摘要:

Gum tragacanth (GT), affirmed as GRAS within the USA since 1961, was evaluated as ‘ADI not specified’ by JECFA in 1985. Within the EEC, GT has been permitted temporarily as a food additive (E413), without an ADI, since 1974; a decision regarding its permanent status must be reached before the end of 1988.† This review collates the dietary, toxicological, immunological and chemical data available and presents the pre‐requisite data concerning the ‘Need’ and low levels of utilization of GT.

ISSN:0265-203X    

DOI:10.1080/02652038909373733

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Male Wistar rats were fed a defined formula diet free from non‐starch polysaccharides and either containing no additive or supplemented with gum arabic or cellulose or starch. Food and faeces were analysed by bomb calorimetry both to assess the effect of these substances on the apparent digestibility of dietary gross energy and to ascribe digestible energy values to the supplements. The former was not affected by starch and was decreased more by cellulose than by gum arabic. The energy values obtained were 17.4 ± 0.4 kJ/g starch, 1.7 ± 0.6 kJ/g cellulose and 14.7 ± 0.5 kJ/g gum arabic. The latter is consistent with the high apparent digestibility of gum arabicin vivoand casts doubt on the validity of growth assay procedures that suggest a near‐zero energy value for gum arabic.

ISSN:0265-203X    

DOI:10.1080/02652038909373734

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

An alkaline hydrolysis method is described for the release of boundN‐nitrosoproline (NPRO) from cured meats that is more efficient than an enzymic method reported previously. The bound NPRO contents of 17 cured meats analysed ranged between non‐detectable and 578μg/kg (mean 143μg/kg). Administration of defatted meat powder, prepared from such meats, to rats led to increased excretion of free NPRO in the urine that could not be inhibited by concurrent administration of ascorbic acid. The significance of these findings with regard to the use of such cured meats inin vivo N‐nitrosation studies is discussed.

ISSN:0265-203X    

DOI:10.1080/02652038909373735

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A survey of Polish malt and beer for volatileN‐nitrosamines has been conducted.N‐Nitrosodimethylamine was found in malt at levels ranging from 0.2 to 3.6μg/kg (average 1.5μg/kg) and in beer at levels up to 0.3μg/kg (average 0.2μg/kg). The use of indirect malt dryers is credited with the low levels of N‐nitrosamines found.

ISSN:0265-203X    

DOI:10.1080/02652038909373736

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A simple and sensitive procedure is described for the analysis of aflatoxins B1B2, G1and G2in cereal and animal feedstuff samples. Aflatoxins are extracted with dichloromethane:water (10:1). Gel permeation chromatography (GPC) using a column packed with Bio‐beads S‐X3 and dichloromethane:hexane (3:1) as the eluent is used for clean‐up of extracts prior to separation and quantification of aflatoxins by HPLC. The eluent fraction containing the aflatoxins is concentrated by evaporation under reduced pressure and the aflatoxins separated by reverse phase HPLC on an ODS column. Quantitative results have been obtained at levels down to 1μg/kg, and average recoveries from samples of wheat, maize and compound feed spiked at levels of 10 and 40μg/kg were greater than 80%, 70% and 65% respectively.

ISSN:0265-203X    

DOI:10.1080/02652038909373737

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Twenty samples of maize collected from healthy growing crops and at harvest time and during storage were screened for fourFusariumtoxins (deoxynivalenol, diacetoxyscirpenol, T‐2 toxin and zearalenone) by gas chromatography‐mass spectrometry and thin‐layer chromatography. Seventeen samples (85%) contained one or more of these toxins. Zearalenone was present in 15 samples at levels ranging between 0.1 and 16 ppm. Deoxynivalenol, diacetoxyscirpenol and T‐2 toxin were found in 11, 6 and 13 samples respectively, all at levels below 1 ppm. This work documents the first reported natural occurrence ofFusariumtoxins in New Zealand maize, and it is concluded that all four of the mycotoxins studied are prevalent in apparently healthy standing crops as well as in stored maize.

