RESUMO
1. The performance of White Leghorn laying hens on diets providing pearl millet (Pennisetum typhoides) at 300 and 600 g/kg to replace maize, part per part, or "maize mix" isoenergetically and isonitrogenously in the first experiment and at 600 g/kg diet to replace maize in toto, part per part, in the second experiment were examined. In the first experiment, 3 groups of 12 laying hens were placed on each of the 5 dietary treatments for 3 x 28 d, whereas in the second experiment, each of the two diets was offered to 10 groups of 15 laying hens for 6 x 28 d. 2. Inclusion of pearl millet in the diet at the expense of maize, part per part, did not significantly influence hen-day egg production, feed intake, feed efficiency and body weight in either experiment. Incorporation of pearl millet isoenergetically at the expense of "maize mix" at any level, i.e. 300 g or 600 g/kg (Experiment 1), also did not influence hen-day egg production but at the end of periods 2 and 3 did result in decreased feed intakes with consequent improvements in feed efficiency. 3. Egg weight in general showed a tendency to improve with diets providing pearl millet at 600 g/kg. 4. Profits from egg sales over feed cost were directly proportional to the inclusion of pearl millet in the diet either at the expense of maize, part per part, or "maize mix" isoenergetically.
Assuntos
Ração Animal , Galinhas/fisiologia , Grão Comestível , Ovos/normas , Oviposição , Ração Animal/análise , Animais , Peso Corporal , Cálcio/análise , Galinhas/crescimento & desenvolvimento , Ingestão de Alimentos , Grão Comestível/análise , Feminino , Fósforo/análise , Proteínas/análise , Zea mays/análiseRESUMO
Weanling male albino rats (45-60 g) were used to study the effects of varying sprouting periods on the nutritional quality of normal yellow corn. The yellow corn (YC) was sprouted for 24, 36 and 48 h (SYC24, SYC36, SYC48). The unsprouted corn (UYC) and casein (CA 100) served as negative and positive controls. African yam bean (AYB) was sprouted for 48 h and blended with the corn in a 70:30 (protein basis). Sprouting for 48 h caused decreases in most of the parameters tested except for the liver weight and N and calcium (CA) balance. The 24 h sprouting produced increases except for weight gain and PER, liver weight and N, phosphorus (P) and Ca intake and retention. The UYC produced increases higher than those of the test groups except for digested N, NPU, liver moisture, Fe intake and absorption. Casein significantly increased all parameters than for the test groups except for digested and retained N, P and Fe intakes. The advantages of sprouting for 24 or 36 h out-weighed those of 48 h.
Assuntos
Zea mays/normas , Animais , Peso Corporal , Ingestão de Alimentos , Fezes/análise , Alimentos Fortificados , Masculino , Valor Nutritivo , Proteínas/análise , Proteínas/metabolismo , Ratos , Fatores de Tempo , Aumento de Peso , Zea mays/análiseRESUMO
Conflicting results exist in the literature on the conversion of eicosapentaenoic acid (EPA) to trienoic prostaglandins and its influence on the formation of dienoic prostaglandins from arachidonic acid (AA). Tissues from animals fed fish oils produce little, if any, trienoic prostaglandins and reduced amounts of dienoic ones. Excretion of the major urinary metabolite of PGI2 is not reduced in humans taking fish oil, however, and substantial amounts of one derived from PGI3 have been found, by GC/MS. We have addressed this possible species difference by examining the urine of rats fed fish oil for 2.3 dinor-6-keto-PGF1 alpha and its delta 17 analog, formed from PGI2 and PGI3, respectively, and compared them with rats fed corn oil. Fatty acid differences in erythrocyte and aortic lipids were also determined. Rats fed fish oil do make PGI3 from eicosapentaenoic acid in vivo and do not suppress their production of PGI2, despite having more EPA than AA in aortic lipids.
