Resistant starch improvement of rice starches under a combination of acid and heat-moisture treatments

• Published in: Food chemistry Vol. 191; pp. 67 - 73
• Main Authors: Hung, Pham Van, Vien, Ngo Lam, Lan Phi, Nguyen Thi
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15-01-2016
• Subjects: Acetic Acid - chemistry; Acid hydrolysis; Amylose - chemistry; Citric Acid - chemistry; Heat-moisture treatment; Hot Temperature; Humidity; Lactic Acid - chemistry; Oryza - chemistry; Physicochemical properties; Resistant starch; Rice starch; Solubility; Starch - chemistry; Viscosity; Acid hydrolysis; Resistant starch; Rice starch; Heat-moisture treatment; Physicochemical properties
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2015.02.002

•Rice starches were subjected to acid and heat-moisture treatments.•Degrees of polymerization of the treated rice starches significantly reduced.•Resistant starch contents of the treated rice starches were significantly improved.•The crystalline structure of the starches did not change after treatment.•Citric acid had the most impact on starch characteristics and RS formation.
The effects of a combination of acid and heat-moisture treatment on formation of resistant starch (RS) and characteristics of high-amylose, normal and waxy rice starches were investigated in this study. The degrees of polymerization of the rice starches treated with citric acid, lactic acid or acetic acid were significantly reduced as compared to the native starches. The RS contents of acid and heat-moisture treated rice starches were in a range of 30.1–39.0%, significantly higher than those of native rice starches (6.3–10.2%) and those of heat-moisture treated rice starches (18.5–23.9%). The acid and heat-moisture treatments reduced swelling power and viscosity, but increased solubility of the starches, while the crystalline structure did not change. Among the organic acids used, citric acid had the most impact on starch characteristics and RS formation, followed by lactic acid and acetic acid. The results are useful in production of RS for functional food application.