Effect of microwave irradiation on internal molecular structure and physical properties of waxy maize starch. (August 2017)

• Record Type: Journal Article
• Authors: Yang, Qingyu; Qi, Liang; Luo, Zhigang; Kong, Xiangli; Xiao, Zhigang; Wang, Pingping; Peng, Xichun
• Is Part Of: Food hydrocolloids. Volume 69(2017)
• Page Start: 473
• Page End: 482
• Publication Date: 2017-08
• Subjects: Waxy maize starch -- Chain length distribution -- Microwave -- Property; HPAEC-PAD High performance size exclusion chromatograph -- GPC-MALS Gel permeation chromatography coupled with multiangle light scattering -- XRD X-Ray diffraction -- DSC Differential scanning calorimetry -- CLD Chain length distribution -- DB Degree of branching -- wms-ns Native maize starch -- wms-m5 Waxy maize starch treated by microwave irradiation for 5 min -- wms-m10 Waxy maize starch treated by microwave irradiation for 10 min -- wms-m20 Waxy maize starch treated by microwave irradiation for 20 min -- PT Pasting temperature -- PV Peak viscosity -- BD Breakdown -- SB Set back -- FV Final viscosity -- BU Brabender unit; Hydrocolloids -- Periodicals; Food additives -- Periodicals; Colloïdes -- Périodiques; Aliments -- Additifs -- Périodiques; Colloids; Food additives; Periodicals; Electronic journals; 664.06
• DOI: 10.1016/j.foodhyd.2017.03.011
• Languages: English
• ISSNs: 0268-005X

Abstract

Abstract: Native waxy maize starch was treated at a moisture content of 30% by microwave irradiation for 5 min, 10 min and 20 min, respectively. The molecular structure and physical properties of waxy maize starch were characterized. Compared with native maize starch, lower population of short chains of amylopectin (A chain), higher proportion of short B1 and long B2 and B3 were observed in irradiated starches. 1 H NMR data showed that α-(1, 6) glycosidic linkages were destroyed more easily than α-(1, 4) glycosidic linkages during microwave treatment. A increase in gelatinization temperatures and a decrease in the molecular weight, the relative crystallinity, ΔH, viscosities and syneresis were observed after microwave treatment. Gelatinization temperatures were positively correlated with long chains B3 with DP > 36, while ΔH and syneresis were negatively correlated with them. The extent of the changes induced by microwave treatment for different times revealed that the major degradation occurred in internal chain (amorphous region) at the first stage (microwave treatment for 5 min), the external chain (crystalline region) mostly destroyed at the second stage (microwave treatment for above 10 min). The foregoing data indicated that the molecular structure of amylopectin is a critical factor determining physical properties. Graphical abstract: Fig. Gel permeation chromatograms of native and irradiated waxy maize starches. Highlights: Native waxy maize starch was treated by microwave irradiation. The molecular structure and physical properties of irradiated starch were characterized. Lower population of A chain, higher proportion of B1, B2 and B3 chains were observed. α-(1, 6) glycosidic linkages were destroyed easily than α-(1, 4) glycosidic linkages. The molecular structure of amylopectin is a critical factor determining physical properties.