated in the present study. The method was based on immunoaffinity cleanup followed by analysis using an HPLC-UV technique. The method was validated in-house for two matrices as follows: linearity (R² > 0.99) was established in the range of 20–1000 μg kg^–1; accuracy (expressed as recovery) ranged from 78.7 to 106.5% for all the analytes; good intermediate precision (relative standard deviation < 12%), and adequate detection and quantitation limits (< 4.4 and < 13.3 μg kg^–1, respectively) were achieved. Furthermore, the estimated measurement expanded uncertainty was determined to be 4–24%. The validated method was successfully applied to the analysis of 31 baby formulas and Korean rice wines marketed in Korea.     

Underlying reasons for waxy rice flours having different pasting properties

The underlying reasons for three waxy rice varieties, Yang-fu-nuo (Y), Su-yu-nuo (S), and Guang-ling-xiang-nuo (G), having different flour pasting properties were examined. The pasting properties of the isolated waxy rice starches did not correlate with those of the corresponding waxy rice flours. Examining the pasting properties of the flours in 0.5 mM AgNO₃ solution, treated with dithiothreitol and protease, suggested that rice protein and amylase activity were the main causes of the pasting property differences among the rice starches and flours. Starch isolated from Y flour had a larger proportion of A and B₁ chains, longer average chain length and longer exterior chain length, which explained its higher gelatinisation temperature, higher pasting consistency, greater extent of retrogradation, and the firm texture of cooked Y rice.     

Simultaneous determination of nine lignans using pressurized liquid extraction and HPLC-DAD in the fruits of Schisandra chinensis

The pressurized liquid extraction and HPLC-DAD was developed for extraction and determination of bioactive lignans in Schisandra chinensis. The efficient PLE conditions employed methanol as extraction solvent, 125 °C of extraction temperature, 5 min of static extraction time and only one cycle. A rapid HPLC-DAD method was described for simultaneous determination of nine lignans, including schisandrol A, gomisin J, schisandrol B, tigloylgomisin H, angeloylgomisin H, schisandrin A, γ-schisandrin, gomisin N and schisandrin C. The extraction efficiency of PLE was observed to be comparable with reflux and sonication. In addition, the contents of nine lignans in S. chinensis from different regions were analysed by PLE and HPLC-DAD method.     

辣椒籽油的提取及组成的研究

本文研究了辣椒籽油的提取方法,采用三因素三水平正交试验方案,考察了料液比、温度、时间对辣椒籽油及辣椒素提取的影响。同时,采用气相色谱面积归一化法测得辣椒籽油主要由棕榈酸、硬脂酸、油酸、亚油酸和亚麻酸组成。     

Mechanisms of arsenate adsorption by highly-ordered nano-structured silicate media impregnated with metal oxides

The highly ordered mesoporous silica media, SBA-15, was synthesized and incorporated with iron, aluminum, and zinc oxides using an incipientwetness impregnation technique. Adsorption capacities and kinetics of metal-impregnated SBA-15 were compared with activated alumina which is widely used for arsenic removal. Media impregnated with 10% of aluminum by weight (designated to Al10SBA-15) had 1.9-2.7 times greater arsenate adsorption capacities in a wide range of initial arsenate concentrations and a 15 times greater initial sorption rate at pH 7.2 than activated alumina. By employing one- and two-site models, surface complexation modeling was conducted to investigate the relationship between the aluminum oxidation states in different media and adsorption behaviors shown by adsorption isotherms and kinetics since the oxidation phase of aluminum incorporated onto the surface of SBA-15 was Al-O, which has a lower oxidation state than activated alumina (Al2O3). Surface complexation modeling results for arsenate adsorption edges conducted with different pH indicated thatthe monodentate complex (SAsO(4)2-) was dominant in Al10SBA-15, while bidentate complexes (XHAsO4 and XAsO4-) were dominant in activated alumina at pH 7.2, respectively. In kinetic studies at pH 7.2 + 0.02, Al10SBA-15 had only a fast-rate step of initial adsorption, while activated alumina had fast- and slow-rate steps of arsenate adsorption. Therefore, it can be inferred that the monodentate arsenate complex, predominant in Al10SBA-15, leads to faster adsorption rates than bidentate arsenate complexes favored with activated alumina. An arsenate adsorption behavior and arsenate surface complexation were thought to be well explained by aluminum oxidation states and surface structural properties of media.     

