Regarding food borne intoxications, the accumulation of biogenic amines must be avoided in all kinds of food products. Moreover, biogenic amines can function as precursors for the formation of carcinogenic N-nitrosamines when nitrite is present. To estimate the food safety of the dry fermented sausages available on the Belgian market, a screening of the residual sodium nitrite and nitrate contents, biogenic amines and volatile N-nitrosamine concentrations was performed on 101 samples. The median concentrations of residual NaNO2 and NaNO3 were each individually lower than 20mg/kg. In general, the biogenic amine accumulation remained low at the end of shelf life. Only in one product the amounts of cadaverine and putrescine reached intoxicating levels. Concerning the occurrence of N-nitrosamines, only N-nitrosopiperidine and N-nitrosomorpholine were detected in a high number of samples (resp. 22% and 28%). No correlation between the presence of N-nitrosamines and the biogenic amines content was observed. Although the N-nitrosamines could not been linked to specific product categories, the occurrence of N-nitrosopiperidine could probably be attributed to the use of pepper.

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The commonly applied HPLC method to determine biogenic amines in dry fermented meat after dansylation was compared with an alternative dabsylation procedure. The use of dabsyl chloride at 70°C resulted in a 25-min reduction of the derivatisation time, in comparison with the dansylation at 40°C. Furthermore, the use of irritating ammonia to remove the excess of dansyl chloride can be avoided. Introduction of the SPE cleaning procedure on the C18 cartridge resulted in a reliable and sensitive method of biogenic amines determination in a complex protein-fat matrix, which is typical of dry fermented sausages.The biogenic amines tryptamine (TRYP), phenethylamine (PHE), putrescine (PUT), cadaverine (CAD), histamine (HIS), serotonin (SER), tyramine (TYR), and the natural polyamines spermidine (SPD) and spermine (SPM), were separated by means of gradient HPLC, using the two coupled C18 Chromolith reversed-phase columns.

We report the regeneration of protoplasts isolated from two embryogenic cell lines of Gossypium hirsutum L. cv. Coker 312 initiated from hypocotylderived callus. Protoplasts plated on cellulose nitrate filters and placed over feeder layers formed embryogenic callus from which plants were regenerated. Plating efficiency up to 12.8% depended upon the cell line. Addition of phytohormones to the protoplast medium had no stimulating effect on plating efficiency. The influence of feeder cells and conditioned medium on plating efficiency was significantly different for the two cell lines.

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