bluuebunny/crossref_metadata_2025 huggingface dataset:
Proteolytic activity of crude cell‐free extract of Lactobacillus casei and Lactobacillus plantarum
Authors: Hegazi F. Z. , Abo‐Elnaga I. G.
Published: November 2006

Crude cell‐free extracts of some strains of each L. casei and L. plantarum were assayed for their amino‐, imino‐ and endopeptidase as well as the caseinolytic activity. L‐alanine‐, L‐phenylalanine‐ and L‐leucine‐p‐nitroanilide but not L‐glutamic acid‐p‐nitroanilide, were hydrolyzed by all the strains indicating an amino‐peptidase activity. The activity of proline iminopeptidase was very low compared to that of the aminopeptidase. L. casei could be distinguished from L. plantarum by its high endopeptidase activity against succinyl‐phenylalanine‐ and glutaryl‐phenylalanine‐p‐nitroanilide. The caseinolytic activity of cell‐free extract of L. casei ATCC 393 was about one seventh the caseinolytic activity of intact cells, suggesting that the bulk of the cellular proteinase activity is located in the cell wall. It appears that a metallo aminopeptidase and a probable cysteine one are involved in the hydrolysis of amino acid‐p‐nitroanilide, whereas the endopeptidase activity appears to be related to a cysteine enzyme. Incubation of gels with L‐leucine‐p‐nitroanilide after electrophoresis allowed the revealing of 2 zones of aminopeptidase activity in a strain of L. casei and only one in two others, but in L. plantarum it did not allow the revealing of any. The high proteolytic activities of L. casei compared to those of L. plantarum may explain its more frequent occurence in cheese and its probable role in the ripening of many cheese varities.
Qualitätsveränderungen während der Lagerung von Gemüseerbsen (Pisum sativum L.) 1. Mitt. Äußere und sensorische Qualitätsmerkmale
Authors: Böttcher H.
Published: November 2006

Während der Lagerung von Gemüseerbsen sind bei den Frischmasseverlusten, der kombinierten Druck‐ und Scherfestigkeit und den Boniturnoten für die äußere und sensorische Qualität meist lineare oder mit der Lagerdauer degressiv ablaufende Veränderungen in Richtung eines Qualitätsabbaues festzustellen. Bei den Fäuleverlusten (y = β1(x — z)n; x = Lagerdauer in Tagen; x > z) variiert vor allem die makroskopisch symptomfreie Zeitspanne z sehr stark. Bei allen Merkmalen erweist sich der Einfluß der Lagertemperatur als dominant, bei einigen zusätzlich auch die Ernteform (mit und ohne Hülsen), während jährliche Anbaubedingungen und Sorten in ihrer Bedeutung stark zurücktreten. Lagergut ohne Hülsen zeigt einen schnelleren Rückgang der äußeren Qualität, der sensorischen Qualitätsmerkmale und der fäulnisfreien Zeitspanne z als solches mit Hülsen, so daß die temperaturabhängige Haltbarkeit nur durch zwei verschiedene Regressions‐funktionen mit dem Modell y = β1e‐cθ (Θ = Lagertemperatur in °C; c = Maßzahl der Schnelligkeit des Rückganges der Lagerdauer) dargestellt werden kann. Lagertemperaturen von 0 °C verhindern bei Gemüseerbsen die Nachreifeerscheinungen nicht, verzögern sie aber sehr.
Fractionation of proteins in reconstituted skim‐milk
Authors: Omar M. M. , Śmietana Z.
Published: November 2006

Properties of the dried milk were improved when calcium chloride was added to the raw milk prior to the drying process. Solubility, wettability, undenatured whey protein and protein retention indices of the dried milk were increased and the reconstitutability was improved. The elution profile of the protein fractions on a Sephadex G‐100 column differed according to the forward preheating of the raw milk and the addition of calcium chloride.
Charakterisierung und Einsatzmöglichkeiten einer Pektatlyase aus Erwinia carotovora
Authors: Wegener Ch. , Henniger H.
Published: November 2006

Das phytopathogene Bakterium Erwinia carotovora bildet bei Kultur im submersen Verfahren extrazellulär Pektatlyase. Der Einfluß von Substrat, Temperatur, Wasserstoffionenkonzentration, Ca+ + und PO4− − − auf die Aktivität dieses Enzyms sowie seine Temperaturstabilität wurden untersucht.

Cx‐Cellulase und Protease treten als Nebenaktivitäten auf und wurden teilweise in die Untersuchungen einbezogen.

Mögliche Anwendungsgebiete der Pektatlyase in der Lebensmittelindustrie und im wissenschaftlichen Bereich werden diskutiert.
Determination of foaming properties of proteins
Authors: Gassmann B. , Kroll J. , Cifuentes S.
Published: November 2006

Comparing typical examples of equipment for performing the whipping operation, dispersions and colloidal solutions (13%) respectively of 9 diverse protein based whipping agents were differently aerated, and the foaming properties were determined. Whipping was performed in an industrial manner (batch operation at atmospheric pressure and continuous operation using compressed air and static dispersors) as well as devices widely used in laboratory (household‐type mixer and motor‐driven plungers moving in vertical glass cylinders) were employed. Moreover a new direct current motor‐driven whisk/stirrer, the steplessly adjustable rotation speed of which had been made constant and independent of the rheological properties of the protein solutions to be whipped, was tested.

Foaming properties measured suggest that only the new laboratory whipping principle reflects the actual performance of protein based whipping agents and that it is far better adapted to large‐scale processing then the laboratory equipment most commonly used. Optimum foam forming need distinct rotation speeds and stirring times as well as pH values typical for each product. In creating sugar containing protein foams with a high degree of aeration however in no case of laboratory operational conditions the amount of energy and air available for whipping was sufficiently large. Because of the advantages of the new whipping principle over the otherwise tested ones the motor output and the stirring conditions now are being improved.
Die quantitative Bestimmung des Proteingehaltes der Milch mittels Ultraviolettspektralphotometrie 4. Mitt. Die Bestimmung des Proteins aus konservierten Milchproben
Authors: Reichardt W. , Schüler E. , Sieber L. , Schüler E.
Published: November 2006

Es wird über die Ergebnisse der quantitativen Bestimmung des Proteingehaltes von konservierten Milchproben mit Hilfe der Ultraviolettspektralphotometrie berichtet. Außer der Konservierung mittels Borsäure, Bronopol, Kupfersulfat, Kaliumdichromat und Ammoniumperoxodisulfat sind die Lagerung der Milch bei Temperaturen unter 0 °C und die Gefriertrocknung geprüft worden. Neben Bronopol und Kupfersulfat erweisen sich bei der Proteinbestimmung mittels Absorbanzmessungen bei 210 nm, 235 und 280 nm sowie 210 und 220 nm besonders die physikalischen Konservierungsverfahren als geeignet. Für die tägliche Justierung des Spektralphotometers wird die Anwendung von Lösungen und Quarzfiltern mit definierter Absorbanz empfohlen.
Comparative study of the influence of an inhibitor of monoaminooxidase (nialamide) on the calcium and phosphorus metabolism in slow and fast‐growing rats
Authors: Campos M. S. , Barrionuevo M. , Reche A.
Published: November 2006

Nialamide was supplied to slow‐growing animals in doses of 20 mg/100 g of diet for 15 or 30 days. The dose for fast‐growing animals was 10 mg/100 g of diet. The digestive utilization of calcium and phosphorus decreases significantly when adult slow‐growing rats receive the drug for 30 days. This fall is already important in fast‐growing rats when they receive nialamide for only 15 days. In the same way the falls in the retention of calcium and phosphorus in adult rats are only evident when the period of treatment is through 30 days, even females being in negative balance of phosphorus. The amount of calcium retained decreases significantly in fast‐growing rats and so does phosphorus impressively after only 15 days of treatment.
Water binding of proteins in the processing frankfurter‐type sausages Part. 1. Water‐binding ability of freeze‐dried meat fractions containing myofibrillar and stromal proteins
Authors: Heinevetter L. , Gassmann B. , Kroll J.
Published: November 2006

As soon as possible and 48 h after slaughter respectively, from both blade‐bone muscle groups of cattle and pig carcasses the „thick pieces”︁ were excised, extracted, and fractionated. Residues and precipitates from water and salt extracts resulted were freeze‐dried, and an improved Baumann capillary suction apparatus was used to measure their water binding capacity (WBC) with and without addition of 2% sodium chloride and/or heating to 80 °C. With one exception the WBC results followed a relative pattern demonstrating the final residues (stromal proteins and leavings of myofibrillar proteins) binding the highest amount of added water, precipitates of dialysis (mainly containing myofibrillar proteins) a remarkable amount and powdered meats the least. As scanning electron micrographs confirmed, there were no fibrous structures in the precipitates resulted from dialysis of salt solutions (1.0 mol/1). Heating decreased the spontaneous water uptake of all fractions. Addition of sodium chloride had only a noticeable capillary‐suction and swelling effect on unheated samples. Hence swelling of undissolved protein structures (extraction of myosin and possibly of actomyosin) is therefore not the only way for water binding in frankfurter‐type sausages.
Fate of phytic acid during bread making
Authors: Chhabra P. , Sidhu J. S.
Published: November 2006

The effect of malt addition and yeast concentration on the hydrolysis of phytic acid during different stages of bread making has been reported. There was a considerable hydrolysis of phytic acid with the addition of yeast and malt. In the breads of S‐308 and WL‐711 wheat varieties, the loss of phytic phosphorus was 6.6. 8,1; 24.6, 23.0 and 26.6, 27.7% in case of nonyeasted, 1.5% and 3% yeasted dough of whole wheat flour (Atta) respectively. However in white bread, the loss of phytic phosphorus was 14.0 and 18.4; 46.2 and 41.5; 51.7 and 49.4%, in non‐yeasted, 1.5% and 3% yeasted doughs of S‐308 and WL‐711 wheat varieties respectively. A significant loss of phytic acid was observed at a yeast level of 1.5 and 3% and with 0.4% malt addition as compared with the control. Most of the phytic acid was hydrolysed during the fermentation and proofing stages in both types of bread samples.
Phytate hydrolysis during breadmaking in several sorts of Polish bread
Authors: Bartnik M. , Florysiak J.
Published: November 2006

The quantitative changes of phytates taking place during preparation of some sorts of Polish bread were investigated. Sorts of bread chosen for investigation were produced from raw materials with a high phytate content: flour of high extraction, soy bean flour, bran and wheat germ. The content of phytic phosphorus was determined in all components (raw materials), intermediate products and bread. The degree of phytate hydrolysis during preparation of different sorts of bread varied and depended both on the initial amount of these compounds in raw materials used and on the technological process adopted. The most intensive hydrolysis of phytate took place during preparation of rye breads: about 80% of the initial value were hydrolyzed. Almost in all sorts of wheat bread the degree of hydrolysis of phytate was much less: only about 25–60% of these compounds were decomposed. In case of “mixed” bread (wheat and rye one) undecomposed phytate varied from 6% to 49% of the initial value.
Orientierende Untersuchungen zum Stoffwechsel verschiedenartiger akalorischer Verbindungen mit fettähnlichen Eigenschaften bei der Ratte
Authors: Aust L. , Mieth G. , Proll J. , Elsner A. , Behrens H. , Gerhard W. , Brückner J. , Noack R.
Published: November 2006