Comparison of four molecular typing methods for the differentiation of Salmonella spp

A total of 57 strains of Salmonella spp. were differentiated by random amplification of polymorphic DNA (RAPD) fingerprinting using three different primers (OPL-03, primer 1, and primer A); by Enterobacterial Repetitive Intergenic Consensus (ERIC) fingerprinting; by ribotyping-PCR; and by Single Strand Conformation Polymorphism (SSCP). From the 57 strains, RAPD fingerprinting with primers OPL-03, 1, and A produced 42, 51, and 54 fingerprint patterns respectively. ERIC fingerprinting produced 50 patterns; ribotyping-PCR produced four patterns, and SSCP produced 11 patterns. Combinations of two different typing methods generally increased the discrimination of Salmonella strains. A combination of two different RAPDs or a combination of RAPD and ERIC was better than the other combinations. Discrimination using a combination of RAPD (primer 1 or primer A) and ERIC, which could differentiate all 57 Salmonella strains, was better than the combination of two RAPDs. This study indicated that the use of a combination of RAPD (primer 1 or primer A) and ERIC should be useful for the differentiation of field-isolated Salmonella strains and epidemiological studies.     

Anthocyanin changes in the Korean purple-fleshed sweet potato,Shinzami, as affected by steaming and baking

As hydrophilic pigments, anthocyanins reduce the incidence of cancer and cardiovascular diseases. In this study, the anthocyanin content and composition following steaming and baking of the roots of the Korean purple-fleshed sweet potato variety “Shinzami” were evaluated using liquid chromatography with diode array detection and electrospray ionisation/mass spectrometry (LC-DAD-ESI/MS). Anthocyanins of Shinzami were composed of mono- or di-acylated forms of p-hydroxybenzoic acid, caffeic acid and ferulic acid with the basic structure of cyanidin 3-sophoroside-5-glucoside or peonidin 3-sophoroside-5-glucoside. A total of 15 individual anthocyanins were isolated and confirmed, one of which was presumed to be a newly identified compound, peonidin 3-feruloyl-p-hydroxybenzoyl sophoroside-5-glucoside. Additionally, the amounts of di-acylated cyanidin 3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside and peonidin 3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside were the highest (137.0 and 565.9 mg/100 g DW, respectively) among cyanidin and peonidin compounds. After steaming, the total anthocyanin content was reduced by nearly a half, while roasting only slightly reduced the total anthocyanin content.     

Chemical composition and inhibitory parameters of essential oil and extracts of Nandina domestica Thunb. to control food-borne pathogenic and spoilage bacteria

The aim of this study was to examine the chemical composition of the essential oil isolated from the floral parts of Nandina domestica Thunb. by hydrodistillation, and to test the efficacy of essential oil and various organic extracts against a panel of food-borne pathogenic and spoilage bacteria such as Bacillus subtilis ATCC6633, Listeria monocytogenes ATCC19166, Staphylococcus aureus KCTC1916, S. aureus ATCC6538, Pseudomonas aeruginosa KCTC2004, Salmonella typhimurium KCTC2515, Salmonella enteridis KCCM12021, Escherichia coli 0157-Human, E. coli ATCC8739, E. coli 057:H7 ATCC43888 and Enterobacter aerognes KCTC2190. The chemical composition of essential oil was analysed by GC-MS. It was determined that 79 compounds, which represented 87.06% of total oil, were present in the oil. The oil contained mainly 1-indolizino carbazole (19.65%), 2-pentanone (16.4%), mono phenol (12.1%), aziridine (9.01%), methylcarbinol (4.6%), ethanone (3.3%), furfural (2.96%), 3,5-dimethylpyrazole (1.29%) and 2(5H)-furanone (1.32%). The oil (1000 ppm/disc), and various organic extracts of hexane, chloroform, ethyl acetate and methanol (1500 ppm/disc) exhibited promising antibacterial effect as a diameter of zones of inhibition (9-18 and 7-13 mm) and MIC values (62.5 to 1000 and 250 to 2000 microg/ml), respectively against the tested bacteria. Also the oil had strong detrimental effect on the viable count of the tested bacteria. These results indicate the potential efficacy of plant-based natural products such as essential oil and organic extracts of N. domestica to control food-borne pathogenic and spoilage bacteria.     

Isolation and identification of an antiproliferative substance from fructose–tyrosine Maillard reaction products

We isolated a substance from fructose–tyrosine Maillard reaction products (MRPs) and investigated its antiproliferative effect on six human cancer cell lines. The ethyl acetate fraction of fructose–tyrosine MRPs showed a strong antiproliferative effect; this fraction was isolated and purified using silica gel column chromatography, semipreparative RP-HPLC, and recycling HPLC. The structure of the purified compound was determined using spectroscopic methods. The isolated compound was identified as 2,4-bis(p-hydroxyphenyl)-2-butenal (C₁₆H₁₄O₃, HPB242). HPB242 inhibited cell growth in a dose-dependent manner (10–80 μg/ml) on the six human cancer cell lines. The IC₅₀ values of HPB242 on the six human cancer cell lines were 17.34 μg/ml (MCF-7), 29.21 μg/ml (HCT-116), 34.57 μg/ml (H-460), 34.87 μg/ml (HepG2), 48.77 μg/ml (PC-3), and 55.83 μg/ml (MKN-45).