ISSN:0265-203X    

DOI:10.1080/02652038909373738

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Procedures for the determination of medroxyprogesterone acetate (MPA) in adipose tissue collected at time of slaughter allowing the control of MPA application to veal calves are described. Screening radioimmunoassays after sample clean‐up were sufficient for a first survey of MPA treatments in livestock herds. Validation of all positive samples was performed by two‐dimensional (silica gel diol phase and RP‐18 phase) HPLC/RIA immunograms. Megestrol acetate and melengestrol acetate with cross‐reactivities of 31% and 0.3% respectively were clearly separated by the RP HPLC. With an absolute detection limit of 4 pg MPA/tube (90% relative binding) negative control samples did not exceed 6 pg/tube, equivalent to 6 pg/g fat in the validating method. Seventeen days after intramuscular (i.m.) injection of 24 mg MPA only 32 pg MPA/g fat were found, while i.m. injection of 60 mg MPA and a waiting period of 19 days resulted in 2700 pg MPA/g fat. After feeding two calves 20μg MPA per head daily for 1 week followed by 200μg MPA per head daily for 2 weeks 359 and 468 pg MPA/g fat were measured. In plasma as well as in adipose tissue more than 80% of the whole immunoreactive material was MPA itself, without indications for the presence of cross‐reacting MPA metabolites as confirmed by HPLC/RIA immunograms. Based on day of slaughter ratios of accumulation of MPA from plasma into fat of MPA‐fed veal calves were 52 and 72 respectively. In urine MPA was only detectable a few days after injection; as compared to a plasma concentration of 950 pg MPA/ml the amount in urine was only 37 pg MPA/ml and also 325 pg unidentified MPA‐equivalents/ml.

ISSN:0265-203X    

DOI:10.1080/02652038909373739

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

After dosing laying hens orally with tetracycline (TC) through either drinking water (0.25 and 0.5 g/1 for 5 days) or feed (300 and 600 ppm for 7 days), and chlortetracycline (CTC) through feed (600 ppm) residues were determined by an agar plate diffusion technique in cylinders withBacillus cereusas test‐organism, separately for albumen and for yolk. The sensitivity threshold was 0.07μg/g in albumen and 0.15μg/g in yolk for TC and 0.01μg/g in albumen and 0.06μg/g in yolk for CTC. Drug excretion via egg was 3‐fold higher for TC than for CTC. The drug was excreted preferentially into the yolk (about 75% of the total amount) and the elimination period lasted between 6 and 11 days for TC and 9 days for CTC, after treatment. Tetracycline use in laying hens is discussed, taking into consideration the proposals presented by the joint FAO/WHO Expert Committee on Food Additives.

ISSN:0265-203X    

DOI:10.1080/02652038909373740

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The elimination into bovine milk ofß‐lactam antibiotic residues (procaine penicillin G, cloxacillin, ampicillin, oxacillin, cephalexin) following intramammary administration of 10 preparations marketed in France was studied. The quantitative analysis of residues was carried out by a microbiological agar diffusion method usingBacillus stearothermophilus.Sensitivity ranged from 0.001 I.U./ml for procaine penicillin G and 0.001μg/ml for ampicillin to 0.02μg/ml for cephalexin. The mean periods of elimination on which withholding times are based were between four and seven milkings according to the drugs administered.

ISSN:0265-203X    

DOI:10.1080/02652038909373741

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A competitive enzyme immunoassay (EIA) for the detection and quantitation of zeranol has been developed. The assay involves the use of excess second antibody adsorbed onto the walls of a microtitration plate well. Enzyme‐labelled zeranol, prepared by theN‐succinimidyl ester method, and standard or samples are added to the wells followed by zeranol‐specific monoclonal antibody. The working range of the EIA is between 10 and 800 pg/well with a limit of detection of 10 pg/well (CV ≤ 10%). Comparison of radioimmunoassy with the EIA gave a correlation coefficient of 0.99. This EIA offers an alternative to the well‐documented radioimmunoassay with regard to sensitivity, specificity and precision.

ISSN:0265-203X    

DOI:10.1080/02652038909373742

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor