RESUMO
Aldehydes in foods can conveniently be characterized and determined by thin-layer chromatography (TLC) after converting them into their dimethones. For further confirmation the dimethones can be cyclized on the TLC plates or in solution to give octahydroxanthenes. Aldehydes also can be determined as their barbiturates. The aldehydes could be determined as dimethones and octahydroxanthenes in amounts up to 5 micrograms and as barbiturates in amounts up to 7.5 micrograms at their UV maxima.
Assuntos
Aldeídos/análise , Barbitúricos/análise , Análise de Alimentos , Xantenos/análise , Fenômenos Químicos , Química , Cromatografia em Camada FinaRESUMO
Effect of processing temperature on the changes in free nucleotides, nucleosides and bases in goat and sheep meats was investigated. The major changes in nucleotides and related compounds took place during first 30 min of heating and the rates of changes were maximum at 60 degrees C and minimum at 100 degrees C. At 120 degrees C, thermal degradation of inosinic acid proceeds at significant rates but below 100 degrees C major changes are brought about by phosphomonoesterases (5'-mononucleotidases) during initial stages of heating.
Assuntos
Manipulação de Alimentos , Carne/análise , Nucleosídeos/análise , Nucleotídeos/análise , Purinas/análise , Pirimidinas/análise , Animais , Cabras , Temperatura Alta , OvinosRESUMO
Changes in free nucleotides, nucleosides and bases during preparation of pre-cooked dehydrated minced meats from goat and sheep are reported. Major changes took place during cooking stage only; the changes during dehydration were relatively minor. Addition of EDTA at 500 ppm level significantly reduced the rate of dephosphorylation during curing process. Concentration of free nucleotides and related compounds were very low in commercially prepared accelerated freeze dried meat chunks.
Assuntos
Carne/análise , Nucleosídeos/análise , Nucleotídeos/análise , Purinas/análise , Uracila/análise , Animais , Culinária , Manipulação de Alimentos , Conservação de Alimentos , Liofilização , Cabras , Índia , OvinosRESUMO
A simple and convenient procedure based on reversed-phase paper and thin-layer chromatography is reported for the detection and estimation of N-nitrosamines in food products, particularly cured meat. The method can easily be applied in tropical regions when plenty of sunshine is available. It is particularly useful in food-testing laboratories where sophisticated analysical instruments such as the gas chromatograph, mass spectrometer, etc., are not available. By this procedure, it is possible to detect up to 10 mug and to estimated up to 75-mug (reversed phase) and 50-mug (thin layer) amounts of N-nitrosamines.
