[Mechanism of alcohol action on gastric secretion].

In chronic experiment on dogs (3 dogs with Pavlov's miniature stomach, 3 dogs with Heidenhain's miniature stomach) the mechanism of action of alcohol (8%-150 ml) on gastric secretion was clarified. For this purpose the new inhibitor of gastric secretion--glycopeptide was utilized, which action was preset in laboratory of G.K.

[Allowable fluctuations in the data on the content of lipid-complex components in food products in chemical composition tables].

The extension of the experimental and literature data about total lipids, fat acids, sterins used for edition chemical Tables. In results has calculated mean and coefficient of variation. For the most food, exception egg, liver and so on, content of sterins has 85 divided by 50 mg/100g of foods.

[Calculation method in determination of dietary fiber in food products].

A new calculation method was suggested for the determination of insoluble and soluble food fibres. The method was based on the data of chemical analysis of cellulose, lignin, pectin, and hemicelluloses with the usage of experimentally determined correlation coefficient. Insoluble food fibres are calculated according to the sum content of cellulose, lignin, and 2/3 of hemicelluloses multiplied by the corresponding correlation coefficient.

New metrological characteristics of analytical methods of analysis used for safety control of food and environmental materials.

MQS and MQSm are new metrological characteristics of the limit of determination of methods used for safety control of foods and environmental objects. MQS is the minimum quantity of an analyte that can be determined by any applicable method in an analytical sample. MQSm is the minimum quantity of analyte that can be measured in the test solution in an interlaboratory, method-performance study of a specific method, under the condition that MQSm < or = MQS.

Methods of analysis for toxic elements in foods. Part IV. General method of ashing for the determination of toxic elements.

As a result of the request of the Codex Alimentarius Committee on Methods of Analysis and Sampling, a general method for ashing of foods for the determination of toxic elements was assembled. This method consolidates the results of more than a decade of interlaboratory work of numerous USSR food laboratories and specifies the details of wet and dry ashing procedures.

Methods of analysis for toxic elements in food products. 3. Limit of determination of methods for assuring safety.

To evaluate the suitability of the analytical methods used in determining food safety, a new metrological characteristic "MQS" is suggested. MQS is defined as the absolute minimum quantity in micrograms of a substance that can be determined in a test solution (solubilized test portion). MQS accounts for 2 factors: (a) the necessity for a reliable determination of ML (maximum permitted level, i.

Methods of analysis for toxic elements in food products. 2. Review of USSR standards on determinations of heavy metals and arsenic.

Methods of analysis prescribed by USSR standards for Hg, Pb, Zn, As, Cd, Cu, Fe, and Sn in foods are described: for Hg--colorimetry of tetraiodide mercurate and atomic absorption spectroscopy (AAS); for Pb, Cd, Zn, and Cu--polarography; for Cu--colorimetry with sodium diethyldithiocarbamate and zinc dibenzyldithiocarbamate; for As--colorimetry with silver diethyldithiocarbamate; for Sn--colorimetry with quercetin; and for Fe--colorimetry with o-phenanthroline. All of the methods have the necessary metrological characteristics, including intralaboratory repeatability value (r), interlaboratory reproducibility value (R), minimum quantity of the element to be determined in the analytical test portion (MQSM), and the coefficients that account for mercury and arsenic losses during analysis. Establishing constant r- and R-values for the methods under consideration is expedient because (a) the methods suggested are used for safety purposes; and (b) the optimum amount of the element studied in the test sample is determined, to a certain degree, by the mass of the test portion.

Methods of analysis for toxic elements in food products. 1. Mineralization methods to determine heavy metals and arsenic according to the USSR standard.

Results of the work of 22 laboratories in the USSR on optimizing methods for mineralizing foods to determine Pb, Cd, As, Zn, Cu, Sn, and Fe are summarized. Recommendations are given on dry and wet mineralization as related to the analyte and the kind of food product. Optimum amounts of test portions for 22 food groups are also recommended according to the element of interest.

[Biological variability and accuracy in determining macro- and microelements in fish].

The statistical analysis of 911 personal observations and literature findings on the mean content of ash, sodium, potassium, calcium, magnesium, iron, zinc, copper and manganese in different species of fish has brought to the conclusion on the absence of any reliable interspecies differences in the content of macro- and trace elements in fish muscle tissue (except for sodium and zinc). The evaluation of the analytical accuracy in the assessment and biological variability of the mineral composition of the fish muscles has shown that the values of both these components are comparable and should be taken into account in the development of new tables on the chemical composition of food products.

[Dynamics of biometal distribution in breast milk].

The results of 352 atomic-absorption measurements of the concentrations of 8 basic biometals in breast milk samples from women of different age were investigated by variation-statistical and correlative analysis. It was found that in all the cases the distribution patterns of biometals were asymmetric. K, Na, Fe and Mn were marked by logarithmic distributions, whereas Ca, Mg, Zn and Cu by power distributions with the index 1/2.

[Changes in the nutritive value of food products after thermal culinary handling].

The data were summarized for the first time concerning the losses of the basic food substances (protein, fats, carbohydrates, Na, K, Ca, Mg, P, Fe, vitamins A, B1, B2, PP, C) and caloric value as a result of the different methods of culinary treatment: cooking, frying, stewing, baking, and so forth. It was shown that the greatest losses of vegetable foods are observed during frying, those of animal foods during cooking. It was also shown that the least losses of nutritive substances of vegetable foods are observed during cooking without water pouring off.

[Determination of sulfur-containing amino acids in food products].

To define the most accurate method for determination of sulfur-containing amino acids in foods, the possibility was tried of using a method suggested by Moore. The method is based on preliminary oxidation of cystine and methionine by performic acid and transformation of these substances to acid hydrolysis resistant cysteic acid and methionine sulphone. Model experiments and use of foods (wheat flour, grade II, and protein part of chicken egg) demonstrated that exposure of proteins to performic acid brings about oxidation of sulfur-containing amino acids to the hydrolysis-resistant forms which may be defined by chromatography with a greater accuracy.

[Use of gas chromatography for studying the change in sugar content of vegetables during cooking].

Gas liquid chromatography was used to study variation in the content of ordinary sugars and polysaccharides (starch, hemicellulose, pectins, cellular tissue) in cabbage, carrot, beef, and onion during culinary treatment (cooking). It was shown that cooking of vegetables leads, apart from extraction of ordinary sugars, to partial hydrolysis of polysaccharides including starch, and saccharose inversion as a result of which the content of ordinary sugars increases in the broth. At the same time a considerable part of ordinary sugars break down depends on cooking duration and proceeds especially vigorously in beef (50%) and onion (39%).