Hydrogenolytic depolymerization of procyanidin polymers from hi-tannin sorghum bran.
Depolymerization of procyanidin polymers into oligomers enhances their bioavailability and bioactivity because oligomers are bioavailable. Hydrogenolysis was applied in this study to depolymerize hi-tannin sorghum bran procyanidin polymers into oligomers. The yield and composition of oligomers under different hydrogenolysis conditions was investigated. Results showed that raising temperature from 50 to 100 °C significantly increased total yield of oligomers. Higher temperatures (150 and 200 °C) produced monomers with lower yield. The highest yield of oligomers (38.8%) was obtained using 1 MPa hydrogen whereas 3 MPa hydrogen in reaction vessel decreased yield. Total yield of oligomers reached the highest at 1-3 h and then decreased with prolonged reaction time. Yield increased with palladium-on-carbon (Pd/C, a catalyst) amount from 0.5 to 3 mg and plateaued with Pd/C amount from 3 to 10 mg. The maximum yield of produced oligomers was achieved under 100 °C, 1 MPa hydrogen pressure, 1-3 h, and 3-10 mg Pd/C.
['Li|Zheng|Z|', 'Zeng|Jijiao|J|', 'Tong|Zhaohui|Z|', 'Qi|Yajing|Y|', 'Gu|Liwei|L|']
D044946:Biflavonoids D001704:Biopolymers D002392:Catechin D002851:Chromatography, High Pressure Liquid D004043:Dietary Fiber D006358:Hot Temperature D058105:Polymerization D044945:Proanthocyanidins D045868:Sorghum D013634:Tannins
Depolymerization Procyanidins Hydrogenolysis Catechin Epicatechin