Showing papers in "Journal of Food Safety in 1978"
TL;DR: P. morganii and E. aerogenes would appear to have the capability of forming sufficient histamine in scombroid fish products to elicit food poisoning outbreaks.
Abstract: A total of 112 bacterial strains representing 38 species were tested for their potential to elicit food poisoning outbreaks via histamine formation in foods. Proteus morganii and Enterobacter aerogenes displayed a quantitative superiority in terms of histamine production on a trypticase-soy broth-histidine (TSBH) medium and a tuna fish infusion broth (TFIB). When bacteria were incubated under standardized conditions in TSBH medium, histamine accumulated to levels exceeding 50 nmoles/ml of media with a total of 23 strains, including 13 of 15 P. morganii strains, 3 of 3 E. aerogenes strains, 3 of 12 Hafnia alvei strains, 1 of 4 Providencia alcalifaciens strains, 1 of 5 Enterobacter cloacae strains, 1 of 1 Proteus rettgeri strains, and 1 of 1 Citrobacter diversus strains. However, only 8 of the 15 P. morganii strains and the 3 E. aerogenes strains were capable of generating histamine in excess of 200 nmoles/ml in the TSBH medium. Of the 23 strains capable of appreciable histamine production in TSBH medium, P. morganii and E. aerogenes were, by far, the most prolific histamine producers in TFIB. Of the organisms tested, only P. morganii and E. aerogenes would appear to have the capability of forming sufficient histamine in scombroid fish products to elicit food poisoning outbreaks.
90 citations
TL;DR: It was found that bacteria attach readily to the meat surfaces, and Pseudomonas EBT/2/143 attached most readily to all meat surfaces examined.
Abstract: The attachment of bacteria to chicken and beef meat with and without fascia was studied. It was found that bacteria attach readily to the meat surfaces. The kinetics of attachment depend on the bacterial strain, as well as on the meat surface. Of the bacteria tested, Pseudomonas EBT/2/143 attached most readily to all meat surfaces examined. Chicken breast with fascia was the best surface for attachment.
A study was also made of the effects of storage on the multiplication of the attached bacteria and the feasibility of removing them. A high level of Salmonella infantis was found in comparison to the other bacteria after 24 h of storage at 20°C.
More investigations are needed to find out whether other serotypes of salmonellae will multiply to similar levels on these surfaces.
After micro-colonies began to form, the newly generated bacteria were easy to remove. The hygienic consequence of this phenomenon is discussed.
67 citations
27 citations
TL;DR: The results indicated that α-chaconine which is absorbed from the gastrointestinal tract after oral administration persists in various tissues, much of it in bound (nonextractable) form (in microsomal fraction) of brain, liver, and heart tissues.
Abstract: The distribution, absorption, metabolism and tissue binding of radioactivity were studied in hamsters after oral and intraperitoneal administration of α-chaconine-(3H). The material was well absorbed from the gastrointestinal tract and nearly 25% of the label was excreted in 7 days via urine and feces. The excretion was higher in urine (24%) than in feces (1%). Tissue concentrations of radioactivity peaked at 12 h following po administration, with the highest concentrations being in lungs, liver, spleen, skeletal muscle, kidney and pancreas, with heart and brain containing moderate amounts. Excretion of chloroform-soluble products in the feces was 100 higher than that of chloroform-insoluble metabolites after oral and ip administration. In urine, the activity was predominantly in the chloroform-insoluble form and the chloroform-soluble metabolites were relatively small in amounts (0.29, 0.85 and 2.45% versus 0.0, 0.14 and 0.19 for 12, 24 and 72 h, respectively). After 7 days, the chloroform-soluble metabolites in urine increased to 20% of the excreted radioactivity, while the amount of chloroform-insoluble metabolites was less than 1%. Subcellular distribution of the labeled compound indicated the highest concentration of radioactivity in the nuclear and microsomal fractions of brain, liver, and heart tissues. Binding of radioactivity was observed in brain, testes, kidney, lung, liver and heart. All of the label in brain appeared to be in bound form. The results indicated that α-chaconine which is absorbed from the gastrointestinal tract after oral administration persists in various tissues, much of it in bound (nonextractable) form (in microsomal fraction).
17 citations
TL;DR: In this paper, surface and core samples from raw beef rounds were examined for the presence of and the logarithmic level of salmonellae, and the results showed that salmonella survived in the core and on the surface of some but not all inoculated rounds cooked to an internal temperature of 130°F.
Abstract: Raw beef rounds were surface inoculated with salmonellae. Some of the rounds were mechanically blade tenderized. Both surface and core samples from each round studied were examined for the presence of and the logarithmic level of salmonellae. Mechanical tenderization increased the level of salmonellae found in core samples by about one logarithm. Large samples taken from cores of rounds which were not tenderized contained small numbers of salmonellae. Dipping inoculated rounds into a 50 ppm chlorine solution did not prevent the occurrence of salmonellae in core samples of mechanically tenderized units. Salmonella survived in the core and on the surface of some but not all inoculated rounds cooked to an internal temperature of 130°F.
14 citations
TL;DR: In this paper, a study was made of the effect on the concentration of lead in canned fruits and juices when these food products were stored in their original containers after opening, and found that products in nonlacquered cans showed significant increases in lead concentration with time.
Abstract: A study was made of the effect on the concentration of lead in canned fruits and juices when these food products are stored in their original containers after opening. Samples stored in a refrigerator were analyzed for lead upon initial opening, 2 days after opening, and 5 days after opening. Products in nonlacquered cans showed significant increases in lead concentration with time. The increase of lead in the food product could have an effect on estimates of average dietary intakes of lead if this practice is found to be widespread.
12 citations
TL;DR: Theobromine (0, 2, 4, and 8 mg/ml) had little effect on growth and aflatoxin production by Aspergillus parasiticus NRRL 2999 in a glucose-mineral salts-yeast extract medium, indicating that the anti-aflatoxigenic activity of cocoa beans is not due to the presence of this methylxanthine as mentioned in this paper.
Abstract: Theobromine (0, 2, 4, and 8 mg/ml) had little effect on growth and aflatoxin production by Aspergillus parasiticus NRRL 2999 in a glucose-mineral salts-yeast extract medium, indicating that the anti-aflatoxigenic activity of cocoa beans is not due to the presence of this methylxanthine.
11 citations
TL;DR: Methylhydrazine, the main metabolite of N-methyl-N-formylhydra-zones, was detected in the cooking steam of the mushrooms False morels, Gyromitra esculenta as mentioned in this paper.
Abstract: Methylhydrazine, the main metabolite of N-methyl-N-formylhydra-zones, was detected in the cooking steam of the mushrooms False morels, Gyromitra esculenta. About 25% of the original amount of acetaldehyde-N-methyl-N-formylhydrazone was decomposed during cooking process to methylhydrazine and residues of N-methyl-N-formylhydrazine was detected as well.
9 citations
TL;DR: Caffeine (1,3,7-trimethylxanthine) was inactive as a mutagen at the hgprt locus in two human lymphoblast lines at concentrations up to 20 mM and did not induce 8-azaguanine-resistant mutants in Salmonella typhimurium at similar levels.
Abstract: Caffeine (1,3,7-trimethylxanthine) was inactive as a mutagen at the hgprt locus in two human lymphoblast lines at concentrations up to 20 mM. In addition, caffeine did not induce 8-azaguanine-resistant mutants in Salmonella typhimurium at similar levels.
6 citations
TL;DR: In this article, a study was carried out to determine if the presence of ascorbic acid interferes with the colorimetric determination of nitrite by the technique of separate addition of color reagents.
Abstract: A study was carried out to determine if the presence of ascorbic acid interferes with the colorimetric determination of nitrite by the technique of separate addition of color reagents. It was shown that ascorbate can destroy some of the nitrite during pre-incubation with sulfanilamide, one of the color reagents used to form the diazo compound. An alternative method of analysis is suggested in which ascorbic acid, in the concentration range normally found in foods and cured meat products, does not interfere.
4 citations
TL;DR: The inhibitory effect of sodium nitrite upon glucose catabolism by Staphylococcus aureus was investigated using [U–1 4C] glucose, liquid chromatography, and gas-liquid chromatography and the production of acetoin was induced by the addition of acetate to the Sodium nitrite containing medium.
Abstract: The inhibitory effect of sodium nitrite upon glucose catabolism by Staphylococcus aureus was investigated using [U–1 4C] glucose, liquid chromatography, and gas-liquid chromatography
Acetate and acetoin are the end-products of glucose metabolism by S aureus at 37°C and pH 63 In the presence of inhibitory levels of sodium nitrite, acetate and lactate with traces of pyruvate and acetoin are the end products Acetate production per unit of growth is significantly lower in the sodium nitrite inhibited cultures The decreased acetoin accumulation was not due to inhibition of diacetyl reduction The production of acetoin was induced by the addition of acetate to the sodium nitrite containing medium
TL;DR: The effect of aspartame (1-aspartyl-1-phenylalanine, methyl ester) was studied using the protozoan, Tetrahymena pyriformis using yeast extract medium to study the growth rate and rate of synthesis of DNA, RNA, protein, lipids or glycogen.
Abstract: The effect of aspartame (1-aspartyl-1-phenylalanine, methyl ester) was studied using the protozoan, Tetrahymena pyriformis. Aspartame at levels up to 2500 ppm in a protease peptone —- yeast extract medium neither changed the growth rate nor rate of synthesis of DNA, RNA, protein, lipids or glycogen. Cells exposed to as much as 2500 ppm aspartame had a normal morphology. The dipeptide was adsorbed at a level of 0.0353 mg/105 cells when (14C) aspartame was added at 2000 ppm to early log cultures and allowed to incubate for 45 min.