Assuntos
Dieta , Epoprostenol/biossíntese , Óleos de Peixe/farmacologia , 6-Cetoprostaglandina F1 alfa/análogos & derivados , 6-Cetoprostaglandina F1 alfa/metabolismo , 6-Cetoprostaglandina F1 alfa/urina , Animais , Ácido Eicosapentaenoico/sangue , Ácido Eicosapentaenoico/metabolismo , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Ácidos Graxos/sangue , Ácidos Graxos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Óleos de Plantas/farmacologia , Ratos , Ratos Endogâmicos , Zea mays/análiseRESUMO
To combat vitamin deficiencies in populations whose dietary staple is maize, the fortification of maize meal with riboflavin and nicotinamide has been recommended. Subsequently, part of the milling industry has voluntarily fortified the meal with these two vitamins. In the present study, the concentrations of added riboflavin and nicotinamide were determined by high-performance liquid chromatography in 43 samples from a wide area. With the exception of three samples, concentrations of these vitamins were below the recommended level, and most were less than half this amount. Fortification programmes require regular monitoring by an independent authority.
Assuntos
Alimentos Fortificados/normas , Niacinamida/análise , Riboflavina/análise , Zea mays/análise , Deficiência de Vitaminas/prevenção & controle , Humanos , África do SulRESUMO
Two commercially available bone meal products (grades 0-12-0 and 6-12-0) were examined. Samples were prepared according to AOAC method 2.007, and total and available phosphorus contents were determined. Portions of these preparations were reground to pass through successively smaller sieves, and subsequent analyses indicated the availability of phosphorus to be directly proportional to fineness of grind. A quantity of the citrate-insoluble fraction of the bone meal was obtained by following AOAC extraction procedures. Agronomic studies were conducted that compared this insoluble fraction with the original bone meal material and with reagent grade Ca(H2PO4)2.H2O. The data indicated poor correlation between the analytically defined and agronomically determined availability of phosphorus.
Assuntos
Minerais/análise , Fósforo/análise , Zea mays/análise , Produtos Biológicos , Tamanho da PartículaRESUMO
The selenium content of hard and soft wheat, barley, oats, rye and corn grown in approximately 100 different locations of Greece has been determined fluorimetrically. The mean values +/- SD for these cereal types were 0.29 +/- 0.19, 0.21 +/- 0.12, 0.16 +/- 0.10, 0.14 +/- 0.10, 0.19 +/- 0.10 and 0.12 +/- 0.08 ppm Se (dry weight basis), respectively. Based on data for selenium in corn from 96 different locations, a geobotanic map of Greece for the selenium in soil available for uptake by plants was prepared. Macedonia, West Epirus, south-east Thessaly, north-east Sterea Hellas and the Aegean Islands produce corn deficient or low in selenium, but only sporadic selenium-deficiency diseases in animals have been observed in many of these areas, probably because the farm animals are given mixed food or they are free to graze. No areas with toxic levels of selenium in soil were found.
