Methods to improve rice protein dispersal at moderate pH

• Published in: Food science and biotechnology Vol. 29; no. 10; pp. 1401 - 1406
• Main Authors: Mun, Saehun, Surh, Jeonghee, Shin, Malshick
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.10.2020; Springer Nature B.V; 한국식품과학회
• Subjects: Alginic acid; biotechnology; Chemistry; Chemistry and Materials Science; Dispersal; Dispersion; emulsifiers; emulsions; Food industry; Food processing industry; Food Science; Nutrition; Pectin; pectins; pH effects; Proteins; Rice; rice protein; Sodium alginate; Solubility; Sonication; Zeta potential; 식품과학; Water solubility; Rice protein; Pectin; Emulsion
• ISSN: 1226-7708; 2092-6456; 2092-6456
• DOI: 10.1007/s10068-020-00799-3

Dispersion of rice protein (RP) at a neutral pH is highly important for its application in the food industry. We analyzed the solubility of RP at different pH conditions and found higher solubility at pH < 3 and pH > 8 than at a neutral pH. Furthermore, at pH 2, the RP solubility improved from 30 to 63% with sonication; however, the samples precipitated when the pH was increased from 2 to 7. To circumvent this, anionic pectin and sodium alginate were added to the RP solution at pH 2. Pectin formed a complex with RP at pH 2, showing a shift in the zeta-potential from 17.3 mV (RP only) to − 1.0 mV (RP plus 1% pectin). Interestingly, the formation of this RP-pectin complex allowed RP to remain dispersed when the pH was increased to 7. Moreover, a stable emulsion could be prepared using the RP-pectin complex as an emulsifier.