摘要:

AbstractThe colour of subjectively‐chosen tomato fruit of three contrasting cultivars at each of five stages of ripeness were measured on a tri‐stimulus colour difference meter. The values were introduced into a formula previously developed for calculating objective limits for each ripening stage, but satisfactory separations were not achieved. When the colour components for areas on the side‐walls of tomatoes were introduced into a revised formula, good discrimination was achieved between classes of fruit from fairly ripe to fully ripe. Similar measurements carried out on areas near the stylar scar and used with an alternative formula led to efficient separation of less ripe fruit into distinct classes. It is suggested that the revised formula can be applied to any cultivated tomato line except colour mu

ISSN:0022-5142    

DOI:10.1002/jsfa.2740351202

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractOil content has been found to range from 1.2–1.9% in a wide range of diverse field bean (Vicia faba) cultivars, populations and selections and from 1.4–2.8% in a narrower range of pea cultivars. The ranges in fatty acid composition for beans and peas respectively were palmitic, 13.9–21.0% and 12.0–16.6%, stearic 2.2–3.5% and 2.5–4.2%, oleic 15.0–33.0% and 14.2–33.3%, linoleic 41.3–59.7% and 43.7–60.9%, linolenic 2.6–4.9% and 6.4–13.4%. Environment exerted a significant effect on the oil content of field beans but cultivar differences remained apparent. The analysis of whole or milled field beans stored for up to 5 years showed only minor losses of oil and component fatty acids. In both species over 90% of the total oil content was found in the cotyledons. Cultivar differences in whole grain oil content were associated with the concentration of oil in the cotyledons and appeared independent of the relative proportions of either embryo or seed coat. The interrelationships between oil content and other seed characteristics were also determined and the significance of these results in relation to plant

ISSN:0022-5142    

DOI:10.1002/jsfa.2740351203

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractGranules of15N‐labelled urea (150 kg N ha−1), with or without the urease inhibitor hydroquinone, were broadcast on to small plots of winter oilseed rape in March. Ammonia volatilisation losses were estimated by a15N balance procedure in which the amount of15N in the plants, plus that in the soil to 70 cm depth, was determined 18 days after urea application. All the urea‐N was recovered in soil and plants from plots given either urea alone or urea plus hydroquinone; hence there was no volatilisation of ammonia. Although the soil pH was high enough (7.7 to 8.0) for ammonia loss, this did not occur because the soil was too cold, too wet and had a high cation exchange cap

ISSN:0022-5142    

DOI:10.1002/jsfa.2740351204

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractIn a comparison of methods for estimating the cell‐wall content of forage, each of three methods was compared separately with the other two in regression analyses. Subtraction of unextracted protein from cell‐wall values removed differences in regression slopes. Parallel slopes, but different intercepts showed that different methods of extracting forage removed different amounts, rather than different proportions of non‐protein, cell‐wall material. With different extraction methods in use, cell‐wall values are meaningful among laboratories using identical analytical procedures, and then only if interference from unextracted protein is

ISSN:0022-5142    

DOI:10.1002/jsfa.2740351205

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe micrometeorological mass balance method has been assessed with a view to its use in the determination of ammonia (NH3) loss from grazed swards. The method involves the measurement of wind speed and the concentration of NH3in air at different heights above the sward at its windward boundary and a position leeward of the grazed area. The flux of NH3is calculated from these measurements and a continuous record of wind direction. Quantitative recovery of NH3from air flows up to 10 litre min−1was achieved using a simple trap containing dilute orthophosphoric acid and a gas dispersion tube. Wind speed measured at a height of 0.25 m at six different positions above a previously grazed sward varied by<2%. The NH3concentration at the same positions was affected by the distance between the windward edge of the sward and the sampling position (i.e. the fetch) and by heterogeneity in the distribution of sources of NH3(urine‐ or dung‐affected areas). However, the normalised horizontal flux through 0.25 m (wind speedXNH3concentration/fetch) varied by less than ±8.1% probably due to mixing through fluctuations in wind direction (approximately ±30° on the mean) as air passed over the sources of NH3during each measurement period. Plots of wind speed or NH3concentration versus logarithm of height indicated that each approximated a linear relationship. This facilitated the calculation of the NH3flux per unit land area and reduced the total error to about 10%. The total loss of NH3derived by summing losses during individual sampling intervals of 2 to 18 h within a 24 h period was essentially the same as that derived by averaging wind speeds and NH3concentrations measured continuously over the same 24 h period. The flux of NH3from a ryegrass sward grazed by yearling steers ranged from 0.01 to 0.14 kg N ha−1h−1during a 2 day grazing period within a 28 day rotation and during the 5 days following removal of animals. A pronounced diurnal variation was observed in the flux of NH3, the maximum occurring between 13.00 and 20.00 hours on each day. Rainfall and low rates of evapotranspiration reduced the flux to<0.02 kg N h−1h−1. The total loss of NH3during 28 days wa

ISSN:0022-5142    

DOI:10.1002/jsfa.2740351206

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe study evaluates the efficacy of three common market‐grade culinary vegetable oils—groundnut oil, cottonseed oil and coconut oil—in preserving the internal quality of freshly laid eggs coated with them and stored under tropical room conditions of 25–32°C and 40–85% r.h. for 36 days. All three vegetable oils significantly (P<0.01) limited diurnal weight losses of the eggs to 0.013–0.016 g as against 0.186 ± 0.013 g for the untreated eggs over 36 days storage. Liquefaction of the yolk and albumen was also significantly reduced (P<0.05) such that the albumen pH of the oiled eggs increased from 7.65 to only 8.35–8.65 after 36 days when the untreated eggs had an albumen pH of 9.80. Subsequently, the yolk index of oiled eggs dropped by only 0.10–0.13 after 36 days and remained significantly superior (P0.05) improvement ov

ISSN:0022-5142    

DOI:10.1002/jsfa.2740351207

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe effect of exogenous short‐chain n‐alcohols on the concentrations of main aroma components in mature intact Red Delicious apples and aged apple tissue discs has been studied. Storage of intact apples in an atmosphere containing ethanol vapours for 24 h resulted in a more than threefold increase in the sum of ethyl ester concentrations. The simplified model of tissue discs was applied to examine the influence of various ethanol concentrations on rate and time course of ester formation. On supplying a range of n‐alkan‐1‐ols and 2‐keto valeric acid in equimolar amounts to the discs, maximum conversion into esters was found with butanol and pentanol. The possibility of an in vivo aroma enrichment before processing of fruits i

ISSN:0022-5142    

DOI:10.1002/jsfa.2740351208

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractThe transverse distribution of calcium across median slices of Cox's Orange Pippin apples affected by watercore was compared with that in slices from the remaining bulked sound fruit in samples at harvest. Concentrations of calcium were lower in all zones of apples with watercore. In affected apples, proportions of calcium were higher in the outer zones and much lower in the core zones.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740351209

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractConcentrations of dry matter, nitrogen and major mineral constituents in samples of Cox's Orange Pippin and Crispin fruit from interplanted trees were measured for 4 years. Similar measurements were made over a 6 year period in Cox and Spartan fruit samples from trees interplanted in another orchard. Concentrations varied greatly in all varieties from year to year. In comparison with Cox, fruit calcium concentrations were higher for a given mean mass per apple in Crispin in all years and in Spartan for 4 of the 6 years at harvest. Concentrations of nitrogen, potassium, magnesium and phosphorus were lower in Crispin and Spartan than in Cox fruit at harvest in all years, but dry matter and sodium concentrations differed only in some years. Changes in concentrations during fruit growth were measured in 2 years for each comparison. Differences between nitrogen, phosphorus and potassium concentrations in either Crispin or Spartan and Cox apples were evident throughout fruitlet enlargement in both years. Calcium concentrations were higher in Crispin and Spartan fruitlets than in Cox fruitlets of equivalent mass. Variations in the concentrations of potassium, magnesium and calcium from tree to tree were greater for Cox than Crispin samples but relationships between potassium and magnesium concentrations were similar for both varieties.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740351210

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY

摘要:

AbstractTwo UK wheats of similar protein content but differing in hardness have been conditioned at temperatures of 4, 10.5, 19 and 28°C to a moisture content of 15.5%, using lying times in the range 2 to 24h. The milling performance of the wheats has been assessed in terms of flour yield, moisture content and grade colour figure (GCF). Flour yield was expressed as straight‐run milling yield (SR) and also as total yield (TE) which included flour from the impact finishing of by‐products. The use of a conditioning temperature of 28°C increased TE and SR for the hard wheat and TE for the soft wheat, but decreased SR for the latter. Both types showed a reduction in flour yield when a lying time of 2h was employed. The use of temperatures above or below 19°C led to improved GCF results. The combination of low temperatures and short lying times brought about reductions in flour moisture content but these reductions were shown to be only partially responsible for the accompanying decreases in flour

ISSN:0022-5142    

DOI:10.1002/jsfa.2740351211

出版商:John Wiley&Sons, Ltd    

年代:1984

数据来源: WILEY