摘要:

AbstractA series of meat‐and‐bone meal samples was prepared during batch cycles in a commercial dry‐rendering plant, in which offal was cooked to the usual end‐point, then the cooker contents were held at high temperatures for prolonged periods. The expected decrease in nutritive value was not detected by chick assays even for meals that had been heated at 145 ºC for 2 h after end‐point. An apparent increase in nutritive value was detected in meals heated at 115 ºC for up to 80 min after end‐point. Since chick assays were carried out using diets similar to industrial formulations, it is concluded that the experimental processing conditions had no detrimental effect on the meals as feed additives. Available lysine values showed no trends with processing conditions and tended to confirm that the biological value of the meal protein had not suffered. Results of chemical analyses showed some variability, attributable mainly to sampling errors that are hard to avoid when obtaining a small sample representative of the 5 to 10‐kg portions of meal used

ISSN:0022-5142    

DOI:10.1002/jsfa.2740250902

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractEleven meat meals were prepared by batch dry rendering hard and soft offal from sheep and beef cattle. Meat meals prepared from hard offal (sheep heads, calves heads and trotters) had high calcium and collagen contents and low essential amino acid contents. Their nutritive values as determined by chick growth tests were low. On the other hand meat meals prepared from soft offal (sheep guts and rumens) had low calcium and collagen contents and high essential amino acid contents and nutritive values.Pressure cooking for ½ hour at 275 kPa tended to decrease the nutritive value of sheep heads and trotters but prolonged pressure cooking for 1½ hour at 275 kPa reversed the trend.The greater influence of the raw materials on meat meal quality compared to the effects of processing were discusse

ISSN:0022-5142    

DOI:10.1002/jsfa.2740250903

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe limiting conditions of grain moisture content (m.c.) and storage temperature for growth ofFusariumand production of the mycotoxin, zearalenone, were defined in maize, wheat, barley and oat culture. Grain moisture content was the major influence on establishment of the fungus, but storage temperature directly affected the rate of zearalenone synthesis. All the grains tested were susceptible to invasion byFusariumabove 18% m.c. (calculated on a wet‐weight basis), even when stored at 7 ºC. In the range 15 to 18% m.c. the grain was increasingly at risk as the storage temperature was raised. Maximum zearalenone yields (500 to 2000 μg/g grain) were obtained in cultures stored at 12 and 18 ºC, even though mycelial growth had been reduced. At 25 ºC, where there was rapid mycelial growth and almost total utilisation of grain after two months' storage, toxin yields were seldom higher than 100 μg/g

ISSN:0022-5142    

DOI:10.1002/jsfa.2740250904

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe concentrations of formic, acetic, propionic and butyric acids required to prevent growth ofFusariumin wheat grain cultures were determined. The cultures were maintained at 31% moisture content and stored for 4 weeks at 25 ºC followed by 6 weeks at 12 ºC, which were optimum conditions for growth ofFusariumand synthesis of the mycotoxin, zearalenone. Under these conditions the critical concentration of all the acids, whether used singly or in combination, was between 1000 and 10 000 parts/million (equivalent to 0.1% and 1% w/w). At 1000 parts/million and below the fungus was able to develop and zearalenone synthesis was not affected except where acetic acid was used alone, when higher toxin yields were recorde

ISSN:0022-5142    

DOI:10.1002/jsfa.2740250905

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractA rapid and simple procedure for the separation, identification and quantitative analysis of common fruit sugars and non‐volatile organic acids has been developed. Acids were precipitated as their lead salts from fruit ethanolic extracts and the sugars in the remaining supernatant and washings were partitioned into aqueous methanol. These preparations with internal standards were dried and converted to their trimethylsilyl derivatives for analysis by gas‐liquid chromatography. In model studies, conditions which permitted full recovery of sugars from the lead salts of acids, while minimising the loss of acids, were investigated. For fruit acids reported present in measurable amounts (10 mg/100 g of fruit), replicate analysis of aliquots from the same extract was within ±5% for malonic, phosphoric, succinic, malic, citric, ascorbic and galacturonic acids and within ±12% for quinic acid. The use of the method, its advantages and limitations, in determining individual and total sugars and acids is illustrated on some New Zealand grown fruit (New Zealand grapefruit, mountain pawpaw, tangelo, apricot). Total sugars and total acids determined by this procedure gave comparable results with those obtained by using standard A.O.A.C. proce