Assuntos
Grão Comestível/análise , Selênio/análise , Geografia , Grécia , Hordeum/análise , Secale/análise , Solo/análise , Zea mays/análiseRESUMO
Aflatoxins, metabolic products of the molds Aspergillus flavus and A. parasiticus, may occur in foods and feeds. These toxins cannot be entirely avoided or eliminated from foods or feeds by current agronomic and manufacturing processes and are considered unavoidable contaminants. To limit aflatoxin exposure, the U.S. Food and Drug Administration (FDA) has set action levels for these toxins in foods and feeds involved in interstate commerce. FDA continually monitors food and feed industries through compliance programs. This report summarizes data generated from compliance programs on aflatoxins for the fiscal year 1986. Commodities sampled included peanuts and peanut products, corn and corn products, tree nuts, cottonseed, milk, spices, manufactured products, and miscellaneous foods and feeds. Correlations were highest between aflatoxin contamination and geographical areas for corn/corn products and cottonseed/cottonseed meal. Higher incidences of aflatoxin contamination in corn and corn products designated for human consumption were observed in samples collected in the southeastern states (32 and 28%, respectively). A higher incidence of contamination was observed in corn designated for animal feed from Arkansas-Texas (74%) than from the southeastern states (47%). Only 3% of feed corn from corn belt states contained detectable aflatoxins. All aflatoxin-contaminated cottonseed was collected in the Arizona-California area; 80% of cottonseed meal analyzed from this area also contained detectable levels of aflatoxins.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Aflatoxinas/análise , Ração Animal/análise , Contaminação de Alimentos/análise , Arachis/análise , Condimentos/análise , Óleo de Sementes de Algodão/análise , Nozes/análise , Sementes/análise , Estados Unidos , Zea mays/análiseRESUMO
Turnip root, parsnip root, potato tuber, and corn kernels have been used as adulterants in the preparation of horseradish sauce and horseradish powder. The diagnostic histological features of horseradish root and its known adulterants are described and illustrated as viewed through a polarizing microscope with cross polars and a first order red plate. A procedure which can be used to detect any of the known adulterants in horseradish is described. The adaptation of a previously reported semiquantitative method is also discussed.
Assuntos
Condimentos/análise , Contaminação de Alimentos , Verduras/análise , Microscopia de Polarização , Solanum tuberosum/análise , Amido/análise , Zea mays/análiseRESUMO
An indirect method for the determination of trace bound selenomethionine (SeMet) has been developed. SeMet reacts with cyanogen bromide (CNBr) quantitatively in the presence of SnCl2 to form CH3SeCN, and after extraction with CHCl3 is acid-digested to form Se(IV). Selenium(IV) reacts with 4-nitro-o-phenylenediamine reagent to form 5-NO2-piazselenol which is then determined by gas chromatography equipped with electron capture detector. The sensitivity of this method (CNBr-piazselenol-GC method) is 6 ng SeMet/g of sample. Trace-bound SeMet in plants and some biological materials has been successfully determined by this method and its content has been compared with the total selenium in the sample.
Assuntos
Selênio/análise , Selenometionina/análise , Oligoelementos/análise , Animais , China , Cromatografia Gasosa , Alho/análise , Rim/análise , Oryza/análise , Plantas Medicinais/análise , Selênio/sangue , Selenometionina/sangue , Selenometionina/urina , Suínos , Triticum/análise , Zea mays/análiseRESUMO
A liquid chromatographic method using on-line sample cleanup, reverse flow analytical column loading, gradient elution, and postcolumn derivatization with iodine permits direct, rapid determination of aflatoxins B1, B2, G1, and G2, as well as ochratoxin A and zearalenone. Limits of quantitation are 5 ppb for the aflatoxins and ochratoxin A and 30 ppb for zearalenone. This procedure performs well as a multimycotoxin screen for cereal grains and oilseeds, with more limited success in complete animal feeds.
