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Biomedical subjects

T Fazio

Publications and source records attributed to T Fazio.

At least 55 records · Page 3Linked to original sources
PubMed1973

Effect of sodium nitrite and sodium nitrate on botulinal toxin production and nitrosamine formation in wieners.

Wieners were formulated and processed approximating commercial conditions as closely as possible. Twenty-four batches of product were made with the addition of six levels of sodium nitrite (0, 50, 100, 150, 200, and 300 mug/g), four levels of sodium nitrate (0, 50, 150, and 450 mug/g), and two levels of Clostridium botulinum (0 and 620 spores/g). After formulation, processing, and vacuum packaging, portions of each batch were incubated at 27 C or held for 21 days at 7 C followed by incubation at 27 C for 56 days. The latter storage condition approximated distribution of product through commercial channels and potential temperature abuse at the consumer level. Samples were analyzed for botulinal toxin, nitrite, and nitrate levels after 3, 7, 14, 21, 28, and 56 days of incubation. When nitrite was not added, toxic samples were detected after 14 days of incubation at 27 C. At the lowest level of nitrite added (50 mug/g), no toxic samples were observed until 56 days of incubation. Higher levels of nitrite completely inhibited toxin production throughout the incubation period. Nine uninoculated samples, representing various levels and combinations of nitrite and nitrate, were evaluated organoleptically. The flavor quality of wieners made with nitrite was judged significantly higher (P = 0.05) than of wieners made without nitrite. The nine samples were negative for 14 volatile nitrosamines at a sensitivity level of 10 ng/g. The results indicated that nitrite effectively inhibited botulinal toxin formation at commercially employed levels in wieners and that detectable quantities of nitrosamines were not produced during preparation and processing of the product for consumption.

Botulinum Toxins↗
PubMedDate not supplied

Cytogenetic analysis in congenital hypothyroidism.

In order to evaluate the possible role of genetic factors in the pathogenesis of congenital hypothyroidism (CH), we investigated the occurrence of chromosome aberrations in a consecutive series of 47 patients with CH and 208 matched healthy controls. No abnormal karyotype was found in CH patients. In 5 CH patients and in 3 healthy controls a number of heterochromatin variants was detected. Although chromosomal variants are devoid of phenotypic effects, the frequency of these variants was higher in CH patients than in the control group (10.6% vs 1.4%, p less than 0.005). These findings suggest that the association of congenital hypothyroidism with chromosomal variants may reflect more than chance concurrence.

Chromosome Aberrations↗
PubMedDate not supplied

Reactions of antioxidants in foods.

The chemical transformations of BHT and BHA in the deep-fat frying of potatoes were studied. Approximately 80% of the BHT and its associated decomposition products was lost from the lard after six batches of french fries. This may have been due to steam distillation caused by the water boiled out of the potatoes. In contrast, 80% of the radiocarbon introduced as radiolabelled BHA was retained by the frying medium even after 12 batches of french fries. The concentration of intact BHA decreased to undetectable levels after four batches. Because of the complexity of the products formed in the heated fats, studies were undertaken on the thermolysis of a hydroperoxy derivative of BHT, 2,6-di-tert-butyl-4-hydroperoxy-4-methylcyclohexa-2,3-dienone++ + (HBHT). The product mixture, which was identified by mass spectrometry and gas chromatography-mass spectrometry, included BHT, 2,6-di-tert-butyl-4-hydroxy-4-methylcyclohexa-2,5-dienone and 3,5-di-tert-butyl-4-hydroxybenzaldehyde. Elemental compositions of other unidentified products were determined by high-resolution mass spectrometry.

Butylated Hydroxyanisole↗
PubMedDate not supplied

Sulphite stabilization and high-performance liquid chromatographic determination: a reference method for free and reversibly bound sulphite in food.

A high-performance liquid chromatographic (HPLC) post-column reactor combination has been developed for the determination of sulphite (free and reversibly bound) in 15 different foods. The foods were treated with a pH 5.1 buffered aqueous 2% formaldehyde solution to convert the labile sulphite to the relatively stable hydroxymethylsulphonate. Reverse-phase ion-pairing HPLC with a post-column detector consisting of an initial reaction with KOH followed by colorimetric reaction with Ellman's reagent buffered at pH 6.3 were used for separation and quantitation. The photometric detector at 412 nm quantitated the strongly absorbing 3-carboxy-4-nitrothiophenolate anion, the product of the sulphite reaction with Ellman's reagent. The recovery at levels of 5-100 ppm as sulphur dioxide was greater than 90% by reverse isotope dilution assay. Repetitive analysis of a single grape juice extract containing 20 ppm SO2 showed a relative standard deviation of 2.2%.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Volatile N-nitrosamines in Polish malt and beer.

A survey of Polish malt and beer for volatile N-nitrosamines has been conducted. N-Nitrosodimethylamine was found in malt at levels ranging from 0.2 to 3.6 micrograms/kg (average 1.5 micrograms/kg) and in beer at levels up to 0.3 microgram/kg (average 0.2 micrograms/kg). The use of indirect malt dryers is credited with the low levels of N-nitrosamines found.

Beer↗
PubMedDate not supplied

A review of sulphites in foods: analytical methodology and reported findings.

Sulphites in various forms have been added to foods for centuries. Their use became an issue of concern when certain sensitive individuals exhibited adverse reactions to sulphite residues in foods. Analytical methods were developed to monitor these compounds at the regulatory limit of 10 ppm. In this report, analytical methods for determining sulphites in foods are reviewed, along with a critique of their chemistry and procedural schemes. An assessment of the key features of each method category is presented together with some comparative data. The classification scheme used is based upon the fact that determination of the sulphite content of a food is influenced more by the treatment and cleanup of the test solution than by the final determinative step. Based on a 60-year database, the Monier-Williams procedure still remains the method of choice.

Chemical Phenomena↗
PubMedDate not supplied

Optimized Monier-Williams method for determination of sulfites in foods: collaborative study.

A collaborative study was conducted of the Food and Drug Administration (FDA)-optimized Monier-Williams method for determining sulfites in foods. Twenty-one industry and government laboratories participated in the study, which was jointly sponsored by the National Food Processors Association and FDA. Familiarization samples were shipped to each collaborator. Collaborators were permitted to proceed to the main study only after they demonstrated ability to perform the method to ensure that the study tested the performance of the method itself and not that of the individual laboratories. The study design involved 3 food matrixes (hominy, fruit juice, and protein [seafood]). Each matrix was prepared at 3 sulfite levels--the regulatory level, half the regulatory level, twice the regulatory level--and as a blank. All test samples were analyzed as blind duplicates, which gave each collaborator a total of 24 test portions. Collaborative recoveries gave a reproducibility (among-laboratories) coefficient of variation that ranged from 15.5 to 26.6% for sulfite determined as SO2 by weight in the 3 foods at the 10 ppm level. The optimized Monier-Williams method has been approved interim official first action to replace the AOAC modified Monier-Williams method, 20.123-20.125.

Food Analysis↗
PubMedDate not supplied

Liquid chromatographic methodology for the characterization of orange juice.

Liquid chromatographic (LC) methodology potentially useful for the characterization of orange juice, with particular regard to detecting adulteration of orange juice by computer pattern recognition analysis, has been developed. After dilution with methanol the juice is extracted with hexane to remove the carotenoids, which are chromatographed on a C18 column with an acetonitrile-methanol-methylene chloride mobile phase and detection at 450 nm. Further extraction of the juice with methylene chloride isolates the methoxylated flavones, which are chromatographed by reverse phase LC with an acetonitrile-methanol-water mobile phase and detection at 280 nm. The flavanone glycosides remaining in solution are chromatographed on a C18 column with an acetonitrile-water mobile phase and detection at 280 nm. The precisions of the heights of the 32 LC peaks selected for pattern recognition analysis were determined from 5 replicate analyses of a single juice. Coefficients of variation of the replicates ranged from 0.3 to 4.5%, with an average of 2.1%. Adulteration of products with sodium benzoate-fortified pulpwash or grapefruit juice can be detected by this method. Pattern recognition analysis of the data obtained for 80 authentic and 19 adulterated orange juices showed that the method is potentially useful for distinguishing between authentic and adulterated products.

Beverages↗
PubMedDate not supplied

Liquid chromatographic determination of basic nitrogen-containing polynuclear aromatic hydrocarbons in smoked foods.

Several smoked foods were analyzed for basic nitrogen-containing polynuclear aromatic hydrocarbon (NPAH) content by a relatively rapid liquid chromatographic (LC) technique. The analyzed products included both domestic and imported market basket commodities. Nanogram quantities of NPAH standards were detected by UV and fluorescence detectors connected in series. The NPAHs were extracted from basic aqueous ethanolic solution into cyclohexane, extracted from cyclohexane into 6N HCl, and extracted back into cyclohexane after neutralization of the acid. The NPAHs were then purified by filtering the extract through deactivated basic alumina. The eluate from this step was concentrated to dryness, and the residue was dissolved in 95% ethanol and analyzed by LC, using a Vydac C-18 column and acetonitrile-water (9 + 1) as the mobile phase. Recoveries of 3 NPAHs, 5,7-dimethylbenz(a)acridine, dibenz(a,j)acridine, and dibenz(a,h)acridine, each added to salmon and sausage at the 5 ppb level, ranged from 62 to 101% by fluorescence measurement and from 64 to 106% by UV measurement. None of the NPAHs used as standards were found by either fluorescence or UV detection at levels greater than or equal to 5 ppb in any of the foods analyzed.

Animals↗
PubMedDate not supplied

Gas chromatographic determination of fatty acids and sterols in orange juice.

A gas chromatographic (GC) method has been developed for the simultaneous quantitation of fatty acids and sterols in orange juice, using a bonded phase fused silica capillary column of intermediate polarity, splitless automatic injection, and flame ionization detection. Sample preparation has been simplified by using 1 g C-18 adsorbent in a disposable minicolumn to extract 2 mL orange juice. Methylation of fatty acids and silylation of the sterols were carried out in the eluted extract (low polarity lipid fraction). The method precision was 7%; recoveries ranged from 83 to 113%. The precision of the injection technique was 2%. Seven major fatty acids and 5 sterols in orange juice were quantitated by the GC method and identified by GC/mass spectrometry. Quantitative data for several orange juice samples indicated that the levels of the compounds of interest were in the 1.3-72.0 mg/L range. The results demonstrate that bonded phase fused silica capillary GC has great versatility and potential for the quantitative determination of fatty acids and sterols.

Beverages↗
PubMedDate not supplied

Current trends in levels of volatile N-nitrosamines in fried bacon and fried-out bacon fat.

Commercially processed bacon samples purchased from the Washington, DC, retail market have been periodically analyzed since 1971 for the presence of volatile N-nitrosamines in the fried product. During that time, a downward trend in the concentration of N-nitrosopyrrolidine has been observed, and between 1978 and 1980 it plateaued at 4-30 ppb, with an average of 11 ppb. A recent survey, however, indicates a change in this downward trend, with N-nitrosopyrrolidine found at levels ranging from 1 to 65 ppb, average 21 ppb. Volatile N-nitrosamines were found at levels up to 110 ppb in the fried product and up to 85 ppb in the fried-out bacon fat.

Animals↗
PubMedDate not supplied

Reevaluation of Monier-Williams method for determining sulfite in food.

The Monier-Williams distillation procedure has a long history of successful use for determining sulfite in fruit products and wine; however, a systematic evaluation of its accuracy and precision with other food matrices has not been undertaken. We found that the Monier-Williams distillation yielded greater than 90% recovery of sulfite added to foods such as table grapes, hominy, dried mangoes, and lemon juice. Less than 85% recovery was obtained with broccoli, soda crackers, cheese-peanut butter crackers, mushrooms, and potato chips. These results may, in fact, accurately reflect the residual levels of sulfite if a portion of the sulfite undergoes irreversible reaction with some food components. Analysis of commercial food products gave sulfite levels ranging from 1400 ppm in dried apple slices to 25 ppm in cream sherry.

Chemical Phenomena↗