ISSN:0022-5142    

DOI:10.1002/jsfa.2740250906

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractLipids extracted with water‐saturatedn‐butanol from flour and flour‐water doughs were examined to determine the extent of oxidations and other changes which occurred in mixing and resting dough. Extracted lipids were converted to fatty acid methyl esters (FAME) and quantified by gas‐liquid chromatography (g.l.c.) using heptadecanoic acid (17 : 0) as internal standard. The original flour or dough and the corresponding solvent‐extracted residues were acid hydrolysed, and the hydrolysate lipids converted to FAME for g.l.c. determination of the total lipid and residual unextracted lipid contents. The total flour or dough lipids equalled the extracted lipids + unextracted lipids, except where there were unavoidable autoxidative losses of linoleate (18 : 2) and linolenate (18 : 3).The unextracted flour lipids (13% of total lipids) were not oxidised during dough mixing. There were no changes in any of the extracted lipid classes other than free fatty acids (FFA) and monoglycerides (MG) which showed losses of 18 : 2 and 18 : 3 after aerobic dough mixing. Losses of FFA and MG are attributed to lipoxygenase activity during dough mixing and the period immediately after. The small amount of 18 : 2 in the “free” petroleum ether‐extracted FFA appeared to be unaffected by lipoxygenase.Recoveries of FFA other than 18 : 2 or 18 : 3 were constant, indicating no lipolysis of glycerolipids and no general oxidation or degradation of FFA. Experiments with [U‐14C]palmitic acid confirmed that there was no oxidation, degradation or re‐esterification of FFA.Much of the non‐polar lipids (steryl ester, triglyceride, diglyceride, FFA, MG) and almost all of the polar lipids were bound on dough mixing. Binding was non‐selective with regard to fatty acid composition. Triglyceride was the only lipid class bound to a greater extent in anaerobic dough than in aerobic dough. Some selectivity of binding between lipi

ISSN:0022-5142    

DOI:10.1002/jsfa.2740250907

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe resin and essential oil contents of hops (Humulus lupulusL., var., Pride of Ringwood) together with cone weight were studied over a period of 4 weeks prior to and 1 week subsequent to the estimated time of normal harvesting. The petrol ether‐ and methanol‐soluble fractions of the hop cone showed no significant change during this period. Essential oil and α‐acid contents increased gradually over the sampling period, whilst cone weight increased up to the estimated time of normal harvesting and decreased thereafter. The results indicate that, with the particular variety studied, harvesting could have been conducted over a 4‐week period without significantly affecting α‐acid or hop cone yield. The advantages of harvesting high‐yielding hops over a 4‐week period rather than planting an earlier maturing but lower‐yielding vari

ISSN:0022-5142    

DOI:10.1002/jsfa.2740250908

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractResponses of maize (Zea maysL.) to several rates of N as ammonium nitrate and urea were determined on Mountview silt loam in greenhouse pots, with other nutrients applied uniformly. Harvests of tip halves of leaves, remaining tops and roots were made at 28, 36 and 47 days after planting. Yields of dry matter and uptake of N, P, K, Ca, Mg, Mn and Zn by the maize tops increased markedly with amount of applied N and length of growth period. Concentrations of N, P, Ca, Mg, Mn and Zn both in leaves and entire tops also increased at 28 and 36 days with rate of applied N, but K concentrations decreased. Dilution of other nutrients with response to N was the dominant trend at 47 days. Concentrations of all nutrients in the roots decreased with continuing growth and most nutrients were diluted with increasing response to higher N rates as a result of greater translocation to the tops.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740250909

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe effects were studied of the processes of degumming, neutralisation, bleaching and deodorisation on the content and composition of the various fractions of unsaponifiables in soya bean oil. The effect of each of the various technological steps on the decrement of the investigated unsaponifiables in the processed oils was different. When compared with the crude oil, the refined soya bean oil contained less tocopherols (by 31 to 47%), sterols (by 25 to 32%) and squalene (by 15 to 37%). No significant differences were observed in the compositions of the sterol and tocopherol fractions of the crude and refined soya bean oils.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740250910

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractIn connection with the production of leaf protein in quantity, the effects of fertilisers and frequency of cutting on the yields of dry matter and extractable protein were studied with hybrid Napier grass (gajraj) during 1969 to 1973 using a laboratory‐scale extraction unit. The protein N extracted ranged from 21 to 38%: extractability was not affected greatly by fertiliser treatment, but there were seasonal and yearly variations. With liberal dressings of fertilisers, the crop can be expected to yield 40 metric tons of dry matter, 6000 kg of crude protein and about 2000 kg of extractable protein from a hectare per year in India. The fibrous residue, even after two extractions, contains 6 to 12% of crude protein and could still be used as cattle fee

ISSN:0022-5142    

DOI:10.1002/jsfa.2740250911

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY