摘要:

AbstractA method for extracting and fractionating organic phosphates is described. In the fractions, inositol hexaphosphate (IHP) was determined with a carbon detector after high pressure liquid chromatography (h.p.l.c). Sample preparation consisted of a single mild extraction with 0.1M EDTA in 0.3M‐NaOH and a preseparation by gel filtration. Adenosine‐5‐triphosphate (ATP) could also be separated and determined in this way. With a number of samples, clean‐up by gel filtration could not prevent deterioration of the anion exchange column, used in the h.p.l.c. determination. IHP was then determined as total P after isolation by two consecutive gel filtrations. Limits of detection were 5‐50 μg P/g when determining IHP by h.p.l.c. and 0.05‐0.5 μg P/g when determining IHP as total P after isolation by gel filtration. Limits of detection when determining ATP by h.p.l.c. were 5‐50 ng P/g. Results of applying the method to soil and various organic materials are give

ISSN:0022-5142    

DOI:10.1002/jsfa.2740290702

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractMethods for the extraction and separation of hordein fractions from single or half‐seeds of barley have been evaluated. Sodium dodecylsulphate‐polyacrylamide gel electrophoresis at pH 8.9 gave rapid and reproducible separations of reduced and alkylated hordein, and this system was used to analyse hordein fractions from 88 barley varieties. On the basis of this character the varieties can be divided into 29 groups, each containing between one and 25 varieties. The largest group can be further divided into four subgroups on the basis of minor hordein polypeptide differences revealed by a second electrophoretic system, urea polyacrylamide gel electrophoresis at pH 4.6. Of the samples of the varieties studied, all except five contained seed homogeneous with respect to hordein polypeptide pattern. It is concluded that analysis of hordein polypeptide patterns from single seeds is of great potential value, both for the commercial identification of grain samples and as an aid to existing techniques for the establishment of varietal distinctn

ISSN:0022-5142    

DOI:10.1002/jsfa.2740290703

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractA rapid automated colorimetric method of estimating the thiocyanate ion released from forage brassicae is described. The freeze‐dried kale sample is treated with a buffered myrosinase solution and the extract analysed for thiocyanate ion on a continuous flow analyser incorporating dialysi

ISSN:0022-5142    

DOI:10.1002/jsfa.2740290704

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractSix sides of beef were chilled under widely differing conditions and the toughness measured at locations across a slice of the round. When beef carcasses were held for 6 h before chilling at 2°C, the variation in toughness across each muscle was usually small and regions of toughness varied between animals. Such variations are unimportant commercially and, for most experimental purposes, locations within each muscle may be randomised with little loss of information. The exception was theM. biceps femorisin which the caudal region was consistently tougher than the cranial region. When chilled to 7°C in 24 h, the cold‐shortening toughness was induced to a depth of about 4 cm. The resulting variation was often so large that it made the average toughness value virtually meaningl

ISSN:0022-5142    

DOI:10.1002/jsfa.2740290705

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThe effect of slaughter method on the residual haemoglobin content of theM. longissimus dorsiand the amount of blood lost at exsanguination of sheep was investigated. The influence of stunning method (electrical, 90 V, or captive bolt pistol), pithing and bleeding‐out position were examined. Sheep bled lying lost more blood than those bled hanging and electrically‐stunned animals lost more blood than those stunned with a captive bolt pistol; pithing had no effect. The residual haemoglobin content of the muscle did not vary significantly between methods and there was no relationship between it and the amount of blood lost at slaugh

ISSN:0022-5142    

DOI:10.1002/jsfa.2740290706

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractThree sugars were tried as carbon sources for the synthesis of total lipids, triglycerides and sterols inFusarium oxysporum.Glucose at 3% level gave the maximum. Polar lipids in the mycelium varied from 4.2 to 9.7%. An increase in glucose concentration led to increased production of saturated fatty acids. Nine salts containing either the ammonium or nitrate ions were used as a nitrogen source. Potassium nitrate was best for lipid synthesis and ammonium bicarbonate yielded polar‐rich lipids. The content of free fatty acid was relatively higher on ammonium salts. Except for the minor changes in the fatty acid make‐up, no definite differences could be observed. The optimum pH was found to be 5.5. At this pH, triglycerides and free sterols were in considerably higher concentration. The proportion of linoleic acid remained more or less constant between the pH range of 3.5 and 6.5 while that of linolenic acid showed the maximum value at pH of 4.5. C:N ratios of 30 and 300 were found to be the optimum among narrow and wide ran

