RESUMO
Cyclopropenoid fatty acids (CPFAs), found in cottonseed, have been shown to have detrimental health effects to susceptible livestock. Previous quantitative analytical methods for the determination of CPFAs expressed these acids in terms of their relative abundance with respect to other fatty acids in the oil, necessitating the concurrent analysis of other fatty acids. The proposed analytical method describes the quantitation of three relevant CPFAs for cotton (malvalic acid, sterculic acid, and dihydrosterculic acid) in cottonseed in micrograms per gram fresh weight of sample. The method involves extraction of the oil, saponification, and derivatization of the free fatty acids with 2-bromoacetophenone to give the phenacyl esters. These esters are then separated by dual-column reverse-phase high-performance liquid chromatography and quantitated via external standards. This is the first method to include external calibration standards for CPFAs and, as such, is capable of direct quantification with no further data conversion required. CPFA data generated from the analysis of cottonseed, cottonseed meal, and cottonseed oil produced in the United States in 2002 are presented.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Óleo de Sementes de Algodão/química , Ciclopropanos/análise , Ácidos Graxos Monoinsaturados/análise , Ácidos Graxos/análiseRESUMO
Insect-protected corn hybrids containing event MON 863 protect corn plants against feeding damage from corn rootworm (Diabrotica), a major North American insect pest. Corn event MON 863 contains a gene that expresses an amino acid sequence variant of the wild-type Cry3Bb1 insecticidal protein from Bacillus thuringiensis. The purpose of this study was to compare the composition of corn containing event MON 863 with that of conventional nontransgenic corn. Compositional analyses were conducted to measure proximates, fiber, amino acids, fatty acids, minerals, folic acid, thiamin, riboflavin, vitamin E, antinutrients, and certain secondary metabolites in grain and proximates and fiber content in forage collected from a total of eight field sites in the U.S. and Argentina. Compositional analyses demonstrated that the grain and forage of event MON 863 are comparable in their nutritional content to the control corn hybrid and conventional corn. These comparisons, together with the history of the safe use of corn as a common component of animal feed and human food, support the conclusion that corn event MON 863 is compositionally equivalent to, and as safe and nutritious as, conventional corn hybrids grown commercially today.
Assuntos
Toxinas Bacterianas , Plantas Geneticamente Modificadas/química , Sementes/química , Zea mays/química , Zea mays/genética , Aminoácidos/análise , Animais , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/genética , Besouros , Endotoxinas/genética , Ácidos Graxos/análise , Expressão Gênica , Proteínas Hemolisinas , Inseticidas , Minerais/análise , Valor Nutritivo , Controle Biológico de VetoresRESUMO
Glyphosate tolerant wheat MON 71800, simply referred to as MON 71800, contains a 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) protein from Agrobacterium sp. strain CP4 (CP4 EPSPS) that has a reduced affinity for glyphosate as compared to the endogenous plant EPSPS enzyme. The purpose of this work was to evaluate the compositional equivalence of MON 71800 to its nontransgenic parent as well as to conventional wheat varieties. The compositional assessment evaluated the levels of proximates, amino acids, fatty acids, minerals, vitamins, secondary metabolites, and antinutrients in wheat forage and grain grown during two field seasons across a total of eight sites in the United States and Canada. These data demonstrated that with respect to these important nutritional components, the forage and grain from MON 71800 were equivalent to those of its nontransgenic parent and commercial wheat varieties. These data, together with the previously established safety of the CP4 EPSPS protein, support the conclusion that glyphosate tolerant wheat MON 71800 is as safe and nutritious as commercial wheat varieties.