40 research outputs found
MODERN EDUCATION OF ENGINEERS - NEW CHALLENGES AND POSSIBILITIES
A review is given concerning the present state and recent trends in the further development
of the teaching activity of the Department
QUALITY ASSURANCE OF CEREALS - PAST, PRESENT, FUTURE
The today accepted requirements and the system of quality assurance is a
result of long-term development starting with food regulations of ancient
societies, continuing with activity of Trade Guilds in Middle Ages and with
the beginning of modern food legislation in 19-th century till today´s
harmonization of food standards at international level.
The problems of quality assurance in connection with globalization and present
situation in Central East-European countries as well as the future trends in
quality assurance are discussed. Particularly the food safety requirements,
breeding technologies, functional foods, and new analytical and quality
control methods are investigated
A glikémiás index in vivo meghatározási lehetőségei
A glikémiás index (GI) bevezetésével lehetőség nyílt az élelmiszerek újfajta csoportosítására, amelynek alapja fizikai tulajdonságaik, illetve kémiai összetételük helyett az emberi szervezetben előidézett biológiai válasz. A GI könnyen definiálható, értelmezhető; meghatározása azonban számos problémával jár. Becsléséhez gyakran in vivo, humán kísérletekre van szükség, amelyek nehézségeket rejtenek magukban. A mérendő vérglükóz koncentrációját ugyanis számos tényező befolyásolja. Az önkéntesek szempontjából fontos tényezők: a vérvétel módja, az alany egészségi állapota, étkezési szokásai valamint az egyének közötti természetes biológiai variabilitás. Emellett az élelmiszeripar feldolgozó műveleteinek hatásával is számolni kell. Az in vivo GI meghatározását az említett tényezők figyelembe vételével, szigorú szabályokat betartva kell végrehajtani. Jelen dolgozat tárgya az egyes meghatározó faktorok és a nemzetközileg elfogadott in vivo GI módszer leírása. The introduction of glycaemic index (GI) provides us to range products not only according to their physical and chemical properties but their effects in the human body (biological response). The principle and definition of GI is very simple, nevertheless its prediction gives a big problem to nutritionists and food technologists. In vivo (human) studies are generally used to determine the GI of a novel food, however, the in vivo tests have several disadvantages and difficulties. The measured blood glucose is namely dependent on several factors. The blood sampling, the health state and nutritional habits of subjects as well as the natural variability among volunteers play important role. Moreover also the effects of food processing have to be taken into account. The determination of the in vivo GI thus needs strict regulation and control. The aim of present study is to describe the influencing factors and to demonstrate the standardized and worldwide accepted in vivo GI method
A glikémiás index fogalma és in vitro meghatározási lehetőségei
A glikémiás index (GI) bevezetésével lehetőség nyílt az élelmiszerek újfajta csoportosítására, amelynek alapja fizikai tulajdonságaik, illetve kémiai összetételük helyett az emberi szervezetben előidézett biológiai válasz. A GI könnyen definiálható, értelmezhető, meghatározása azonban számos problémával jár. Becsléséhez gyakran in vivo, humán kísérletekre van szükség, erre azonban sokszor nincs lehetőség, illetve megfelelő apparátus. Az in vitro mérések fejlesztése ezért rendkívüli jelentőséggel bír. Elmondható azonban, hogy az in vitro mérések tekintetében jelenleg nincs általánosan elfogadott, minden termék esetén jól használható módszer. Az eljárások nem egységesek, a minta előkészítéstől az eredmények kiértékeléséig az egyes lépések eltérőek lehetnek. A cél tehát egy olyan standardizált és nemzetközileg elfogadott eljárás kidolgozása, mely helyettesíteni képes az in vivo kísérleteket, ugyanakkor jól alkalmazható a legtöbb élelmiszer esetében. Jelen tanulmányban az in vitro módszerek összefoglalását téztük ki célul, azok pontos leírását és a közöttük meglévå különbségek feltárását, bemutatását. The introduction of glycaemic index (GI) provides us to range products not only according to their physical and chemical properties but their effects in the human body (biological response). The principle and definition of GI is very simple, nevertheless its prediction gives a big problem to nutritionists and food technologists. In vivo (human) studies are generally used to determine the GI of a novel food, however, the in vivo tests have several disadvantages (human subjects, blood sampling, special safety requirements, higher cost). Therefore the development of in vitro methods plays an extremely important role. The recently used in vitro methods are very various and they can be different on several ways thus the value of the predicted GI is quite diverse. The main goal is to develop a standardized, generally accepted method which can replace the human studies moreover gives reliable results on GI. The aim of this study is to summarize and describe in vitro GI methods focusing on their methodological differences