Assuntos
Aflatoxinas/análise , Ração Animal/análise , Óleo de Sementes de Algodão/análise , Grão Comestível/análise , Ocratoxinas/análise , Resorcinóis/análise , Zearalenona/análise , Arachis/análise , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Zea mays/análiseRESUMO
Using high-resolution two-dimensional polyacrylamide gel electrophoresis we studied the polymorphism of protein amounts in some genotypes of maize and pea. This type of variability seems to be rather common and insensitive to environmental conditions, as attested by the comparison of the patterns of two maize lines harvested in two different years. A large-scale experiment involving 5 lines, 7 of their hybrids, and 6 organs (or physiological stages) of maize allowed us to examine numerous polypeptides regarding their genetic variability, their amount differences between organs and the inheritance of their abundance. Genetic and organ variations are not independent: polypeptides whose amount varies from one organ to another are, for the most part, genetically variable (59%), while the stable polypeptides are not often genetically variable (18%). We found a striking organ specificity for (i) the extent of quantitative variability (from 2.3-15.4% of the polypeptides), (ii) the occurrence and the type of variation for a given polypeptide (an intensity difference seen in an organ can disappear or even be reversed in another one), (iii) the kind of inheritance (additive/non-additive): combining the 6 organs and the 7 hybrids we found 101 cases of non-additivity (4% of the total) which concern as many as 72 different spots, that is to say that in most cases a polypeptide displaying nonadditivity in an organ seems to display additivity in the other ones. Moreover, for most of the polypeptides with nonadditive inheritance the hybrid spot presents an intensity similar to that of the most intense parental spot.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Fabaceae/genética , Variação Genética , Proteínas de Plantas/análise , Plantas Medicinais , Zea mays/genética , Eletroforese em Gel Bidimensional/métodos , Eletroforese em Gel de Poliacrilamida , Fabaceae/análise , Genótipo , Fenótipo , Proteínas de Plantas/genética , Polimorfismo Genético , Zea mays/análiseRESUMO
A new and simple procedure has been developed that allows the direct transesterification of lipids, using aluminium chloride as a catalyst and methanol as the esterifying alcohol. The concentration of the salt and reaction conditions have been investigated for the different lipid classes. Comparative studies, performed with boron trifluoride-methanol, indicate that the same values are obtained when using either reagent. In addition, the method has been adapted for transesterification in the presence of silica gel and other adsorbents, thus allowing the preparation of fatty acid methyl or ethyl esters directly from samples previously fractionated by thin-layer chromatography. This new reagent is very stable and easy to handle, the fatty acids being generated in the same tube without further purification steps.
Assuntos
Compostos de Alumínio , Lipídeos/análise , Alumínio , Cloreto de Alumínio , Animais , Bovinos , Cloretos , Cromatografia Gasosa , Cromatografia em Camada Fina , Grão Comestível/análise , Eritrócitos/análise , Ésteres/análise , Ácidos Graxos/análise , Ácidos Graxos/sangue , Ácidos Graxos/urina , Óleos de Peixe/análise , Humanos , Indicadores e Reagentes , Metanol , Leite/análise , Óleos de Plantas/análise , Zea mays/análiseRESUMO
Testou-se o efeito de extratos proteícos de milho à base de NaC1 5% sobre a produçäo de aflatoxina B, em meio de cultura líquido contendo, 2% de extrato de levedura e 20% de sacarose. Dois métodos de extraçäo foram avaliados a partir do peso seco do micélico do fungo Aspergillus flavus e da quantidade de aflatoxina B produzida. Os extratos proteícos das três variedades testadas estimularam o crescimento micelial do fungo. Obteve-se uma maior concentraçäo proteíca nos extratos previamente tratados com acetona. Contudo, os dois métodos se mostraram igualmente viáveis como instrumento na diferenciaçäo varietal do milho, caracterizando a suscetibilidade de "Pipoca Americana" com altos níveis de aflatoxina produzida. "Centralmex N" e "Centralmex O2" apresentaram uma menor produçäo de aflatoxina que o controle. Os resultados sugerem que a composiçäo proteíca do milho pode apresentar elementos tanto eliciadores como inibidores à produçäo de aflatoxina B
Assuntos
Aspergillus flavus/crescimento & desenvolvimento , Proteínas de Vegetais Comestíveis , Extratos Vegetais/metabolismo , Zea mays/análise , Aflatoxinas/biossíntese , Meios de Cultura , GenótipoRESUMO
A study was carried out in Swaziland to assess the relationship between aflatoxin exposure, hepatitis B infection, and the incidence of liver-cell carcinoma, which is the most commonly occurring malignancy among males in Swaziland. Levels of aflatoxin intake were evaluated in dietary samples from households across the country, and crop samples taken from representative farms. Prevalence of hepatitis B markers was estimated from the serum of blood donors, and liver cancer incidence was recorded for the years 1979-83 through a national system of cancer registration. Across 4 broad geographic regions, there was a more than 5-fold variation in the estimated daily intake of aflatoxin, ranging from 3.1 to 17.5 micrograms. The proportion of HBV-exposed individuals was very high (86% in men), but varied relatively little by geographic region; the prevalence of carriers of the surface antigen was 23% in men, and varied from 21 to 28%. Liver cancer incidence varied over a 5-fold range, and was strongly associated with estimated levels of aflatoxin. In an analysis involving 10 smaller subregions, aflatoxin exposure emerged as a more important determinant of the variation in liver cancer incidence than the prevalence of hepatitis infection. Aflatoxin estimates from crop samples appeared to be a reasonable surrogate for dietary measurements. A comparison with dietary aflatoxin levels measured in an earlier survey in Swaziland suggested that programmes aimed at reducing contamination levels had had some success.
Assuntos
Aflatoxinas/análise , Portador Sadio/epidemiologia , Hepatite B/epidemiologia , Neoplasias Hepáticas/epidemiologia , Aflatoxinas/efeitos adversos , Doadores de Sangue , Portador Sadio/imunologia , Exposição Ambiental , Essuatíni , Fabaceae/análise , Feminino , Hepatite B/imunologia , Anticorpos Anti-Hepatite B/análise , Antígenos de Superfície da Hepatite B/análise , Humanos , Neoplasias Hepáticas/etiologia , Masculino , Plantas Medicinais , Sistema de Registros , Análise de Regressão , Zea mays/análiseRESUMO
Ninety-five isolates of Aspergillus and Penicillium species from selected dried foods were examined for their ability to produce cyclopiazonic acid (CPA). The isolates were grown in sterile synthetic liquid medium at 28 degrees C for 8 days in the dark. The medium and mold mycelia were then extracted with chloroform. CPA was semiquantitatively determined by thin layer chromatography through visual comparison with standards. The cultures of A. flavus were also examined for their ability to produce aflatoxin. One A. tamarii and all 13 P. urticae isolates produced CPA, whereas only 19 of the 31 (61%) A. flavus isolates produced CPA, and 6 (19%) A. flavus produced aflatoxin. All 13 P. urticae isolates also produced patulin and griseofulvin. CPA-producing A. flavus was found in all food types but not in all samples. CPA-producing P. urticae was found only in dried beans and macaroni.
Assuntos
Aspergillus/metabolismo , Microbiologia de Alimentos , Indóis/metabolismo , Micotoxinas/biossíntese , Penicillium/metabolismo , Aflatoxinas/análise , Cromatografia em Camada Fina , Meios de Cultura , Fabaceae/análise , Farinha/análise , Nozes/análise , Plantas Medicinais , Zea mays/análiseRESUMO
Naturally contaminated corn and cottonseed samples were screened for aflatoxin B1 (AFB1) by a direct competitive enzyme-linked immunosorbent assay (ELISA). Samples were blended 5 min in an extraction solvent of methanol-water-dimethylformamide (70 + 29 + 1) and filtered. Filtrates were assayed by direct competition between AFB1 in the corn and cottonseed samples and AFB1-peroxidase conjugate for binding to specific antibody adsorbed to a solid phase microtiter plate. Standard curves prepared using the extract of AFB1-free corn and cottonseed samples, and extraction solvent only, showed negligible interference by the sample extract in the performance of ELISA. The AFB1 content in corn and dehulled cottonseed samples as determined by ELISA ranged from 7 to 422 micrograms/kg and 7 to 3,258 micrograms/kg, respectively. When ELISA estimates of AFB1 in corn were compared with values obtained by thin layer chromatography (CB method), the correlation coefficient (n = 10) was 0.95. Average interassay and subsample coefficients of variation for ELISA in corn were 21.4 and 22.0%, respectively. When ELISA estimates of AFB1 in cottonseed were compared with values obtained by liquid chromatography (Pons method), the correlation coefficient (n = 15) was 0.96. Using this ELISA, 36 duplicate sample extracts can be screened for AFB1 in less than 2 h.
Assuntos
Aflatoxinas/análise , Contaminação de Alimentos/análise , Aflatoxina B1 , Óleo de Sementes de Algodão/análise , Ensaio de Imunoadsorção Enzimática/métodos , Indicadores e Reagentes , Zea mays/análiseRESUMO
The selenium (Se) level in barley and maize from 43 communes of Qidong county, a high risk area of liver cancer in China, were assayed. An inverse correlation between the Se level and the liver cancer incidence was observed. An inverse correlation was also observed between the blood Se level and liver cancer incidence of the local residents. When selenite solution was sprayed on the crops during their preflowering, the content of Se in barley and maize was increased by 6 fold over the control. It is suggested that the increase of blood Se level of the residents who live in the low-Se areas by this method be useful in the prevention of liver cancer.
Assuntos
Neoplasias Hepáticas/epidemiologia , Selênio/análise , China , Hordeum/análise , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/prevenção & controle , Selênio/sangue , Zea mays/análiseRESUMO
Small charcoal/alumina cleanup columns have been effectively used to remove interfering materials from grain, feed, and food extracts prior to chromatographic determination of trichothecene mycotoxins. A thin layer chromatographic method has been developed that can simultaneously detect part per billion concentrations of deoxynivalenol, fusarenon X, nivalenol, T-2 toxin, HT-2 toxin, neosolaniol, and diacetoxyscirpenol in food and feed samples. Recoveries of 90-99% can be obtained. The use of charcoal/alumina cleanup columns in conjunction with liquid chromatography and gas chromatography of trichothecenes is also discussed.
Assuntos
Ração Animal/análise , Análise de Alimentos , Micotoxinas/análise , Sesquiterpenos/análise , Tricotecenos/análise , Óxido de Alumínio , Carvão Vegetal , Cromatografia em Camada Fina , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Solventes , Espectrofotometria Ultravioleta , Zea mays/análiseRESUMO
To answer the need for simple, economical, rapid methods for mycotoxins, a procedure for screening and quantitation of ochratoxin A was developed. A methanol-aqueous KCl extraction is used, followed by cleanup with clarifying agents and partition into chloroform. Part of the chloroform extract is used for screening and the other part for quantitation by thin layer chromatography (TLC). The screening procedure takes 40 min, using a silica gel/aluminum oxide minicolumn developed for this purpose. The limits of detection are 80 and 10 micrograms/kg, respectively, for minicolumn screening and TLC quantitation. Ammonium sulfate is efficient in cleaning samples of corn and cassava; cupric sulfate is better with peanuts, beans, and rice. Tests were conducted on triplicate spiked samples of yellow corn meal, raw peanuts, dried black beans, polished rice, and cassava flour at different levels (400, 200, 80, 40, and 10 micrograms/kg). Recoveries ranged from 86 to 160% and the coefficients of variation ranged from 0 to 26%.
Assuntos
Microbiologia de Alimentos , Ocratoxinas/análise , Sulfato de Amônio , Arachis/análise , Cromatografia em Camada Fina , Fabaceae/análise , Frutas/análise , Oryza/análise , Plantas Medicinais , Zea mays/análiseRESUMO
In an effort to provide further evidence for the hypothesis that a mycotoxin is involved in the aetiology of Balkan endemic nephropathy and that the latter is associated with the occurrence of urinary system tumours, a survey was made of ochratoxin A contamination of cereal samples from an area of Bulgaria where both endemic nephropathy and urinary system tumours are prevalent and from non-endemic areas. In all, 130 samples of beans, maize and wheat flour were analysed. Ochratoxin A levels were 16.7% (25-27 micrograms/kg) in bean samples from the endemic area and 7.1% (25-50 micrograms/kg) in those from the control areas: in maize samples, the levels were 27.3% (25-35 micrograms/kg) and 9.0% (10-25 micrograms/kg), respectively.