|Qiu, Shuang - China Agricultural University|
|Yin, Lijun - China Agricultural University|
Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2017
Publication Date: 3/7/2017
Publication URL: https://handle.nal.usda.gov/10113/5649492
Citation: Qiu, S., Yadav, M.P., Yin, L. 2017. Characterization and functionalities study of hemicellulose and cellulose components isolated from sorghum bran, bagasse and biomass. Food Chemistry. 230:225-233.
Interpretive Summary: Previous studies in our lab have reported a method to produce a potentially useful food additive called Corn Fiber Gum (CFG). In this case, the word “gum” does not mean that this material would be used as a chewing “gum”, but rather as a food ingredient composed of complex carbohydrates that can serve as an emulsifier of oil-in-water. The U.S. beverage industry uses hundreds of tons of high quality emulsifiers each year for stabilizing citrus oil in soft drinks and for preventing the separation of oil and water in salad dressings plus hundreds of other applications. The most commonly used emulsifier, “gum arabic” is an imported gum that is expensive and is often in short supply due to political and environmental issues in the African countries of origin. To solve this problem, we previously extracted and purified a new type of “gum” called “corn fiber gum (CFG)” from an abundant and inexpensive byproduct of corn processing called “corn fiber.” A similar bio-based fiber gum can also be prepared from other agricultural products and byproducts such as bran from grain sorghum, bagasse produced after squeezing the juice out of sweet sorghum and biomass sorghum, which is a type of sorghum that is bred to yield large plants with abundant biomass. In addition to bio-based fiber gum, another valuable carbohydrate component, called cellulose rich fraction may also be obtained from the same sources for other applications. Because the gum from corn fiber was a good emulsifier, we decided to see if that was the case for these new sorghum bio-based fiber gums. In this study we found for the first time that bio-based fiber gums from all three sorghum sources are as good as CFG or even better than it for stabilizing flavor in oil-in-water emulsion system. We also found that the water insoluble cellulose rich fraction isolated from all these sorghum sources have very good water holding capacity and they make fiber gel. This fiber gel can be used in many food products as non-caloric bucking agent. These results will benefit U.S. sorghum processors and sorghum farmers by increasing the value of their low value by-products and sorghum biomass.
Technical Abstract: This study was undertaken in order to isolate and compare three carbohydrate-rich fractions: Hemicellulose A (Hemi A), Hemicellulose B (Hemi B) and cellulose-rich residue (CRF) from sorghum bran (SBR), sorghum bagasse (SBA) and sorghum biomass (SBI). The monosaccharide composition of the purified Hemi. A and Hemi. B fractions from each of the three sorghum sources was measured. Higher Ara/Xyl values (1.01 and 0.84 respectively) in the Hemi. A and Hemi. B from SBR indicated a more branched structures. The Hemi. A and Hemi. B fractions from SBA and SBI have Ara/Xyl values of 0.14 to 0.31, indicating less branched structures. The analysis of insoluble dietary fiber (IDF), soluble dietary fiber (SDF) and total dietary fiber (TDF) showed that TDF and IDF contents in original sorghum materials were in the following order: SBA'SBI'SBR. The CRF from SBA was richer in IDF (94.91%) than CRF from SBR and SBI (85.67 and 87.40% respectively). Hemi. B fractions from all three sorghum sources were completely soluble in water and so they were rich in SDF (63.60 to 83.92%). During the water holding capacity (WHC) measurement, both the drum and spray dried CRF from all three sorghum sources show high WHC (22.76 to 35.27 g water/g CRF). The emulsification study in oil-in-water emulsion system, investigated by measuring mean particle size of oil droplets during 7 days storage at 60 degrees C showed that the Hemi. B from all three sorghum sources had a better emulsion stability than the well-studied corn fiber gum (CFG).