Poster Topical Area: Dietary Bioactive Components

Location: Hall D

Poster Board Number: 314

P08-056 - Grain Sorghum Bran Polyphenols and Gut Microbial Fermentation Patterns

Monday, Jun 11
8:00 AM – 3:00 PM

Objectives
The objectives were to measure the phenolic contents of black and sumac grain sorghum bran and their antioxidant capabilities and to determine the fermentation patterns of sorghum bran phenolic extracts in normal weight (NW) overweight/obese (O/O) individuals.

Methods
Black and sumac sorghum bran samples were analyzed for total phenolics (TP), total proanthocyanidins (TPC), total anthocyanins (ACY), and radical scavenging capabilities using Folin-Ciocalteu's assay, 4-Dimethylaminocinnamaldehyde (DMAC) assay, HPLC, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. Phenolic extracts were purified and dried to powder form. Fresh fecal samples were collected from 12 NW and 12 O/O individuals, and incubated for 24 hours with anaerobic fermentation media and six treatments: no treatment (blank), 75 mg fructooligosaccharides (FOS), 47 mg black sorghum bran extract (B), 26 mg sumac sorghum bran extract (S), FOS + B, and FOS + S. Aliquots were collected at 0, 6, 12, 18, and 24 hours for analysis. Short chains fatty acid production was determined by quantifying butyrate (BA), propionate (PA), and acetate (AA) through gas chromatography. All statistical analyses were performed using two-way ANOVA with Tukey's test post hoc. Significance level was determined as P<0.05.

Results
Sumac bran had significantly higher TP (42.2±1.6 mg/g) and TPC (7.8±0.5) than black bran (28.0±1.6 mg/g TP and 0.4±0.1 TPC), while black bran had significantly higher levels of ACY (1.2 ± 0.003 mg/g) than sumac bran (0.14 ± 0.01) (P<0.01). Black bran polyphenols showed significantly greater scavenging abilities than sumac bran (P<0.01). Analysis of 12 subject's data showed that FOS + S trended higher than FOS in total SCFA, BA, PA, and AA production for the first 12 hours in NW group, and in BA for the first 18 hours in O/O group.

Conclusions
Black and sumac sorghum bran are excellent sources of polyphenols and show considerable radical scavenging capabilities in vitro. Gut microbial fermentation patterns may vary in response to FOS combined with varying classes of polyphenols from sorghum bran.








Funding Source: Arkansas Grain Sorghum Promotion Board

CoAuthors: Danielle Ashley – University of Arkansas; Cindi Brownmiller – University of Arkansas; Sun-Ok Lee – University of Arkansas

Wing Shun Lam

University of Arkansas
Fayetteville, Arkansas