Chromatographic analysis of cadaverine to detect incipient spoilage in mutton.

Suitability of measuring cadaverine for rapid assessment of bacterial quality of fresh and stale mutton (showing signs of incipient spoilage) was examined. HPTLC for rapid screening and detection and HPLC for accurate quantification was employed. Analysis of over 150 samples of varying degrees of freshness and postmortem age showed that in more than 90% of the samples, no cadaverine was detectable when meat was deemed acceptable with <10(6) orgs/g. However, when meat showed incipient spoilage, as judged by off odour and dull colour, cadaverine was detected in the range of 1-5 ppm. Such meat samples had a bacterial load of 10(7) orgs / g or more. HPTLC analysis allowed the simultaneous analysis of 5-6 samples and the total time including extraction was 1.5-2 h. As only easily available chemicals and equipment were required, it was a simple, rapid and inexpensive technique. HPTLC detection of cadaverine can therefore be recommended for the rapid assessment of bacterial quality of mutton and HPLC can be used for accurate quantification.

Inhibitory effect of spices on in vitro histamine production and histidine decarboxylase activity of Morganella morganii and on the biogenic amine formation in mackerel stored at 30 degrees C.

The inhibitory effects of clove, cinnamon, cardamom, turmeric and pepper on the histamine production and histidine decarboxylase activity of Morganella morganii (a potent histamine-producing bacteria in fish) was examined at 30 degrees C using HPLC. Cinnamon and clove exhibited a significant (P < 0.01) inhibitory effect, whereas turmeric and cardamom had a moderate effect. These spices were applied to whole mackerel at a level of 3% and their inhibitory effect on biogenic amine formation at 30 degrees C was also examined. As in the in vitro study, clove and cinnamon showed a significant (P < 0.05) inhibitory effect on histamine, putrescine and tyramine formation but not on that of cadaverine. Cardamom and turmeric exhibited a moderate effect and pepper was ineffective. Therefore, clove and cinnamon are more helpful than cardamom and turmeric in the minimization of the formation of toxic histamine in mackerel.

Altered Free Fatty Acid Levels in Fresh or Canned Mutton as Indicators of Spoilage.

Chromatographic profiles of neutral lipids from canned mutton products can indicate the presence of spoiled meat presterilization, particularly from changes in free fatty acid levels. Gas liquid chromatography analysis of free fatty acids of lean meat showed a 15-fold increase in palmitic, stearic and oleic acid contents as a result of canning spoiled meat when compared to insignificant increases in canned fresh meat.

Thin-layer chromatographic determination of aldehydes encountered in foods as dimethones, octahydroxantheines and barbiturates.

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.

The estimation of N-nitrosamines in tropical regions by reversed-phase paper and thin-layer chromatography.

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.