ISSN:0022-5142    

DOI:10.1002/jsfa.2740290707

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractCertain aspects of lipid metabolism inFusarium oxysporumwere studied using acetate‐1‐C14and H3P32O4for incorporation of radioactivity into the fungal mycelium. During initial stages of growth of the organism (up to 1 h of incubation) the phospholipid fraction exhibited relatively higher specific activity values indicating its rapid rate of synthesis. Higher turnover rates were observed for phosphatidic acid (PA) and polyglycerophosphatides (PGP). It is postulated that PGP represents a labile pool where PA synthesised in excess of the metabolic needs of the cell is stored to be subsequently used during periods of intense phospholipid biosynthesis. In pulse and chase experiments, higher specific activities were observed for PA, PGP and cardiolipin (CL) fractions after 1‐day chase on unlabelled media. Rapid turnover rates were observed for PA, PGP and cardiolipin (CL) fractions. It is suggested that these are involved in the growth of new cells and (or) in the cell repair processes. In cells grown both under normal and carbon‐starvation conditions, the specific activity pattern of phosphatidyl choline (PC), and phosphatidyl ethanolamine and phosphatidyl glycerol (PE + PG measured collectively) was very similar indicating similarity in the metabolism of these two classes of phosphatides. Addition of sodium arsenite, alloxan, p. benzoquinone and citric acid in the incubation media was found to affect the synthesis of lipid classes in different ways. For example, among the polar lipids, PA, PC, PE + PG, CL and SGP + FFA fractions were inhibited by p.benzoquinone, while the incorporation of label from C14was found to be stimulated into the phosphatidyl inositol f

ISSN:0022-5142    

DOI:10.1002/jsfa.2740290708

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractSeven varieties of rice belonging to dwarfindica, tallindicaandjaponicaclasses were stored as paddy as well as milled rice at 1‐3°C, room temperature (RT) and 37‐40°C in the dark and also at RT in the light for 3.5 years. Various physicochemical properties were measured in the samples at intervals. The aging process in rice appeared to be characterised by: (a) an increase in volume expansion and a steady decrease in solids loss upon cooking, (b) an initial increase followed by a steady decrease in the power of hydration (water uptake at 96 and 80°C, equilibrium moisture content), (c) probably a slow decrease in the solubility of the amylose and a slow increase in the gelatinisation temperature, (d) an initial increase followed by a steady decrease in paste viscosity and setback, and (e) a sharply decreasing viscograph breakdown. The process was retarded effectively by storage in the cold. Conversely, it was greatly hastened by storage at high temperature and to some extent by exposure to light. In addition, the process occurred much faster and/or to a greater extent in high‐amylose (total as well as insoluble) rather than in low‐amylose varieties, and to some extent in milled rice rather tha

ISSN:0022-5142    

DOI:10.1002/jsfa.2740290709

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

摘要:

AbstractNew Zealand White rabbits, aged between 5 and 8 weeks, were offered diets based on oatmeal together with up to 500 g kg−1of ground oat husk, or 500 g kg−1of ground barley straw or 400 g of a purified cellulose. The rabbits gained about 40 g liveweight per day when fed a well‐balanced control diet (in which oatmeal, grassmeal, corn oil and fishmeal were the main constituents) and, apart from one occasion, there was no significant reduction in this rate of gain even when the diets offered contained up to 500 g kg−1of these fibre sources. Food consumption increased from 80 g day−1to 115 g day−1as the acid detergent fibre concentration in the diet increased from 39 to 270 g kg−1. Digestible and metabolisable energy contents of the diets fell as the fibre concentration rose but the rabbits were able to adjust their intakes and maintain their daily metabolisable energy intakes constant at about 1100 kJ. The proportion of fat in the body dry matter fell as the fibre concentration in the diet was raised. A minimum dietary fibre content of 100 g kg−1as measured by the acid detergent fibre or crude fibre techniques is suggested for optimum

ISSN:0022-5142    

DOI:10.1002/jsfa.2740290710

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY

ISSN:0022-5142    

DOI:10.1002/jsfa.2740290711

出版商:John Wiley&Sons, Ltd    

年代:1978

数据来源: WILEY