摘要:

AbstractThe deposition of oil, major lipid classes, and the constituent fatty acids of the oil palm fruit mesocarp were investigated to gain a better insight into the accumulation of these components. The oils were extracted with chloroform‐methanol 1:2 (v/v) and were fractionated by silicic acid column chromatography into classes. Fatty acids were analysed by gas‐liquid chromatography. Shortly after anthesis, lipids, mainly phospho‐ and glyco‐lipids, were a small proportion of the mesocarp. With time the lipid content increased, until at maturity it accounted for about 60% of fresh mesocarp weight. Approximately 97% of the lipid at maturity was neutral lipid, essentially triacylglycerol. Maximum oil quantity was obtained at 22 weeks after anthesis. The active lipid accumulation period was from weeks 18 to 22 after pollination. Contrary to previously published data, palmitic, oleic and linoleic acids were characteristically present at all stages of oil accumulation. Linolenic acid was present in the neutral lipids from immature mesocarp of the oil palm fruit, but was probably diluted out in mature palms. Appreciable amounts of linolenic acid were present in the polar lipid fr

ISSN:0022-5142    

DOI:10.1002/jsfa.2740370902

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractPleurotus ostreatus(oyster mushroom) was cultivated in a peat moss based substrate. Acid‐hydrolysed peat and non‐hydrolysed peat were used in the preparation of the spawn and in the further stage of growing the mushroom fruiting bodies. For comparison,P. ostreatuswas also cultivated on paper. Three harvests of mushrooms were obtained in 45 days. The highest total yield gave 10% conversion of peat substrate into mushroom biomass. The mushrooms had 36% crude protein content and all the essential amino acids were pres

ISSN:0022-5142    

DOI:10.1002/jsfa.2740370903

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe efficacy of HNO 3 −HClO4and HNO 3 −HClO4‐HF digestion mixtures for wet ashing of selected plant samples of field and greenhouse origin for Fe, Mn and Zn analyses was studied. The ternary digestion mixture was required for the determination of Fe, but not of Mn and Zn, in six unwashed field‐grown samples, including four botanical Standard Reference Materials from the US National Bureau of Standards. The ternary digestion mixture was also required for the analysis of Fe in both washed and unwashed tops of field‐grown flax (Linum usitatissimumL.). However, washing appreciably reduced plant Fe and Mn, presumably by removing soil contamination. In addition, the superiority of the ternary digestion mixture for Fe analysis was much less for the washed samples. The contents of Fe, Mn and Zn in washed tops of greenhouse‐raised flax and soya beans (Glycine maxL. Merr.) were similar with both digestion mixtures. It is recommended that in plant nutrition studies involving Fe, the efficacy of HNO 3 −HClO4digestion procedures be routinely checked by completely dissolving any

ISSN:0022-5142    

DOI:10.1002/jsfa.2740370904

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractFuor years after15N labelled fertiliser nitrogen (as Ca(NO3)2and equivalent to 400 kg N ha−1) was applied to permanent grass swards growing in lysimeter monoliths, approximately one‐quarter remained immobilised in soil organic matter. In the intervening years similar but non‐labelled applications were made. Although differing rainfall regimes applied during the experiment had significantly affected nitrogen uptake by plants and nitrate loss in drainage, they caused no significant effect on the tracer nitrogen remaining in the soil, the ranges were 85–97 kg N ha−1and 79–94 kg N ha−1respectively for the 135 cm deep clay and silt loam soil monoliths. Labelled nitrogen unaccounted for in crop, drainage or soil was presumed to have been denitrified. These losses averaged 62 and 49 kg N ha−1on the clay and silt loam soils respectively; again the differing rainfall regimes caused no significant differences. The ratio between estimates of labelled nitrogen denitrified and of annual nitroux oxide loss was approximately 9:1 for both soils. The conversion from permanent grass to winter wheat in autumn 1981, involving killing and then burying the sward, resulted in no pronounced increase in net mineralisation of labelled nitrogen. However, the balance between crop uptake and the quantity leached did change. Labelled nitrogen assimilated was less for the wheat (growing without addition of fertiliser nitrogen) than for the grass in its last year, and the quantity leached was considerably greater than under grass swards that were supplied with an average rainfall distribution. Following the first wheat harvest total nitrogen leached averaged 51 and 44 kg N ha−1on the clay and silt loam soils respectively. Rates of nitrous oxide emissions during the autumn following sward destruction were greater than in earlier years, but this enhanced loss was of short duration. The crop clearly benefited from the succession of nitrogen applications made to grass, as grain yield and total nitrogen uptake exceeded 7 t ha−1and 120 kg N ha−1respectively on both soils. These quantities exceed the national averages for winter wheat and are also considerably greater than for crops from lysimeters which received no nitrogen fertiliser thro

