|LIU, YAN - China Agricultural University|
|QIU, SHUANG - China Agricultural University|
|LI, JINLONG - China Agricultural University|
|CHEN, HAO - China Agricultural University|
|TATSUMI, EIZO - Japanese International Research Center For Agricultural Sciences (JIRCAS) - Japan|
|YIN, LIJUN - China Agricultural University|
Submitted to: Carbohydrate Polymers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2014
Publication Date: 11/16/2014
Publication URL: http://handle.nal.usda.gov/10113/60403
Citation: Liu, Y., Qiu, S., Li, J., Chen, H., Tatsumi, E., Yadav, M.P., Yin, L. 2014. Peroxidase mediated conjugation of corn fibeer gum and bovine serum albumin to improve emulsifying properties. Carbohydrate Polymers. 118:70-78.
Interpretive Summary: The need to add value to corn milling by-products has prompted us to prepare corn fiber gum (CFG) and change it into a better flavor stabilizer. Corn bran/fiber is obtained from corn dry or wet milling industries. It is an abundant low value material used for animal feed. We have found that CFG, deficient in protein, is an inferior flavor stabilizer in comparison to protein rich CFG. To increase the flavor stabilizing capacity of protein deficient CFG, a commercial protein was attached to it by using an enzyme. Bovine serum albumin (BSA), a readily available commercial protein, has the appropriate structure to bind with CFG. So this protein was reacted with CFG in the presence of an enzyme (horseradish peroxidase) to form their conjugate. The conjugate was fully characterized and its flavor binding capacity was studied. The CFG and BSA conjugate showed an increase in its oil binding capacity in comparison to CFG or BSA alone. This process is a simple and economical food grade green technique to introduce protein onto CFG for converting it into a better flavor stabilizer for a soft drink system. These findings will benefit U. S. corn processors by adding value and creating an additional market for their by-products. It will also benefit U. S. manufacturers of CFG who will be able to produce a constant supply of improved quality corn fiber gum emulsifiers at reasonable prices. The generation and recovery of additional valuable product from corn milling by-products will also indirectly help to reduce overall cost of fuel ethanol produced from corn kernels.
Technical Abstract: The emulsifying properties of corn fiber gum (CFG), a naturally-occurring polysaccharide protein complex, were improved by kinetically controlled formation of hetero-covalent linkages with bovine serum albumin (BSA), using horseradish peroxidase. The formation of hetero-crosslinked CFG-BSA conjugates was confirmed using ultraviolet-visible and Fourier-transform infrared analyses. The optimum CFG-BSA conjugates were prepared at a CFG:BSA weight ratio of 10:1, and peroxidase:BSA weight ratio of 1:4000. Selected CFG-BSA conjugates were used to prepare oil-in water emulsions; the emulsifying properties were better than those of emulsions stabilized with only CFG or BSA. Measurements of mean droplet sizes and zeta potentials showed that CFG-BSA-conjugate stabilized emulsions were less susceptible to environmental stresses, such as pH changes, high K ionic strengths, and freeze-thaw treatments than CFG- or BSA-stabilized emulsions. These conjugates have potential applications as novel emulsifiers in food industry.