An analytical method using GC/MS was developed for bisphenol A (BPA) in foods and BPA was determined in canned foods and fresh foods such as vegetables, fruit and meat. BPA was extracted with acetone from the samples and the extract was concentrated at under 40°C in vacuo to afford an aqueous solution, which was washed with hexane after alkalization and extracted with 50% diethyl ether-hexane after acidification. Extracts were cleaned up on a PSA and/or a C₁₈ cartridge column, and BPA was derivatized with heptafluorobutyric anhydride and determined by GC/MS (SIM). This method was applicable to the detection and determination of BPA residues in food samples at the level of 1 ng/g. Among canned foods, BPA was found in 6 corned beef, 1 chicken, 9 sweet corn and 3 bean samples at the levels of 17∼602 ng/g, 212 ng/g, 2.3∼75 ng/g and 3.5∼26 ng/g, respectively. BPA was also detected in 1 retort soup and 1 retort pack product at the levels of 11 ng/g and 86 ng/g, respectively. As for dairy products, BPA was not detected in butter and milk. Among fresh foods, BPA was detected in 2 fish and 3 liver samples at the levels of trace (tr)∼6.2 ng/g and tr∼2.2 ng/g, respectively. In vegetables, fruits and chocolates, a trace level of BPA was detected in only 1 chocolate. Traces of BPA were also detected in 3 samples of 6 boxed lunches.

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A simple and rapid method using capillary zone electrophoresis (CZE) for the determination of milt protein (MP), which contains mainly protamine, and polylysine (PL) in food additive preparations and processed foods was developed. CZE separation was performed on poly(vinyl alcohol)-coated capillaries at a column temperature of 20°C with 120 mmol/L phosphate buffer (pH 2.5) as the running buffer.
The influence of various components in food additive preparations on CZE analysis of MP and PL was examined. Egg white lysozyme, glycine, sodium acetate, glycerol, fumaric acid, calcium carbonate, dextrin, emulsifiers and sodium polyphosphate and pyrophosphate had no effect. No peak of protamine was detected in preparations containing metaphosphate.
The analysis method for processed foods was composed of extraction with 4% formic acid, precipitation of macromolecular compounds with ethanol, concentration in a water bath and determination by CZE. The average recoveries were 108.4% for protamine sulfate (PS) in red bean sticky rice, and 81.3% for PL in white rice, 118% in egg sandwiches, and 115% in shiraae. The limits of detection of PS in red bean sticky rice and PL in white rice were both 50 ppm.

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Buddleja yellow colorant derived from Buddleja officinalis Maxim. has recently been approved for use as a new kind of natural colorant for food additives in China. In order to distinguish Buddleja yellow colorant from other yellow colorants, two known phenylpropanoid glycosides, acteoside (=verbascoside) and poliumoside, were isolated from the colorant as marker substances for Buddleja yellow colorant. Poliumoside has not been detected in B. officinalis Maxim. previously. These phenylpropanoid glycosides were not detected in the fruits of Gardenia jasminoides Ellis or in the stamens of the flowers of Crocus sativus L., which also contain crocetin derivatives as coloring components, using a photodiode array and mass chromatograms. Thus, an analytical HPLC method was developed to distinguish foods that have been colored with yellow colorants containing crocetin derivatives, using phenylpropanoid glycosides as markers.

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A method for qualitative and quantitative analyses of polysorbates in powdered soup by HPLC was studied. Polysorbates in samples were extracted with acetonitrile after rinsing with n-hexane to remove fats and oils. The extract was cleaned up using a Bond Elut silica gel cartridge (500 mg). The cartridge was washed with ethyl acetate and polysorbates were eluted with a small amount of acetonitrile-methanol (1 : 2) mixture. The eluate was treated with cobalt thiocyanate solution to form a blue complex with polysorbate. In order to determine polysorbate, the complex was subjected to HPLC with a GPC column, using a mixture of acetonitrile-water (95 : 5) as a mobile phase, with a detection wavelength of 620 nm.
The recoveries of polysorbate 80 added to powdered soups were more than 75% and the determination limit was 0.04 mg/g.
When the proposed method was applied to the determination of polysorbates in 16 commercial samples of powdered soup for instant noodles and seasoning consomme, no polysorbates were detected in any sample.

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Fukuronori extract (FE), which is mainly composed of polysaccharides, and is an extract of the seaweed Gloiopeltis furcata, is permitted for use as a food thickening agent by the Ministry of Health and Welfare, Japan. In order to study the subchronic toxicity of FE, F344 rats of both genders were administered FE at concentrations of 0% (basal diet, control group), 0.5%, 1.5% and 5.0% in basal powder diet for 90 days, and observation of general condition, recording of body weight and food consumption, examination of hematology and blood chemistry, measurement of organ weight, and pathological examination were performed. Food consumption tended to increase in both sexes given FE at 1.5% and 5.0% throughout most of the experimental period. This was, however, considered not to be a toxic effect because the differences in body weight were small. Total cholesterol and triglycerides in serum decreased significantly (p<0.05) and not significantly, respectively, in males of the 5.0% group. These changes were considered to be related to the intake of FE, but the differences were slight and within physiological ranges. Hematological and pathological examination revealed neither any particular adverse effect nor any significant difference from the control. Hence, dietary intake of 5.0% of FE, 3,362 mg/kg/day for males and 3,594 mg/kg/day for females as mean daily intake, for 90 days was considered to be a no observable adverse effect level in rats.

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When performing multiresidue analysis of pesticides, the recovery of thiometon was less than 20% from carrots and eggplants, but about 100% from garlic chives and welsh onions. The recovery of thiometon was found to depend on the lot of ethyl acetate. A 2-year-old lot of ethyl acetate caused degradation of thiometon, but a fresh lot of ethyl acetate did not. Analysis showed that ethyl acetate stored for 2 years contained about 5 μL/mL of acetaldehyde. Thiometon was also degraded by acetone or acetonitrile, when acetaldehyde was added to them, in the same manner as by aged ethyl acetate.
The fact that the recovery of thiometon from welsh onions was about 100% indicated that some of the mercaptans in allium vegetables may prevent thiometon degradation. Mercaptans such as L-cysteine and 3-mercaptoproionic acid were confirmed to prevent the degradation of thiometon and disulfoton.
These findings show that mercaptans may be useful additives for analyzing thiometon and disulfoton.

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The contents of the main pigments and other ingredients in commercial lac color products were determined by HPLC using an RP-18 column with 0.1 mol/L citric acid buffer solution-methanol (16 : 5) as the mobile phase, and a photodiode array (PDA) detector set at 280 nm and 490 nm. The main pigments were confirmed by PDA and electrospray ionization mass spectrometry. Laccaic acids A, B, C and E were detected in all lac color products, and the ratio of content of laccaic acid A in all products was over 50%. The total contents of laccaic acids A, B and C in lac color food additive products and reagent products were 775∼858, 797 and 779 g/kg, respectively. As for the contents of ingredients except pigments in commercial food additive products, the maximum moisture content was about 10%, and ether-soluble substances amounted to 0.5∼3.6%.

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Modification of HPLC conditions for the determinations of raw materials, intermediates and subsidiary colors (organic impurities) in 5 kinds of food azo colors were studied in order to analyze them simply and rapidly. The organic impurities were determined by HPLC using L-column ODS and a gradient system (0.02 mol/L ammonium acetate solution for 10 min, and a gradient with a mixture of acetonitrile and water (7 : 3)). The organic impurities in 163 samples of azo colors subjected to inspection in fiscal year 1999 were determined under the proposed HPLC conditions. It was found that the contents of organic impurities in 163 samples were less than the limit of Japan's Specifications and Standards for Food Additives, 7th Edition.

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Daily intake of isoflavones (daidzin, glycitin, genistin, daidzein, glycitein, and genistein) was determined quantitatively, based on the market basket method. Acid hydrolysis during extraction of foods was chosen to convert phytoestrogenes into the respective aglycons, facilitating HPLC analysis and allowing quantitation of total isoflavones as aglycones including both originally present glycosides and “free” aglycones. The isoflavones were extracted from samples with methanol and determined by reversed-phase HPLC analysis using a linear gradient of methanol-water as the eluent. From the results of hydrolysis, the daily intake of total isoflavon was 38.1 mg/adult Japanese.
The values obtained by the market basket method and the National Nutrition Survey method were similar.

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Ten samples of retail packed lunches purchased from convenience stores were determined for 11 phthalates and di(2-ethylhexyl) adipate (DEHA) in August 2000, 2 months after the prohibition of DEHP-containing PVC gloves in Japan. Each homogenized sample was extracted with acetonitrile, partitioned with n-hexane, and cleaned up using Florisil^® and PSA^® columns. Phthalates in the extract were determined by GC/MS (SIM). The limits of detection were 14.9 ng/g for di(2-ethylhexyl) phthalate (DEHP) and 18.6 ng/g for dibutyl phthalate (DBP). Levels of phthalates in packed lunch samples were 45 to 517 ng DEHP/g (198 ng/g, average), ND to 90 ng DEHA/g, and ND to 10.0 ng BBP/g. Diisononyl phthalate (DINP) was detected in one sample at 76 ng/g. Average DEHP level in ten samples was 4% of that in 1999. The contents of other phthalates were also reduced. DBP was not detected in any sample. Recovery of deuterated isomers added as surrogates was 27.9% for DNP-d₄, and 40.6 to 101.5% for the other phthalates.

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Simple and rapid methods for the determination of sucralose in foods were developed using anion-exchange chromatography (AEC) with pulsed amperometric detection and reverse-phase HPLC with refractive index detection. Sucralose was extracted with water or methanol, and the extracted solution was cleaned up on a Sep-Pak C₁₈ cartridge and a Sep-Pak Alumina N cartridge. The AEC separation was performed on a CarboPac PA1 column (4.0 mm i.d×250 mm) using 100 mmol/L sodium hydroxide-50 mmol/L sodium acetate solution as the mobile phase at a flow rate of 1.0 mL/min. The recoveries of sucralose from foods were 80.6∼102.0%, and quantitation limits from foods except chewing gum were 0.5 μg/g (2 μg/g from chewing gum). The reverse-phase HPLC separation was performed on an Inertsil ODS-3V column (4.6 mm i.d×150 mm) using methanol-water (25 : 75) as the mobile phase at a flow rate of 1.0 mL/min. The recoveries of sucralose from foods were 80.2∼121.2%, and quantitation limits from foods except chewing gum were 5 μg/g (20 μg/g from chewing gum).

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A method for the determination of sucralose in various foods by RI-HPLC and ion chromatography with a pulsed amperometric detector (PAD-IC) was developed.
Chopped or homogenized samples were packed into cellulose tubing with 0.01 mol/L hydrochloric acid containing 10% sodium chloride and were dialyzed against 0.01 mol/L hydrochloric acid for 24 hours. The dialyzate was passed through a Bond Elut ENV cartridge, and the cartridge was washed with 0.2 mol/L NaOH and water. Sucralose was eluted from the cartridge with methanol. The extract was taken to dryness in an evaporator and the residue was re-dissolved in water.
Sucralose was separated on an Inertsil ODS-3V column with a mobile phase of acetonitrile-water (15 : 85) and an RI detector. It was also determined on a CarboPak PA1 column with a mobile phase of 100 mmol/L NaOH-75 mmol/L CH₃COONa, using a PAD detector.
The recoveries of sucralose from various kinds of foods spiked at 50 μg/g and 200 μg/g ranged from 88∼105%. The detection limit in samples was 10 μg/g for RI-HPLC and 1 μg/g for PAD-IC.

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The antigenicity and phototoxicity of water-soluble extract from Salacia reticulata (SRE) were examined in guinea pigs. In a study of active systemic anaphylaxis reaction, neither the oral administration group (64 or 320 mg/kg, 5 times/week, 3 weeks) nor the subcutaneous administration group (64 mg/kg, 1 time/week, 3 weeks) exhibited any anaphylactic reaction. Moreover, sensitization with serum obtained from these animals did not induce passive cutaneous anaphylaxis reaction in normal animals. In a phototoxicity study, oral administration of SRE (320 mg/kg) induced neither erythema nor edema. These results suggest that SRE is not antigenic or phototoxic.

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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.

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Dioxin concentrations and homologue profiles were examined in plucked new shoots, crude tea and its hot water extracts, soils and atmosphere in tea orchards. The rate of dry provisions in crude tea has increased 4 times as that of the plucked new shoots. However, dioxin concentrations except O₈CDD in crude tea have increased only 2 to 3 times as those of the plucked new shoots. O₈CDD concentration increased remarkably during processing. Little dioxins were detected in hot water extracts of crude tea leaves.

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