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Modern methods of plant analysis

About: The article was published on 1964-01-01 and is currently open access. It has received 1991 citations till now.

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Citations
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Journal ArticleDOI
TL;DR: It is probable that inactivation of lysine during processing is one factor contributing to the low nutritive value of commercially produced coconut meal.
Abstract: Coconut meal, the residual product after extraction of oil from the dried flesh of the coconut, is available in many parts of the world. In large areas of the tropics it is the only locally produced ingredient of feeding-stuffs that contains moderate amounts of protein (18-25 yo of the dry matter). The results of research on the nutritive value of this product are, however, disappointing, and the tendency is to use coconut meal in ruminant feeding rather than in the diets of non-ruminants, although it is for the latter that the need is more urgent. Results for the nutritive value of coconut meal have been reviewed by Mitchell, Hamilton & Beadles (1945) and Curtin (1958). It would seem likely that a considerable amount of damage is done to the protein of coconut meal during processing and that a product of better quality could be obtained were less severe methods used. Jones, Finks & Johns (1923) found no difference in biological value between solvent-extracted and screw-pressed meals, but later experiments by Mitchell et al. (1945) demonstrated that coconut meal produced by an extraction process in which the temperature never exceeded 75" had a higher biological value than a product prepared by the 'usual drastic methods'. Various workers (Lea & Hannan, 1950; Henry & Kon, 1950; Bensabat, Frampton, Allen & Hill, 1958) have shown that one of the changes accompanying severe processing conditions is a combination of the e-amino group of lysine with the keto group of a carbohydrate. It has been suggested that this reaction biologically inactivates the amino acid and it has been shown that for certain proteins the measurement of ' available lysine ' provides an indication of nutritive value (Carpenter, Ellinger, Monroe & Rolfe, 1957; Lea, Parr & Carpenter, 1960; Clegg, 1960; Boyne, Carpenter & Woodham, 1961). In view of the fact that figures quoted by Curtin (1958) and Peters (1960) indicate that lysine is the most limiting amino acid in coconut protein, it is probable that inactivation of lysine during processing is one factor contributing to the low nutritive value of commercially produced coconut meal. I t has been shown for other feed ingredients that the solubility of protein in various solvents is decreased by heating and that this effect may be indirectly related to

30 citations

Journal ArticleDOI
TL;DR: A partially purified preparation of a water-soluble, heat-resistant, nonspecific exotoxin produced by a strain of Macrophomina phaseolina, isolated from Phaseolus mungo L. mungi caused inhibition of seed germination, wilting of cut seedlings, stunted growth of young seedlings and loss of permeability of the cell membrane.
Abstract: A partially purified preparation of a water-soluble, heat-resistant, nonspecific exotoxin produced by a strain ofMacrophomina phaseolina, isolated fromPhaseolus mungo L. could reduce Cu++ ions and produced a red colour with 2,4-dinitrophenyl hydrazine reagent. It caused inhibition of seed germination, wilting of cut seedlings, stunted growth of young seedlings and loss of permeability of the cell membrane. Seedlings ofP. mungo, grown in presence of the toxin showed a slight increase in the contents of protein and total RNA over control, but a significant increase in the specific activities of F-1, 6-BP aldolase and G-6-P isomerase.

30 citations

Journal ArticleDOI
TL;DR: The cuticle together with the hypodermis and associated musculature contains more of the total chitinase activity of the cockroach body than any other body fraction, although the saliva and digestive juices also display notable activity.

30 citations

Journal ArticleDOI
TL;DR: In this article, the authors examined trends in δD and δ 18 O of leaf cellulose for three species growing across climatic gradients caused by elevation and slope aspect in southeastern Utah, USA.

30 citations

Journal ArticleDOI
TL;DR: C. ambrosioides oil proved superior to aluminium phosphide and ethylene dibromide, synthetic fumigants, at 0.29 μl ml− 1 and significantly protected 1 kg of pigeon pea seeds from microbial attack for up to 6 months.
Abstract: Essential oils isolated from 35 aromatic plants of Gorakhpur Division, India, were screened at 0.36 μl ml− 1 against four dominant fungi Aspergillus flavus Link, A. niger van Tieghem, A. ochraceus Wilhelm and A. terreus Thom found on stored pigeon pea (Cajanus cajan Linn.) seeds. Chenopodium ambrosioides Linn. and Citrus aurantium Linn. oils exhibited strong antimycotic activity (100% mycelial inhibition). The minimum inhibitory concentration of C. ambrosioides oil was less (0.07 μl ml− 1) than that of C. aurantium oil, against all the test fungi. Both the oils were fungicidal at higher doses (1.71–2.78 μl ml− 1). C. ambrosioides oil exhibited broad fungitoxic spectrum against 16 other storage fungi of pigeon pea seeds. The oil remained effective with increased inoculum load, and physical factors had no adverse effect on its toxicity. C. ambrosioides oil proved superior to aluminium phosphide and ethylene dibromide, synthetic fumigants, at 0.29 μl ml− 1 and significantly protected 1 kg of pigeon pea seeds...

30 citations

References
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Book ChapterDOI
01 Jan 1963
TL;DR: In this article, a physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln.
Abstract: Kann ein physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), so besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln. Hierzu gehoren die Bestimmung der Reaktions- und Substratspezifitat sowie die Ermittlung der Bedingungen, unter denen eine optimale Wirkung des Enzyms gegeben ist. Wesentlich zur Charakterisierung ist ferner die Untersuchung der Stabilitat des Enzyms und dabei insbesondere die Feststellung, ob es sich um ein Ferment handelt, das zur vollen Aktivitat dialysable Cofaktoren benotigt. Falls diese Frage bejaht wird, ist auch die Bestimmung der unerlaslichen Cofaktoren anzuschliesen. Uberdies bietet auch der Nachweis der Lokalisation des Enzyms in der Zelle (oder im Zellverband) eine entscheidende Moglichkeit zur Charakterisierung des Fermentes. Hinzu kommt schlieslich noch die Untersuchung der Wirkung einzelner Inhibitoren1 auf das Enzym, die zu weitgehender Klarung des Reaktionsmechanismus beitragen kann und eine Abgrenzung der Eigenschaften des untersuchten Fermentes gegenuber ahnlichen Enzymen erlaubt.

2 citations

Book ChapterDOI
01 Jan 1962
TL;DR: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins and rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
Abstract: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins. Generally speaking denaturation can be defined as a process or sequence of processes in which the spatial arrangement of the polypeptide chains within the molecule is changed from that typical of the native protein to a more disordered arrangement (Kauzmann 1959). The terms “configuration”, “conformation” and “state of folding” are widely used for spatial arrangement. It is probably best to follow the suggestion of Blout (1960) and restrict the use of “configuration” to its original sense, i.e. the spatial arrangement around an asymmetric carbon atom, and to use “conformation” for the shape of the molecule in its entirety. The properties discussed in the previous Chapter i.e., viscosity, diffusion, sedimentation, and light scattering — can all furnish information on the overall shape of proteins or other macromolecules and changes in this shape with environment. Thus Doty, Bradbury and Holtzer (1956) were able to show using these methods, together with streaming birefringence, that poly-γ-benzyl-L-glutamate could exist in two conformations, the α-helix and the solvated randomly coiled form, depending on the solvent. The change from α-helix to random coil was accompanied by marked changes in the optical rotatory properties of the polypeptides. It is to be expected that an α-helical structure should contribute to the rotatory power of a polypeptide since helices are asymmetric and not superimposable on their mirror images. The work on polypeptides has shown that rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.

1 citations