ISSN:0022-5142    

DOI:10.1002/jsfa.2740370905

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe yeast flora in samples of 13 different whole‐crop maize silages was shown to be predominated byCandida krusei, C. lambica, Saccharomyces dairensis, S. exiguus, C. holmiiorC. milleri. All these strains fermented glucose but, except for the latter three species, not sucrose, α‐trehalose or raffinose. Under conditions resembling those in silage, i.e. at pH 4.0 in the presence of a complex nitrogen source, all strains assimilated lactic and acetic acids. This result suggests that the predominant yeasts in silage should not be distinguished into lactate utilisers and lactate non‐utilisers. All strains, except those ofSaccharomyces dairensis, tolerated acetic acid (5 g litre−1) and grew at pH 4.0 in a mineral salts medium containing lactic acid (10 g litre−1), acetic acid (5 g litre−1) and yeast extract (1 g litre−1). Growth in this medium was completely inhibited by the cationic detergent Arquad C33W (20 mg litre−1), propionic acid (5 g litre−1), benzoic acid (5 g litre−1) or salicylic

ISSN:0022-5142    

DOI:10.1002/jsfa.2740370906

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractNotable seasonal changes of the levels of purine alkaloids, caffeine and theobromine, in the stem and leaves of the new shoot of tea (Camellia sinensis(L) O. Kuntze cv. Yabukita) were observed, suggesting metabolism and/or translocation of the alkaloids. The alkaloids decreased significantly in August and in October and November while total nitrogen increased appreciably in November and December. The results indicate that the alkaloids have no role in the storage of nitrogen during the winter months.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740370907

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractAn examination of reject bacon samples supplied directly from a factory showed that some samples described by a sensory panel as oily and fishy contained significantly higher levels of long chain polyunsaturated fatty acids (PUFA) in their fat than normal samples. When bacon samples obtained from retail outlets were similarly analysed and then subjected to sensory assessment, those found to contain long chain PUFA were given significantly higher scores for oily and fishy flavour. Observations on the fatty acid composition of fishy bacon samples as compared to non‐fishy ones and further investigation into the diets of pigs producing suspect carcasses led to the conclusion that too high a content of fish products in the diet was the main cause of the problem. Contrary to what had been believed, fresh non‐fishy bacon samples did not develop fishy flavour after storage at −20°C for 15 weeks. Perceived fishiness was not related to total copper content as determined by atomic absorption spectr

ISSN:0022-5142    

DOI:10.1002/jsfa.2740370908

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractHighly specific antisera of high titre to sterigmatocystin hemiacetal has been produced in rabbits and used to set up a microtitration plate enzyme‐linked immunosorbent assay. Novel conjugation procedures were used in synthesis of both immunogen and the material used to make the assay solid phase. The assay has been validated for the determination of sterigmatocystin in barley—extraction conditions are such that the toxin is converted quantitatively to the more soluble hemiacetal f

ISSN:0022-5142    

DOI:10.1002/jsfa.2740370909

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe physicochemical, milling and cooking characteristics of three commercial varieties of paddy viz. Jaya, PR 106 and Pb. Basmati no. 1 as affected by different dates of sowing nursery and transplanting, were investigated. Grain yield was adversely affected with late sowing and transplanting dates. Significant differences were recorded on the yield of head rice and brokens in the three varieties grown under different sowing and transplanting dates. The effect of normal and late dates of sowing on 1000‐kernel weight and grain dimensions was significant for both paddy and milled rice. Protein content of rice was not affected by sowing dates but late transplantings resulted in higher values. Free fatty acids in rice and bran were significantly increased with late sowing and transplanting dates, however, the amylose content decreased under these situations. Late transplanting dates decreased the minimum cooking time but increased the solid losses in gruel. The late transplantings deteriorated the organoleptic properties of cooked rice and had higher values for clearing and spreadin

ISSN:0022-5142    

DOI:10.1002/jsfa.2740370910

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractAn enzyme‐linked immunosorbent assay for the detection of 3‐acetyldeoxynivalenol has been set up with an antiserum preparation raised against a bovine serum albumin—3‐acetyldeoxynivalenol hemiglutarate conjugate. The assay is an indirect, double antibody immunoassay performed on microtitration plates, and is sensitive (with a limit of detection of 1 pg per well) and specific. The assay has been validated for application to rice with a sensitivity of 1 ng g−1. Sample extraction is a simple solubilisation procedure. The immunoassay described has a number of advantages over conventional methods of

ISSN:0022-5142    

DOI:10.1002/jsfa.2740370911

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY