ISSN:0027-769X    

DOI:10.1002/food.19970410102

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractAusgehend von positiven Wirkungen bei Molkentrinkkuren im Altertum, im Mittelalter und in der Neuzeit wird aus heutiger Sicht über die ernährungsphysiologische Bedeutung der Molke berichtet. Die Eiweiße sind wesentliche Bestandteile der Molke und zählen auf Grund ihrer Aminosäuren‐Zusammensetzung zu den biologisch hochwertigsten Proteinen. Sie weisen daneben wesentliche funktionelle Eigenschaften auf, die in Form verschiedener Molkenprodukte (Pulver, Proteinkonzentrate und ‐isolate) einen vielseitigen Einsatz in Lebensmitteln, Diätlebensmitteln und Getränken ermöglichen. Die Molkenproteine haben in der Säuglingsernährung als molkenproteinangereicherte Diäten sowie bei Kuhmilchprotein‐Intoleranz als Molkenprotein‐Partialhydrolysate ein bedeutendes Einsatzgebiet. Aktuelle Forschungsthemen sind biologisch aktive Peptidsequenzen, die bei der Verdauung wirksam werden und auf Sekretionsvorgänge von Enterohormonen sowie als Immunmodulatoren eine Rolle spielen. Sie können dazu betragen, den biologischen Wert der Molkenproteine unter erweiterten Gesichtspunkten zu beurteilen und neue Ersatzformen und ‐gebiete zu erschließen. Auf weitere Anwendungen (z. B. bei Adipositas, Gicht, Niereninsuffizienz) wird hingewiesen. Hinsichtlich der mengenmäßig in Molke dominierenden Lactose wird auf ihre Bedeutung für die gesunde Entwicklung des Säuglings (Anpassung an den erhöhten Gehalt in der Muttermilch) sowie auf Lactoseintoleranz und Galactosämie eingegangen. Bei den Mineralstoffen werden die hohe Nährstoffdichte für Calcium (Prophylaxe für Osteoporose), die günstigen Ca: P und K: Na Verhältnisse (Blutdrucksenkung bei letzterem), die Förderung der Mineralstoffresorption durch Lactose sowie der hohe Iodgehalt der Molke behandelt. Die Molke ist reich an B‐Vitaminen, die bei entsprechendem Verzehr zu deren Bedarfsdekkung wesentlich beiträgt. Hervorzuheben ist das Vitamin B12in Milch und Molke, das bei lacto‐ovo‐vegetarischer Ernährung die einzige Quelle dieser für die Blutbildung und Zellteilung unerläßlichen Nährstoffs ist. Abschließend wird eine ernäh

ISSN:0027-769X    

DOI:10.1002/food.19970410103

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe specific integral hydrophobicity of denatured forms of legumin and legumin‐T from broad beans was evaluated through their hydration heat capacities. These were calculated as differences between partial heat capacities obtained from differential scanning microcalorimetry data and heat capacities in the gas phase, which were calculated by the use of the method of additive group contributions, taking into account the expansion of protein molecule in the gas phase. It is shown that there is no significant difference between the data for denatured forms of both proteins. The comparative evaluation of the hydration heat capacities of native forms of legumin and legumin‐T was carried out. It is shown that the native legumin‐T has a greater value of the hydration heat capacity and respectively is more hydrophobic than the native legumin. On the basis of the values of differences between the heat capacities in denatured and native states it is shown that the accessible hydrophobic surface of the native legumin‐T related to a mean amino acid residue is 8‐13 Å2greater than that of the nati

ISSN:0027-769X    

DOI:10.1002/food.19970410104

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractFour field strains ofLactobacillus plantarum(LS 4, 19, 21, 133) obtained from fufu (a semi‐solid product obtained by boiling fermented cassava ‐Manihot esculentaCrantz) and a type strain DSM 2017 were grown on different carbon sources to induce galactosidase production. LS 21 produced the highest concentration of α‐ and β‐galactosidase with 0.28 μmol/1 and 0.28 μmol/1 respectively on lactose and galactose. Milk obtained from soybean seeds treated with the enzyme mixture for 24 h showed a 99, 98 and 96% reduction respectively in the raffinose, stachyose and sucrose content when compared with the dry soybean seed. Glucose and galactose which were not detected in the dry seeds became readily available after soaking in both enzyme mixture and distilled water.Although there was reduction in the nutritional composition of both milk samples, reduction of phytic acid and trypsin inhibitor is beneficial to the consumers. The result of the sensory evaluation showed that the milk prepared from enzyme‐treated soybean seeds was rated better in terms of flavour, texture, appearance and

ISSN:0027-769X    

DOI:10.1002/food.19970410105

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractProducts like biscuits and weaning mixture incorporating fermented rice‐dehulled blackgram‐whey slurries were developed and analysed for sensory and nutritional evaluation. Rice and dehulled blackgram flour blend mixed in 70:30 proportion and fermented with whey at 35 °C for 18 h was the most acceptable blend for the preparation of biscuits as well as weaning mixture. Crude‐protein, true‐protein, non‐protein nitrogen, fat and ash contents of the developed products whether incorporating fermented or unfermented cereal‐legume‐whey blends did not differ significantly. Antinutritional factors were significantly less andin vitrodigestibilities of starch and pr

ISSN:0027-769X    

DOI:10.1002/food.19970410106

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractFive vegetable proteinsuyacoating meals were formulated to contain 100:0, 75:25, 50:50, 25:75 and 0:100% groundnut: soyabean in addition to a mixture of spices and seasonings used in traditional preparation oftsire‐typesuya.Slices of beef loin muscles were coated with the formulated meals and roasted at 175 °C for 15 min. Samples of the hot freshly cookedtsirewere held in heated (68 °C) dry or humidified holding chambers for 90 or 180 min. The amount of coating meals bound by the beef slices decreased significantly (P0.05) by variations in coating meal. However, moisture content in the rawtsireincreased (P<0.05) with increasing proportion of soyabean in the coating meals. Sensory qualities oftsiredeclined significantly (P<0.05) only when the groundnut was completely replaced. Weight losses associated with hot chamber holding of the cookedtsirewas significantly (P<0.05) reduced by humidifying the chamber. Increased proportions of soyabean in coating meals reduced (P<0.05) weight losses bytsireonly after an extended holding per

ISSN:0027-769X    

DOI:10.1002/food.19970410107

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe antifungal activity of the lactoperoxidase (LPO) system with glucose oxidase (GOD) as source of hydrogen peroxide was determined in salt solution and in apple juice. The test organismsRhodutorula rubraandSaccharomyces cerevisiaewere cultivated aerobically in apple juice,Mucor rouxiiwas grown on wort agar adjusted to pH 4.5.Aspergillus nigerandByssochlamys fulvawere kept on malt extract agar. Spores of the filamentous fungi were harvested by suspension in salt solution supplemented with Tween 80® and checked microscopically. The antifungal activity of the combined enzyme system was tested with initial counts of approx. 105cfu · ml−1(yeast cells or spores) suspended in salt solution supplemented with 25 mg · l−1thiocyanate and 20 g · l−1glucose or in apple juice supplemented with the same amount of thiocyanate. The tests were performed with 25 ml of the medium in 100 ml Erlenmeyer flasks shaken at 28 °C under aerobic conditions. Inactivation was achieved for all test organisms in both media. The yeast strains were found to be least stable whileB. fulvawas most resistant. A combination of 5 U · ml−1LPO with 0.5 to 1 U · ml−1GOD was sufficient for complete inactivation of this mold in salt solution within 2 h. The enzyme system also showed antifungal activity in apple juice at acid pH (3.2), although its effectiveness was reduced. In this medium,B. fulvawas inactivated by 20 U · ml−1LPD and 1 U · ml−1GOD within 4 h.R. rubraandS. cerevisiaewere unable to survive in apple juice at 5 U · ml−1LPO combined with 1 U · ml−1GOD. For inhibition by GOD alone, higher amounts of this enzyme were needed and even then onlyM. rouxiiandR. rubrahave been affected within the concentration range

ISSN:0027-769X    

DOI:10.1002/food.19970410108

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractA survey was carried out to obtain data on the occurrence ofFusariummycotoxin in wheat and flour samples collected from local markets in Egypt and to study the influence of gamma‐irradiation on controlling the occurrence of these mycotoxins in wheat, flour and bread. Deoxynivalenol (DON) was detected in five samples of wheat at levels ranging from 103 to 287 μg/kg and one sample each of flour and bread at concentrations 188 and 170 μg/kg. Zearalenone (ZEN) was detected in ten samples of wheat at levels from 28 to 42 μg/kg and four samples each of flour and bread at concentrations of 95 and 34 μg/kg, respectively. T‐2 toxin was detected only in one sample each of wheat, flour and bread at concentrations of 2.9, 2.2 and 2.3 μg/kg, respectively. Gamma‐irradiation at dose level of 6 kGy completely eliminated fungal flora in flour and wheat. DON, ZEN and T‐2 toxin concentrations are reduced to 85, 20 and 2.0 μg/kg for wheat and to 125, 45, and 1.0 μg/kg for flour after 4 kGy exposure and a sharp drop inFusariumtoxin levels occurred at 6 kGy and was eliminated at 8 kGy. Bread prepared from 6 kGy was contaminated withFusariumtoxin at levels below 5 μg/kg. It was noticed that gamma‐irradiation reduce greatly the natural occurrence ofFusariummy

ISSN:0027-769X    

DOI:10.1002/food.19970410109

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractThe stability of lutein, a major xanthophyll, was investigated under various storage conditions. Continuous exposure of lutein‐containing samples to cold white fluorescent light (4600 lux) at 25 °C resulted in the degradation of lutein at 0.8%‐10.7% per day in the samples containing ascorbic acid, ascorbic acid + KOH and H2O (as control) over a period of 75 days. It was found that ascorbic acid could retard lutein degradation (0.04% ‐ 2.5% per day) at temperatures from −30 °C to 50 °C under the alkaline condition in darkness. High temperature promoted the degradation of lutein in all the samples. Under the alkaline condition and at low temperature (‐12 °C), the stability of pure lutein was similar to that of the lutein extracted from the algaChlorella protothecoidescultivated hete

ISSN:0027-769X    

DOI:10.1002/food.19970410110

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY

摘要:

AbstractMethyl linoleate (ML) was autoxidised at room temperature in the dark. In comparison to hexanal, (E)‐ and (Z)‐2‐octenal, only very small amounts of (E)‐2‐nonenal were formed, indicating that linoleic acid was not an important precursor of the latter aldehyde. Palmitoleic acid in form of its methyl ester (MP) was studied as an alternative. Aroma extract dilution analysis revealed (E)‐2‐nonenal followed by (E)‐2‐octanal and (Z)‐2‐nonenal as the most potent odorants of autoxidised MP. Accordingly, in a butter oil sample in which the concentrations of either palmitoleic acid or linoleic acid were doubled, (E)‐2‐nonenal increased for 73 percent after addition of MP but only for 10 percent after that of ML. This difference indicates that the cardboard off‐flavour of butter oil is mainly caused by an autox

ISSN:0027-769X    

DOI:10.1002/food.19970410111

出版商:WILEY‐VCH Verlag GmbH    

年代:1997

数据来源: WILEY