European Journal of Nutrition (v.20, #3)
Freie und gesamte Aminosäuren im Muskelfleisch vom Weißblutfisch (Champsocephalus gunnariLönnberg) und vom Krill (Euphausia superbaDana) by W. Partmann (163-171).
Im Muskelgewebe von auf See gefrorenem Weißblutfisch Champsocephalus gunnariLönnberg und Krill Euphausia superbaDana wurden die Aminosäurenzusammensetzung, die freien Aminosäuren und einige andere physiologisch interessante Verbindungen bestimmt. Die geringen Gehalte an labilem energiereichem Phosphat und Nicotinamid-adenindinucleotid beim Weißblutfisch deuten darauf hin, daß die glykolytischen Prozesse bereits nach dem Einfrieren auf See nahezu abgeschlossen und in übereinstimmung mit Befunden am Muster der freien Aminosäuren und verwandten Verbindungen von nur maßiger Bedeutung für den Stoffwechsel waren. Die Aminosäurenzusammensetzung im eßbaren Anteil vom Weißblutfisch stimmte mit der von anderen Fischen bekannten weitgehend überein. Auch die Schwanzmuskulatur vom Krill war in den Gehalten an Aminosäuren mit denen anderer Krebse vergleichbar. Die Anteile insbesondere an essentiellen Aminosäuren beim Weißblutfisch und beim Krill entsprachen den Anforderungen, die an ein biologisch hochwertiges Eiweiß zu stellen sind.In the muscle tissue of sea-frozen ice fish (Champsocephalus gunnariLönnberg) and of krill (Euphausia superbaDana) the amino-acid composition, the free amino acids and some other compounds interesting from a physiological point of view were determined. The low contents in labile energy-rich phosphate and nicotinamide adenine dinucleotide in ice fish suggest that the glycolytic processes were nearly completed already after freezing on sea and that they had been of only moderate significance for the metabolism, as was demonstrated also by findings on the pattern of the free amino acids and related compounds. The composition of the amino acids of the edible parts of ice fish largely corresponded to other fish. The amino acid composition of the abdominal muscle tissue of krill and of other crustaceans was comparable as well. The shares particularly of essential amino acids in ice fish and krill fulfilled the requirements of a protein of high biological value.
Keywords: Weißblutfisch; Krill; Muskelfleisch; Aminosäuren
Enzymatic degradation of polar lipids in deep-frozen parsley by R. Duden; A. Fricker (172-181).
Under the frozen storage at usual storage temperatures of leafy tissues not pretreated by heat, enzymatic lipid degradation reactions take place, which lead already after a few weeks to a considerable or complete loss of the native polar lipids. These degradation processes being accompanied by a deterioration of the flavour have been studied in greater detail in parsley leaves.Among the reaction products we found large amounts of 6-acylmonogalactosyl diglycerides (formed from monogalactosyl diglycerides by enzymatic transacylation) and phosphatidic acid (formed from phospholipids through phospholipase-D action). The generally assumed reaction sequence: formation of free fatty acids by acyl hydrolases followed by hydroperoxidation through lipoxygenase and degradation o f the hydroperoxides into off-flavour compounds may hence take place, if at all, only to a limited extent.Considerable phospholipase D as well as minor acyl transferase activities are still detected at −24‡C, whereas at −32‡C the lipid loss is very low.Deterioration processes can be avoided by blanching, a treatment not leading to any substantial quality loss.Während der Gefrierlagerung von thermisch nicht behandelten Blattgeweben laufen bei praxisüblichen Lagerungstemperaturen enzymatische Lipidabbaureaktionen ab, die schon nach wenigen Wochen zu einem weitgehenden oder vollständigen Verlust der nativen polaren Lipide führen. Diese von einer Geschmacksverschlechterung begleiteten Prozesse wurden am Beispiel von Petersilieblättern näher untersucht.Unter den Reaktionsprodukten befanden sich beträchtliche Mengen von 6-Acylmonogalaktosyldiglyceriden — entstanden durch Transacylierung aus Monogalaktosyldiglyceriden — sowie von Phosphatidsäure, deren Bildung durch Einwirkung von Phospholipase D auf Phospholipide zu erklären ist. Die vielfach angenommene Reaktionsfolge: Spaltung der Lipide durch Acylhydrolasen, Hydroperoxidation der gebildeten freien Fettsäuren durch Lipoxigenase und Zerfall der Hydroperoxide in Off-flavour-Komponenten spielt möglicherweise nur eine untergeordnete Rolle.Die Phospholipase D ist selbst bei −24‡C noch sehr wirksam. Acyltransferasewirkungen sind in geringerem Umfang ebenfalls noch bei dieser Temperatur erkennbar. Bei −32‡C werden die Lipide nur noch in sehr geringem Umfang angegriffen.Die Verderbprozesse können durch Blanchieren unterbunden werden, ohne daß die Petersilie dadurch eine wesentliche Qualitätseinbuße erleidet.
Keywords: galactolipids; phospholipids; frozen storage; parsley
Efficiency of conventional versus marker technique for shortening the time in digestion trials by E. A. Khafagi; Y. I. El-Talty; M. S. Samy (182-187).
Investigation was carried out to determine the digestibility of the main nutrients (DM, CP and energy) in digestion trials using some roughages in order to reduce the collection period and to study the suitable time of the marker technique and its application. This study revealed the following results: (1) The average recovery of chromic oxide in feces were 99.71±3.75% in the 3rd day (after administrating the marker), 95.17±1.03% in the 5th day and 96.53±2.35% in the 7th day. It could be concluded that this marker is indigestible and could be used as an ideal one. (2) There were no significant differences between the digestibility values with the conventional method and those of the two short-period techniques (the first three days and the first five days collection periods). The percentage differences were not exceeding 6 % except some deviations with CP digestibility in one trial (hay: rice straw mixture). These two methods seemed to be reliable in practice. (3) The same differences were found between the digestion coefficients, which conducted from the cenventional method, and those of the marker technique using three times for collection except high deviations were found with one trial in the last two procedures. Using marker technique appeared promising from the 3rd day up to the 7th day after its administration.
Keywords: digestion trials; time shortening; marker technique
Changes in composition and enzyme activities of mitochondrial and post-mitochondrial fractions of tissues of rats given mustard oil diet with carnitine and/or fish oil by J. K. Gill; R. Sood; Dr. S. P. Ahuja; P. P. Gupta (188-193).
The effects of short-term feeding of a 20 % mustard oil (containing 47 % erucic acid) diet with 0.1 % carnitine and/or fish oil on the activity of enzymes of lipid metabolism in mitochondrial and post-mitochondrial fractions of heart, liver, and skeletal muscles of rats were determined to study the reversal of erucic acidinduced lipidosis. Histopathological changes were also studied.The inclusion of fish oil or fish oil plus carnitine in a mustard oil diet, especially the latter, eliminated the histopathologically detectable lipidosis in heart and skeletal muscles. The reason for this appears to be the increased activity of lipase and phospholipase in tissue homogenates and of cholesterol ester hydrolase in the post-mitochondrial fraction; and also an increase in mitochondrial succinate dehydrogenase which may increase the utilization of the liberated fatty acids. The results suggest that the erucic acid-induced lipidosis is prevented or eliminated by increased lipolysis and oxidation of fatty acids when such a diet is supplemented with carnitine and/or fish oil.
Keywords: enzyme activity; mitochondria; mustard oil; carnitin; fish oil
Physicochemical characteristics of lentil varieties as related to their cookability by Hani M. El-Saied; Ahmed E. El-Shirbeeny (194-199).
Some physical and chemical characteristics of three varieties of lentil were studied along with their cookability. Gelatinization temperature and peak viscosity were found to be independent of amylose content as well as protein and amino acid contents. The maximum volume-expansion ratio was positively correlated with amylose content and independent of protein and amino acid contents. Seed coats of the tested varieties were very fine and seemed to be an unimportant factor for their cookability. No correlation was found between phytic acid phosphorus content and cookability of the tested varieties. The amino acids were determined quantitatively by the amino acid analyser. Glutamic acid was found in higher level, whereas the other amino acids were found in variable amounts.
Keywords: lentil varieties; cookability; physicochemical characteristics
Cooking-quality of broad-bean varieties as influenced by some physicochemical measurements by Hani M. El-Saied; A. El-Farra Abdel-Hamid (200-207).
Cooking and processing-characteristics of eight Egyptian dry broad-bean varieties were studied along with some of their chemical and physical tests. Good correlation was found between their cooking-quality and their contents of seed coat and phytic acid as well as their amylograms. Seeds of Giza 2 variety contained the lowest contents of seed coat and phytic acid phosphorus and showed the lowest peak viscosity, which were associated with excellent cooking and processing-characteristics. The cooked seeds of this variety were soft and absorbed more water as well as the liquid after cooking contained more color intensity. Other tested varieties contained more of these chemical and physical tests, which were associated with variable cooking and processing-characteristics. Conversely, Rebaya 40 variety contained the highest contents of these chemical and physical tests, which were associated with less cooking and processing-characteristics. Moreover, the water absorption of the raw seeds was correlated to the water absorption of cooked seeds as well as their cookability in the tested varieties. The cooking-quality was not significantly correlated with gelatinization temperatures, protein content and amino acid composition. The amino acids were determined quantitatively by the amino acid analyser, and the predominant amino acids were found to be aspartic acid and glutamic acid, whereas the other acids were found in variable amounts. The nutritional value of broad-bean protein, generally, showed that they are deficient in methionine and isoleucine, compared with the provisional reference of amino acid pattern of the Food and Agricultural Organization of the United Nations.
Keywords: broad bean; cookability; physicochemical measurements
Unconventional protein sources: apricot seed kernels by G. N. Gabrial; F. I. El-Nahry; M. Z. Awadalla; S. M. Girgis (208-215).
Hamawy apricot seed kernels (sweet), Amar apricot seed kernels (bitter) and treated Amar apricot kernels (bitterness removed) were evaluated biochemically.All kernels were found to be high in fat (42.2–50.91 %), protein (23.74–25.70 %) and fiber (15.08–18.02 %). Phosphorus, calcium, and iron were determined in all experimental samples.The three different apricot seed kernels were used for extensive study including the qualitative determination of the amino acid constituents by acid hydrolysis, quantitative determination of some amino acids, and biological evaluation of the kernel proteins in order to use them as new protein sources.Weanling albino rats failed to grow on diets containing the Amar apricot seed kernels due to low food consumption because of its bitterness. There was no loss in weight in that case. The Protein Efficiency Ratio data and blood analysis results showed the Hamawy apricot seed kernels to be higher in biological value than treated apricot seed kernels.The Net Protein Ratio data which accounts for both weight, maintenance and growth showed the treated apricot seed kernels to be higher in biological value than both Hamawy and Amar kernels. The Net Protein Ratio for the last two kernels were nearly equal.
Keywords: apricot seed kernels; amino acid composition; PER-data
Determining the kinetic behaviour for the secretion of milk toxin as related to dosage level of aflatoxin B1 by S. E. Megalla; Y. Y. Kamel; Dr. H. M. Abdel-Fattah; A. H. Hafez (216-222).
39 species which belong to 14 genera were isolated from 110 milk samples collected from different dairy sources at Assiut City. The most frequent fungi wereA. niger, A. flavus andCladosporium cladosporioides, followed byCurvularia spicifera andPenicillium corylophilum. The remaining species were of rare occurrence.The milk toxin was detected in the milk of lactating animals next day after the toxin-containing ration was fed.The level of milk toxin is gradually decreased when the feeding programme was interrupted.When the animals supplied a ration containing the same concentration of aflatoxin for successive days, the milk toxin concentration was maintained at the same level.The total amount of milk toxin secreted was less than one per cent of the amount of aflatoxin B1 received.The concentration of milk toxin secreted by goats was higher than that of dairy cows.Milk toxin failed to be detected five days after the feeding programme was discontinued.
Keywords: milk toxin; toxic feeds; feeding test; aflatoxin-synthesis
The effect of L-tryptophan loading on glucose tolerance in kwashiorkor children by El -M. M. El-Bassousy; F. A. El-Shobaki; Sh. M. El-Sallab (223-228).
Keywords: kwashiorkor; glucose tolerance; tryptophan loading
Buchbesprechungen by Brüll; Wirths; D. Senczek; Fricker; F. Matzkies; K. H. Bäßler; H. Glatzel; H. -D. Belitz (229-232).