In human nutrition research, nuclear analytical techniques, particularly neutron activation analysis (NAA), are used mainly for thein vitro study of trace elements. According to work sponsored by the IAEA, up to 15 trace elements and 5 minor elements of nutritional interest may be determined in biological materials by NAA with good accuracy and precision. A programme is described in which NAA was used for the determination of 14 trace elements and one minor element in human milk. NAA also plays an important role in the certification of reference materials for nutritional studies.
Authors:Andrea Lugasi, Márta Horacsek and Éva Martos
Az étrend-kiegészítők olyan élelmiszerek, amelyek koncentráltan tartalmaznak tápanyagokat, köztük vitaminokat és ásványi anyagokat, valamint egyéb élettani vagy táplálkozási hatással rendelkező anyagokat. Hazánkban az étrend-kiegészítőket az Európai Unióhoz történt csatlakozás óta előzetes engedélyezés nélkül, az Országos Élelmezés- és Táplálkozástudományi Intézetnél tett bejelentéssel egy időben piacra lehet helyezni. A termékek forgalmazását, összetételét, jelölését, a fogyasztó felé történő kommunikációját számos jogszabály határozza meg, ugyanakkor bizonyos területeken, a közösségi szinten harmonizált rendeletek hiánya jelentős problémákat okozhat. A tanulmány második részében (első rész: Orv. Hetil., 2010,
1563–1572.) az étrend-kiegészítőkben előforduló összetevők táplálkozás-élettani értékelésének folyamata, a felmerülő közegészségügyi problémák, valamint az étrend-kiegészítők táplálkozásban betöltött szerepének bemutatására kerül sor. Orv. Hetil., 2010,
Authors:F. Szira, I. Monostori, G. Galiba, M. Rakszegi and A.F. Bálint
Wheat-based food has great importance in human nutrition: in European countries they provide 20–30% of the daily calorie intake, and additionally, the wholemeal and healthy food becomes even more popular. Mineral content in grains is dependent on genetic and environmental factors (varieties, soil type, geographical location of the growing area, etc.), therefore, it is complicated to estimate how many percentage of the daily micronutrient requirements can be covered by wheat-based products. In this study, copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se) and zinc (Zn) contents of 13 commercial wheat flour products, and the white flour and wholemeal of 24 winter type bread wheat varieties were studied to estimate the nutritional value of these products. All investigated samples were produced in Hungary. Significant variation was revealed in the case of all mineral elements in the different brands of wheat flours. Generally, the white flour enriched with germ showed higher mineral contents than the average values of normal white flours. Furthermore, the wholemeal has higher Cu, Fe, Mn and Zn, but not higher Se contents than the white flours. Mo content was also higher in some brands of white flour than in wholemeal.The investigated winter wheat varieties showed significant differences in the case of Fe, Mn, Se and Zn contents, but none of the varieties showed outstandingly high micronutrient content. The milling process — as it was expected — reduces the concentrations of four elements (Fe 33%; Mn 88%; Zn 71%; Cu 44%); however, the Se and Mo concentrations were not affected significantly. Using the average micronutrient content in the wholemeal of varieties, the daily Mn and Fe requirement can be covered by the consumption of about 250 g wholemeal. Additionally, the daily Mo requirement could be met by the daily consumption of 140–190 g of commercial white or wholemeal flour.
Earlier studies on protein antinutrients and allergens naturally present in legume seeds have shown that these compounds are responsible for the impaired performance of experimental animals when exposed for a long term. These reactions were characterized by lowered nutritional performance, reduced growth, pure digestion and absorption, changes in gut motility, structural damage in small intestine and diarrhoea. A lot of efforts were made for gathering data on heat stability and resistance to chemical or enzyme treatments of these compounds to reduce or eliminate these harmful effects.A novel research approach has described that these compounds have a special regulatory role in the gut metabolism and modulate hormone and immune responses which resulted in a novel concept of “nonnutritive biologically active compound”. These studies revealed that the chemical structure of these compounds was responsible for the induction of such physiological reactions as increased endogen N-loss, change in the plasma amino acid concentration or plasma lipid composition with reduction of total cholesterol level or developing of harmful immune responses to luminal antigens resistant to the gut digestion. Resent studies were therefore related to the description of their interaction with the gut metabolism and understanding of the modulation of gut immune responses to luminal antigens.This review was inspired to summarise the research efforts on the above field performed by the Nutritional and Biological Units of the Central Food Research Institute.
Authors:Sz. Szélpál, Zs. Kohány, E. Fogarassy, I. Galambos, A. Koris, J. Csanádi, Gy. Vatai and C. Hodúr
The largest quantities of by-products of dairy processing originates from the cheese making. Whey proteins are used for animal feeding and human nutrition as well, for example in dry soups, infant formulas, and supplements. The fat components of the whey might impair its use. The aim of our experiments was to investigate the separation of the lipid fraction of whey. The microfiltration is said to be a gentle and energy efficient method for this task. During the measurements 0.2 μm microfiltration membranes were used and the membrane separation was enhanced by vibration, inserting static mixer and air sparging. The de-fatting efficiency, the retention of the whey components, the flux values, and the resistances in different combinations were compared in this paper.
Plants are the basis of the human nutrition and have been selected and improved to assure this purpose. Nowadays, new technologies such as genetic-, metabolic engineering and genomics approaches allow further improvement of plants. The nutritional quality of a crop is not only dependent on its energy supply in the form of sugars/starch, but also on the amino acid composition of its storage proteins. Potato, the most important non-cereal food crop, is deficient in the sulphur containing amino acids, methionine and cysteine. The manipulation of the targeted amino acid biosynthesis can be a way to circumvent this problem. Cysteine is synthesised from
-acetyl-L-serine formed by serine acetyltransferase (SAT). The main results and some unpublished ones are summarised here. They present the key role of SAT enzyme in the biosynthesis of cysteine and the biotechnological approaches of nutritive value improvement through elevation of cysteine content.
The behaviour of iodine in the environment is of interest both in relation to radioecology and human nutrition. Radiochemical techniques were used to evaluate various aspects of the behaviour of iodine in the environment. The natural iodine content of plant, water and soil samples collected from three sites was determined using preconcentration neutron activation analysis (PNAA). The effect of initial chemical speciation on the distribution of iodine between various soils, sediments and waters was evaluated using I-131 tracer. Iodide was found to adsorb more extensively than iodate, although for most of the solid/water systems examined, a substantial portion of the iodate was slowly reduced to iodide. Experiments involving gamma irradiation suggest that much of the sorption of iodide and reduction of iodate involved microbial processes. Distribution coefficients measured using I-131 were comparable with values based on the natural I-127 content.
Authors:C. Baskett, V. Spate, M. Mason, C. Reams and J. Morris
The selenium excreted in urine can be measured to assess the dietary status of selenium, an essential trace element in human nutrition. The objectives of this work were: 1) to develop a procedure, capable of high sample throughout, by which the major interferences can be reduced such that selenium concentrations can be measured in urine by Neutron Activation Analysis (NAA) using77mSe (17.4 s; and 2) to apply the method to a human dietary selenium study in which several selenium monitors were compared. The method involves a pre-irradiation arsenic-coprecipitation separation of the selenium from urine in the presence of a high specific-activity75Se tracer. The processed urine samples are analyzed using NAA. The procedure was applied to 58 urine specimens longitudinally collected from 12 subjects consuming three different levels of selenium. A dose-response relationship was observed in urine as well as a high correlations with both serum and whole blood selenium concentrations.
Authors:Yong Chung, Sun Kim, Gwang Sun, Jong Lim, Jong Moon, Kye Lee, Young Kim, Jong Choi and Ju Lee
The analysis of mineral contents in space foods is needed to obtain an information on a comprehensive elemental composition
as well as the investigation on the effects of human nutrition and health based on the dietary intake of mineral elements.
Recently, six items of new Korean space foods (KSFs) such as kimchi, bibimbap, bulgogi, a ramen, a mulberry beverage and a
fruit punch which was developed by the KAERI, and the contents of more than 15 elements in the samples were examined by using
instrumental neutron activation analysis (INAA). Five biological certified reference materials, NIST SRM were used for analytical
quality control. The results were compared with those of common Korean foods reported, and these results will be applied toward
the identification of irradiated foods.