摘要:

AbstractThe analysis of the main components present inAvena sativaseed epicuticular wax is reported, using a simplified chemical procedure. The main components are esters (21.1%), hydrocarbons (15.5%) and free acids (14.1%).

ISSN:0022-5142    

DOI:10.1002/jsfa.2740340302

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractClose, largely linear, relationships were found between volatile fatty acids (VFA) determined by gas chromatography, total organic acids (TOA) determined colorimetrically, biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) in the soluble fraction of piggery slurries. Samples were taken from untreated and aerobically‐treated slurries. All correlations were significant atP=0.001, with values ofrranging between 0.88 for the correlation of VFA and COD, to 0.97 for the correlation of TOA and BOD5. VFA accounted for up to 69% of BOD5and 55% of COD. It is suggested that organic acids could replace soluble BOD5in some situations, since the correlations were good. Prediction of COD from organic acids, or BOD5from COD, were less accurate, particularly when concentrations were low, since COD contains a biologically inert fraction, which varies with storage. Soluble organic nitrogen was not useful in predicting BOD5or COD, correlating only atP=0.0

ISSN:0022-5142    

DOI:10.1002/jsfa.2740340303

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe variability of energy excretion by adult roosters starved for 24 h or force‐fedvarying levels of dextrose following a 24‐h fast was studied in three separate balance trials. A fourth balance trial was conducted to determine the available energy content of several feedstuffs. Dry matter and energy excretion were measured in the first three trials and available energy was determined as true metabolisable energy (TME) for adult roosters and as apparent metabolisable energy (AME) corrected to zero nitrogen retention for growing rats and pigs in the fourth trial. A significant (p<0.05) positive correlation (r=0.81) between body weight (range 1.9–2.8 kg) of roosters and energy excretion was observed. Energy excretion by roosters tended to vary with the level of dextrose force‐fed and the calculation of TME of dextrose produced values equal to its gross energy at high (50–60 g) levels of intake. The TME content of nine feedstuffs varying in chemical composition are given and compared with AME values determined with rats

ISSN:0022-5142    

DOI:10.1002/jsfa.2740340304

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractMaris Kestrel kale sown on 4 June 1980 was harvested on 14 occasions between 5 August 1980 and 18 March 1981 and the plants were divided into leaf lamina, petiole and stem. Samples were freeze‐dried, milled and analysed for digestible organic matter (DOMD), crude protein (CP), S‐methyl cysteine sulphoxide (SMCO, the haemolytic factor) and thiocyanate ion (SCN−, a goitrogen) contents. DOMD contents were low at the first harvest due to low organic matter contents and at the last harvest due to low digestibilities. Between these harvests average lamina, petiole and stem contents were 769, 842 and 840 g kg−1DM respectively. CP contents declined from 5 August to 17 September when average lamina, petiole and stem contents were 206, 96 and 121 g kg−1DM respectively. From 5 August to 14 October average lamina, petiole and stem SMCO contents were 5.44, 6.64 and 10.56 g kg−1DM, respectively, compared with 9.04, 7.39 and 9.40 g kg−1DM, respectively, from 11 November to 24 February. SCN‐ contents fluctuated up to 15 December and then remained constant at a slightly lower level. Average lamina, petiole and stem contents were 0.29, 0.15 and 0.08 g kg−1DM respectively. Whole plant contents were calculated taking account of the relative dry matter yields of lamina,

ISSN:0022-5142    

DOI:10.1002/jsfa.2740340305

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe flake size of ammonia‐treated vermiculite (ATV) controlled the release of ammonium ions to plants, the smaller the flake the more rapid the release. Nitrogen released from fine ATV (0.25–0.5 mm) produced a yield of oats superior to that obtained using either ammonium nitrate or ammonium sulphate; it also gave a 10% greater oven‐dry weight of potatoes than did either ammonium nitrate or IBDU, the slow‐release N fertiliser, and 7% greater than sulphur‐coated urea. Coarse ATV (2.8–4.0 mm) gave significantly smaller yields of oats and potatoes than did any of the other N fertilisers. With ryegrass, the slower release of N from the coarse ATV gave three relatively uniform intermediate yields over the season compared with two high and one low with ammonium nitrate, ammonium sulphate and fine ATV. This suggests a possible application in grassland

ISSN:0022-5142    

DOI:10.1002/jsfa.2740340306

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractSaline extract solutions from seeds of bothPhaseolus vulgarisandVicia fabavarieties were prepared and tested for their total polyphenolic content and effect on intestinalD‐Glucose transport across rat ileumin vivo. IntestinalD‐glucose transport was significantly reduced (PPhaseolus vulgaris, var.albus) is closely related to the polyphenolic content. Clear differences in the mode of action of the extracts were also observed. Extracts with appreciable polyphenolic content caused both a reversible and a lasting inhibitory effect on glucose transport, whilst extracts with negligible polyphenolic content only induced a reversible inhibition. Polyamide treatment of the extracts decreased their ability to inhibit glucose transport, but their inhibitory effect was not completely abolished by the treatment, further suggesting the presence of some other anti‐absorptive factor(s) in th

ISSN:0022-5142    

DOI:10.1002/jsfa.2740340307

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractA method for the purification of indole glucosinolates from cruciferous plants using ion‐exchange chromatography on DEAE‐Sephadex A‐25 is described. The procedure is suitable for the isolation of indole glucosinolates from both seed and leaf tissue. Using this preparative technique a fraction containing intact indole glucosinolates is obtained which can be used for subsequent purification of the individual components. Alternatively, the indole glucosinolates can be desulphated on‐column, and the resulting desulpho‐derivatives purified in high yield by high‐performance liquid chr

ISSN:0022-5142    

DOI:10.1002/jsfa.2740340308

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractThe isogenicopaque‐2 (o2) and its normal counterpart of maize (Zea maysL.) hybrid ‘B14 × B37’ were used as a model system and grown under different levels of nitrogen fertility to test the importance of the kernel N sink (zein accumulation) relative to kernel osmotic potential, dry matter accumulation, grain yield and protein nutritional quality. Self‐pollination and reciprocal crosses were made with seveno2 hybrids and their normal counterparts in order to determine the effect of the kernel N sink and/or vegetative characteristics on kernel dry weight accumulation. The results indicate that with a small supply of nitrogen, both normal ando2 kernels produced only small amounts of zein, and kernel weights and grain yields were comparable. As the level of nitrogen increased, zein accumulated preferentially in normal, but not ino2, and differences in kernel weight and grain yield between these two genotypes became greater. The reduction of dry matter accumulation ino2 kernels relative to normal kernels when grown under high N levels may result from the accumulation of free amino acids and their catabolic products in the kernel as a consequence of a small N sink. These osmotica contributed to a more negative osmotic potential which may favour water movement, but reduce solute movement into the kernel. Increased zein accumulation in normal kernels enhanced kernel weight and grain yield but reduced protein nutritional quality. The concentration of lysine and tryptophan as a percentage of protein decreased as the level of N fertiliser and kernel protein in the normal kernel increased. On the other hand, theo2 mutant failed to deposit additional N as zein; therefore, the concentration of these two essential amino acids remained constant regardless of N levels. However, when lysine and tryptophan were expressed on an area (kg ha−1) basis, the amino acid yields of these two genotypes were

ISSN:0022-5142    

DOI:10.1002/jsfa.2740340309

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740340310

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY

摘要:

AbstractA ‘fishy’ or ‘crabby’ taint in brown eggs from commercial flocks was associated with the use of capelin meal as a protein supplement and was reproduced under controlled conditions. Analysis of eggs and samples of the meal established that trimethylamine (TMA) was responsible for the taint and that the meal may contain rich sources of TMA in the form of TMA oxide and choline. Only certain hens were affected and their ability to metabolise TMA was very low as indicated by the oxidation of an intravenous dose of14C‐TMA and the activity of hepatic TMA oxidase. Oxidation of the14C‐TMA was further depressed by feeding the meal or injecting non‐radioactive TMA. Experiments with hens and chickens which had been bred for sensitivity to the inhibition of TMA oxidation by thionamides (and rapeseed meal) gave no indication that the meal supplied a potent inhibitor of this kind. It was concluded that the tainting is caused by overloading hens with TMA and that these hens have a genetic defect which impairs their synthesis of TMA oxidase and consequently their ability to metabolise TMA. The removal of this defect from commercial flocks by selective breeding would probably prevent tainting by both fish and r

ISSN:0022-5142    

DOI:10.1002/jsfa.2740340311

出版商:John Wiley&Sons, Ltd    

年代:1983

数据来源: WILEY