Additional information to the in vitro antioxidant activity of Ginkgo biloba L.

The in vitro antioxidant and free radical scavenging activity of the ethanol extract from Ginkgo biloba L. was examined in different systems. The extract showed hydrogen-donating ability, reducing power, copper-binding property, free radical scavenging activity in a H2O2/.OH-luminol system and it could prevent the autoxidation of linoleic acid. All these properties are involved in the overall antioxidant activity of Ginkgo biloba which makes it suitable for the prevention of human disease in which free radicals play an important role.

[The effect of keeping condition and genotype on the electrophoretic properties of pork proteins]. / Einfluss der Haltungsbedingungen und des Genotyps auf das Elektrophoreseverhalten von Schweinefleischproteinen.

Besides differentiation of animal species the electrophoretic methods are efficient also in determinations of the factors effecting the protein patterns. The goal of this study is to compare the effect of the genotype and the keeping conditions on the electrophoretic behaviour of the pork meat proteins. Isoelectric focusing was found to be more efficient than SDS-PAGE concerning studies of the effect of these factors. An optimal separation has been achieved with an ampholyte-mixture at pH ranges 2-11, 5-7 and 7-9. Peroxidase activity of the separated myoglobines of the meat samples was stained for detecting the differences in protein zones according to the keeping conditions. The myoglobin zones stained with o-dianisidin were evaluated by densitometry. The protein zones of the organic meat samples showed higher intensity than those of the control-samples.

Comparison of some components of pigs kept in natural (free-range) and large-scale conditions.

A new pig genotype of Hungarian Large White (75%) × Mangalica (pig with curly bristles, 25%) was used in the experiments. The experimental group was kept in a farming system under strictly natural circumstances until a body weight of 120 kg was attained. Neither antibiotics nor yield-increasing hormones were given to this group. The control group was kept in the usual large-scale farming conditions until body weight of 120 kg was attained. In most cases, protein, zinc, and copper levels and, in some cases, iron levels were significantly higher in some major cuts (neck-end (Boston-butt), loin, ham) of the 'free-range' pigs (n = 12) in comparison with the control animals kept in large-scale farming conditions. There was, on average, 15% less cholesterol in the muscles and 30% less cholesterol in the liver and less linoleic acid in all tissues of 'free-range' pigs than in the control group. There was less fat, but the amount of thiamin and riboflavin in the liver of the naturally kept pigs was twice that in the controls. In respect of TBA-reactive compounds, there were no significant differences between the two groups, but superoxide dismutase (SOD) showed significantly higher activities in all cuts from pigs kept in a large-scale farming system. This may be the effect of a higher level of linoleic acid in the fat.

Determination of thiamine (vitamin B1) and riboflavin (vitamin B2) in meat and liver by high-performance liquid chromatography.

HPLC methods described so far for the determination of thiamine and riboflavin in meat samples have used mostly fluorescence detection. The aim of this work was to elaborate a suitable method with UV detection for this purpose and to compare the thiamine and riboflavin contents obtained for meat and liver samples from various pig groups. Homogenized spare rib, chop, ham and liver samples were treated with acid and heated (at 121 degrees C, 30 min), followed by enzymatic digestion to release the vitamins. After a clean-up procedure the simultaneous determination of thiamine and riboflavin was performed with a Nucleosil ODS (3 microns) packed column at 45 degrees C. The mobile phase was phosphate buffer (pH 3.0)-acetonitrile (84:16, v/v) containing 5 mM sodium heptanesulphonate. The relative standard deviation was 5% for thiamine and 12% for riboflavin in meat and 8% for thiamine and 5% for riboflavin in liver for four parallel determinations.

Changes of some lipid and lipid peroxidation characteristics in obese people as a result of a low energy diet.

In blood samples of 54 obese persons (13 men, 41 women) some lipid components, malondialdehyde (MDA), and the activities of free radical protecting enzymes superoxide-dismutase (SOD) and glutathione-peroxidase (GSHpx), were determined before and after a seven-day slimming diet of 2.1 MJ/day. Body weight, triglycerides, HDL-cholesterol, and HDL-3-cholesterol all decreased, total cholesterol increased after the seven days hospitalization. After continuing the slimming diet (5.0-6.3 MJ/day) at home, HDL-2-cholesterol increased and total cholesterol returned to the initial value after three months. MDA decreased in the groups of hyperlipoproteinemia II/a and II/b and also in the group with high cholesterol and triglyceride levels (above 5.7 and 2.7 mmol/l). Correlation coefficients refer to the dominant role of high TG in the intensity of lipid peroxidation. The activity of SOD fell after the slimming, independent of lipid parameters. GSHpx activity remained unchanged except a drop in the male participants having high cholesterol levels. The behavior of the free radical protecting enzymes needs further examination.

Longitudinal examinations in the course of dietotherapy of mentally retarded obese in-patients.

Mentally retarded obese in-patients were fed by low-energy diet (4.2-4.6 MJ) for 9 months. During this period, an average of 13 +/- 4.5 kg loss of body mass occurred in men and 16 +/- 2.7 kg in women. Anthropometric measurements were performed before starting the dietotherapy and in the ninth month. Changes of body fat could be followed well when calculated according to BMI. Less reliable results were obtained with skinfold thickness measurements, presumably due to body deformities. Results of clinical laboratory tests, which were carried out before starting the dietotherapy and in the fourth and seventh months, suggested that a low-energy-containing diet with balanced nutrient content and adequate protein intake did not impair protein metabolism, favourably affected serum triglyceride and cholesterol levels, but resulted in an unfavourable decrease in the HDL-cholesterol content.

[Experimental 3-month study of safety of textured soybeans Becsei]. / Issledovanie bezopasnosti ispol'zovaniia Bechenskoi teksturirovannoi soi v trekhmesiachnom éksperimente.

The authors conducted a three-month safety test of a textured soy (TS) product manufactured by the Agricultural Plant, Boly. Young male and female rats received semisynthetic diets containing 8, 18 and 38% of TS protein or casein supplemented with methionine, as the only source of protein. The effect of the diet containing 18% of TS protein on the growth, on certain parameters of protein and fat metabolism and on the zinc and copper status corresponded to that produced by 18% of casein supplemented with methionine. When the content of TS protein was lower or higher than the optimal (18%), the development of rats fell behind the control ones receiving adequate amount of casein. High doses of TS protein produced a favourable effect on lipid metabolism in the liver, but its effect on zinc metabolism was unfavourable. No signs of toxic action of the TS product were recorded during the three-month safety test of TS.

Measurement of some antinutritive factors in meat products containing texturated vegetable protein (TVP).

The alpha-(1,6)-galactosyl oligosaccharide and phytic acid contents of sausages containing TVP were examined. The results show how the meat industrial technologies affect the oligosaccharide and phytic acid contents of the end-products. According to these experiences, the small quantities present in the end-products are not considered to be harmful to health but may show unexpected effects when compared to traditional products. With the knowledge of the concentrations of the measured oligosaccharides and phytic acid, after adequate calibration, the real TVP content of the finish-product can be determined according to the method elaborated by the authors.

Lipid characteristics and malondialdehyde level in the sera of obese people.

In the blood sera of 70 obese persons (26 men, 44 women) some lipid components and malondialdehyde (MDA) level were determined before slimming. The people were classified into groups of hyperlipoproteinaemia on the basis of laboratory results, according to Fredrickson and Lees. In 32 people with high blood cholesterol level (above 5.7 mmol) there were negative correlations between MDA and high-density lipoprotein (HDL) fractions. Correlation coefficients were the greatest in the group IIa of hyperlipoproteinaemia (HDL-C. r = -0.74; HDL-2-C. r = -0.54; HDL-3-C. r = -0.78). Correlations were not found in subjects with a normal cholesterol level. The results were attributed to the formation of oxidized cholesterol products, caused by lipid peroxidation, which may decrease the HDL synthesis. It seems that in hypercholesterolaemia coupled with obesity, lipid peroxidation can contribute to the reduction in HDL levels, which is an important protective factor against cardiovascular diseases.

Nutritive value of different grape musts (Vitis vinifera L.).

Musts of 11 different grape sorts were analyzed for titratable acids, total sugars, nitrogen, vitamin B group (B1, B2, B6, pantothenic acid) and macro- and micro elements (K, Ca, Mg, Fe, Zn, Cu, Mn, Mo). Analyses were done on samples collected in 1983 and 1984. The nutritive value of each sample was characterised by indices based on the nutrient concentrations and recommended dietary allowances (RDA). The nutritive values of the various grape must sorts were generally similar to those of the following vintage. Favourable climatic conditions had a positive effect on the nutritive values.

The effect of improper feeding on the lipid peroxidation of meat animals.

Pigs of 50 kg bodyweight were fed without premix for two months before slaughtering. Their loin samples showed a lower degree of lipid peroxidation (indicated by a higher antioxidative capacity) than other pig groups which had consumed various premix levels. Malonaldehyde concentration increased in the blood sera and livers of 7-week-old chickens treated with a high dose of an ionophoric coccidiostatic agent, Salinomycin. Premix deprivation resulted only in a trend to decrease lipid peroxidation. The possible effects of lipid peroxidation and its degradation products on the physico-chemical characteristics of meat and human health is discussed. The results urge that improper feeding practices should be avoided and optimal premix applications should be found which correspond to the actual requirements.

Trypsin and chymotrypsin inhibitor activities in plant foods from Vietnam and Hungary.

A method for the determination of chymotrypsin inhibitor activity and a screening test for evaluating higher activities of trypsin inhibitor were elaborated. The protease inhibitor activities of the most important plant foods from Vietnam and Hungary were determined. In cereals and legume seeds the activity of chymotrypsin inhibitors is generally lower than that of the trypsin inhibitors. In various soy products (isolates, texturates) the extent of lowering of chymotrypsin inhibitor activity was less than that of trypsin inhibitor related to raw soy bean. The cooking process according to the usual kitchen technique of Vietnam has more effect on the higher trypsin inhibitor level of soy bean than on other legumes of average activity.

