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1.
Zusammenfassung Eine Auswertung von etwa 15 000 mikrobiologischen Bestimmungen von essentiellen Aminosäuren (EAS) in Nahrungspflanzen bzw. deren Teilorganen und anatomisch differenzierten Zonen ergaben biochemische Zusammenhänge, die zu folgenden Schlüssen führten:Die bisher auf die menschliche Nahrung und das tierische Futter beschränkten Begriffe, essentielle Aminosäuren und EAS-Index nachB. L. Oser, die somit termini technici der Human- und Tierernährung darstellen, bedürfen einer Erweiterung auf die Pflanze, da die für das Tier lebensnotwendigen Aminosäuren nach unseren Befunden auch eine analoge Bedeutung für die Lebensfunktionen der Pflanze besitzen.In bestimmten pflanzlichen Gewebezonen, in denen Zellteilungen oder andere für das Leben der Pflanze entscheidend wichtige Prozesse ablaufen, findet sich eine im Verhältnis zum Rohprotein günstige Anreicherung essentieller Aminosäuren, die wiederum zu einer hohen Biologischen Eiweißwertigkeit führt, ausgedrückt als EAS-Index nachB. L. Oser, während andere Zonen, z.B. Speichergewebe, nur niedrige EAS-Indices aufweisen.Aus diesem Grunde wird vorgeschlagen, solche mit Vitalprozessen verknüpften pflanzlichen Gewebezonen zur besseren Kennzeichnung ihrer ernährungsphysiologischen Bedeutung für Mensch und Tier Vitalzonen oder — gemäß einem Vorschlag vonJ. Kisser, Wien — Aktivzonen zunennen.Beweise für die Richtigkeit der Überlegungen, die zu dieser Benennung führen, werden durch ein umfangreiches Untersuchungsmaterial geliefert.
Summary About 15 000 microbiological determinations of essential amino acids (EAA) in food plants respectively in their different organs and in differentiated zones (as regard anatomy) showed biochemical relations, which lead us to the following conclusions:Untill present notions as Essential Amino Acids and the EAA-Index (B. L. Oser) are termini technici of human and animal nutrition. They are restricted to the metabolism of men and animals. According to our investigations those notions have to be extended, as the essential amino acids — essential for men and animals — are obviously essential for life function in plants too.In certain zones of plant tissue, where cell division or other active processes, important for plant life, take place, we find a favorable increase of essential amino acids, leading to a high biological value of proteins (EAA-Index according toB. L. Oser), while other zones, e.g. storage tissues, have only a low EAA-Index.In order to better mark the signification (as regard human nutrition) we propose to call those active plant tissues showing a high EAA-Index: Vitalzonen (vitalzones) oder — according toJ. Kisser-Wien — Aktivzonen (active zones).An extensive experimental material justifies the accuracy of our deduction and the necessity of the new term.

Résumé Environ 15 000 dosages microbiologiques des acides aminés essentiels (EAA) dans les plantes alimentaires, dans leurs organes ou dans les zones anatomiques différenciées ont donné des relations biochimiques qui ont abouti aux conclusions suivantes:Jusqu'à présent les notions acides aminés essentiels et Indice d'amino acides selonB. L. Oser (les deux comme termini technici de l'alimentation des hommes et des animaux) sont limitées à la nourriture de l'homme et au fourrage des animaux. Mais nos travaux expérimentaux montrent que cette notion doit être étendue aux plantes puisque les acides aminés essentiels sont également essentiels pour les fonctions vitales des plantes.Dans certains tissue végétaux dans lesquels se produisent les divisions cellulaires, ou dans les zones qui sont très importantes pour les opérations du métabolisme végétal, on trouve une augmentation favorable des acides aminés essentiels, par rapport à la protéine brute. Cette augmentation amène une haute valeur biologique des protéines (Indice selonB. L. Oser), tandis que d'autres zones (par exemple les tissus de réserve) n'ont qu'une valeur biologique faible.C'est pourquoi nous nous proposons — pour bien marquer leur importance nutritive — de nommer ces tissus vitaux — qui dirigent le métabolisme végétale: Vitalzonen (zones vitales) ou selonJ. Kisser-Wien: Aktivzonen (zones actives).Notre opinion se fonde sur un ensemble considérable de données experimentales.
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2.
Zusammenfassung Das von den anatolischen Bergbauern aus den Beerenzapfen vonJuniperus drupacea bereitete Mus (Andiz Pekmezi) enthält außer beträchtlichen Mengen an Zucker (hauptsächlich Glucose, Fructose und Saccharose) und einem ansehnlichen Eiweißgehalt beachtliche Konzentrationen an wasserlöslichen Vitaminen.Besonders hoch ist der (relative) Gehalt an Vitamin B1, Vitamin C, Nikotinsäure und meso-Inosit, mittel an Vitamin B2, Pantothensäure und Vitamin B6, gering an Biotin und vor allem an Folsäure.Insgesamt ist das Andiz Pekmezi hinsichtlich seines Vitamingehaltes den vitaminreichsten Pflanzensäften vergleichbar.
The jam, which is prepared from the strobiles ofJuniperus drupacea by the farmers in the mountains of Anatolia was analyzed. Besides considerable amounts of sugars (mainly glucose, fructose and sucrose) and protein it contains valuable concentrations of water soluble vitamins.Very high is the (relative) amount of thiamine, ascorbic acid, nicotinic acid and inositol, considerable the one of riboflavin, pantothenic acid and vitamin B6, low of biotin and folic acid.All together, the vitamine content of Andiz pekmezi is comparable with that of the plant saps most rich in vitamins.
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3.
In the present investigation several mutants isolated during mutagenic studies of pigeonpea were analysed for Ca, Mg, Fe, Zn, Cu, Mn, Cr, Ni. The results have revealed changes in the concentrations of macro and micro mineral elements in the mutant seed material. These changes in concentrations are attributed to the altered genetic structure; due to mutations, the plant system might have absorbed and stored more or less amounts of the elements in the seeds.  相似文献   

4.
Summary A comparative study has been carried out on amylase, urease and trypsin-inhibiting activities in the soybean varieties Adams, Harosoy and Lincoln and in soybean plant material of Harosoy. No significant quantitative difference was found between these activities in the three varieties. Two pH optima, at 5.5 and at 6.4 were found for amylase activity from all three varieties of soybeans. Although the temperature of 60° was most favourable for Adams-, Harosoy-and Lincoln-amylase, the latter lost almost all its activity at 70° whereas that of Adams remained constant.No urease and trypsin-inhibiting activities and only slight amylase activity could be detected in the leaves, stems and empty pods of the soybean plant. Young seeds (three weeks after setting) were compared, on the basis of dry weight, to mature seeds and were found to contain 50% of the trypsin inhibiting activity, 34% of the amylase and only 3% of the urease of the latter.
Zusammenfassung Eine vergleichende Studie wurde durchgeführt über Amylase-, Urease- und Trypsin-hemmende Wirkung der Sojabohnen-Sorten Adams, Harosoy und Lincoln sowie in Sojabohnenpflanzen der Sorte Harosoy. Keine mengenmäßig-signifikanten Unterschiede in der Wirkung fanden sich bei den drei Sorten. Zwei pH-Optima ergaben sich für die Amylase-Aktivität der drei Sojabohnen-Sorten bei 5,5 und 6,4. Obwohl die Temperatur von 60° sehr günstig für die Amylase der Sorten Adams, Harosoy und Lincoln war, verlor die Amylase der letztgenannten Sorte fast ihre gesamte Wirksamkeit bei 70°, während die der Sorte Adams dabei konstant blieb.Keine Urease- und Trypsin-hemmende Wirkung und eine nur leichte Amylase-Aktivität konnte in den Blättern, Sproßachsen und in den leeren Hülsen der Sojabohnen-Pflanze nachgewiesen werden. Junge Samen (drei Wochen nach der Aussaat) wurden auf Trockengewichtsbasis mit reifen Samen verglichen. Es wurde bei den jungen Samen — im Vergleich zu den reifen — eine nur 50%ige Trypsin-hemmende Wirkung, eine 34%ige der Amylase und eine nur 3%ige der Urease ermittelt.

Resumen Se ha efectuado un estudio comparativo sobre las actividades de la amilasa, la ureasa y el inhibidor de la tripsina en las variedades de porotos de soya Adams, Harosoy y Lincoln, así como en algunas partes vegetativas de la variedad Harosoy. No se encontraron ningunas diferencias cuantitativas entre las actividades de estas variedades. Se encontraron dos valores optimales del pH, 5.5 y 6.4, para la amilasa de todas las tres variedades de porotos de soya. Aunque la temperatura más favorable para la amilasa de las variedades Adams, Harosoy y Lincoln fuera 60°, esta última perdió casi toda su actividad a 70°, mientras que la actividad de la variedad Adams se quedó sin cambiar.No se pudo demostrar la presencia de ureasa y actividad inhibidora de la tripsina en las hojas, los tallos y las cápsulas vacías de las plantas de soya, y se encontró solamante una ligera actividad de amilasa en estas partes vegetativas. Se compararon, en base seca, semillas nuevas (a las tres semanas de formarse) con semillas maduras. Se encontró que las primeras exhibieron 50% de la actividad inhibidora de la tripsina, 34% de la actividad de amilasa y solo 3% de la actividad de ureasa, en comparación con las actividades de las semillas maduras.

Resumé Une étude comparative a été faite sur les activités de l'amylase, l'uréase et l'activité inhibitrice de la trypsine, dans les variétés de fèves de soya: Adams, Harosoy et Lincoln ainsi que sur différents stades de l'appareil végatatif du soya Harosoy. Aucune différence quantitative, significative, ne fut trouvée entre les activités dans les trois variétés. Deux pH optima à 5.5 et à 6.4 furent trouvés pour l'activité de l'amylase de toutes les trois variétés de fèves de soya. Bien que la témperature de 60° fut la plus favorable pour l'amylase de Adams, Harosoy et Lincoln, l'amylase de ces 2 derniers perdit presque toute son activité à 70° tandis que l'amylase dAdams resta constante.Ni activité d'urease, ni activité inhibitrice de trypsine ainsi que très peu d'amylase ne furent observés dans les feuilles, tiges et gousses vides de la plante soya. De jeunes semences (trois semaines après la fécondation) furent comparées, sur la base du poids sec, à des semences adultes et furent trouvées contenir 50% de l'activité inhibitrice de la trypsine, 34% de l'amylase et rien que 3% de l'uréase par rapport aux graines adultes.


with 3 figs.  相似文献   

5.
Nitrogen compounds constitute the greatest proportion of the dry weight of mushrooms. These nitrogen compounds are partly protein and partly non-protein. A modified Heneberg-Stohman's method was used to separate non-protein from protein nitrogen, as well as to determine raw fiber content in mushrooms, since the methods used previously for this purpose are time-consuming and complicated. Elemental analysis of crude fiber was performed to confirm the uniformity of isolated products. The content of total crude fiber (fungin) and the proportion of chitin and cellulose in it were determined. The chitin content of 15 species of field grown edible mushrooms was in the range of 1.87–6.93% of total dry mass and 34.51–67.72% of isolated fungin.  相似文献   

6.
Potato purée and wheat flour were blended at ratio of 7:1 w/w with 2 parts per weight of soybean protein concentrate (SPC) and/or faba bean-protein micellar mass (PMM). Two snack foods were formulated and deep fried. Spices, onion, parsley and chicken stock were added to the aforementioned two recipes to formulate meat ball analogues. Data revealed good acceptability of all products. Moreover, they can be considered as a good source for some essential amino acids; protein (26%); lipids (20%); carbohydrates (48%) and minerals. The in vitro digestibility ranged between 61.0% and 66.9%.  相似文献   

7.
The research presents analytical data on three varieties of a commonly consumed vegetable, Lesianthera africana, in southern Nigeria. The Etoi (bitter) variety seemed to possess the best (p0.01) nutritional value (highest lipid, protein, calories, iron, calcium, phosphorus, least fiber) but highest toxic components (mg/100 g: 1.62 HCN; 17.6 oxalate; 1630 glucosinolates), which are far below toxic limits. The Ikot Abasi (riverine) variety was found to be highly (p0.01) fibrous (18.1 mg/100 g dry matter) but low in micronutrient minerals. The Etinan (flavorful) variety was found to be moderately nutritious. The findings are discussed in relation to nutrient interactions and recommendations are made regarding dietetic use.  相似文献   

8.
Proximate composition and mineral content of raw and cooked leaves of two edible tree spinach species (Cnidoscolus chayamansa and C. aconitifolius), known locally as chaya, were determined and compared with that of a traditional green vegetable, spinach (Spinicia oleraceae). Results of the study indicated that the edible leafy parts of the two chaya species contained significantly (p<0.05) greater amounts of crude protein, crude fiber, Ca, K, Fe, ascorbic acid and -carotene than the spinach leaf. However, no significant (p>0.05) differences were found in nutritional composition and mineral content between the chaya species, except minor differences in the relative composition of fatty acids, protein and amino acids. Cooking of chaya leaves slightly reduced nutritional composition of both chaya species. Cooking is essential prior to consumption to inactivate the toxic hydrocyanic glycosides present in chaya leaves. Based on the results of this study, the edible chaya leaves may be good dietary sources of minerals (Ca, K and Fe) and vitamins (ascorbic acid and -carotene).  相似文献   

9.
Résumé Dans notre étude submicroscopique des réserves nutritives de l'orge, nous avons pu mettre en évidence d'une façon précise, l'existence des films protéiques longitudinaux et transversaux se trouvant à l'intérieur du grain d'amidon. Un film transversal semble trancher une partie du corps du grain d'amidon, ce qui a été confirmé par l'étude d'une suspension alcoolique (préparée aux Ultra-Sons) et ombragée (métalisée) avec du chrome.Des coupes fines démontrent que les lamelles protéiques sont disposées radialement à l'intérieur des grains d'amidon, et que la structure de l'amidon d'orge est disposée en couches concentriques.Une fissure médiane caractéristique pour les Hordeae a été mise en évidence, ainsi que celle d'une bande pectique à l'intérieur des parois cellulaires. La structure fine de la cellulose en forme de lattice, a pu être ressortie, de même que l'existence de Ponts Intercellulaires avec des Desmosomes.La fixation (OsO4 suivie de AWP) et l'inclusion dans du methacrylate (buthyl+methyl) 4:1 a été choisie, vu que ce procédé donnait les meilleurs résultats.La fixation avec UO2 (NO3)2 donne aussi de bons résultats, tandis que celle à l'iode doit encore être développée.
Summary Submicroscopic studies of barley endosperm showed that protein membranes are radialy disposed inside the starch granules. A perpendicular membrane seems to separate a part of the starch granule. The granular consistency of these starch granules has been put into evidence, as well as a medial fissure, caracteristic for Hordeae, well defined.Besides, it was possible to show that the interior of the cell wall consists of a pectic band, and that adjacent cells are connected by intercellular bridges with desmosomes.No great difference was found between fixation with OsO4 followed by AWP, and the one with H2 Pt Cl6.Fixation with uranil nitrate UO2 (NO3)2 was also tried, but the material not yet studied.The fixation with iodide has still to be developped as it is known that iodide, even in dilute concentrations, may form an undesirable coat arround the starch grain.Methacrylate was prefered to araldite, as it can be evaporated under the electronic beam and is well recommended byWykoff (32) andBahr (3). Plexiglas inclusions have still to be tried out.The staining with (OSO4+AWP) and evaporation of the inclusion material, gives the possibility to obtain pictures of the cell interior tel quel, which opens new pathways for the future.

Zusammenfassung Elektronenmikroskopische Studien des Gerstenendosperms zeigten, daß Proteinfilme im Stärkekorn radial gelegen sind. Haftproteine und Lipoproteide konnten besser zur Geltung gebracht werden. Zwickelprotein dagegen nur in einigen Fällen.Ein konzentrischer Aufbau der Stärkekörner, sowie die für die Hordeae charakteristische Medianspalte, wurde nachgewiesen.Es scheint, daß eine Proteinmembran einen Teil der großen Stärkekörner, von der Hauptmasse trennt. Diese Erscheinung konnte außerdem durch Oberflächenstudien hervorgehoben werden.Der Feinbau der Zellwände und das Vorhandensein einer Pektinschicht im Inneren der Zellmembranen konnte durch Fixierung mittels (OsO4+AWP) und Verdunstung des Methacrylats, hervorgehoben werden.Diese neue Technik erlaubte noch das Vorhandensein von Interzellularbrücken und Desmosomen zu zeigen.Kein großer Unterschied konnte zwischen der Fixierung mit (OsO4+AWP) und H2Pt Cl6, gefunden werden.Wegen Zeitmangel konnte das mit Uranyl-Nitrat UO2(NO3)2 fixierte Material nicht untersucht werden.Methacrylat wurde dem Araldit und Plexiglas als Einbettungsmittel vorgezogen, da es durch Elektronenstrahlen verdampft werden kann.Diese Methode ermöglicht in der Zukunft das Studium der Änderungen, die im Inneren von Zellen durch physikalische und chemische Mittel hervorgerufen werden.
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10.
Zusammenfassung An Albinoratten wurde zusätzlich zum normalen Grundfutter Preßsaftkonzentrat von Tomaten wuchsstoffbehandelter Pflanzen und unbehandelter Pflanzen verabreicht. Bei Beginn der Verfütterung und nach Beendigung derselben wurde jeweils eine Paarung durchgeführt und die Sterblichkeit des Nachwuchses registriert. Es konnte eine erhöhte Mortalität bei Zusatz von Preßsaftkonzentrat behandelter Pflanzen beobachtet werden, doch war der Unterschied nicht statistisch gesichert. Die Orgngewichte der Elterntiere nahmen unter dem Einfluß des Zusatzes ab, und zwar verstärkt, wenn er von wuchsstoffbehandelten Pflanzen stammte. Die Differenz zwischen behandelt und unbehandelt war signifikant für Milz und Nebenniere.
Summary In addition to the usual standard food, albino rats were fed with the concentrated press-juice of tomatoes, grown on plants treated with growth substance and on untreated plants. At the beginning and at the end of the feeding period, the animals were copulated and the mortality of the new generations was registrated. The mortality was higher in the new generations of animals fed with juice of tomatoes from treated plants, however the difference not being statistically significant. The weight of different organs of the parental animals decreased by the influence of the juice. The decrease was greater, when the juice was taken from tomatoes of treated plants. The difference between treated and untreated was statistically significant for spleen and suprarenal gland.
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11.
The availability of -carotene from Spirulina as compared to standard all trans -carotene was studied by the liver and kidney vitamin A storage method. After 21 days of vitamin A depletion, the rats were repleted with -carotene from Spirulina and a standard source at two dietary levels (60 and 120 µg/day) for a 10 day period. At lower levels, the liver storage levels of vitamin A and the percent of -carotene absorption were comparable to those of the standard. At higher levels both these parameters of the Spirulina fed group were significantly (P<0.01) inferior to the standard source fed group. However, the Spirulina fed group showed better (P<0.05) growth than the standard fed group did at both low and high levels of feeding.  相似文献   

12.
Summary -carotene has been oxidized with a lipoxidase-linoleate system. Chromatography of the products shows that several of the bands have spectra corresponding to epoxide of -carotene. Three of the other fractions have been examined more closely by spectrophotometric methods and it is suggested that they are conjugated polyene ketones.Oxidation of -carotene by a ferrous phthalocyanine — linoleate system shows that the products vary depending upon the physical state of the oxidizing system.
Zusammenfassung -Karotin wurde durch ein Lipoxydase-Linoleat-System oxydiert. Die Chromatographie der Oxydationsprodukte zeigt, dass mehrere Banden typische Spektren zeigen, die auf das Epoxyd von -Karotin hinweisen. Drei andere Fraktionen wurden mittels der spektrophotometrischen Methode genau untersucht; es wäre möglich, dass diese Substanzen konjugierte Polyen-Ketone wären. Die Oxydation von -Karotin durch ein System Eisen-2-Phthalocyanin-Linoleat zeigt, dass die Produkte variieren mit dem physikalischen Zustand des Oxydations-Systems.

Résumé Le carotène- a été oxydé par le système lipoxidase-linoléate. La chromatographie des produits d'oxydation montre plusieurs bandes dont les spectres correspondent aux époxydes du -carotène. Trois autres fractions ont été examinées de près par les méthodes spectrophotométriques, et il est possible de suggérer que ce sont des polyénes conjugués à fonctions cétones à qui nous ne pouvons pas encore donner de formules. L'oxydation du -carotène par le système phthalocyanine ferreux-linoléate, montre que les produits d'oxydation varient en fonction de l'état physique du système oxydant.
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13.
Mango (Mangifera indica) is a fruit that grows in tropical regions. The aim of this work was to isolate the starch from two varieties of mango highly consumed in Mexico (criollo and manila), and to evaluate its chemical composition, along with some morphological, physicochemical and functional properties. Mango starch had an amylose content of about 13%, the fat content of criollo variety starch (0.1–0.12%), was similar to that of commercial corn starch used as control (0.2%); both mango starches had higher ash amount (0.2–0.4%) than corn starch. Mango starches presented a smaller granule size (10 m) than corn starch (15 m), along with an A-type X-ray diffraction pattern with slight tendency to a C-type. All values of water retention capacity (WRC) increased with the temperature. When the temperature increased, solubility and swelling values increased and in general, mango starches had higher values than corn starch. Both mango starches had gelatinization temperatures lower than the control, butcriollo variety starch presented higher enthalpy values thanmanila variety and corn starches. Overall, it was concluded that due to its morphological, physicochemical and functional properties, mango starches could be a feasible starch source with adequate properties, suitable for using in the food industry.  相似文献   

14.
The composition and quality of edible tender stems or cladodes of 3 Prickly Pear Cactus species (Opuntia amyclaea, O. ficus-indica, and O. inermis) were studied at different stages of development. This traditional Mexican vegetable is called nopalitos in Spanish and cactus leaves in English. Cladodes harvested when 20 cm in length have the following average composition per 100 g: 91.7 g of water, 1.1 g of protein, 0.2 g of lipid, 1.3 g of ash, 1.1 g of crude fiber, 4.6 g of complex carbohydrates and 0.82 g of simple sugars, 12.7 mg of ascorbic acid and 28.9 µg of carotenes. The cladode's juice has an average pH of 4.6, 0.45% titratable acidity and 6.9% soluble solids. The components which varied most during development of the cladodes were: carotenes, acidity and total carbohydrates which increased, and protein and crude fiber (acid-detergent) which decreased. The nutritive value of the tender cladodes in the stages of growth at which they are commonly harvested and consumed (15 to 25 cm long weighing 50 to 80 g per stem), was similar for the 3 species.  相似文献   

15.
Three hull-less barleys, Washonupana (WSNP), Waxbar (WXB), and Bangsa (BGS), were fed to broiler chicks in 21% protein diets containing 0.5% cholesterol in replicate trials. A corn-based diet, with added cholesterol, served as a control. Alternate diets were supplemented with -glucanase (ENZ). -glucan content ranged from 4.9% to 6.1% and soluble dietary fiber (SDF) from 3.6% to 7.5% in the barleys. Data from the two trials were pooled for statistical analysis by the SAS General Linear Models procedure. In body weight gain, chicks fed WSNP — ENZ were lower (P<0.05) than all other treatments. The -glucanase supplement to the WXB and BGS barley tended to improve gains, but the differences were not significant for either barley. Feed to gain ratios were lowest (P<0.0001) for corn fed chicks and lower (P<0.05 toP<0.0001) for those fed the barley+ENZ diets compared to barley –ENZ. Chicks fed barley diets had lower (P<0.05) total serum cholesterol (TSC) and LDL-cholesterol than those fed corn diets, regardless of ENZ supplementation. For chicks on barley –ENZ diets, TSC levels for WSNP, WXB, and BGS were 146, 152, and 142 mg/dl respectively and for chicks on barley +ENZ diets, 218, 200, and 178 mg/dl. LDL-cholesterol levels followed the same trend and there was little difference in serum triglycerides. The BGS+ENZ lowered TSC 30% from the corn control compared to 10.7% and 18% for WSNP+ENZ and WXB+ENZ, suggesting additional hypocholesterolemic factors, possibly tocotrienol and SDF other than 13, 14 -D-glucans.Contribution No. J-2487, Montana Agricultural Experiment Station. This research was supported, in part, by a grant from the Montana Wheat and Barley Committee, Great Falls, MT, U.S.A.  相似文献   

16.
Twenty three cultivars of carrot (Daucus carota L.) roots consisting of fifteen local and eight exotic cultivars were analysed for various chemical constituents including dry matter, total soluble solids (TSS), -carotene, total and reducing sugars, phenolics, phosphorus, zinc, manganese, copper, iron, sodium potassium and ash. In addition other characteristics such as days to maturity, root weight and length, flesh thickness, core diameter, number of forked and cracked roots per plot have been studied. Yellow carrots were found to have maximum root length, water soluble carbohydrates and minimum -carotene content. The exotic cultivars were found to have higher TSS content than the local cultivars, while the latter cultivars had higher mineral contents than the former. However, on the average, dry matter content, total water soluble sugars, reducing and non-reducing sugars were found to be greater in exotic cultivars than in local ones, but -carotene, phenols and phosphorus contents were greater in local cultivars. A significant positive correlation between -carotene content, ash percentage and days to maturity was observed. A wide variation in chemical constituents and plant characteristics was observed indicating a high genetic variability in the material under study.  相似文献   

17.
-carotene in leaf protein extracted from some species is destroyed in a few days when incubated with salt as a preservative. Its shelf-life can be greatly extended by pretreatment with oxalate, ascorbate mercaptans, phenolic substances, extracts made from leaves in which carotene is more stable, and by tight compaction. Treatment with alum reverses the protective effect of these chemical pretreatments, it also increases the lability of carotene in leaf protein extracted from species which usually give a relatively stable product. In these preparations of leaf protein, which were heated to 90 °C during preparation, carotene is only partially extractable into some solvents which are miscible with water. It seems therefore to be present in more than one state, but differences in extractability could not be correlated with differences in lability.  相似文献   

18.
Banana flour prepared from two cooking banana varieties, namely Alukehel and Monthan, were evaluated for their physical and biochemical characteristics. The yields of flour averaged 31.3% for Alukehel and 25.5% for Monthan. The pH of the flour ranged from 5.4 to 5.7. The bulk density and particle size distribution were also measured. The average chemical composition (% dry matter) of the flours were as follows: crude protein, 3.2; crude fat, 1.3; ash, 3.7; neutral detergent fiber, 8.9; acid detergent fiber, 3.8; cellulose, 3.1; lignin, 1.0 and hemicellulose, 5.0. Carbohydrate composition indicated the flour to contain 2.8% soluble sugars, 70.0% starch and 12.0% non-starch polysaccharides. Potassium is the predominant mineral in banana flour. Fresh green banana is a good source of vitamin C, but almost 65% is lost during the preparation of flour. Oxalate content (1.1–1.6%) of banana flour is probably nutritionally insignificant. The overall results are suggestive of the potential of green bananas as a source of flour.  相似文献   

19.
The uniqueness of purslane (Portulaca spp.) asthe richest vegetable source of omega-3 (-3)fatty acids is well documented. However, purslane hasnot been domesticated or fully evaluated for itsnutritive value. The objective of this study was todetermine the influence of planting date on chemicalcomposition of purslane accessions. Eight accessionsfrom different geographical locations were planted 12days apart, and whole plants harvested at full bloom. Chemical analysis (DM basis) of leaves showedsignificant differences among varieties for all thecharacteristics measured. Accession by planting dateinteraction influenced (p < 0.05) levels of crudeprotein, total lipids, and carbohydrate contents. Wild Greek accession had the highest, while aBeltsville (Maryland) wild type had the lowest crudeprotein content (27.1 vs 20.5%) at the secondplanting date. Crude protein, lipid and ash levelswere most influenced (p < 0.05) by planting date. Total lipids varied from 4.0–5.8% and 3.7–5.1% forthe first and second planting dates, respectively. Selected fatty acid content indicated significantly(p < 0.05) higher levels of 18: 26, and18: 33 in the Dutch Garden accession comparedwith other varieties. The Egyptian wild accession hadthe lowest level of 18: 33. The ratio of 3 to 6 acids, which ranged from 5.5 to22.3 indicated a highnutritive value of purslane compared to other oilcrops such as soybeans and perrilla. The high levelsof protein in purslane compete with those of othercommercially important vegetable crops. The studyshows that, in spite of its genetic diversity, purslaneremains one of the most abundant terrestrial vegetablesources of Omega-3 fatty acids and other essentialnutrients potentially beneficial for humans as well asanimals.  相似文献   

20.
The effects of natural compounds, vitamin C and quercetin, present in fruitsand vegetables, on the DNA damaging activity of a food carcinogen N-methyl-N-nitro-N-nitrosoguanidine (MNNG) were examinedusing the comet assay. Vitamin C, at a concentration of 50 M,inhibited MNNG-induced DNA damage in human lymphocytes. Quercetin,up to a concentration of 10 M, increased the extent of DNA damage,but at concentrations above 10 M decreased damage below controlvalues. Furthermore, quercetin had a strong antioxidant activity againstoxidative damage evoked by H2O2 at 10 M. The resultsobtained suggest that vitamin C and quercetin may have anti- orpro-oxidative properties depending on the state of the cell.  相似文献   

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