Aqueous re-dispersibility of starch nanocrystal powder improved by sodium hypochlorite oxidation. (January 2016)

• Record Type: Journal Article
• Authors: Wei, Benxi; Zhang, Bao; Sun, Binghua; Jin, Zhengyu; Xu, Xueming; Tian, Yaoqi
• Is Part Of: Food hydrocolloids. Volume 52(2016:Jan.)
• Page Start: 29
• Page End: 37
• Publication Date: 2016-01
• Subjects: Starch nanocrystal -- Re-dispersibility -- Sodium hypochlorite -- Oxidation; Hydrocolloids -- Periodicals; Food additives -- Periodicals; Colloïdes -- Périodiques; Aliments -- Additifs -- Périodiques; Colloids; Food additives; Periodicals; Electronic journals; 664.06
• DOI: 10.1016/j.foodhyd.2015.06.006
• Languages: English
• ISSNs: 0268-005X

Abstract

Abstract: In this study, the aqueous re-dispersibility of starch nanocrystal (SNC) powder was significantly improved by sodium hypochlorite (NaClO) oxidation, with more than 2% (w/w) active chlorine. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses verified the oxidation process of SNC. The oxidation degree (carboxyl groups content) increased from 0.41% to 0.581% (w/w) while the applied active chlorine increased from 1% to 4% (w/w). X-ray diffraction showed that NaClO oxidation induced minor destruction to SNC when the applied active chlorine exceeded 2%, and the relative crystallinity decreased from 45.6% to 42.8%. Due to the introduction of carboxyl groups, the zeta potential of oxidized SNC (OSNC, under 2% active chlorine level) suspension (re-dispersed from oven-dried OSNC powder) reached to −23 mV. Consequently, a high degree of individualized SNC with the particle size of 20 nm was obtained and the suspension maintained the stability for at least 20 days. Graphical abstract: Highlights: The re-dispersibility of starch nanocrystal powder is improved by oxidation. Oxidized starch nanocrystal suspension stays stable for 20 days. Starch nanocrystal maintains its structure after oxidation.