Ferulic acid is a kind of hydroxycinnamic acid, which belongs to phenolic acid. Ferulic acid is widely present in plant cell walls and is an important structural component of cell walls. According to the structure, it is divided into two types: cis and trans. The vast majority of plant cell walls are trans ferulic acid, which is a fibrous crystal; cis ferulic acid is a yellow oily substance, which is less abundant in nature. Ferulic acid has a variety of physiological functions, such as anti-inflammatory, anti-virus, anti-radiation, anti-apoptosis, anti-cancer, etc., and has a good physiological health care effect. Ferulic acid has many applications in the food industry. It can be used as a natural food preservative to inhibit the peroxidation of fatty acids and inhibit the growth of microorganisms. In addition, polysaccharides rich in ferulic acid will gelatinize in the presence of peroxidase and hydrogen peroxide. This property can be used to gelatinize polysaccharides to prepare food gums. The molecular structure of pectin is relatively complex and consists of multiple domains. The most abundant domains are homogalacturonan (HG) and rhamnogalacturonic acid (RG).
The white radish pectin was modified with ferulic acid and horseradish peroxidase, which changed the color, rheological properties, surface microstructure, and group properties of the pectin. Compared with the original pectin, the modified pectin turns yellow, and the DPPH free radical scavenging rate is significantly enhanced, which significantly enhances the anti-oxidation property of the white radish pectin. The rheological properties of pectin changed, the viscosity of modified pectin increased, and G'increased, and the sample was more solid. The surface microstructure of white radish pectin changes under the action of ferulic acid and peroxidase. Ferulic acid makes the originally dispersed pectin molecules tightly connected together. In addition, the maximum absorbance of pectin and the peak of the characteristic absorption peak of the group changed, indicating that ferulic acid treated pectin to form a new substance. Ferulic acid and horseradish peroxidase treatment can improve the functionality of pectin. This research result provides a new method for improving the functional properties of pectin and provides a theoretical basis for the promotion of modified production of other polysaccharides.