Corn fiber gum-soybean protein isolate double network hydrogel as oral delivery vehicles for thermosensitive bioactive compounds

Authors: YAN, WENJIA - China Agricultural University; ZHANG, BOYA - China Agricultural University; Yadav, Madhav; FENG, LIPING - China Agricultural University; YAN, JINXIN - China Agricultural University; JIA, XIN - China Agricultural University; YIN, LIJUN - China Agricultural University

Submitted to: Food Hydrocolloids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/13/2020
Publication Date: 3/18/2020
Citation: Yan, W., Zhang, B., Yadav, M.P., Feng, L., Yan, J., Jia, X., Yin, L. 2020. Corn fiber gum-soybean protein isolate double network hydrogel as oral delivery vehicles for thermosensitive bioactive compounds. Food Hydrocolloids. https://doi.org/10.1016/j.foodhyd.2020.105865.
DOI: https://doi.org/10.1016/j.foodhyd.2020.105865

Interpretive Summary: Corn fiber gum (CFG) is a sugar polymer that is present in the cell wall of corn kernels. CFG is isolated from corn bran, which is a low valued by-product of corn kernels milling. CFG contains a small amount of phenolic compounds in addition to the major sugar components. Previous studies have found that CFGs can be connected to each other through phenolic groups to form hydrogels when treated with an enzyme called “laccase”. But the hydrogels formed by simple enzyme treatment is not strong enough to encapsulate drugs or bioactive compounds and act as their delivery vehicle in human body. To solve this problem, we have prepared double network hydrogels by using a mixture of CFG and soy protein isolate (SPI). The hydrogel formation of CFG and SPI were initiated by adding laccase and gluconic acid lactone in the same mixture. During such hydrogel formation, the CFG and SPI hydrogels become intertwined with each other and form a double network hydrogel. This CFG-SPI double network hydrogel was studied to use it as an oral delivery system for the heat sensitive bioactive material (vitamin B2). The studies in our laboratory set up found that CFG-SPI double network hydrogel had a high efficiency to deliver vitamin 2 in human body system. These findings will help to increase the utilization of CFG and WPI polymers in food and pharmaceutical applications and may benefit US corn and soybean growers. The utilization of these products may improve the markets for corn and soybean processing by-products. The production of novel hydrogel products and their utilization for delivering bioactive compounds in human digestive system may also benefit the U.S. consumers, food and pharmaceutical industries and ultimately the U.S. economy.

Technical Abstract: Corn fiber gum (CFG)-soybean protein isolate (SPI) double network (DN) hydrogels, with varied concentrations of CFG, were fabricated at room temperature in order to develop a biocompatible vehicle for the oral administration of thermosensitive bioactive compounds. Riboflavin (vitamin B2) was encapsulated in the gel as a model bioactive compound. The compound release properties of these DN hydrogels were investigated in simulated gastric and simulated intestinal fluids (SGF and SIF). DN hydrogels with 0.25% of CFG were found to be the most desirable of those assayed for the oral administration of bioactive compounds. The results of low-field nuclear magnetic resonance (LF-NMR) relaxometry measurement, degree of proteolysis, and scanning electron microscopy (SEM) showed that, in comparison with the SPI hydrogel, the pH-responsive DN hydrogels protected the riboflavin due to their low swelling ratio in the SGF, before significant release in the SIF due to large swelling and CFG matrix erosion together with the proteolysis of SPI. The release mechanisms of riboflavin through the DN hydrogels in the simulated intestinal fluid followed non-Fickian diffusion based on Peppas' semi-empirical equation.