Pseudofette auf der Basis vollständig substituierter langkettiger Ester und Ether von Polyhydroxyverbindungen (Saccharose, Triglycerol und Polyethylenglycol) verhalten sich mehr oder weniger indifferent gegen‐über gastrointestinalen Enzymsystemen, entfalten aber zugleich spezifische metabolische Wirkungen auf den Lipidstoffwechsel, insbesondere auf die Cholesterolsynthese in der Leber, den Lipidspiegel des Serums und die fäkale Cholesterolexkretion. Zwischen den getesteten verschiedenartigen Verbindungen bestehen Gemeinsamkeiten und Unterschiede, die als Indizes für eine Struktur‐Wirkungsspezifität zu werten sind. Diesbezügliche Beziehungen werden im Rahmen der Arbeit näher untersucht und kritisch beleuchtet.
Chromatographische Trennungen mono‐ und oligomerer Kohlenhydrate aus biologischen Materialien mit Hilfe von HPLC‐Glassäulen
Authors: Gey M. , Müller W.
Published: November 2006

Mit Hilfe der HPLC werden mono‐ und oligomere Kohlenhydrate an Silikagelen mit chemisch gebundenen Aminopropylgruppen oder mit in situ imprägniertem Aminmodifier (Piperazin) getrennt. Grundlage der Zuckeranalysen sind selbstgefüllte HPLC‐Säulen aus Glas. Diese zeichnen sich durch hohe Trennleistungen aus, besitzen praktikable Säulenverschlüsse, sind chemisch inert und können in verschiedenen Längen auch mit anderen HPLC‐Sorbentien gepackt werden.

An Hand von qualitativen und quantitativen Ermittlungen der Kohlenhydrate in verschiedenen Lebens‐und Genußmitteln und in säurehydrolytisch oder enzymatisch abgebauten Polysacchariden (z. B. Stärke, Regeneratfaser) werden die Einsatzmöglichkeiten der HPLC‐Analysentechnik mit Glastrennsäulen demonstriert.
Studies on freezing of partially dehydrated spinach
Authors: Ragab M.
Published: November 2006

Spinach (Spinacea oleracea) was dehydrated at 70 °C, partially dehydrated frozen (dried to its critical moisture ratio and frozen at −20 °C) and frozen at −20 °C. Results indicated that the time required for spinach dehydration was 7 h. Thus, the moisture ratio was 10.1 and 0.054 for the fresh and dried spinach, respectively. The critical moisture ratio during dehydration process was 2.20 after 2.65 h of drying time.

Reducing sugars, free amino nitrogen, ash, iron and magnesium were slightly decreased in the partially dehydrated frozen spinach relative to the fresh samples. Dehydration markedly degraded the total chlorophyll, chlorophyll a, chlorophyll b, carotenoides and ascorbic acid whereas the freezing of partially‐dehydrated spinach and freezing process were less effective. On the other hand, freezing of partially dehydrated spinach increased phaeophytin. There were no changes in pH‐values of studied preserved samples.

Freezing of partially dehydrated spinach improved the reconstitution of product at 100 °C and at room temperature (25 °C) comparing to dehydration. The drip loss of frozen spinach was 16.4% after 105 min of thawing time.

Cooked fresh and frozen spinach were better in colour, flavour, texture, appearance and shape and over‐all acceptability than that of dehydrated cooked one. Moreover, freezing of partially dehydrated spinach improved the aforementioned properties.
Estimation of the biological value of food proteins by a modified equation of the essential amino acid index and the chemical score
Authors: Ihekoronye A. I.
Published: November 2006

A modified essential amino acid index equation incorporating a digestibility factor (MEAAI), and a chemical score index (CSI) were developed from the essential amino acid profile of 18 different food proteins hydrolysed by the combined but sequential action of papain and pronase E enzyme systems. The essential amino acid composition of whole egg was used as a reference standard. The following equations were proposed.

magnified image

In which a is the value of the limiting amino acid in the sample, and ae is the corresponding value in whole egg.

Both equations were used to calculate the biological value of different protein foodstuffs. There was a close agreement between values obtained using the equations and reported values for the same foodstuffs published in the literature. There was also a close correlation (r = 0.665) between data obtained using MEAAI and those obtained using CSI in estimating biological values, suggesting that either equation could be used reliably and solely to estimate protein biological value of foods.
The influence of mechanolytic procedures on the content of antinutritive compounds in rapeseed (Short communication)
Authors: Kroll J. , Kujawa M. , Baumgrass R.
Published: November 2006

As already described the mechanolysis is an useful method for improvement of functional properties of protein preparation caused by changes of structures, splitting of covalent bindings and by combining of mechanolytical and chemical modification [1–3].

In connection with an aimed decomposition of antinutritive compounds of rapeseeds (first of all of glucosinolates) the mechanolysis is not used as far as we know.

For a decrease or destruction respectively of toxic compounds of rapeseeds numerous treatments (processes) have been described inclusing the treatment of seeds or meals with heavy metals [4, 5]. The disadvantage of this „metal treatment”︁ methods is the relatively high amount of needed heavy metals (about 1% or more). In the case of Cu++ this concentration could cause toxic effects in animals after feeding.

By now we have found, that a mechanolytical treatment of rapeseed meal in presence of a comparatively small content of heavy metal ions is a way to reduce the content of VOT and progoitrin of these preparations. Further more the mechanolysis leads to inactivation of myrosinase.
Fungal flora of malting of Zea mays Linn.
Authors: Fapohunda S. O.
Published: November 2006

Malting is a vital stage before fermentation of Zea mays to produce alcoholic beverages. Due to the raising of moisture level the grains are often associated with some moulds. Two of these fungi, i.e. Aspergillus flavus and Aspergillus terreus were isolated by the dilution plate technique. They reduced the percentages of oil, protein and carbohydrates of malted mays grains and increased the ash and fibre contents. Investigation on some cultural conditions indicated that alkaline pH enhanced the growth of A. terreus, and both species exhibited luxuriant mycelia growth and sporulation when incubated under an alternating light and dark regimes (at 24 h regular interval).
Stabilität und Veränderbarkeit von Ernährungsgewohnheiten
Authors: Lewerenz G.
Published: November 2006

