ABSTRACT
Three fluorigenic reagents were tried in order to increase the sensitivity of the detection of various amines. The derivatives formed were then used to develop a reversed-phase high-performance liquid chromatographic (HPLC) procedure for the separation of at least five amines. Dns-C1 and fluorescamine were rejected. The chromatogram of Dns-amines from red wine was overcrowded with unidentifiable peaks. It was then postulated that ammonia or phenol derivatives or other by-products of the Dns derivatization reaction interfered with the separation of amines. Fluorescamine, although it produced highly fluorescent derivatives, had the drawback of reacting with di- and polyamines to give more than one derivative and this interfered with the resolution. o-Phthaldialdehyde (OPT) was used successfully for the derivatization of amines in red must and wine. The method involved the reaction of amines with OPT in the presence of mercaptoethanol followed by extraction of the derivatives with ethyl acetate. A reversed-phase HPLC system was developed for the separation of OPT derivatives of agmatine, cadaverine, ethanolamine, histamine, phenylethylamine, putrescine, tryptamine, tyramine, spermine and spermidine within 40 min.
Subject(s)
Amines/analysis , Wine/analysis , Chromatography, High Pressure Liquid/methods , Dansyl Compounds , Fluorescamine , Fruit , o-PhthalaldehydeABSTRACT
A total of 223 retail samples consisting of pork sausage (105), ground pork (25), pork chops (50), barbecued pork (33), turkey sausage (3) and chicken pieces (7) was analyzed and revealed the presence of Salmonella sp. in 16.14% of the samples. Of the 10 different serotypes isolated, Salmonella agona was predominant.
ABSTRACT
The bacteriological quality of 180 units of frankfurters, obtained from grocery stores in Ontario (Canada) was investigated. About 67% of the samples had aerobic plate counts (APC) in the range of 107 - 109/g; 48% had APCs in the range of 108-109/g and APCs of four samples exceeded 109/g. One sample was positive for Staphylococcus aureus and three samples contained Escherichia coli . Enterococci (<1000/g) were recovered from 48 samples. Aerobic plate counts of cooked frankfurters from snackbars did not exceed 500/g. Cooking of frankfurters for 6.5 min at 90 C resulted in APCs of <100/g. Neither salmonellae nor Clostridium perfringens were isolated. It was concluded that temperature abuse following manufacture was mainly responsible for the high counts.
ABSTRACT
The incidence of Salmonella organisms in 69 packages of raw chicken pieces obtained from retail stores was 34.8%. Eleven different serotypes were isolated.
ABSTRACT
A total of 108 samples of fresh refrigerated ground beef, 99 samples of frozen hamburger patties, and 107 fried hamburgers, purchased from retail stores and fast-food outlets in Ontario, were analyzed for their bacteriological quality. About 44% of non-frozen ground beef samples had aerobic plate counts exceeding 50 million/g; 50 of 108 samples (46.3%) contained Staphylococcus aureus and 46 of these 50 samples (88%) exceeded 1000 organisms/g; 43 of 108 samples were positive for Escherichia coli with 38 samples (88.4%) exceeding 500 organisms/g. About 19% of frozen hamburger patties had aerobic plate counts in excess of 10 million/g; 93 of 99 samples (93.9%) contained S. aureus with 83 of these samples (89.3%) exceeding 1000 organisms/g; 28 of 99 samples were positive for E. coli with 7 of these samples (25%) exceeding 500 organisms/g. About 96.3% of fried hamburger samples had aerobic plate counts of less than 10,000/g.
ABSTRACT
Four types of luncheon meats, bologna, chicken loaf, ham, and macaroni cheese, each manufactured by four different companies, were purchased from four major retail outlets in Ontario over a period of 16 weeks during the summer of 1975. Bacterial evaluation included determination of total aerobic plate count, coliforms, Escherichia coli , Staphylococcus aureus , Clostridium perfringens , salmonellae, and enterococci. Bacteria of public health significance were not a problem except for a high incidence of enterococci in all samples. S. aureus counts exceeded 1000/g in 20% of 30 positive samples out of a total of 159 samples. Total aerobic plate counts exceeded 5,000,000/g in 46.5% of the samples. Wide variation in bacteriological quality of the products between manufacturers was found.
