bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Amadori rearrangement products on the non‐enzymic browning in model systems
Authors: Pokorný J. , Pilková L. , Davídek J. , Valentová H.
Published: November 2006

The Amadori product was prepared from D‐glucose and L‐alanine after Hashiba. The browning process was investigated by determining the absorbance at 520 nm, in aqueous solutions at 110 °C for 5–8 h. Because of the limited access of oxygen and its low solubility in the reaction medium, the browning proceeded after zeroth order kinetics with the maximum browning rate at pH = 8–9. The browning rate remained unaffected by additions of sodium sulphite, rutin. propyl gallate (except when present at high levels), iron(III)chloride or copper(II)chloride but decreased in presence of L‐cysteine or iron(II)chloride. Hydrogen peroxide bleached the pigment but did not inhibit the subsequent browning of reaction products. Under experimental conditions the solution of Amadori product did not darken with substantially greater rate than the solution of D‐glucose and L‐alanine. Lower additions of D‐glucose to the solution of Amadori product moderately increased the reaction rate while additions of L‐alanine or L‐hydroxyproline moderately decreased the browning rate.
Increased concentrations of liver cholesterol in rats fed lactulose (Short communication)
Authors: Beynen A. C.
Published: November 2006

The disaccharide lactulose (β‐D‐galactopyranosyl‐(1‐4)‐D‐fructofuranose) is thought to be poorly hydrolized by intestinal enzymes but is broken down by microorganisms in the colon. Thus lactulose shares with pectin similar characteristics [1]. Lactulose is used in the food industry and in the treatment of constipation. There is preliminary evidence that dietary lactulose (5%, w/w) causes increased cocentrations of serum and her cholesterol in rats when compared with pectin [2]. This paper describes dose‐response relationships between dietary lactulose and cholesterol in either serum or liver.
Dünnschichtchromatographische Analyse künstlicher organischer Lebensmittelfarbstoffe
Authors: Meyer R. A. , Gründig F. , Schäfer R. , Schneider J.
Published: November 2006

Nach einer Literaturübersicht über die Dünnschichtchromatographie künstlicher organischer Lebensmittelfarbstoffe wird die Trennung von 17 Lebensmittelfarbstoffen an Schichten von Cellulose und Kieselgel mit den Laufmitteln n‐Propanol/Wasser (67 + 33) und Essigsäureethylester/Methanol/Ammoniak, konz. (60 + 20 + 20) beschrieben. Die hRf‐Werte und die Nachweisgrenzen der einzelnen Farbstoffe werden angegeben. Mit Hilfe des Dünnschicht‐Scanners CS‐910 werden die Spektren von 7 roten Farbstoffen und die Eichkurven für Cochenillerot und Echtrot aufgenommen.
Investigation of the effects of extrusion cooking on antinutritional factors in soybeans employing response surface analysis Part 1. Effect of extrusion cooking on trypsin‐inhibitor activity
Authors: Petres J. , Czukor B.
Published: November 2006

A Brabender 20 DN laboratory scale extruder was used to study the effect of processing parameters on trypsin‐inhibitor activity in dehulled soyabeans employing response surface analysis. Process variables examined were: Temperature of die (150, 160 and 170 °C), feed moisture content (12, 16 and 20%) and screw speed (80, 120 and 160 rpm). Trypsin‐inhibitor activity of extruded products was measured. The correlation with a multiple determination coefficient, (R2 = 0.976) and the mathematical model developed in this study were found to be significant.
Interaction between the peptide glutathione and linoleic acid hydroperoxide
Authors: Zamora Rosario , Millán F. , Hidalgo F. J. , Alaiz M. , Maza Maria P. , Olías J. M. , Vioque E.
Published: November 2006

Incubation experiments in order to study the influence of some parameters in the fluorescence products formation have been carried out. It has been observed a greater efficiency with the relation linoleic acid hydroperoxide:glutathione, 2:1, and a temperature of 37 °C. The complex formed working with labelled linoleic acid has been separated in two main fractions. The first one (without radioactivity) is fluorescent with excitation and emission maxima at 350 nm and 440 nm, respectively. It has been confirmed that this fraction consists of a complex of glutathione and short chain aldehydes. The fluorescence of the complex did not decrease by treatment with NaBH4 or with pH. The NH2 and SH groups take part in the lipid‐peptide complex formation. The second, highly radioactive fraction includes free hydroperoxides and short chain hydroxy fatty acids.
Analysis of the essential oil of Mexican oregano (Lippia graveolens HBK)
Authors: Pino J. , Rosado A. , Baluja R. , Borges P.
Published: November 2006

The composition of the volatile oil of Mexican oregano (Lippia graveolens HBK) isolated by steam distillation was investigated by means of column chromatography, gas chromatography and mass spectrometry. A total of 33 components were identified including 22 hydrocarbons, 4 alcohols, 4 ethers, 2 phenols and 1 ketone. Of the 33 components observed in the present study 7 were identified in Mexican oregano for the first time.
Fractionation and characterization of yeast proteins
Authors: Rajcheva‐Roshkova Z. G. , Djukiandjiev S. V. , Pavlova K. I.
Published: November 2006

Fractional profile of proteins from baker's, brewer's, and alcoholic yeasts was studied, applying a consecutive treatment of commercial biomasses, with solutions with a gradient of ionic strength and pH. It was found that a large part (35‐50%) of total proteins from investigated biomasses is extracted by means of 0.01 M KCl, pH 7.0, which together with proteins extracted by means of 0.65 M KCl, pH 9.5, makes the part of the easily extractible proteins (50‐64% of the total protein amount). The remaining part of proteins is extracted by means of alkaline solutions only. The amino‐acid composition of the isolated fractions indicated that they are suitable for usage as food product ingredients.
Lipolytic activities of two strains of Aspergillus aculeatus associated with the spoilage of two food sources
Authors: Adisa V. A.
Published: November 2006