Az élelmiszerbiztonság analitikai kérdései, különös tekintettel a klímaváltozásra = Analytical challenges of food safety with particular reference to the climatic change
As forecasted by the Intergovernmental Panel on Climate Change (IPCC) of the UN, the World Meteorological Organization, the Hungarian VAHAVA (Change-Effect-Response) project, as well as the National Climate-Change Strategy accepted by the Hungarian Parliament, the expected climate change in the Carpathian Basin will have unfavourably impacts on the Hungarian agriculture, food security and food safety, causing increasing risks of human and animal health. Particular attention should be given to toxigenic moulds and their toxins. Concerning locally grown agricultural crops, the mycological safety of cereal grains, spice paprika, some fruits (apples and grapes) and their processed products might be increasingly contaminated while pistachia, peanuts, cocoa- and coffee-beans represent the main sources of mycotoxin risks of imported commodities. Toxigenic moulds and their toxic secondary metabolic products are important from points of view of both microbiological and chemical food safety, thus, their detection/investigation is one of the main challenges of food analysis in the XXIth century. The mycotoxin problem is of particular importance due to the fact that the mycotoxins are much more resistant to effects of food processing than the microscopic moulds generating them. Thereby products which don’t contain any more viable mould propagulas may still contain mycotoxins. The presence of low concentrations of mycotoxins in food or feed are not recognizable to the consuming persons and animals, while the accumulation of this toxic compounds in the body could cause long term very serious and chronic health problems. A serious difficulty in controlling this sítuation is sampling and sample preparation to obtain representative test portions due to the very uneven distribution of mycotoxins in the most frequently contaminated commodities. Because the time- and labour-intensity of „classical” microbiological and conventional food analytical methods, there is a need for rapid, sensitive, easy-to-use and non-destructive means for detecting moulds and mycotoxins in large number of samples. The paper briefly summarizes analytical methods for determination of mould biomass or detection of mycotoxins in such complex matrices as foods. Such techniques are: impedimetric estimation of mould contamination of food, NIR spectroscopic detection of mouldiness of paprika powder, NIRs estimation of mycotoxins in grains, detection of volatiles of mould-origin by chemical sensor arrays (electronic noses), estimation of various mycotoxins by different high performance chromatographical and immunochemical methods, application of immuno- or nano-sensors utilising the optical waveguide lightmode spectroscopy, or, the surface plasmon resonance method. The correlative instrumental methods must be calibrated first against reference properties and the instrumental data are evaluated with the help of chemometric methods. Related to the last aspect, certain software developments as qualitative classification tools made by Hungarian scientists are pointed out
The Dedicatory Presentation in Late Antiquity: The Example of Ausonius
This is the publisher's version, also available electronically from http://www.jstor.org/stable/23064230?seq=1#page_scan_tab_contents.No abstract is available for this item
Factors Affecting Precipitation of Calcium Lactate from Fermentation Broths and from Aqueous Solution
Lactic acid is one of the most important organic acids which is being extensively used around the globe in a range of industrial and biotechnological applications. Lactic acid can be produced either by fermentation or by chemical synthesis but the biotechnological fermentation process has several advantages compared to the other one. However fermentation broth contains a number of impurities which must be removed from the broth in order to achieve more pure lactic acid. Efficiency of recovery is crucial to the economy of the whole process as well since the costs of separation and recovery are responsible for more than half of the entire cost of production. In the traditional procedure, the heated and filtered fermentation broth is concentrated to allow crystallization or precipitation of calcium lactate, followed by addition of sulphuric acid to remove the calcium in form of calcium sulphate. The disadvantage of this procedure is the relatively high solubility of calcium lactate which causes product loss in the crystallization step. Therefore we investigated the effects of four operating parameters of the crystallization/precipitation process from two different fermentation broths and from an aqueous solution. Thus we applied three central composite statistical designs, in which the examined parameters were the temperature of the solution, the duration of the process, the effect of ethanol addition to the solution as well as the effect of multi-cycle precipitation after separation of the precipitated calcium lactate. According to the results, more than 50 percent calcium lactate precipitation increase can be obtained from fermentation broth by adding sufficient amount of ethanol and adjusting the proper temperature of the process