Determination of Carotene in Forage: A Modification of the Guilbert Method

Peterson, W. J.; Hughes, J. S.; Freeman, H. F.

doi:10.1021/ac50106a007

Cited by 60 publications

(21 citation statements)

References 4 publications

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“…The limited information on the vitamin A equivalents of feedstuffs reported in the Beef NRC (2000) and Dairy NRC (2001) were obtained by older methods, which can overestimate or underestimate pro-vitamin A content. In some of the early methods, carotenes were separated from xanthophylls first with saponification and then by solvent-solvent partitioning (Guilbert, 1934; Peterson et al, 1937). Later methods separated carotenes from xanthophylls by using open column chromatography (Martin et al, 1968).…”

Section: Resultsmentioning

confidence: 99%

Concentration of pro-vitamin A carotenoids in common beef cattle feedstuffs1

Pickworth

Loerch

Kopec

et al. 2012

Journal of Animal Science

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Quantification of the pro-vitamin A carotenoids in feedstuffs commonly fed to livestock has been ignored for many years. A greater dietary concentration of vitamin A has the potential to limit adipogenesis in cattle, thereby reducing carcass quality and value. A survey of 18 feedstuffs commonly fed to beef cattle was conducted for determination of vitamin A equivalents based on analysis of carotenoids. The pro-vitamin A carotenoids of interest were β-carotene, α-carotene, and β-cryptoxanthin. Collaborators in 5 states collected the feedstuffs and then shipped them to The Ohio State University for compilation and analysis. Carotenoids were extracted from the feedstuffs and then quantified using HPLC with photodiode array analysis. Fresh fescue pasture contained approximately 10 times more vitamin A equivalents than hay and 5 times more than corn silage (39,865, 2,750, and 6,900 IU of vitamin A/kg of DM for fresh pasture, hay, and corn silage, respectively). Beta-cryptoxanthin and α-carotene could not be detected in any forage samples. Hay and corn silage vitamin A equivalents decreased over extended periods of time from harvest to sample collection. Corn was the only feedstuff to have appreciable concentrations of all 3 pro-vitamin A carotenoids quantified. Corn processing had a minimal impact on the vitamin A equivalents. High-moisture corn contained 54% more vitamin A equivalents than whole shelled corn (378 and 174 IU of vitamin A/kg of DM, respectively). Pro-vitamin A carotenoids were more concentrated in corn coproducts than in whole shelled corn. The drying of distillers grains with solubles may significantly degrade β-carotene (800 and 480 IU/kg of DM for wet and dry distillers grains, respectively). Soybean-based feedstuffs contain a small concentration of pro-vitamin A carotenoids, at 55 and 45 IU of vitamin A/kg of DM for soybean meal and soybean hulls, respectively. Overall, there was considerable variation in the pro-vitamin A content of feedstuffs based on location and storage conditions. An extensive analysis of feedstuffs would need to be conducted for an accurate estimation of the vitamin A content of feedlot cattle diets.

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Section: Resultsmentioning

confidence: 99%

Concentration of pro-vitamin A carotenoids in common beef cattle feedstuffs1

Pickworth

Loerch

Kopec

et al. 2012

Journal of Animal Science

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“…The concentration of p-carotene was measured a t 440 mg in an Erelyn Colorimeter after extraction, purification, adsorption, and elution of the pigment with 5% acetone in petroleum ether on a celite-magnesium oxide column. The method is essentially that of Guilbert (6) as modified by Peterson et al (11). All carotene ralues cited are the average of two determinations and are expressed on the basis of 1 0 % moisture eontent.…”

Section: Methodsmentioning

confidence: 99%

Nutritive Value of Central American Corns.

Bressani

Campos

Squibb

et al. 1953

Journal of Food Science

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“…Seaber (1940) grinds the material with silver sand, extracts it with a mixture of acetone and petroleum ether, and then hydrolyses the extract with methyl alcoholic potash. More recently, Kon & Thompson (1940) have compared the methods of Ferguson & Bishop, as representative of the methods in vogue in England, with the Peterson et al (1937) modification of Guilbert's method considered to be representative of the American methods. The English method has been observed to give higher results, which are found statistically to be significant.…”

Section: The Technique Of Carotene Estimationmentioning

confidence: 99%