The production of extracellular lipolytic enzymes by 2 strains of Aspergillus aculearus associated with the deterioration of peanuts and a marketed margarine in Nigeria and the effects of temperature and pH on the activities of the enzymes were investigated. Lipolytic enzymes were detected within 2 days of incubation at 35 °C in 4 out of 6 natural oils and in 3 out of 4 synthetic glycerides used irrespective of strain type. The lipolytic enzymes of both strains hydrolysed both natural oils and synthetic glycerides to free fatty acids. There was correlation between the mycelium produced to the quantity of free fatty acids produced in medium within the first 8 days of incubation. There was a general increase in mycelium production with increase in incubation period. The enzyme activities were at peak at 30‐35 °C and at pH 6‐7.
Effects of some technologies of curing uncomminuted meat products on their flavour Part 1. Changes in the contents of fatty acids as meat flavour precursors
Authors: Miteva E. , Trendafilova Z. , Chakurov M.
Published: November 2006

A study was made of the fatty‐acid composition of phospholipids and the fraction of free fatty acids in two uncomminuted pork products, loin and neck, manufactured by three technologies: I, brine curing; 11, dry curing; 111, dry curing using%.6% honey. A higher phospholipid content was found in the loin products. Brine curing caused a more intensive lipid hydrolysis in both types of meat products. The free fatty‐acid fraction in the meat products manufactured by technologies II and III was richer in unsaturated fatty acids, which are some of the most important meatflavour precursors.
Effect of roasting and autoclaving on phytic acid content of chickpea
Authors: Hussain B. , Khan S. , Ismail M. , Sattar A.
Published: November 2006

Chickpea cultivars CM‐68, (2‐44, Kabuli, CM‐72 and 6153 were analysed for phytic acid, phytate phosphorus and total phosphorus. The effect of roasting and autoclaving on these constituents of whole seed and cotyledons was determined. The data revealed that roasting and autoclaving significantly decreased (P i 0.05) the phytic acid of chickpea cultivars. Phytic acid of whole seed was reduced to a range value of 16‐60% and 16‐64% by roasting and autoclaving respectively depending upon the cultivar. In the cotyledon, the phytic acid was reduced to a range value of 32‐68 % and 18‐68 % during roasting and autoclaving respectively. Similar effect of these treatments was observed in phytate phosphorus however, total phosphorus was little affected.
Dietary interactions of lima bean (Phaseolus lunatus) trypsin inhibitor, haemagglutinin and cyanide Part 2. Effect on pancreatic and intestinal α‐amylase (EC 3.21.1.1) in growing albino rats
Authors: Aletor V. A.
Published: November 2006

A total of 108 growing albino rats was used to evaluate the dietary interactions of the major lima bean antinutritional factors trypsin inhibitor (TI), haemagglutinin (Hgg) and cyanide (CN) with respect to their effects on pancreatic and intestinal α‐amylase activities. The results indicate that when fed at the same level of activity as found in the raw lima bean (RLB) these factors had no significant (p > 0.05) influence on pancreatic α‐amylase activity whether acting individually or in combination. However, when acting alone, CN appeared to depress pancreatic amylase level more than when interacting with TI or Hgg or both. Amylase activity was significantly (p < 0.01) depressed by the dietary treatments in both the small and large intestine while caecal levels were not. The most severe depression in amylase activity was elicited by the RLB diet. The haemagglutinin‐containing diets appeared generally associated with lower levels of intestinal amylase activity.

From the present finding it is suggested that these factors alone cannot fully account for the magnitude of the depression of intestinal amylase activity which is contingent upon the ingestion of RLB by experimental rats.
Fortschrittsbericht Lipidperoxydation 2. Mitt. Sekundäre Reaktionen
Authors: Mörsel J.‐Th. , Meusel D.
Published: November 2006

Lipide und lipidhaltige Lebensmittel werden durch autoxydative Vorgänge. verändert. Die dabei gebildeten Hydroperoxide stellen als eigentliches Primärprodukt gleichzeitig den Ausgangspunkt für vielfältige sekundäre Reaktionen dar. Als sekundäre Primärprodukte werden dabei Di‐ und Trihydroperoxide, Hydroperoxyepidioxide, Endoperoxide und Hydroxyepoxide gebildet, die zum Teil nur als Minorkomponenten auftreten. Die Bildung der primären Autoxydationsprodukte kann zum einen durch viele Faktoren, z. B. erhöhte Temperatur, Sauerstoff, Metallionen und Sensibilisatoren beschleunigt, zum anderen aber auch gehemmt werden (z. B. durch natürliche und synthetische Antioxydantien). Die Spaltung der Hydroperoxide wie auch die der sekundären Primärprodukte führt zu flüchtigen Verbindungen, die den sensorischen Wert fetthaltiger Lebensmittel negativ beeinflussen. Gleichzeitig verbleiben aber Spalt‐ und auch Polymerisationsprodukte im Substrat, die dessen oxydative Stabilität verringern.
Volatile constituents from a guava (Psidium guajava L.) natural flavour concentrate
Authors: Pino J. , Gutierrez Sarah , Rosado A.
Published: November 2006

The volatile constituents of a commercially produced guava natural flavour concentrate were isolated by simultaneous distillation‐extraction with diethyl ether. The resultant essence was analyzed by capillary gas chromatography and GC‐MS technique. A total of 29 compounds was identified, from which 10 substances could be described for the first time as guave fruit constituents.
Tension of oil‐water interface and properties of O/W emulsions in dependence of faba bean globulins
Authors: Schmandke H. , Schultz M. , Schmidt G. , Schneider Ch. , Andersson O.
Published: November 2006

Compared with faba bean globulin the improved flow, gelifying, surface and emulsifying properties of aqueous solution of the corresponding acetylated derivatives are reflected in O/W emulsions by their enhanced stability.
Mould growth on black table olives and prevention by sorbic acid, methyleugenol and spice essential oil
Authors: Kivanç Merih , Akgül A.
Published: November 2006

Thirty‐two mould strains were isolated from Turkish‐style black table olives. Four of these isolates were identified as Aspergillus ochraceus, two as A. niger, 16 as Penicillium clavigerum and 10 as P. expansum. Mould growth was evaluated on olives treated with 500 ppm sorbic acid, 1000 ppm methyl‐eugenol and 1500 ppm çörtük spice (Echinophora sibthorpiana Guss.) essential oil. Olives inoculated with A. parasiticus NRRL 2999 and P. clavigerum were also examined. All samples were stored at 28°C, 15°C and 5°C for 60 days. The lower the temperature, the more time it took the mould to initiate mycelium and spore development. Most inhibition of growth was obtained using sorbic acid in all cases and especially at low temperatures, followed by methyl‐eugenol and essential oil. Decreased inhibition was observed in noninoculated olives. Inhibitory effect of used agents was higher in olives inoculated with P. clavigerum than in olives inoculated with A. parasiticus.
Baking quality versus some biological activities of proteins extracted from the grain of wheat varieties harvested in 1986
Authors: Warchalewski J. R. , Klockiewicz‐Kamińska Ewa
Published: November 2006

Grain of six winter and spring wheat varieties differing in baking quality were included in the study. A number of technological analyses were performed. Albumins, globulins and gliadins were washed out. Location of inhibitory activities of alpha‐amylases in extracted proteins against enzymes of various origin were tested and compared to baking quality of the wheat grain. Also, the location of endogenous amylase activity in extractable proteins was compared to baking quality of the studied varieties. A certain correlation between the incidence of higher inhibition activity against alpha‐amylase of Sitophilus granarius L. and good baking quality has been found. However, location of endogenous alpha‐amylases in grain seems to be a better criterion classifying varieties according to their baking quality. So‐called baking varieties have higher and only activity of endogenous alpha‐amylases located in albumin and gliadin fractions, whereas in poorest, “non‐baking” varieties this activity is also located in the globulin fraction.
Zur Wirkung von Silberkarpfenöl auf Blutdruck und Lipide von spontanhypertonen Ratten
Authors: Wirth M. , Moritz V. , Heine H. , Wagenknecht C. , Mieth G. , Friedrich M. , Steffens W. , Lieder U.
Published: November 2006

Über den hohen n‐3 Fettsäuregehalt der in der DDR akklimatisierten Süßwasserfischarten Silberkarpfen (Hypophthalmichthys molitrix) [1] und Marmorkarpfen (Aristichthys nobilis) [2] wurde bereits berichtet. Auch auf ihre ernährungsphysiologische Bedeutung und auf die Möglichkeit ihrer Verwendung zur Herstellung von diätetischen Erzeugnissen ist hingewiesen worden [3, 4]. In einer ersten tierexperimentellen Studie an spontanhypertonen Ratten (SHR) sollte der Einfluß eines Fischöles, dessen Ausgangsmaterial Silberkarpfen waren, auf Blutdruck und Lipide festgestellt werden. Weiterhin war von Interesse, wie sich die relativ niedrige Dosis von n‐3 Fettsäuren in dem nicht aufkonzentrierten Fischöl, verglichen mit internationalen Fischölkonzentraten, auf den Stoffwechsel auswirkt.
Chemical composition and volatile constituents of canned mango juice
Authors: Ragab M. , El‐Nemr S. E.
Published: November 2006

The chemical composition of mango (Mangifera indica L.) pulp and canned mango juice were evaluated. Canned mango juice was characterized by a lower content of ascorbic acid, free amino nitrogen, reducing sugars and carotenoids than the mango pulp, while the latter was characterized by lower natural total soluble solids, higher pH, lower total sugars and lighter color. The volatile composition of canned mango juice was investigated by means of standard‐controlled distillation‐extraction, liquid‐solid chromatography and gas chromatography‐mass spectrometry. This combination led to the characterization of 64 volatiles, of them 21 hydrocarbons, 25 alcohols, 12 esters, 2 aldehydes, 2 lactons and 2 other compounds. The volatile components of canned mango juice were quantitatively determined in range of 2260 ppb to 10 ppb. Limonene, myrcene, cis and trans‐ocimene, β‐caryophellene and α‐terpinolene were the major hydrocarbons of canned juice; meanwhile, methyl butanoate + ethyl 2‐methyl butanoate, furfural, α‐terpineol and γ‐octalacton were the abundant oxygenated compounds.
Untersuchung der subakuten Toxizität von Glucosylthiazolidin‐4‐carbonsäure an Ratten
Authors: Lewerenz H.‐J. , Plass R. , Bleyl D. W. , Macholz R. , Zeise S. , Kroh L.
Published: November 2006

Glucosylthiazolidin‐4‐carbonsäure, ein frühes Intermediat der Maillard‐Reaktion zwischen D‐Glucose und L‐Cystein, wurde männlichen und weiblichen Ratten in Dosierungen von 0, 25, 50 und 100 mg/kg mit der Schlundsonde über einen Zeitraum von 21 Tagen verabreicht. Als Kriterien der subakuten Untersuchung dienten der Allgemeinzustand der Tiere, das Wachstum, die Futteraufnahme, der Blutstatus, die Bestimmung der Harn‐ und Serumbestandteile einschließlich von Enzymaktivitäten, der Vergleich von Organmassen sowie die makroskopische und mikroskopische Pathologie. Wirkungen auf die Nieren äußerten sich in Oligurie und verminderter spezifischer Masse des Harns bei den Männchen und histopathologischen Veränderungen in den proximalen Tubuli bei den Weibchen. In dieser Untersuchung wurden 25 mg/kg KM als unwirksame Dosis ermittelt.
Mutagenicity of N‐nitrosomorpholine biosynthesized from morpholine in the presence of nitrate and its inhibition by ascorbic acid
Authors: Pérez A. , Fernández S. I. , Garcia‐Roché M. O. , De Las Cagigas A. , Castillo A. , Fonseca G. , Herrera M.
Published: November 2006

N‐nitrosomorpholine biosynthesis and inhibition in mice treated with nitrate, morpholine and ascorbic acid, was studied by means of the mutagenic activity in urine samples. The preincubation method was used and Salmonella typhimurium TA 1535 was the test strain. The results suggest that N‐nitrosomorpholine biosynthesis was carried out when the animals were fed high doses of nitrate, however ascorbic acid was an inhibitor of this process.
Übersichtsartikel. Die Charakterisierung mikrobieller Lipasen. 1. Mitt. Zur Bestimmung der Lipaseaktivität
Authors: Bariszlovich M. , Meusel D. , Tülsner M.
Published: November 2006

Die Auswahl einer geeigneten Methode zur Aktivitätsbestimmung von Lipasen richtet sich nach der vor‐handenen technischen Ausrüstung, den zu untersuchenden Enzymen, der Anzahl der zu untersuchenden Proben, z. B. bei Routineanalysen und dem zu erwartenden Empfindlichkeitsbereich. Für Laboratorien und Institute, die nicht über Einrichtungen zur radiochemischen Analyse verfügen, stellen die titrimetrischen Methoden und vor allem die Kupferseifen‐Methoden mit ihrer hohen Nachweisempfindlichkeit geeignete Verfahren zur Aktivitätsbestimmung von Lipasen dar.
Rheological and sensory characteristics of doughs and cookies based on wheat, soybean, chick pea and lupine flour
Authors: Hegazy Nefisa A. , Faheid Siham M. N.
Published: November 2006

Levels of 5, 10 and 15% of legume flours i.e. soybean, lupine and chick pea were used to supplement cookie. The effect of this supplementation on the rheological properties of the resulting dough was investigated using farinograph and extensograph as objective methods for quality assessment of the final product. It was found that there was an increase in water absorption capacity, dough stability, arrival time, dough development time and mix tolerance index.

Extensograph results indicated that dough resistance to extension, dough energy and proportional number were minimized with increasing the lupine flour in the formula, while it was not changed on dough extensibility. However, soy flour increased resistance to extension, proportional number and energy and diminished dough extensibility. At the same time supplementing wheat flour with chick peas decreased both dough resistance to extension and proportional number while it increased dough extensibility and energy.

For sensory evaluation, it was found that using either until 5% soybean or 10% chick pea or 15% lupine flour could replace the wheat flour in cookies formula without adversely affecting baking performance or altering the physical characteristics of the end product.
The natural occurrence of unusual fatty acids. Part 1. Odd numbered fatty acids
Authors: Diedrich M. , Henschel K.‐P.
Published: November 2006

A literature review of the natural occurrence and effects of odd numbered fatty acids (C11 to C33) in microorganisms, plants and animals is presented. Not only saturated and unsaturated odd numbered fatty acids but also unsaturated fatty acids with unusual position of double bonds seem to be ubiquitous in small amounts.
Effect of acetylation on rheological properties of fish protein isolates during heating
Authors: Pavlova Ludmila A. , Damshkaln Lilija G. , Vainerman E. S.
Published: November 2006

Rheological properties of concentrated dispersions of muscle Pollack proteins acetylated to different degrees as a function of temperature have been studied.

The character of viscosity changes of the partially acetylated isolates is almost identical with that of unacetylated protein. However, the temperatures corresponding to viscosity maxima increase proportionally to the degree of acetylation.

A total acetylation of the free lysine ϵ‐amino groups of Pollack protein results in a significant increase in the critical concentration and/or temperature of the sol‐gel transition.
Conformational stability of ribulose 1,5 biphosphate carboxylase from tobacco leaves according to the differential scanning microcalorimetry
Authors: Burova T. V. , Ya. Grinberg V. , Bauwe H. , Tolstoguzov V. B.
Published: November 2006

Protein conformation is one of the key factors which determine the behaviour of a protein in solution. During the isolation and processing into foodstuffs proteins may undergo significant conformational changes, involving structural changes on different levels — from the secondary level to the submolecular one. One of the most urgent problems related to food protein processing is the regulation of the conformational changes of proteins in order to obtain steady structures with desirable functional properties [1].

The present work is concerned with the effect of pH on the conformational stability of Ribulose 1,5‐Bisphosphate Carboxylase (RBPC) from tobacco leaves. This protein constitutes 50% of the soluble proteins in green leaves of plants [2]. RBPC is an oligomeric enzyme which consists of 16 noncovalently linked subunits: large and small with a molecular mass of 55 and 14 kDa, respectively.
Toxikologische Beurteilung von Saccharosecarbonsäureestern auf der Grundlage subchronischer Fütterungsversuche mit Ratten 1. Mitt. Wirkung von Saccharosefettsäurepolyester
Authors: Lewerenz H.‐J. , Mieth G. , Bleyl D. W. R. , Plass R. , Schliemann
Published: November 2006

Männlichen und weiblichen Ratten wurde ein Saccharosefettsäurepolyester enthaltendes Produkt (SPE) in Futterbeimengungen von 0, 5, 10 und 15% über einen Zeitraum von 13 Wochen verabreicht. Als Vergleichsprodukte wurden Hartfett (HF) und Fettsäureethylester (FEE) in Zusätzen von 7,5 bzw. 4,5% verfüttert. Tieren einer weiteren Gruppe wurde jeweils Standardfutter entsprechend 92,5% der Futteraufnahme bei 15% SPE gegeben. Ein signifikant erhöhter Futterverzehr war bei den männlichen und weiblichen Tieren aller SPE‐Gruppen, der HF‐Gruppe und der FEE‐Gruppe im Vergleich zu den Kontrolltieren zu verzeichnen. Männliche Ratten mit SPE‐Futterzusätzen zeigten Erhöhungen des Serum‐Harnstoff‐N in allen Gruppen, der Aktivität der alkalischen Phosphatase im Serum und der Glucoseausscheidung im Harn bei 10 und 15 % und der Aktivität der Serum‐Leucinaminopeptidase bei 15 %. Bei den weiblichen Tieren stiegen der Blutglucosegehalt und die Aktivität der alkalischen Phosphatase im Serum bei SPE‐Futterbeimengungen von 15% und die Aktivität der Leucinaminopeptidase im Serum bei 10 und 15 % an.
Prediction of total body lipid from total body water in rats. Part 1. Relations between directly measured major body components
Authors: Zahn L. , Freund R. , Hoppe K. , Pisarchuk K. L. , Augustin W.
Published: November 2006

Aimed to the construction of a prediction equation for estimations of lipid content from animal water content body composition was determined by whole body analysis of male rats (1) given access, ad libitum, to a commercial standard diet (n = 144; ranging from 60 to 600 g in weight, and from the 4th to the 34th week of age), and (2) showing striking variations with regard to nutritional state, dietary history, enlarged fat deposition, genetic origin, intestinal microbial status, and advanced age (n = 75). It was shown that a unique coefficient of water content in lipid‐free body mass does not exist.

The results of statistical analysis for the grouped values of percentage body dry matter (x) and percentage body lipid (y) indicate that the latter can be estimated accurately from body water content directly determined by the use of the quadratic regression equation y = −0.2864×+0.01615 x2 with a standard deviation of the procedure sy = ±1.40. This prediction equation is valid for a wide developmental span even under highly different experimental states. Differences between the calculated body lipid contents vs. analytically determined values are smaller than by using a linear regression equation or coefficient(s) of hydration of lipid‐free body mass.
Die enzymatische Wirkung von 3 Isoenzymen der Glucoamylase aus Aspergillus niger auf verschiedene Substrate
Authors: Pusch D. , Rawel H. , Kroh L. , Westphal G.
Published: November 2006

Glucoamylase (E.C.3.2.1.3.) kann aus unterschiedlichen Mikroorganismen isoliert werden. In der Literatur ist die analytische Charakterisierung der Glucoamylase sehr vielfältig angegeben. Ein direkter Zusammenhang zwischen Art des produzierenden Mikroorganismus und Anzahl von Proteinfraktionen besteht nicht. Auf die Anzahl und Aktivität der Isoenzyme der Glucoamylase haben Medienzusammensetzung, Kulturbedingung und Reinigungsverfahren wesentlichen Einfluß.

In der vorliegenden Arbeit wird eine Glucoamylase aus A. niger mittels SDS‐Polyacrylamidelektrophorese nach Laemmli in Isoenzyme getrennt. Es wird nachgewiesen, daß 2 % SDS in einer 0,1 % igen Enzymlösung nur einen geringen Aktivitätsabfall bewirkt und demzufolge die SDS‐PAGE zur Trennung der Glucoamylase B mit anschließender Aktivitätsbestimmung genutzt werden kann. Die Isoenzyme weisen rel. Molekülmassen von 78500, 70800 bzw. 42600 auf. Alle 3 Isoenzyme katalysieren die Hydrolyse von polymeren Substraten (lösliche Zulkowsky‐Stärke, SHP und Kartoffelstärke) sowie von D‐Maltose. Sie sind deshalb Glucoamylasen. GA I weist die geringste und GA II die höchste Enzymaktivität auf.

Die D‐Maltose wird in Abhängigkeit von den Isoenzymen der Glucoamylase quasi kontinuierlich enzymatisch hydrolysiert. Die polymeren Substrate zeigen anfänglich (bis 72 h) eine starke Zunahme der Hydrolyse, die nachfolgend nur noch geringfügig ansteigt.
Determination of Cd, Co, Cu, Fe, Pb, Mn, Ni and Zn in diets: Development of a method
Authors: Barbera Reyes , Farre Rosaura , Mesado Delfina
Published: November 2006

A method useful for the determination of cadmium, cobalt, copper, iron, lead, manganese, nickel and zinc in diets is described. Organic matter is destroyed applying a wet procedure, and element content is measured by flame atomic absorption spectroscopy (FAAS) in the case of copper, iron, manganese, nickel and zinc, and by graphite furnace (GF‐AAS) in the case of cadmium, cobalt and lead. The matrix interference study is carried out. Values found for linearity, detection and quantitation limits as well as accuracy show that the described method is useful to determine the elements taken into account at usual levels in diets.
Untersuchungen zur Fettsäurezusammensetzung von Biomasselipiden
Authors: Engst W. , Petrzika M. , Macholz R.
Published: November 2006

Mittels gekoppelter Kapillar‐Gaschromatographie/Massenspektrometrie werden die Fettsäureprofile von verschiedenen Hefe‐ und Bakterienlipiden sowie von Porphyridium cruentum (Rotalge) und Wolffia arrhiza (Wasserlinse) analysiert. Auf Kohlenwasserstoffen kultivierte Hefen unterscheiden sich von “Kohlenhydrathefen” durch einen hohen Gehalt an ungeradzahligen Fettsäuren (Anteil bis zu 50 %), während Bakterienlipide vor allem durch das Auftreten cyclischer, hydroxylierter und verzweigter Fettsäuren charakterisiert sind. In den untersuchten Wasserpflanzen können bis zu 30 % Arachidonsäure (Porphyridium cruentum) bzw. 60 % Linolsäure (Wolffia arrhiza) nachgewiesen werden.
Zusammenhang zwischen den rheologischen Eigenschaften von grobzerkleinertem Fleisch und dem Gehalt an freiem Wasser
Authors: Pipek P. , Sinevic V. , Sojkova S.
Published: November 2006

Das rheologische Verhalten von grobzerkleinertem, vorgesalzenem Fleisch wurde mit Hilfe der Rotationsrheometrie während des Stehenlassens und bei unterschiedlichen Wasserzusätzen untersucht. Es ergab sich ein enger Zusammenhang zwischen Fließverhalten und Wasserbindungsvermögen.
Ballaststoffstudie. Wirkungen auf Coloncarcinogenese
Authors: Bleyl D. W. R.
Published: November 2006

Die Etiopathogenese der Coloncarcinogenese ist als ein Zwei‐Schritt‐Prozeß, bestehend aus Initiation und Promotion aufzufassen. In der menschlichen Nahrung liegt die Palette der als Initiatoren in Frage kommenden Xenobiotica zumeist in so geringen Konzentrationen vor, daß keiner sie bei einer einfaktoriellen Betrachtung dafür ernsthaft in Betracht zieht.

Demgegenüber kann als gesichert angesehen werden, daß Gallensäuren Promotoreffekte im Zusammenhang mit der Coloncarcinogenese besitzen. Alle Einflußgrößen, die der Promotorwirkung der Gallensäuren zum Tragen verhelfen, bewirken dies anscheinend durch eine Senkung des pH‐Wertes und der dadurch er‐reichten Verschiebung der beiden Gallensäurefraktionen zugunsten der löslichen und/oder durch eine Verstärkung und Ausrichtung der Gallensäuremetabolisierung (7‐alpha‐Dehydroxylierung). Hierauf besitzt der Lipidgehalt in der Nahrung indirekt durch die Induktion der Cholegenese einen wesentlichen Einfluß.

Was bei der Coloncarcinogenese als “protektiver Effekt” der Ballaststoffe verstanden wird (reduzierte Anzahl der Tumorträger und/oder Anzahl von Tumoren/Tier), ist als solcher nicht zu interpretieren. Nachweisen läßt sich lediglich eine herausgezögerte Promotionsphase. Sie wird nur von pflanzlichen Produkten (Kleie, Lupine) und nicht generell von Ballaststoffen erzielt.
Naming and identification of tastes in aqueous solutions
Authors: Pilková L. , Nováková M. , Pokorný J.
Published: November 2006

Several taste substances were tested in aqueous solutions; tannic and tartaric acids were found unsuitable as a standard substance for the taste identification. Monosodium glutamate, sodium hydrogen carbonate and potassium chloride were often identified as salty substances even when the subjects were able to distinguish between the tastes. They probably identified the taste as salty owing to the lack of proper terms, and unsufficient experience with tasting monosodium glutamate and sodium hydrogen carbonate as substances possessing defined tastes different from the salty taste.
Ein Überblick zur digitalen Bildverarbeitung in der Lebensmittelwissenschaft 4. Mitt. Merkmalsbestimmung in Grauwertbildern
Authors: Kozerke W. , Fromhold‐Treu I.
Published: November 2006

Die effektiven Algorithmen der Objektisolierung in Binärbildern können leicht auf Grauwertbilder übertragen werden, wenn ein Entscheidungskriterium bekannt ist, mit dem die Bildpunkte in Objekt‐ und Untergrundpunkte eingeteilt werden können. Hierzu werden drei verschiedene Methoden diskutiert. Außerdem werden Objektmerkmale definiert, die aus dem Grauwert der Objektpunkte resultieren.
Comparative study of the protein patterns of some rapeseed (Brassica napus L.) varieties by means of polyacrylamide gel electrophoresis and high‐performance liquid chromatography
Authors: Raab Barbara , Leman Halina , Schwenke K. D. , Kozlowska Halina
Published: November 2006

Seven rapeseed varieties were characterized by investigation of the patterns of buffer soluble proteins using polyacrylamide gel electrophoresis and high‐performance liquid chromatography (size‐exclusion and cation‐exchange chromatography). Most pronounced differences were found in proteins not belonging to 12 S and 2 S storage proteins having presumably metabolic functions. Quantitative variations dominate within the low molecular mass 2 S storage proteins.
Physico‐chemical and functional properties of proteins from spray dried algae (Spirulina platensis)
Authors: Nirmala C. , Prakash V. , Venkataraman L. V.
Published: November 2006

The nitrogen solubility index of proteins from Spirulina platensis as a function of pH in the range of 1 to 12 has been determined both in water and different concentrations of sodium chloride using the spray dried samples. Solubility characteristics show maximum solubility in the pH range of 8 to 10 in water and pH 6.0 ± 0.5 in 0.5 M sodium chloride. The ultraviolet and visible spectra have maxima at 285 and 620 nm, respectively. Fluorescence emission spectrum shows a maximum emission at 340 nm arising from tryptophanyl groups. The sedimentation velocity experiment shows two major fractions with sedimentation coefficient of 2.8 and 4.9 S. The functional properties of the protein are determined using the spray‐dried sample. The result for water absorption (292 g/100 g), fat absorption (56 g/100 g), foaming and emulsion properties were determined and compared with egg protein as standard. An attempt is made to correlate the changes occurring as a result of spray drying of the functional properties to the physico‐chemical properties of the protein in solution.
Restricted enzymatic hydrolysis of legumin of broad beans (Vicia faba L.) by trypsin in concentrated solutions. Control of hydrolysis process at the expense of change of enzyme‐substrate ratio
Authors: Danilenko A. N. , Dmitrochenko A. P. , Braudo E. E. , Bogomolov A. A. , Rozantsev E. G.
Published: November 2006

Kinetics and mechanism of proteolysis of broad bean (Vicia faba L.) legumin by trypsin in concentrated solutions at different enzyme‐substrate ratios (E/S = 1/40, 1/100, 1/200, 1/1000) were studied. By the method of HPLC it was established that during proteolysis process (E/S = 1/40) take place both protein content decrease in hydrolysate and change of its molecular mass (from 360 to 280 kD), which evidences for the mixed type of proteolysis, including cooperative and non‐cooperative mechanisms. Decrease of E/S from 1/40 up to 1/100–1/1000 leads not only to unproportional drop in proteolysis rate, but also to decrease of the relative contribution of cooperative proteolysis which is, possibly, connected with presence in protein molecule of at least two groups of attack sites, differentiating by their affinity with enzyme. Change of enzyme‐substrate ratio is accompanied also by change of subunit composition of product of non‐cooperative proteolysis (‘modified protein’) and also of temperature and enthalpy of its denaturation.
Influence of different spices on the microbial reduction and storability of laboratory‐processed tomato ketchup and minced meat
Authors: Adegoke G. O. , Sagua V. Y.
Published: November 2006

At 1% (w/w) each of 6 non‐commercial spices (Xylopia aethiopica, Aframomum melegueta, Monodoran myristica, Piper guineense, Icacina spp and Congronema latifolia) when added to laboratory‐processed tomato ketchup and minced meat reduced spoilage microbial populations to different levels. Tomato ketchup spiced with M. myristica remained sterile after 24 h incubation at room temperature (26 ± 2 °C) whilst control samples had bacterial and yeast counts of 1.5 ± 107 cfu/g and 2.0 ± 105 pro‐pagules/g, respectively. X. aethiopica also reduced bacterial populations in tomato ketchup. In spiced minced meat, only X. aethiopica and C. latifolia showed an inhibitory effect on yeasts. Other spices used were not or relatively less effective against bacteria and yeasts.
Effect of processing conditions and cooking on retention of minerals in macaroni
Authors: Yaseen A. A. E.
Published: November 2006

Semolina flour was processed on macaroni in a laboratory scale and dried by means of low and high‐temperature drying. Egyptian commercial macaroni samples were cooked to confirm the laboratory results. Results showed that macaroni samples had a very low level of Na. The amounts of P, Fe, Mn, Cu, Zn, K, and Mg were different. No loss of mineral contents occurred during extrusion. There was no remarkable changes in mineral contents of macaroni after processing and cooking when the conventional low‐temperature drying was compared to high‐temperature drying. About 70% of the minerals were retained in macaroni after cooking except Na and K. Only from 32–39% of the original potassium and sodium were found after cooking for both macaroni dried at low and high temperature.
The behaviour of rapeseed cruciferin on chromatofocusing
Authors: Reva V. A. , Kulibali M. T.
Published: November 2006

Cruciferin, a main storage protein of rapeseeds has been investigated by means of chromatofocusing, isoelectric focusing and electrophoresis in polyacrylamide gels. It was shown, that the half molecules of this oligomeric protein differ from each other by subunit composition. There are specific forms of cruciferin. At low ionic strength the half molecules, or subunits and/or polypeptide chains under denaturing conditions, aggregate to relatively stable complexes, evidently, by means of hydrophobic interactions.
Role of dietary lipids and butylated hydroxy anisol (BHA) administration on albino rats. Part I. Serum unsaturated fatty acids
Authors: Aida M. A. Saad , Abu‐El‐Zahab H. S. H. , Abdallah A. , El‐Sisi S. F.
Published: November 2006

Adult male albino rats were supplemented with edible plant oils, corn maize and cotton seed oils and their semihydrogenated forms (Heliopolis and Sultan cooking fats) for a period of 3 months. In general, the supplementation of tested oils produced increasing effect on the serum levels of total C18: 1, C18:2 and C20:4 unsaturated fatty acids (UFA). The increases were significant in case of feeding corn maize oil and Sultan cooking fat for total and C18: 1 and C18:2 UFA. However, the degree of significance was intensified by the feeding of cotton seed oil and Heliopolis cooking fat. Supplementation of Sultan cooking fat showed a significant increase in serum level of C20:4, while the other tested oils and Heliopolis cooking fat produced very highly significant increase.

Butylated hydroxy anisol (BHA) produced no effect on the level of UFA when administered with dietary tested edible lipid but its role revealed by maintaining the higher level of UFA due to administration of oils and its semihydrogenated analogous.
The chemical composition of laurel leaf oil from various origins
Authors: Pino J. , Borges P. , Roncal E.
Published: November 2006

Composition of laurel leaf volatile oil from different geographical origins was studied by means of gas‐liquid chromatography, column chromatography and coupled gas chromatography‐mass spectrometry. The 37 most important constituents were identified and quantified. Organoleptic quality of Albanian laurel leaf oil was found to be superior to that of samples from France, Italy and Spain.
Interactions of isothiocyanates with egg white proteins
Authors: Kroll J. , Rawel H. , Kröck R. , Proll J. , Schnaak W.
Published: November 2006

Glucosinolates and their very highly reactive breakdown products (mainly isothiocyanates = ITC) belong to one of the most important natural toxicants. This paper deals with the interactions of allyl‐, butyl‐, phenyl‐ and benzyl ITC with egg white proteins resulting in the formation of ITC‐protein‐conjugates. The ITC's react with amino groups by forming thiourea derivatives. Such reactions are well described by changes in the amounts of free amino groups and available lysine. Further reaction sites are sulphhydryl side chains of proteins leading to dithiocarbamate esters. The investigations further show that such reactions are accompanied with a decrease in the solubility of the prepared conjugates. Simultaneously a shift of the isoelectric range to a lower value of pH can also be observed. Changes in electrophoretic patterns and mobility can also be seen due to the strong electrophilic attack of ITC to proteins. Comparison of the 4 investigated preparations shows that benzyl‐ITC is the most reactive partner for egg white proteins.
Effect of fluidized bed drying on properties of dehydrated apples
Authors: Vrač Nevenka , Grüner Matilda
Published: November 2006

Three sorts of apple (Idared, Golden Delicious and Jonathan) were dried in a laboratory‐type fluidized bed dryer. Apples were cleaned, cored, peeled and cut into 10 × 10 × 10 mm cubes or into slices 5 × 3 mm thick and 40 mm long. A part of the samples was dipped for 3 min prior to drying in 0.1% ascorbic acid solution. Drying temperature was 80 °C. Some physicochemical and sensory properties of fresh and dried apples were determined. Moisture content in dried samples varied between 9 and 12%. Greater quantity of water results in lower sensory characteristics. The sensory characteristics of apples were determined by a scoring system with weighed factors in a 20‐point scale. Glucose, fructose, saccharose, citric acid, malic acid and ascorbic acid levels were analysed by enzymatic methods. Contents of glucose, fructose and saccharose in dried apples were substantially unchanged compared to fresh apples. The drying process had the most influence on contents of citric and malic acids. Higher rehydration ratios were measured in spaghetti‐like sclices and in ascorbic acid treated samples. Idared had the best characteristics with regard to physicochemical and sensory results.
Profile‐rank method for the quality evaluation of meat flavours
Authors: Grigoryeva D. N. , Golovnya R. V. , Syomina L. A.
Published: November 2006

A new variant in sensory analysis which combines the advantages of profile and ranking methods is described. The profile‐rank method includes two steps: 1. The selection of the most significant descriptors on the base of calculated weight factors and 2. statistical data processing and the calculation of criteria for the evaluation of the quality of samples under test. The method was applied for the quantified quality determination of 27 samples of meat flavours.
Effects of sodium chloride and relative humidity on growth and sporulation of moulds isolated from cured fish
Authors: Diyaolu S. A. , Adebajo L. O.
Published: November 2006

A total of 14 moulds were isolated from 84 samples of cured fish obtained from several processing centres and retail shops in Lagos, Ogun and Oyo States, Nigeria. Aspergillus niger, A.flavus and A. chevalieri were the most prevalent. With the exception of Basipetospora sp., slight inhibition of mycelial growth and/or sporulation was recorded when isolates were cultured in basal medium containing 5% sodium chloride. The extent of inhibition increased with increasing salt concentrations, and at 25% level all the species had their growth completely inhibited.

When fish substrates inoculated with test fungi were kept inside 65% relative humidity (RH) chambers for 21 days, no detectable utilization of the substrates was recorded for any of the fungal species. Whereas only A. chevalieri and A. restrictus utilized the substrates when placed inside 70% RH chambers, all the test moulds recorded detectable utilization (though at varying extents) of same at 80% and 90% RH levels. The latter RH was the most conductive and under it A. niger, Penicillium sp. and the two isolated Scopulariopsis sp. brought about the greatest loss in weight of the substrates.
Importance and utilization of amaranth in food industry Part I. Characteristic of grain and average chemical constitution of whole amaranth flour
Authors: Dodok L. , Modhir A. A. , Halásová G. , Poláček I. , Hozová B.
Published: November 2006

Amaranth seeds are very small. Their bulk density is 843 g dm−3. Basic analysis of amaranth whole flour from Slovakia proved evidently a high content of proteins (17.7% on dry basis), what is typical for amaranths. The lipid content of amaranth grains is rather high (7.32% on d. b.). Amaranths with their high content of fat are similar to oats. From the point of storage time of the amaranth flour the high content of fat was assumed as an unfavourable factor. The quantity of fiber (4.91% on d.b.) is comparable with more varieties of amaranth cultivated abroad. Amaranth has a relatively high content of Ca, Mg, P, K and Fe. The quantity of thiamine corresponds to the average values of amaranth grown abroad. Riboflavin is present up to quadruple amount in comparison to the literature. The acidity of flour during 6 weeks of resting increased relatively little.
GFAAS determination of selenium in infant formulas using a microwave digestion method
Authors: Alegria A. , Barbera R. , Farré R. , Moreno A.
Published: November 2006

A method for determining the selenium content of infant formulas is proposed. It includes wet digestion with nitric acid and hydrogen peroxide in medium pressure teflon bombs in a microwave oven and determination by graphite furnace atomic absorption spectrometry (GFAAS). The absence of interferences is checked. Values obtained for the limit of detection (19.4 ng/g), precision (RSD = 2.2%) and accuracy by analysis of a reference material show that the method is reliable.
Content of fluorine in vegetables and fruits from an industrial area
Authors: Krelowska‐Kulas M.
Published: November 2006

Content of fluorine in vegetables and fruits from allotments situated in an industrial area as well as in an agricultural area without industrial emissions was determined. The fluorine determination was made by means of a potentiometric method with application of an ion‐selective electrode. Statistically significant differences between the fluorine content in vegetables and fruits from an area contaminated with the emissions of fluorine compounds and the fluorine content in vegetables and fruits from the control area were found. Significant differences between the fluorine content in above‐ and under‐ground parts of some vegetables were stated. The greatest fluorine content appeared in parsley haulm and in black currants.
Rapeseed meal‐glucosinolates and their antinutritional effects Part 7. Processing
Authors: Mawson R. , Heaney R. K. , Zduńczyk Z. , Kozłowska H.
Published: November 2006

This paper surveys the effect of some technological processes based on modified traditional way of obtaining oil from rapeseeds and employing polar solvents and enzymes on the content of glucosinolates and nutritional quality of the end products. Special emphasis has been put on the technologies introduced after 1980 tested mostly on a pilot scale.
Study on nutritive and physico‐chemical properties of buckwheat flour
Authors: Wei Y.‐ M. , Zhang G.‐ Q. , Li Z.‐ X.
Published: November 2006

The protein contents of four buckwheat flours (from two Chinese bitter, one Chinese sweet and one Polish sweet backwheats) are lower than that of Meneba wheat flour. Buckwheat flours are rich in albumin and globulin, but have a lower content of prolamin and glutelin than wheat flour. In buckwheat protein, the Lys content is approximately two times higher than in wheat protein, and the percentage of all other essential amino acids is higher than or near to that of wheat protein.

Buckwheat fluor is rich in K, Mg, Fe, Na, Cu, Mn, Sr, and Li. Its total of mineral content is higher than that of wheat flour.

The gelatinization temperature of buckwheat flour is higher than that of wheat flour, its gelatinization resistance is greater, the water absorption of its starch granules is stronger, the viscosity is higher and increases quickly during cooling.

When adding 10–20% of buckwheat flour to wheat flour, the mixed flour basically maintains the characteristics of wheat flour. When the buckwheat flour proportion is more than 60%, the mixed flour can hardly develop into dough any more. The dough properties have had some basic changes and the judgement becomes impossible.