PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Food Analysis”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1975

[Food analysis for balance studies, especially calcium, magnesium, phosphorus and nitrogen].

The calcium-, magnesium-, phosphorus-, nitrogen- and water-contents have been estimated in raw and processed foods (bread and sausages). These results were then compared with the data in food tables. Surprisingly small differences were recorded, since content-deviations of processed foods are equalized in a whole day menu. Thus, food tables proved to be reliable for the calculation of balance and test diets.

Calcium↗
PubMed1975

[Fluorescence bacterioscopy, a direct method for bacteriological food analysis].

The present bacteriological method which is intended for the simultaneous direct detection of live and dead germs in foods, offers certain difficulties in differentiating between bacterial cells and food consituents of similar forms. Furthermore, gram-negative germs are not disclosed. To overcome these difficulties, the authors performed comparative model experiments with Gram's stain and the fluorescence method, including pure cultures and foods of animal and vegetable origin. Among the fluorochromes tested (primuline, auramine, acridine orange and acridine yellow), acridine yellow has proved to be specially suited and superior to Gram's stain. A method is described which is termed fluorescence bacterioscopy. Its advantages and disadvantages are discussed.

Acridines↗
PubMed1979

The use of glass capillary columns for food and essential oil analysis.

Foods and essential oils represent complex mixtures whose components frequently embrace a wide range of functional groups and volatilities. The analyst concerned with these products may be interested in overall separation or "fingerprinting," in correlating the amount of individual compounds with specific flavor notes, in the detection and measurement of specific substances such as nitrosamines or pesticides, or in following the progress of a biochemical reaction. Analytical speed and the sensitivity of the method may also be important, as well as the ability of reactive compounds to survive the analysis. Toward all of these goals, glass capillary gas chromatography offers distinct advantages.

Chromatography, Gas↗
PubMed1978

Dietary fiber: analysis and food sources.

The sources of dietary fiber are reviewed and the chemistry of the various components discussed in relation to their possible physiological properties and their analytical measurement in foods and the diet as a whole. Complete fractionation of all the polysaccharide species would be a time-consuming exercise; nevertheless some characterization of dietary fiber seems essential to an understanding of any physiological role. The composition of the dietary fiber in a range of foodstuffs is presented, and the relative contributions of the major food groups to the intake of total dietary fiber is outlined.

Cellulose↗
PubMed1977

Analysis of foods for arsenic and selenium by acid digestion, hydride evolution atomic absorption spectrophotometry.

A method based on acid digestion, hydride evolution atomic absorption spectrophotometry for estimating microgram and submicrogram quantities of As and Se in foods was developed and evaluated. Samples up to 3 g dry weight were digested with HNO3-HCIO4-H2SO4. As and Se in aliquots of the digests were reduced with NaBH4 to volatile hydrides, using laboratory-constructed and commercially available generators. As and Se were estimated by transient signal atomic absorbance measurements as the hydrides were decomposed in an Ar-H2-entrained air flame. Recoveries of inorganic As and Se added at levels of 0.1-1.0 microgram/g to a variety of foods ranged from 70 to 125%. Analyses of several standard reference samples indicated the method is capable of recovering native analytes. Detection limits for the determinative step and the method as a whole were as low as 5 and 25 ng, respectively, for both elements.

Arsenic↗
PubMed1979

Derivative formation in the chromatographic analysis of food additives.

The use of derivatization in the analysis of food additivies by chromatographic means has been reviewed. The large majority of these derivatization techniques are employed to facilitate the gas-liquid chromatographic quantitation of various food additives. Silylation, alkylation, acylation, as well as transesterification, saponification, and chemical decomposition techniques are discussed. The review includes procedures for the analysis of emulsifiers and stabilizers, artificial sweeteners, antioxidants, preservatives, gums, and waxes, and draws in part, from work conducted in the authors' laboratory.

Antioxidants↗
PubMed1979

Analysis of foods for iodine: interlaboratory study.

An accurate, reproducible method for less than or equal to 1 ppm iodine in foods is required for nutritional labeling. In order to ascertain the current status of iodine analysis in foods, 7 samples, representing different food classes, were analyzed by 8 laboratories. Six laboratories used their modifications of the Ce-As-I catalytic method preceded by alkaline dry ashing. Two laboratories used neutron activation analysis (NAA), with differing radiochemical separations. The study showed wide discrepancy in analytical results. Mean relative standard deviation for all laboratories was 77.9% between laboratories; 19.1% within-laboratories. Laboratories using NAA had only slightly better precision than did laboratories using the chemical method. The lowest level reported on the entire group of samples ranged among laboratories from 0.0089 to 0.65 ppm. Figures reported by a laboratory are, in general, consistently high or consistently low. The only differences in methodology which may possibly correlate with level of iodine obtained are the use of NAA technique and use of manual, rather than automated, colorimetry.

Colorimetry↗
PubMed1978

Gas-liquid chromatography of triazine herbicides as heptafluorobutyryl derivatives and some applications to analysis in foods.

The heptafluorobutyryl (HFB) derivatives of ten triazine herbicides were prepared by reacting the pesticides with heptafluorobutyric anhydride in benzene, in the presence of trimethylamine or pyridine as catalyst. The reactions produced mainly the mono-HFB products while some of the herbicides had small quantities of the di-HFB derivatives present. The derivatives were 300 fold to several thousand fold more sensitive to electron-capture detection than the underivatized triazines. They also were 5-10 fold more sensitive than the parents by electrolytic conductivity detection in the halogen mode while they were of similar sensitivity with the same detector in the nitrogen mode. The derivatives eluted in the same general order as the parent triazines on stationary phases of OV-1, OV-101, OV-101/QF-1, and OV-210. This method was successfully applied to the analysis of potatoes, peas and tomatoes spiked with various triazines at levels of 0.13-0.86 ppm.

Chromatography, Gas↗