Submitted to: International Food Technology
Publication Type: Abstract Only
Publication Acceptance Date: 3/27/2007
Publication Date: 7/28/2007
Citation: Gu, L., House, S.E., Prior, R.L., Rooney, L. 2007. Contents of procyanidins in sorghum and the bioavailability in weaning pigs [abstract]. International Food Technology, July 28-August 1, 2007, Chicago, Illinois. 2007 IFT Annual Meeting Book of Abstracts, ISSN: 1082-1236. Program No. 227-02.
Technical Abstract: Sorghum is the fifth most important cereal crop in the world. The United States is the largest producer and exporter of sorghum, accounting for 20% of world production. Procyanidins are a unique and important constituent in tannin sorghum. The objective of the present study was to investigate the bioavailability of sorghum procyanidins. Sorghums of different varieties were analyzed for procyanidins using normal phase HPLC. Serum and urine were collected and analyzed for catechins on LC/MS/MS. Chromic oxide was analyzed on ICP-MS. Data were analyzed using t-test or paired t-test. A Sumac brown variety contained 44 mg/g and 19 mg/g of procyanidins in the bran and grain, respectively. Over 80% of the procyanidins in sorghum were polymers with more than 10 constituent catechin or epicatechin units. The red and white sorghums were devoid of procyanidins. Hi-tannin sorghum bran was mixed with 5% chromic oxide and fed to piglets (7-24 kg) via gastric gavage. Forty-seven percent and 89% of ingested procyanidins and chromic oxide were recovered in the digesta 4 hours post dose. Over 60% of the monomers, dimers, and trimers were dispersed in the liquid portion of digesta, but most of the higher oligomers were bound onto the particulate portion of the digesta. Catechin and 3-O-methylcatechin were absent in pig serum before sorghum feeding. Their contents increased and peaked at 18 nM and 43 nM one hour after a single dose of sumac sorghum bran/grain mixture. Extrusion was found to lower the procyanidin content in sorghum. After feeding same amount of extruded sorghum mixture, serum concentrations of catechin and 3-O-methylcatechin reached 66 nM and 110 nM, respectively. Cumulative excretion of catechins in 24-h urine was also significantly higher in pigs fed the extruded sorghum mixture. In summary, procyanidins were absorbed as catechins in the weaning pigs and the extrusion process improved bioavailability.