摘要:

AbstractThe distribution of 10 nutrient elements was assessed in three fractions of herbage samples of perennial ryegrass, tall fescue, white clover and lucerne. The cell wall fraction, prepared by mechanical disintegration of undried material, contained the following proportions of the total herbage content of the major elements: N, 2.9–16.4%; P, 3.0–6.9%; S, 3.6–17.2%; Ca, 11.3–51.8%; Mg. 6.4–27.6% and K, 0.1–1.7%. Substantial though more variable proportions of the trace element cations, Fe, Mn, Zn and Cu were also present in the cell wall fraction. The extent to which the elements were soluble in water was assessed by analysis of the water‐insoluble fraction prepared from freeze‐dried samples of each herbage. The proportions of the total herbage content of the major elements soluble in water were: N, 30–57%; P, 80–92%; S, 35–71%; Ca, 48–69%; Mg. 65–83% and K, 90–96%. With the trace element cations the proportions soluble in water were more variable, though they were generally less than 70% of the total. The extent to which the various elements were soluble in 80% aqueous ethanol was assessed by analysis of the insoluble fraction prepared from freeze‐dried materials. With each of the major elements, smaller proportions of the total herbage content were soluble in 80% ethanol than in water, which may reflect in part the lower solubility of proteins and pectin. With the trace element cations, the differences in solubility between 80% ethanol and water were gen

ISSN:0022-5142    

DOI:10.1002/jsfa.2740360502

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractDifferent varieties of finger millet (Eleusine coracana Gaertn.) were screened for esterase activity colorimetrically and electrophoretically using 1‐naphthyl acetate and acetylthiocholine chloride as substrates. The Indian brown seed coat variety (Purna), the Indian white seed coat variety (Hamsa), hybrids of these designated as HPB (brown) and HPW (white), African varieties (brown) and Indian‐African hybrid varieties (brown) all exhibited 1‐naphthyl acetate hydrolysing activity and showed 6,5,6,5,8 and 8 esterolytic bands respectively on gel electrophoresis. The white seed coat varieties, both parental (Hamsa) and hybrid (HPW), did not possess any acetylthiocholine chloride hydrolysing activity while all the brown seed coat varieties did, the African varieties having greater activities than Indian brown seed coat varieties. Thus, the demonstrable variation in esterase isozymic pattern and cholinester hydrolysing activity with the varieties tested provides a useful genetic marker for identifying different varieties of finger m

ISSN:0022-5142    

DOI:10.1002/jsfa.2740360503

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractSunflower seed respiration rates and respiratory quotients (RQ) were measured by gas‐solid chromatography coupled to a closed system which contained the seed sample. By using a gas sampling valve fitted with a 0.5 ml sample loop, head‐space sampling is eliminated. The system is reliable, reproducible, and the data can be obtained in short time periods, as O2and CO2can be measured simultaneously. With this procedure, a 10°C increase in temperature produced about a two‐fold increase in respiration rates (μlCO2h−1g−1DM) in seed samples at the same moisture level (13%); while a three‐fold increase in seed moisture (7%vs20%) produced a 148‐fold increase in respiration rates at 42°C. High RQ values indicated that high temperatures and low seed moisture may have limited O2uptake by sunflower seed. Under other conditions, the seed respired aerobically and used carbohydrates as an energy source (RQ=1). Germination test indicated that exposure of sunflower seed to very low O2and high CO2levels for 24 h did not adversely affect seed viability. This procedure was successfully applied to obtaining respiration data for soya beans and f

ISSN:0022-5142    

DOI:10.1002/jsfa.2740360504

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractTransverse distribution patterns of calcium, magnesium and phosphorus in Cox's Orange Pippin apples at harvest and subsequent redistribution patterns during storage in air at 0°C were measured. Distribution and redistribution patterns differed from those in Spartan apples measured in the previous year. Orchard calcium sprays increased the proportion of calcium in the outer parts and slightly increased the proportion of magnesium towards the centre of the fruit. Late summer pruning slightly increased the proportion of magnesium in the core at harvest and increased the rate of redistribution of calcium from the core to the outer fruit parts during storage. Redistribution patterns, especially those of magnesium, were drastically altered when low temperature breakdown developed and minerals moved into the affected zones

ISSN:0022-5142    

DOI:10.1002/jsfa.2740360505

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractExamination of the volatile constituents of blackcurrants (Ribes nigrum L.) was undertaken to examine differences in varietal extracts. The compositions of extracts from 10 cultivars grown in southern Tasmania were determined by gas chroma‐tography and mass spectrometry. The patterns of association of the 34 components measured were analysed by principal co‐ordinate analysis, the co‐ordinates being plotted in four dimensions. A close association between oils extracted from selections belonging firstly to the Goliath and Baldwin groups, and secondly to the Boskoop and French groups, has been revealed. This analysis confirms the relationships proposed by Todd in his phenotypic key for identification. The results are discussed in the light of previously distinguished monoterpene and sesquiterpene pheno

ISSN:0022-5142    

DOI:10.1002/jsfa.2740360506

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractQuantitative gas chromatographic analysis of the volatile aroma components has been used as an objective measure of the effects of maturity at harvest, ripeness and storage on the aroma volatiles of kiwifruit. Increasing ripeness is associated with a rapid increase in the levels of aroma volatiles, especially esters, while increasing storage time prior to ripening is accompanied by a decrease in the amount of aroma volatiles.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740360507

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe electrical resistance and the 1.0 kHz dielectric properties of cassava were measured at different moisture content values with the Kiethley digital multimeter and GR 1608‐A impedence bridge respectively. The resistance increased linearly with decreasing moisture content while the Naperian logarithm of the a.c. conductivity decreased linearly with decreasing moisture content. Regression constants were obtained in both cases. The dielectric constant decreased with decreasing moisture conten

ISSN:0022-5142    

DOI:10.1002/jsfa.2740360508

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractA range of spirituous beverages available in Australia has been analysed for the major volatile congeners using gas chromatography. A data bank has been generated and its use and limitations in the detection of illicit spirits is discussed. The spirits include Australian and imported brandies, tequilas, grappas, fruit brandies, wine fortifying spirits, rums, whiskies including bourbon, malt and blended scotch, gins, vodkas and sundry other beverages. Methanol. acetaldehyde, 1‐propanol, 2‐methyl‐1‐propanol, 2‐butanol, 1‐butanol, 2‐methyl‐1‐butanol. 3‐methyl‐1‐butanol, ethyl lactate and ethyl

ISSN:0022-5142    

DOI:10.1002/jsfa.2740360509

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractHeadspace volatiles from grilled, roast and boiled pork were entrained on Tenax GC and analysed by combined gas chromatography‐mass spectrometry. Well‐done grilled pork contained 66 heterocyclic compounds including pyrazines. thiazoles, thiophenes, furans and pyrroles, many of which had not previously been found in cooked pork. The pyrazines accounted for almost 80% of the total headspace volatiles, although most of the other heterocyclic compounds were present only in small amounts. Pork cooked by less severe grilling or by roasting or boiling contained considerably fewer heterocyclic compounds, and headspace volatiles were dominated by aldehydes and alcohols originating from thermal oxidation of li

ISSN:0022-5142    

DOI:10.1002/jsfa.2740360510

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractHunterL,aandbvalues are used to order fish mince colour according to species or processing parameters. Mince colour difference (ΔE) or statistical examination ofL,aandbvalues are used to establish a 3‐dimensional plot to illustrate colour differences between sampl

ISSN:0022-5142    

DOI:10.1002/jsfa.2740360511

出版商:John Wiley&Sons, Ltd    

年代:1985

数据来源: WILEY