摘要:

AbstractIntensive leaf sampling of two Cox apple trees was used to study factors affecting yield of leaf dry matter and the nitrogen and mineral contents of the dry matter. Significant differences were found between main branches of the same tree, between different heights of sampling and between non‐fruiting spur leaves on old wood and leaves on new extension growths. Leaf position on new extension growths also affected composition and there were some significant interactions between the main factors. The significance of the results in relation to routine sampling methods is discussed and the need for further sampling investigations emphasise

ISSN:0022-5142    

DOI:10.1002/jsfa.2740150401

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractA method is described for the separation of butyric, propionic, acetic, formic, succinic and lactic acids from silage extracts by chromatography on columns of silica gel eluted with mixtures of benzene and n‐butanol. Separated acids were estimated by titration with barium hydroxide solution. The method has been applied to silages made from pure species of herbages at different stages of growth and receiving different treatments before ensilage.Lactic acid concentrations up to 11.5% of the dry matter were recorded, giving rise to low pH values. Butyric acid concentrations of up to 5% raised the pH and under these conditions only small amounts of lactic acid were present; propionic acid concentrations rose to 1–2% in some cases and trace amounts of formic acid could be detected. Acetic acid was present in all silages at concentrations of up to 7% of the dry matter, and appeared to fall off as the nitrogen content of the crop decreased. As the herbage matured, the total acid concentration of the silage decrea

ISSN:0022-5142    

DOI:10.1002/jsfa.2740150402

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThe merits of different methods of incorporation of fat into milk diets for calves were studied by determining the apparent digestibility of the fat and its ability to promote a high efficiency of nitrogen retention. All the diets were reconstituted with water and fed in liquid form.Butterfat included in a diet by melting and then blending with spray‐dried separated‐milk powder had an average digestibility of 71.8 ± 5.9% compared with 95.2 ± 1.5% for the butterfat in a spray‐dried whole‐milk powder. The poorer digestibility was associated with markedly lower nitrogen retention. The inclusion of 3.3% of lecithin in the blended butterfat increased the average digestibility of the fat to 88.3 ± 4.2% and also brought about a substantial improvement in nitrogen retention.Palm‐kernel oil in an homogenised spray‐dried milk powder had a mean digestibility of 94.1 ± 1.4%. An addition of 3.3% of lecithin to the oil was associated with a slightly higher digestibility (96.3 ± 1.0%).Tallow containing 3% of added lecithin had a mean digestibility of 70.7 ± 4.44; when melted and then blended with spray‐dried separated‐milk powder compared with 86.8 ± 2.2% when in an homogenised spray‐dried milk powder.It was concluded that, for optimum digestibility of fat in filled (lipid supplemented) milk diets, the fat must be adequately homogenised. Since the inclusion of lecithin is associated with slightly higher digestibility of homogenised fat, its addition is considered desirable to ensure maximum digestibility of the fat.The mean digestibility of tallow added to reconstituted spray‐dried separated milk as a concentrated fat homogenate containing emulsified tallow 30%, separated‐milk solids 3% and water 67% was 85.7 ± 2.5%, compared with 86.5 ± 3.4% for tallow in a reconstituted

ISSN:0022-5142    

DOI:10.1002/jsfa.2740150403

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThe effects of feeding meal mixtures suspended in water, as compared with dry feeding, and the merits of different methods of incorporation of fat into liquid‐fed meal mixtures were investigated in digestibility trials and nitrogen retention studies with Ayrshire bull calves.When calves were changed from filled‐milk diets to meal/hay diets, a markedly better utilisation of dietary protein was found if the meal part of the diet was fed as a suspension in water, for meal mixtures of both low and high fat content, than with the same meal mixtures fed dry. Evidence is presented which indicates that liquid feeding enabled the concentrate part of the diet to by‐pass the rumen and enter directly into the abomasum as is the case with milk‐fed calves. It is suggested that this led to a better utilisation of dietary energy which in turn permitted a more efficient utilisation of protein.With liquid feeding, the mean digestibility of the ether‐extractable material in a meal mixture containing 20% of red palm oil, added in the form of an homogenised milk powder, was 77.9 ± 3.9% compared with 72.7 ± 2.1% for that in a similar diet containing 19.3% of the palm oil and 0.7% of lecithin simply blended with the other components of the diet. The higher digestibility of the homogenised fat was accompanied by a slightly greater retention of nitrogen. The red palm oil of the homogenised milk powder had a mean digestibility of 89.5% when fed to the same calves earlier as part of an all‐milk diet.Further results suggest that the lower apparent digestibility of homogenised fat in liquid‐fed meal mixtures than in all‐milk diets is due partly to the higher daily intakes of calcium and magnes

ISSN:0022-5142    

DOI:10.1002/jsfa.2740150404

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractIn confirmation of an earlier conclusion that volatile esters are not the major natural promoters of superficial scald, it has been shown I mole of butyl acetate in 5000 moles of air gave no increase of scald but produced a marked taint.Vapours of cyclohexane, cyclohexene, benzene andd‐limonene, and n‐hexadecane and hexadec‐I‐ene applied to the surface in ethanol solution reduced scald at suitable concentrations. The last three produced scald‐like injury at higher concentrations.During storage in oiled wraps, cuticle oil and ursolic acid were transferred to the wraps and mineral oil to the apples. A more volatile minor fraction of the mineral oil contributed to the control of scald.Diphenylamine gave better control of scald thanN‐benzylaniline, dibenzylamine and dicyclohexylamine in decreasing order of effectiveness when used as dipping solutions in ethanol. Diphenylamine reduced volatile ester production at 1° but increased it at 20°, increased the production of less volatile esters of the lipid coating, and stabilised a pigment of the lipid coating.Quercetin reduced scald when applied to the fruit surface in ethanol solution, but cyanidin did not.The volatile‐agent theory of scald, the nature of the volatile agents, their means of escape, natural inhibitors and the mechanism of control by diphenylamine and oiled wrap

ISSN:0022-5142    

DOI:10.1002/jsfa.2740150405

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractMoisture determinations in dried vegetables were made after lyophilisation by drying in a vacuum desiccator at 70°, 60° and 50° and room temperature. The findings of Makower&Nielsen could not be corroborated, but it is considered that the results at 50° are a close approach to the moisture content. Since these results are in good agreement with the values found by titration with Karl Fischer reagent after extraction with formamide, the titration method may be accepted as a standard procedure for the determination of moisture in dried vegetables.Determination of the end‐point of drying under vacuum at 70° after lyophilisation of the material appears to be impossible, probably because of thermal decomposition soon after drying starts, probably with

ISSN:0022-5142    

DOI:10.1002/jsfa.2740150406

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractGas storage of green peas was found to be effective only in certain seasons.Peas deteriorated more slowly when stored in pods than when stored shelled. This was not the result of the gas mixture round the peas, wilting, bruising or volatiles. Much material moved from the pods to the peas during storage. The respiration of the peas appeared to change little on shelling but the pods, after removal of the peas, showed a slow rise in rate followed by a slow fall. The movement of a hormone type of compound from the pod to the pea is postulated.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740150407

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThe manner in which sodium metabisulphite is taken up by potato tissue from boiling aqueous solution has been investigated in respect of depth of penetration, extent of uptake and scalding time: uptake relationships. The extent to which45Ca and35S migrate to the centre of potato strips during hot‐air drying after scalding in solutions of45CaCl2and NaH35SO3has been examined autoradiographically.45Ca is more uniformly distributed than35S which shows a greater tendency to concentrate at the strip centres. Losses in measurable SO2during hot‐air dehydration are predominantly chemical rather than physi

ISSN:0022-5142    

DOI:10.1002/jsfa.2740150408

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractFive trials were conducted to elucidate the cause of the growth‐inhibitory effect of carob meal in chick rations, with special emphasis on estimating its productive energy value. The growth‐depressing factor of carob meal could not be extracted with methanol, ethanol or ethyl acetate. Consecutive extractions with cold and hot water left a residue which did not affect growth. The cold‐water extract had a slight, and the hot water extract a distinct, inhibitory effect on feed consumption, without affecting feed utilisation. This reduced feed intake may be due to the presence of tannin‐like compounds, which seem to affect appetite.Supplementation of diets containing carob with fat resulted in growth similar to that of the control. The data presented indicate that carobs do not contain any toxic factors and that their low caloric value is the major factor responsible for growth depression. The energy value of carobs should be calculated on the basis of their sugar content as the only nutrient available to the

ISSN:0022-5142    

DOI:10.1002/jsfa.2740150409

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractA method is described for the determination of the total residual bromide in cacao shell and nib fumigated with methyl bromide. It is applicable to quantities down to I p.p.m.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740150410

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY