title: Synthesis and characterization of a novel antioxidant RS4 by esterifying carboxymethyl sweetpotato starch with quercetin.
abstract: Quercetin is grafted to carboxymethyl sweetpotato starch (CMSS) by esterification. Upon esterification, the water solubility of CMSS decreases and the CMSS-quercetin conjugates (CMSS-Q) are yellowish. FT-IR and 1H NMR indicated the covalent attachment of quercetin to CMSS. Thermogravimetry revealed the superior thermal stability of CMSS-Q over CMSS and native sweetpotato starch (NSS). The in vitro digestibility assays showed that CMSS is highly resistant to digestion while the quercetin graft with degree of substitution (DS) above 0.074 slightly increased its digestibility. The quercetin graft imparted CMSS with strong antioxidant activity and enhanced its thermal stability, which increased with quercetin DS. In vitro cyotoxicity assessment revealed that CMSS-Q is as safe as CMSS and NSS. This study showed that CMSS-Q is a novel antioxidant-resistant starch in RS4 form.
authors: College of Food Science, Southwest University, Chongqing 400715, People's Republic of China.
authors: Xia
authors: X
authors: Lv
authors: College of Food Science, Southwest University, Chongqing 400715, People's Republic of China.
authors: Fayin
authors: F
authors: Ye
authors: College of Food Science, Southwest University, Chongqing 400715, People's Republic of China.
authors: Jinfeng
authors: J
authors: Li
authors: College of Food Science, Southwest University, Chongqing 400715, People's Republic of China.
authors: Jian
authors: J
authors: Ming
authors: College of Food Science, Southwest University, Chongqing 400715, People's Republic of China; Chongqing Engineering Research Centre of Regional Foods, Chongqing 400715, People's Republic of China; Chongqing Sweet Potato Engineering and Technology Centre, Chongqing 400715, People's Republic of China. Electronic address: zhaogh@swu.edu.cn.
authors: Guohua
authors: G
authors: Zhao
mesh_terms: D000975:Antioxidants / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D004951:Esterification; D027723:Ipomoea batatas / Q000737:chemistry*; D011794:Quercetin / Q000737:chemistry*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000031:analogs & derivatives* / Q000737:chemistry*; D013818:Thermogravimetry; D014783:Viscosity
chemical_list: D000975:Antioxidants; D013213:Starch; C034848:carboxymethyl starch; D011794:Quercetin
keywords: 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (PubChem CID:15908); Antioxidant activity; Butylated hydroxytoluene (PubChem CID: 31404); Carboxymethyl sweetpotato starch; Conjugate; Digestibility; Quercetin; Quercetin (PubChem CID: 5280343); Synthesis