title: Impact of single and dual modifications on physicochemical properties of japonica and indica rice starches.
abstract: The japonica (JR) and indica (IR) rice starches were modified by acetylation, hydroxypropylation, cross-linking, and dual modification (cross-linked acetylation and cross-linked hydroxypropylation) and the effects of single and dual chemical modifications of JR and WR on the physicochemical properties were investigated. The JR had a greater substitution degree of acetyl or hydroxypropyl groups than IR. The dual-modified JR showed broader gelatinization temperature range than corresponding single-modified starches, but narrower it in IR. The dual-modified JR and IR showed higher pasting temperature and lower breakdown than their corresponding single-modified starches. The dual modification with JR and IR induced significant increase in gel hardness as compared to the corresponding unmodified and single-modified starches. The dual-modified JR had a greater hardness, gumminess, and chewiness than the dual-modified IR. The different impact of single and dual modification with JR and IR on the physicochemical properties could be due to the differences in the location and distribution of substituent groups on the starch molecules.
authors: Graduate School of Life Sciences and Biotechnology, Korea University, 5-1 Anam-dong, Sungbuk-gu, Seoul 136-701, South Korea; Suseong College, 528-15 Dalgubeol-ro, Suseong-gu, Daegu 706-711, South Korea.
authors: Su-Jin
authors: SJ
authors: Lee
authors: Graduate School of Life Sciences and Biotechnology, Korea University, 5-1 Anam-dong, Sungbuk-gu, Seoul 136-701, South Korea.
authors: Joo Yeon
authors: JY
authors: Hong
authors: Research Institute for Human Ecology, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, South Korea.
authors: Eun-Jung
authors: EJ
authors: Lee
authors: Research Institute for Human Ecology, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, South Korea; Division of Food and Nutrition, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, South Korea. Electronic address: hchung@jnu.ac.kr.
authors: Hyun-Jung
authors: HJ
authors: Chung
authors: Graduate School of Life Sciences and Biotechnology, Korea University, 5-1 Anam-dong, Sungbuk-gu, Seoul 136-701, South Korea. Electronic address: limst@korea.ac.kr.
authors: Seung-Taik
authors: ST
authors: Lim
keywords: Acetylation; Cross-linking; Dual-modification; Hydroxypropylation; Rice starch