In theoretischen Betrachtungen werden Wendepunkte im individuellen Lebenslauf zu Ernährungsgewohnheiten in Beziehung gebracht. Experimentelle Befunde an 439 Versuchspersonen belegen die flexibel‐explorative Einstellung jüngerer Menschen zu Ernährungsproblemen und die Festigung von Ernährungsgewohnheiten in der zweiten Lebenshälfte.
Mechanolyse von Amid‐, Ethyl‐ und Acetylpectinen
Authors: Dongowski G. , Bock W.
Published: November 2006

Aus Pectin und teilweise aus Pectinsäure werden Amid‐, Ethyl‐ und Acetylderivate hergestellt. Beim mechanolytischen Abbau unter normalen pH‐Wert‐Bedingungen durch Schwingmahlung im lufttrockenen Zustand verhalten sich diese Pectinderivate wie übliche Pectine. Es erfolgt eine Hydrolyse von α(1→4)‐D‐glycosidischen Bindungen in den Galacturonanmolekülen unter Abnahme des Molekulargewichtes. Die Amid‐, Ethylester‐ und Acetylgruppen werden jedoch nicht abgespalten. Ein destabilisierender Einfluß einer funktionellen Gruppe auf eine andere während der Mechanolyse wird nicht festgestellt.
Volatile oil composition of sweet basil (Ocimum basilicum L.) cultivating in Turkey (Short communication)
Authors: Akgül A.
Published: November 2006

Sweet basil is one of the most widespread spices in the world. Its dried leaves are used commonly as a flavouring in many food products [1]. A number of different types of basil oil have found and achieved economic importance. European basil oil contains approximately equal proportions of estragole (methyl chavicol) and linalool. Exotic or Reunion basil is an oil rich in methyl chavicol. Methyl cinnamate basil is, as its name suggests, an oil rich in methyl cinnamate. And finally, eugenol basil oil contains eugenol in high percentages [2].

Basil is a spice plant cultivated in some parts of Turkey, and used in soups, desserts, pickles etc. as a flavouring agent. However, no studies have been conducted 90 far on Turkish plant and volatile oil. Therefore, the object of this work was to study the volatile oil composition of Turkish sweet basil cultivated in Erzurum region (East Turkey) having cold climate conditions.
Zur Lipidzusammensetzung von Cyprinidenarten 1. Mitt. Lipidgehalt und Fettsäurespektrum von Silberkarpfen (Hypophthalmichthys molitrix (Val.)) (Wissenschaftlicher Kurzbericht)
Authors: Mieth G. , Wirth M. , Friedrich M. , Steffens W. , Lieder U.
Published: November 2006

Maritime Fischspezies aus planktonreichen Fangregionen spielen wegen ihres hohen Gehaltes an essentiellen Fettsäuren eine zunehmende Rolle bei der alimentären Beeinflussung von Hen‐Kreislauf‐Erkrankungen sowie Fettstoffwechselstörungen. Derartige Fischspezies, wie Makrele, Hering oder Sardine, weisen nämlich nicht nur relativ hohe Gehalte an essentieller Linol‐ oder Linolensäure auf, die bekanntlich in die Prostanoidsynthese einmünden und damit pharmakologische Effekte hervorrufen. Sie enthalten darüber hinaus auch hohe Anteile an n3‐Polyenfettsäuren, insbesondere Eicosapentaen‐ und Docosahexaensäure als Hauptvertreter, denen gleichfalls wichtige spezifische biochemische Funktionen, u. a. bei der Blutdruckregulation und Trombozytenaggregation, beigemessen werden [1‐5].

In diesem Zusammenhang war es von Interesse, auch sestonfressende, ursprünglich in Asien beheimatete Cyprinidenarten, speziell Silberkarpfen, die gegenwärtig zunehmend in der Binnenfischerei Bedeutung erlangen, hinsichtlich ihres Lipidgehaltes und ihrer ‐zusammensetzung Zu charakterisieren.
Zusammensetzung und Qualitätsparameter von Schlachtkörpern verschiedener Geflügelarten
Authors: Richter G. , Gruhn K. , Ochrimenko C. , Meixner B. , Hennig A.
Published: November 2006

Für die gegenwärtig in der DDR produzierten Broiler, Hühner, Mastputen, ‐gänse, ‐enten und ‐cairina wurden die Schlachtkörperzusammensetzung und ‐qualität ermittelt. Den höchsten Schlachtertrag (Körpermasse minus Kopf, Federn, Ständer, Blut und unverwertbare Innereien) erreichten mit 81% die männlichen Mastputen im Alter von 20 Wochen. Danach folgen mit 73% die Broiler und die etwa 6 Monate alten Gänse. Nur 66% Schlachtertrag erzielten die Hühner und 60 Tage alte Gänse. Der Anteil Magen, Herz und Leber an der Körpermasse des nüchternen Tieres variierte zwischen 2,9% bei Puten und 8% bei den Junggänsen und der Abdominalfettgehalt zwischen 0,5% bei Puten und 4,7% bei den 6 Monate alten Gänsen. Den höchsten Gesamtfleischanteil von der Rumpfmasse haben mit 67–70% die Mastputen und den niedrigsten mit 45% die Pekingenten. Das Fleisch wurde in Brust‐ und Schenkelanteil differenziert. Im eßbaren Anteil der Rumpfmasse wurden zwischen 28% Trockenmasse bei Puten und 47% bei Pekingenten sowie 6 Monte alten Mastgänsen ermittelt. Der Rohproteingehalt schwankt zwischen 14% und 20%, der Rohfettgehalt zwischen 7% und 32% und der Rohaschegehalt zwischen 0,8% und 1,0%. Am Brust‐ und Schenkelfleisch wurden als Fleischqualitätsmerkmale der pH‐Wert, die Fleischfarbe, das Safthaltevermögen, der Dripverlust (Masseverlust nach Einfrieren), die Wasserbindekapazität und der Grillverlust ermittelt.
Effects of frying and storage at room temperature on the chemical composition and quality of sweet potato slices
Authors: Ghazi A. , Abd‐El‐Aal M. H. , Khalil M.
Published: November 2006

Fried sweet potato slices were prepared from yellow (Mabrouka) and orange (Abees) tubers. Some chemical and organoleptic qualities were studied. Changes in these qualities which occurred during storage for 3 months at room temperature were also investigated. The results obtained led to the following conclusions: 1. Sweet potato slices had moderate amounts of calcium and phosphorus, and there was no significant difference in mineral content between fresh and fried sweet potato slices. 2. Sweet potato slices contained a fair amount of essential amino acids, especially leucin, valine and lysine, whereas tryptophan and sulphur amino acids were the limiting amino acids. 3. Sliced sweet potato of yellow variety (Mabrouka) dipped in water, then deep fried in cotton seed oil at (180 ± 5)°C for 1.25 min was organoleptical proved to be the best compared with those prepared from orange variety (Abees), or of yellow variety but dipped in 1% citric acid. 4. Storage of fried sweet potato slices (Mabrouka) in polyvinyl packages at room temperature led to gradual increases in their moisture content and peroxide value, while carotenoids content decreased. Furthermore, the fried sweet potato slices were acceptable until the 10th week of storage, then a rancid taste begins to appear.
The effect of phytate on the solubility of the sunflower seed proteins
Authors: Bulmaga V. P. , Lapteva N. A. , Vaintraub I. A.
Published: November 2006

11S protein of the sunflower seed is precipitated by phytate at pH 2.0, a protein‐phytate complex being formed thereby. The number of the phosphate groups bound by the time the precipitation is completed is less than one half of that of the basic groups of the 11S protein. The insolubility of the complex formed interferes with the acid extraction of protein from the sunflower meal and solvent cake. The protein extractability increases sharply after the removal of the phytate.
Krill lipids after frozen storage of about one year in relation to storage time before freezing
Authors: Kolakowska A.
Published: November 2006

Batches of krill (Euphausia superba D.) were frozen immediately after capture and after 12, 24, 48, and 84 h of storage at 3 °C. Composition of lipids (classes), amount of carotenoids, and hydroperoxide value were determined before freezing and after 11 months of storage at −27 °C. Due to the pre‐freezing storage, the lipolytic activity was observed to increase in the frozen krill. At the same time, susceptibility of lipids and carotenoids to oxidation decreased. Freezing the krill 24 h after capture is most effective in inhibiting lipid oxidation and carotenoid decomposition.
Changes of lipoprotein phospholipids during rapeseed processing
Authors: Viden I. , Réblova Z. , Davídek J. , Pokorný J.
Published: November 2006

During rapeseed processing about 0.4—0.8 % lipids are liberated from their bound form and extracted into expeller‐pressed or extracted oils, increasing thus the yield in an oil processing plant, compared with the yield predicted on the basis of Soxhlet extraction [1]. If the liberated lipids originate from lipoproteins denatured during processing, they would contain high percentage of phospholipids. Therefore, we have studied changes of phospholipids during rapeseed processing.
Volatile flavour substances of different apricot cultivars
Authors: Tóth‐Markus M. , Boross F. , Blazsó M. , Kerek M.
Published: November 2006

As a part of a selection study, the aroma of the most common Hungarian and several foreign cultivars was investigated. Four cultivars were studied during three consecutive years, three others only once. The cultivars contained the same main components in different ratios. The quantity of 30 components identified earlier was measured. Statistical evaluation of the results is also given. Sensory descriptive analysis coupled with gas chromatographic separation of aroma extracts was performed, the odour values of individual components were calculated.
Processing aspects of aroma of some food products and improved technique of analysis of volatile compounds
Authors: Griniené E. K. , Venskutonis P. R. J. , Südžiené S. K.
Published: November 2006

On the basis of results of analysis of compounds correlating with flavour the influence of a complex of factors – qualitative parameters of raw materials and main technological processes – on the formation and preservation of flavour properties of sweet and sour cream butter has been determined. The possibility of desirable formation of butter quality has been revealed. Further on investigations of the influence of some milk additives on composition of aroma compounds of wheat bread have been carried out. To isolate the volatiles from bread an improved method of vacuum distillation in a specially designed apparatus has been applied.
Über wertbestimmende Inhaltsstoffe auf einheimischen Standorten kultivierter Sojabohnen
Authors: Mieth G. , Schliemann H. , Marzilger K. , Krausse G. W. , Erhardt V.
Published: November 2006

Sojabohnen eines DDR‐Neuzuchtstammes (Sorte Dorado) wurden in Höchstertrags‐ und Produktionsprüfungen auf 5 bzw. 5 verschiedenen Standorten unter Variation von Düngung, Beimpfung, Beregnung und Sikkation hinsichtlich des Einflusses von Umweltfaktoren auf ihre Zusammensetzung untersucht. Unter günstigen Anbaubedingungen werden durchschnittliche Rohproteingehalte von ca. 42% i. T. und dazu korrespondierende Rohlipidgehalte von ca. 18% erzielt, wobei das durchschnittliche Ertragspotential bei ca. 16 dt/ha liegt.
Estimation of the weekly intake of mercury which may be consumed by university students from the City of Havana
Authors: Menéndez R. , Beltrán G. , Torres O.
Published: November 2006

Mercury is a highly toxic element which may be accumulated in the central nervous system. It causes some symptoms and pains to human beings [5, 6]. Food is the main source of mercury in nonoccupationally exposed population. The use of mercury in industry and agriculture is related to its presence in foods [1–3]. Therefore, the World Health Organization has recommended dietary intake studies of heavy metals [4]. In the present article we inform about the estimated quantities of mercury which may be consumed by 2500 university students from the City of Havana.
Interactions of oxidized lipids with protein Part XVI. Interactions of oxidized ethyl linoleate with collagen
Authors: Pokorný J. , Davídek J. , Chocholatá V. , Pánek J. , Bulantová H. , Janitz W. , Valentová H. , Vierecklová M.
Published: November 2006

The reaction of ethyl linoleate with collagen proceeded at 60 °C following the first order kinetics but during the hydroperoxide decomposition the rate constant of the first order decomposition was substantially lower than that of the second order decompositon. Contrary to cellulose, collagen catalyzed the hydroperoxide decomposition. The amount of total oxidation products rose rapidly at the stage of rapid hydroperoxide formation, and slowly afterwards. The browning reaction was fastest in the stage of maximum hydroperoxide content, and both ether‐insoluble and ether‐soluble pigments were formed, the latter low in nitrogen. The amount of lipid oligomers increased mainly in the reaction stage following the hydroperoxide maximum. Soluble collagen was converted into insoluble forms by the reaction with oxidized lipids. Basic amino acids were blocked by reaction with oxidized lipids but the bonds formed became resistant to acid hydrolysis only in the stage following the hydroperoxide maximum. Changes of sensory profiles could be explained by reactions of flavour‐active carbonylic oxidation products with protein.
Mycotoxins in cereal grain. Part 13. Deoxynivalenol and 3‐acetyl‐deoxynivalenol in wheat kernels and chaff with head fusariosis symptoms
Authors: Perkowski J. , Chełkowski J. , Wakuliński W.
Published: November 2006

In the period of harvest at 1987 field samples of wheat heads with fusariosis symptoms were collected in 18 provinces of Poland. Subsamples of heads infected with Fusarium culmorum (W.G.Sm) Sacc. and Fusarium graminearum Schwabe were analyzed for Fusarium metabolites. In fractions of kernels with visible Fusarium‐damage deoxynivalenol (DON) was present in average amount of 18.7 mg/kg (range 9.6–25.3 mg/kg) and 3‐acetyl DON 1.9 mg/kg. Fractions of kernels without symptoms of visible Fusarium‐damage contained only DON at average 2 mg/kg (range 0.8–3.6 mg/kg). A method of approximate calculation of DON content in a given lot of grain is proposed which may be realized during samples grading.
Biotechnologische und technologische Untersuchungen mit dem bulgarischen Hydrolase‐Enzympräparat “Trichozease SU‐2”
Authors: Kabaktschieva G. , Atanasov W. , Dimitrova T. , Atev A. , Peev P.
Published: November 2006

Es werden Untersuchungen zur Bierherstellung mit dem neuen bulgarischen Hydrolase‐Enzympräparat “Trichozease SU‐2” durchgeführt. Bei der Dosierung von 0,20–0,25 kg/1000 kg Malz wird eine Verminderung der Läuterungszeit der Vorderwürze und von Glattwasser erreicht. Der Gehalt an β‐Glucan und die Viskosität nehmen ab und die Menge an vergärbarem Zucker wird erhöht.
Biochemical characteristics of trypsin inhibitor from wheat grain, Beta variety
Authors: Mossor G. , Skupin J.
Published: November 2006

A homogenous trypsin inhibitor from wheat grain has been characterized. It is a protein of molecular weight 9105 Da and isoelectric point pI = 9.5. It belongs to arginine type inhibitors. The isolated inhibitor does neither inhibit native proteinases from wheat grain n or α‐chymotrypsin, papein and pepsin. However, it inhibits some proteinases from microorganisms and moulds. It is susceptible to the action of hydrogen peroxide. The inhibitory protein consists of all amino acid residues with the largest amount of glutamic acid, proline and arginine, and the lowest of histidine and tyrosine, respectively.
Effects of low methoxy pectin on protein stabilized o/w emulsions
Authors: Schultz M. , Schmidt G. , Schmandke H.
Published: November 2006

The interaction between low methoxy pectin and faba bean globulin or the corresponding acetylated derivative in o/w emulsions is indicated by formation of hydrogen ions. For the globulin this process reaches a maximum within 1 day; in the case of the acetylated globulin that is valid within 6 days. These findings are related to the fact that the stability of globulin stabilized emulsions increases as a result of pectin addition whereas in acetylated globulin stabilized emulsions pectin addition leads to a decrease in stability.
Methodenvergleich zur Bestimmung von L‐Lysin in Aminosäuregemischen — Multivariate Auswertung von Daten aus mehreren ähnlichen Proben
Authors: Weissbach F. , Siegler K. , Kreibich G. , Henrion R. , Henrion G.
Published: November 2006

Die Bestimmung von L‐Lysin hat große Bedeutung für die Ernährung, die Biotechnologie und andere Bereiche. In der Praxis kommen dafür verschiedene Methoden zur Anwendung. Die Auswertung von Daten aus Methodenvergleichen kann nach unterschiedlichen Modellen erfolgen. Der Vergleich von Methoden zur Bestimmung von L‐Lysin in Aminosäuregemischen wurde an 4 Proben (1 bis 30 g/1 L‐Lysin · HCl) aus der biotechnologischen Herstellung dieser Aminosäure von 5 Teilnehmern durchgeführt.

Benutzt wurden insgesamt 10 Varianten der Methoden Aminosäurechromatographie (2), photometrische Bestimmung mit Ninhydrin (1) bzw. Furfural (4) sowie die Bestimmung mit potentiometrischen (2) und amperometrischen (1) Enzymelektroden. Die Auswertung erfolgte mit dem Programmpaket MULTILAB in univariater und multivariater Prozedur. Die Arbeitsweise der Teilnehmer, die Störanfälligkeit der Methoden, ihre Spezifität sowie Einflüsse der Probenmatrix wurden untersucht. Die multivariate Auswertung ringanalytischer Daten mit der Darstellung im Hauptkomponentendisplay erwies sich als sehr aussagekräftig beim Auffinden systematischer Abweichungen. Im Bereich von ±2% lieferten die als übereinstimmend gefundenen Methoden vergleichbare Ergebnisse.
Chemical and sensory properties of black pepper oil (Piper nigrum L.)
Authors: Pino J. , Rodriguez‐Feo G. , Borges P. , Rosado A.
Published: November 2006

The sensory properties of the volatile oil of black pepper were investigated by means of descriptive characterization of GC effluent. In addition, the chemical composition was analyzed with the aid of column chromatography, high resolution GC and MS‐GC. A total of 46 components was identified including (E)‐β‐ocimene, δ‐guaiene, (Z) (E)‐farnesol, δ‐cadinol and guaiol, which are reported for the first time.
The response of addult rats to varying combinations of dietary lysine and threonine
Authors: Mekhael Kamal G. , Bassily Nargis S. , Mekhael Nabila A. , Said Amin K.
Published: November 2006

The response of adult rats fed diets containing amino acid mixtures with varying combinations of lysine and threonine was studied by estimating the change in body weights, organ weights, total nitrogen content of organs and the concentration of free plasma lysine and threonine. Analysis of variance indicates a significant effect of threonine, lysine and a significant interaction due to feeding the two amino acids on the body weights, organ weights and total nitrogen content of various organs. Significant effect on the level of the plasma free amino acid was also shown as a result of feeding the particular amino acid.

Results show that in deficient animals the rates of building body protein are low but are higher in the lysine deficient animals than in the threonine deficient and protein deficient animals. The varying rates of exchanging protein between the various organs in response to changing the levels of amino acids in the diet would mean that total change in body protein or total nitrogen balance may not be satisfactory way to determine the protein or amino acid requirements for maintenance. It seems to be necessary to focus down on protein turnover rates in specific tissues.
Effect of the ingestion of an extract from Bauhinia monandra seeds on rats
Authors: Abreu M. , Castillo A. , Rodriguez A. , González I. , Rodriguez N. , Piñón D.
Published: November 2006

Bauhinia monandra is a leguminous plant that would be used in human nutrition, however it shows a high hemagglutinating activity against trypsin‐treated erythrocytes of rabbit. 2 ml of a NaCl‐solution extract of the seeds was given to a group of rats for 10 days. Intestinal disaccharidase activity was determined. Histopathological and histochemical examinations were also performed. Lectins from Bauhinia monandra seeds did not cause any visible intestinal damage even when they seem to be able to bind to the enterocyte brush border. The low disaccharidase activity in the membrane and enterocyte fractions, which represent the enzyme synthesis level, indicates that lectins could reduce the synthesis of these enzymes rather than inhibit the active sites of the enzymes. This effect could be in turn related with the binding action of lectins, because no effect of the autoclaved extract on the disaccharidase activity was observed.
Studies on enzyme activities of Pleurotus tuber‐regium (Fries) Singer and Tricholoma lobayensis Heim at various fruitbody stages
Authors: Kadiri Mukaila , Fasidi Isola O.
Published: November 2006

Investigations were carried out on the cellulase, amylase, lipase, peroxidase, proteinase, catalase, poly‐phenol oxidase and glucose‐6‐phosphatase activities in very young, young and mature fruitbody stages of Pleurotus tuber‐regium (Fries) Singer and Tricholoma lobayensis Heim. With the exception of glucose‐6‐phosphatase, both mushrooms showed increases in enzyme activities from the very young to mature fruitbody stages. The highest glucose‐6‐phosphatase activity was detected in the young fruitbody stage of both mushrooms. Furthermore, the activities of the enzymes were higher in the pilei of both mushrooms except cellulase and β‐amylase whose activities were higher in the stipes than in the pilei. By comparison, the activities of total amylase, proteinase, lipase and polyphenol oxidase were higher in T. lobayensis than P. tuber‐regium which had higher cellulase activities.
Influence of storage time of duck breast muscles at ‐18°C on rheological properties of gelled tissue and model sausage
Authors: Lesiów T.
Published: November 2006

The influence of storage time of duck breast muscles at ‐18°C on changes of rheological properties of gelled muscle tissue and a model sausage was studied for 200 days. Rheological parameters were determined by the Tyszkiewicz method and the modified Shama‐Sherman method. On the basis of the calculations of rheological parameters it was found that the eight‐element rheological model characterizes best rheological properties of gelled muscle tissue and model sausage. The changes of rheological parameters of model sausage are more complex in comparison with rheological parameters of gelled muscle tissue. In both kinds of samples, the changes of rheological parameters are influenced by the changes occurring in myofibrillar proteins as a result of the so called frozen denaturation. It appears, that in the case of gelled muscle tissue it is possible to use exchangeably the Tyszkiewicz or Shama‐Sherman method while for model sausage its rheological characteristics based on one of these methods exclusively would be insufficient. The changes occurring in rheological parameters of model sausage can not be predicted according to the changes in rheological parameters of gelled muscle tissue. On the other hand, these changes are reflected in significantly different values of consistency of model sausage evaluated organoleptically.
Comparison of changes occurring in rheological properties of gelled tissue and model sausage prepared from duck breast muscles stored at −2°C and −18°C
Authors: Lesiów T.
Published: November 2006

The changes of rheological parameters of gelled tissue and model sausage prepared from duck breast muscles stored at −2°C and −18°C were compared. The changes of conventional elasticity and flowability and the sum of reciprocal immediate elasticity modulus and reciprocal elasticity modulus of gelled tissue, and conventional plasticity and Newtonian viscosity of model sausage are comparable for both temperatures and are higher at −2°C than −18°C. At both temperatures the changes occurring in rheological parameters of model sausage can not be predicted according to the changes in rheological parameters of gelled muscle tissue.
Die Charakterisierung mikrobieller Lipasen 2. Mitt. Zur Bestimmung der Lipasespezifität
Authors: Bariszlovich M. , Meusel D. , Tülsner M.
Published: November 2006

Die Kenntnis der Positions‐, Fettsäure‐ und Stereospezifität mikrobieller Lipasen sowie deren Spezifität gegenüber einzelnen Glyceridklassen gewinnt zunehmend an Bedeutung. Bei der Untersuchung der Spezifität einer Lipase ist die Wahl des Substrats entscheidend für die Aussagekraft der Bestimmung. Entspricht das Substrat nicht dem Untersuchungszweck, kann es zu Fehlinterpretationen und Verwechslungen der Spezifität kommen. Verschiedene Substrate und Analysenverfahren werden vorgestellt sowie Vor‐ und Nachteile ihrer Anwendung diskutiert.Es wird empfohlen, zur Bestimmung der Positionsspezifität Dialkylacylglycerole und 2, 3‐Dioleylbutandiol sowie zur Bestimmung der Stereospezifität enantiomere Dialkylacylglycerole bzw. Diacylalkylglycerole einzusetzen.
Osmotolerant yeast isolates from fruit preserves
Authors: Bhajekar D. V. , Kulkarni P. R.
Published: November 2006

In India traditional fruit preserves are normally prepared in bulk quantity annually. Though lower water activity (aw) due to high sugar concentration and highly acidic nature of these products permits a long shelf‐life, osmotolerant yeasts are mainly responsible for their spoilage. Since no information is as yet available on these osmotolerant yeasts, the present work was aimed at isolating and characterizing these organisms.
Zur Bestimmung von Thiazafluron in Trinkwasser
Authors: Meyer R. A. , Hübner D. , Grübner P.
Published: November 2006

Bei der Verwendung von Trinkwasser als Gießwasser traten Pflanzenschäden auf. Der Verdacht richtete sich auf eine ca. 100 m vom betreffenden Brunnen entfernte Abfüllstation für „Spritzzüge”︁ der Deutschen Reichsbahn. Bei der Prüfung des Wassers nach TGL 27 796/07 (Triazine) wurde eine unbekannte Verbindung nachgewiesen und nachfolgend als Thiazafluron [N,N‐Dimethyl‐N'‐(5‐trifluor‐methyl‐1,3,4‐thiadiazol‐2‐yl)‐harnstoff] identifiziert. Die ursprünglich festgestellte Konzentration von 400 μg/l sank im Verlauf eines Jahres auf die Hälfte. Parallel dazu beobachteten wir den starken Anstieg einer bis jetzt noch unbekannten Substanz, bei der es sich möglicherweise um ein Abbauprodukt des Thiazafluron handelt [1, 2].

In diesem Zusammenhang führten wir Untersuchungen zur Erhöhung der Nachweisempfindlichkeit für Thiazafluron [2] durch. Mit Hilfe einer biologischen Detektionsmethode (Hemmung der HILL‐Reaktion der Photosynthese) gelang uns eine 20fache Steigerung der Nachweisempfindlichkeit gegenüber der o. a. TGL‐Methode [2, 3].
Purification and characterization of a cysteine protease in Vitis vinifera L. grapes (Macabeo variety)
Authors: Expósito J. Marín , Gordillo C. Miguel , Mariño J. I. Maynar , Iglesias J. L. Mesías
Published: November 2006

Protease from Vitis vinifera L. (Macabeo variety) was partially purified (15‐fold) by PVPP and Sephadex gel G‐100 filtration and characterized afterwards by gel electrophoresis. The enzyme had an optimum pH of 2.50 and a Km value of 0.32 mM for haemoglobin. The results of applying diagnostic inhibitors indicated that the enzyme studied was a cysteine‐protease.
Acceleration of Edam cheese ripening using acid fungal protease
Authors: Nasr Mohamed M. , El‐Sayed Magdy M. , El‐Samragy Yehia A.
Published: November 2006

Edam cheese was made from a mixture of cow/goat milk (1:1, v/v). The mixture of both milks was standardized to have 3.2% fat and a casein/fat ratio of 0.7, heated at 72 °C for 15 s, immediately cooled to 40 °C and divided into four portions. Acid fungal protease (Formase 200) was added at levels of 0.5, 1.0 and 2.0 g/kg of curd to the first three portions, and the last one was manufactured without the addition of acid fungal protease to serve as a control sample. The samples of control as well as those of different treatments were analysed for chemical and organoleptic properties when fresh and after 1, 2 and 3 months of storage at 12 ± 1 °C.

The obtained results pointed out that the samples of Formase‐treated‐cheese exhibited higher values of soluble nitrogen/total nitrogen ratio (SN/TN), total volatile fatty acids (TVFA), titratable acidity (TA), and the flavour was developed faster as compared with the samples of control. A good quality Edam cheese could be produced with a high acceptability when Formase 200 was used at level of 1.0 and 2.0 g/kg of curd and the cheese was ripened for 2 months only.
Influence of dietary fat on nutritive utilization of protein in intestinally resected rats
Authors: López‐Aliaga I. , Campos M. S. , Barrionuevo M. , Coves F. , Lisbona F.
Published: November 2006

The effects of different types of dietary fat on the digestive and metabolic utilization of protein were studied in rats with 50% resection of the distal small intestine and in sham‐operated controls one month after surgery. The digestive utilization of protein was not significantly affected in intact animals when olive oil was replaced by butter as the dietary source of fat. In resected rats given either type of diet the apparent digestibility coefficient of protein declined significantly in comparison to intact controls. Intestinal resection decreased the retention of nitrogen significantly in rats given olive oil. The replacement of 2/3 of the dietary supply of olive oil with 1/3 medium chain triglycerides and 1/3 sunflower seed oil improved the metabolic utilization of protein in comparison to resected rats fed olive oil or butter as the only source of dietary fat. However, the addition of ursodeoxycholic acid to the diet containing equal parts of olive oil, medium chain triglycerides and sunflower seed oil failed to improve the metabolic utilization of protein in comparison to that seen in rats given olive oil only. Serum concentrations of total protein, urea and creatinine, albeit with slight changes in the first, remained within normal limits. Despite the lower retention of nitrogen in resected rats, these animals maintained homeostasis without resorting to muscular protein.