A simple analytical method for dibromophenols (DBPs) in flatfiish was developed. 2,4-DBP and 2,6-DBP were extracted from a sample with acetone and n-hexane, cleaned up by treatment with conc. sulfuric acid and concentrated under a stream of nitrogen gas. The resulting extract was subjected to GC/MS. The recoveries of 2,4-DBP and 2,6-DBP were 89.4-96.5% and 81.4-86.2%, respectively, indicating that this method is useful for analysis of 2,4-DBP and 2,6-DBP. In the phenolic-smelling flatfish, 2,6-DBP was detected at the levels of 0.10 μg/g and 0.01 μg/g in skin and muscle, respectively, and 2,4-DBP was detected at the level of 0.02 μg/g in skin.
Sennoside A and B were detected in 21 commercial health tea products surveyed in 2000-2007, but there were 8 products in which the leaves could not be identified as senna because the leaves had become discolored. The results of assay of sennoside levels and TLC chromatograms suggested that processed senna had been used in these products. Next, with reference to tea and health tea manufacturing methods, pharmaceutical senna was roasted or wet-processed experimentally. The results indicated that the discolored leaves contained in commercial health tea were most likely derived from senna leaves. Moreover, sennosides in medicinal doses were detected in some processed senna samples, and were determined to have a cathartic action in mice. Based on morphological confirmation and the results of component analysis, including sennoside, the discolored leaves found in commercial health teas were therefore determined to be senna leaves. There may be possible health risks, including diarrhea.
A rapid and simple method for determination of theophylline, theobromine and caffeine in dietary supplements containing guarana by ultra-performance liquid chromatography (UPLC) has been developed. Theophylline, theobromine and caffeine were extracted from finely powdered samples with water in a boiling water bath for 20 min, then the extracts were filtered and the filtrates were subjected to UPLC. Liquid samples were diluted with water and filteres, and the filtrates were subjected to UPLC. UPLC separation was performed on an AQUITY UPLC BEH C18 column (2.1 mm i.d.×50 mm, 1.7 μm, Waters) with 10 mmol/L ammonium acetate buffer (pH 4.0)-acetonitrile gradient and eluates were monitored at 275 nm. The recoveries of theophylline (spiked at 200 μg/g [tablet] and 50 μg/mL [liquid]), theobromine (spiked at 200 μg/g [tablet] and 50 μg/mL [liquid]) and caffeine (spiked at 1,000 μg/g [tablet] and 250 μg/mL [liquid]) were 97.6-98.7%, 97.3-99.7%, 97.1-105.4%, respectively. The quantitation limits of theophylline, theobromine and caffeine were 10 μg/g (seed, seed powder, tablet and capsule) and 2.0 μg/mL (liquid) each. When this analytical method was applied to commercial dietary supplements, theophylline, theobromine and caffeine were found at concentrations of 4.45 mg/tablet, 5.48 mg/tablet, 139 mg/tablet, respectively. Taking 4 tablets of this product according to the directions on the package could be dangerous to consumers because of possible overdosing of these ingredients.
The potential value of benzyl isothiocyanate (BIT) vapor for food preservation was investigated in comparison with allyl isothiocyanate (AIT) vapor. Measurements of minimum inhibitory concentration (MIC) against various bacteria and fungi indicated that BIT vapor shows higher antibacterial activity towards Gram-positive bacteria, including lactic acid bacteria, than AIT vapor. BIT has a similar inhibitory effect to AIT against Gram-negative bacteria, yeast and fungi, except that it was less effective against Pseudomonas fluorescens JCM 5963. Both BIT and AIT have a strong inhibitory activity against yeast and fungi. AIT vapor suppressed growth of total aerobic bacteria in bigeye tuna meat and pork mince during storage at 10°C and 30°C, while BIT vapor had no effect. Also, AIT vapor strongly inhibited mycelial development of Aspergillus sojae JCM 2251 and Penicillium expansum IAM 13777 inoculated on rice cakes, while BIT vapor only slightly suppressed their growth. BIT has antimicrobial activities, but further studies are needed to establish its suitability for use in food preservation.
Surveillance of consumer complaints related to microbial contamination in soft drinks indicated that tea drinks, and juice and juice drinks were major soft drinks involved in complaints. The frequency of complaints about juice and juice drinks is relatively high in relation to the production amount. Damage to containers during distribution and inappropriate storage of soft drinks by consumers are major causes of complaints. Molds were predominantly associated with complaints and symptoms caused by intake of contaminated soft drinks. To reduce complaints, more support for small companies, and greater education for carriers, dealers and consumers are needed.