Twenty three UK commercially produced ammonia caramels and eight experimentally produced ammonia caramels have been analysed by a range of physical and chemical tests, which include solids content, nitrogen levels, colour intensity and pH. A statistical treatment of the results is reported.

Ammonia↗

PubMedDate not supplied

A method for the analysis of lincomycin in porcine and bovine kidney.

A method of analysis has been developed for the estimation of lincomycin in porcine and bovine kidney. The method employed high performance liquid chromatography and Sep-Pak clean-up of methanolic tissue extracts and nitrogen specific gas chromatographic detection. Using spiked (0.1 mg kg-1) extracts recoveries in the range 40-50% were obtained. Analysis at the 0.05 mg kg-1 level is possible. Fifty four samples of kidney destined for UK sale were analysed for the presence of this drug. No samples were found to contain lincomycin.

Animals↗

PubMedDate not supplied

Determination of aflatoxin B1 levels in peanut butter using an immunoaffinity column clean-up procedure: inter-laboratory study.

Ten United Kingdom laboratories participated in an evaluation of an immunoaffinity column sample preparation procedure used to prepare aflatoxin B1 containing extracts obtained from peanut butters contaminated by aflatoxins. Each laboratory was sent seven randomly numbered samples of roasted peanut butter which included two sets of undisclosed triplicates. These two peanut butters were naturally contaminated with aflatoxin B1 at levels of about 12 and 35 micrograms/kg. The other sample was a nominal blank peanut butter containing approximately 2 micrograms/kg of aflatoxin B1 which was also employed by participants for recovery experiments. Participating laboratories were instructed to follow a protocol regarding the use of the immunoaffinity columns for extract preparation, but were allowed a free choice of instrumental technique for quantification of aflatoxin levels. Mean recovery for spikes was 72%. Coefficients of variation for the results from the 10 participants for the two contaminated roasted peanut butters were, respectively, 45% (on a mean of 13.6 micrograms/kg) and 36% (on a mean of 37.2 micrograms/kg).

Aflatoxin B1↗

PubMedDate not supplied

A survey of the occurrence of agaritine in U.K. cultivated mushrooms and processed mushroom products.

The naturally occurring compound agaritine (beta-N-[gamma-L(+)glutamyl]-4-hydroxy-methylphenyl-hydrazine) has been determined in fresh, dried and processed mushrooms. A method was developed involving extraction of the toxin into methanol, clean-up where appropriate (for processed products) by high-performance size exclusion liquid chromatography and determination by reverse-phase HPLC with electrochemical detection. Diode array UV monitoring was used for confirmation. The method had a recovery of 90-98%, a relative standard deviation of 3-5% and a limit of detection of agaritine of 5 mg/kg on a dry-weight basis. Fresh cultivated mushrooms showed agaritine levels of 100-250 mg/kg and 80-190 mg/kg for two different commercial strains. There were slight differences in levels of agaritine between mushrooms of different sizes, and between those of the same size but harvested at different times (different breaks). Retail processed mushrooms products had low agaritine levels in the range 6-33 mg/kg, with the exception of one dried sliced mushroom product found to contain 6520 mg/kg.

Basidiomycota↗

PubMedDate not supplied

Surveillance and control of aflatoxin contamination of dried figs and fig paste imported into the United Kingdom.

Samples of dried figs and fig pastes from Turkey supplied voluntarily by UK importers and retailers during the period November 1988 to January 1989 showed both a high incidence and high levels of contamination with aflatoxins. In the samples tested, 24% had total aflatoxin concentrations above 10 micrograms/kg, with the highest level being 165 micrograms/kg. More rigorous monitoring of the 1989 fig harvest was undertaken on bulk consignments for all figs from Turkey entering the UK. For whole dried figs 20 kg samples were taken (as 20 sub-samples), and for fig paste 5 kg samples were taken (again as 20 sub-samples). Figs were minced, blended with water and mixed prior to sub-sampling for analysis. Analysis was by immunoaffinity column clean-up with HPLC determination of aflatoxins with fluorescence detection. Examination showed that 11% of 112 consignments of fig paste and 9% of 93 consignments of whole dried figs were contaminated with total alfatoxin concentrations above 10 micrograms/kg, with the highest level of contamination being 40 micrograms/kg. As a result of this surveillance programme 14 consignments of figs were refused entry into the United Kingdom.

Aflatoxins↗