[Lactic acid acidosis with mitochondrial myopathy due to a pyruvate dehydrogenase deficiency]. / Laktatazidose mit mitochondrialer Myopathie auf Grund eines Pyruvat-Dehydrogenase-Defektes.

We report on a patient, now 17 year old, in whom lactic acidosis was detected at the age of 7 while attempting to diagnose the causes of increasing weakness. The laboratory examinations revealed elevated pyruvate, alanine and oxaloacetate levels in serum and also a lowered citrate level. This led us to suspect a disturbance of the pyruvate dehydrogenase complex. Reduced pyruvate dehydrogenase activation in leucocytes and muscle tissue was indeed found. This article reports on the 10 year history of this case and attempts to establish a connection between the various symptoms observed and the underlying metabolic defect.

Phytate content of some foods from plant origin from Vietnam and Hungary.

For the estimation of phytate-ion the iron content of FeIII-phytate complex was determined by spectrophotometry with o-phenanthroline. In most cases phytate-phosphorus was also evaluated. In different food samples iron to phosphorus ratio in phytate generally deviated significantly from the theoretical 1.20 value. Wheat flour products, maize, rice, beans, peas, lentil and soy from Vietnam and Hungary, furthermore several bakery products from Hungary and some imported soy products were analysed for phytate content. The effect of heat and fermentation on phytate content was also checked in breads and other foods. It was concluded that the processes often used in food industry, namely fermentation and thermal load, have relatively slight effect on the phytate content of plant foods. Cooking losses for phytates ranged 1-60% in cereals and legumes according to the usual kitchen technique in Vietnam.

Optimalization of the protein content of canned baby-foods based on their nutritive value.

When planning canned foods the protein value Net Dietary-protein Energy percent = 8% of a 5-month old infant's requirement was considered as constant. The nutritive value required for this purpose was calculated on the basis of amino acid composition, making use of the Morup-Olesen index. Canned foods were made of two protein-containing components, of sunflower-oil and (occasionally) of starch, by computer, keeping the energy value constant, i. e. 1250 kJ, which covers half of the infant's daily requirement. The optimalization based on the protein value is illustrated by the examples of egg-potato, beef-peas and flour-beans pairs, considering the practical requirements as well.

Nonenzyme browning and its effect on protein nutrition.

The nonenzyme browning involves the thermal decomposition of sugars, the caramelization, the decomposition of oxi-acids, the so called "Maillard reaction" between amino acids and carbohydrates, the reaction between oxidized fats and proteins, and those alterations which take place by the alkaline treatment of proteins. The Maillard reaction is of secondary importance in the case of foodstuffs and fodders with low carbohydrate contents (meats, meat meal, fish meal). By the heat treatment, the sulphur-containing amino acids of proteins (cystine, methionine) are damaged primarily because of oxidation, but the decrease in the amount of threonine, serine, tryptophan, and lysine is observable too. According to the formation of enzyme resistant cross-links, the in vitro and in vivo digestibility of protein decreases after the heat threatment and the communication with oxidized fats. Besides the amino acids mentioned, the possibility of enzymatic break-off of leucine and isoleucine is reduced too. In the course of the heating of proteins the occurance of racemization has to be considered too (formation of alloisoleucine). The basic mechanism of the reaction between sugars and simple amino acids is already essentially explained: amino-acids break off after the formation glycosilamines and Amadori products but they are linked irreversibly to some, partly unsaturated decomposition products of sugars, types of 6 and 3 carbon atoms. The decrease in the biological usability of amino acids starts already with the Amadori products. The reactivity of the single amino acids depends on the number of carbon atoms, on the basicity, and on the polarity of the amino acid molecule. The especially highly reactive amino acids of proteins are (1) the essential lysine (because of its 6-HN2 group), (2) other types of basic amino acids, and (3) trypotphan (because of the lability of the indole ring), methionine, cystine and threonine. In the Maillard reaction of tryptophan the --NH--group of the indole ring is involved too. The Maillard reaction is highly influenced by the pH of foodstuffs or other agents. The reduction of pH which may be performed by the increase of fermentation in the baking industry, lessens the decomposition of lysine and tryptophan in proteins. The raise of pH in basic domain enhances the Maillard reaction up to a maximal value but a decrease may be observed when the pH is raised further on. In foodstuffs and in other solid protein-carbohydrate systems the increase of the moisture content generally enhances the Maillard reaction, the sensibility of the single amino acids to the changes int he moisture content is different. In the case of the alkaline treatment of proteins, we must reckon not only with the decomposition of single amino acids, first of all that of cystine by beta-elimination, but with the formation of some amino acid derivatives as lysinoalanine, lanthionine, and in ornithinoalanine too. Presently lysinoalanine is of toxicological importance as proved by experiences on rats...