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This study aimed to explore the effect of induced electric field (IEF) treatment on acid hydrolysis of corn starch by altering the connection modes of sample coils of a 4-reactor IEF system. Results suggested that IEF treatment could enhance the hydrolysis of corn starch and series connection (1. RRRR, η = 16 E Si 2 P in 4 Z Si + Z load ) exhibited higher energy efficiency than parallel (9. (RRRR), η = 4 E Si 2 P in Z Si + 4 Z load ), thus contributing to more extensive hydrolysis. Although no new functional group was formed, the starch granules were partially cracked into pieces and the crystallinity was slightly increased after IEF-assisted hydrolysis. Differential scanning calorimetry results indicated that IEF-assisted hydrolysis increased the gelatinization temperatures but decreased the enthalpy of starch, with a greatest variation was observed by series connection. Rapid visco-analysis showed that IEF-assisted hydrolysis greatly decreased the pasting viscosity of corn starch and also series connection showed the strongest reduction. The obtained results could provide a theoretical guide for the applications of IEF technology in biomaterial processing. [Display omitted] • Induced electric field (IEF) could enhance the acid hydrolysis of corn starch. • IEF-assisted hydrolysis highly depends on the energy efficiency of IEF system. • Series connection of IEF reactors showed the highest energy efficiency. • IEF-assisted hydrolysis largely decreased the pasting viscosity of corn starch. • IEF-assisted hydrolysis increased gelatinization temperatures but decreased enthalpy. [ABSTRACT FROM AUTHOR]

To better understand the correlation between structure and properties in thermoplastic starch biopolymer blend films, the effects of amylose content, chain length distribution of amylopectin and molecular orientation of thermoplastic sweet potato starch (TSPS) and thermoplastic pea starch (TPES) on microstructure and functional properties of thermoplastic starch biopolymer blend films were studied. After thermoplastic extrusion, the amylose contents of TSPS and TPES decreased by 16.10 % and 13.13 %, respectively. The proportion of the chains with the degree of polymerization between 9 and 24 of amylopectin in TSPS and TPES increased from 67.61 % to 69.50 %, and from 69.51 % to 71.06 %, respectively. As a result, the degree of crystallinity and molecular orientation of TSPS and TPES films increased as compared to sweet potato starch and pea starch films. The thermoplastic starch biopolymer blend films possessed a more homogeneous and compacter network. The tensile strength and water resistance of thermoplastic starch biopolymer blend films increased significantly, whereas thickness and elongation at break of thermoplastic starch biopolymer blend films decreased significantly. • The structure-function relationship of thermoplastic starch films was analyzed. • Thermoplastic starch films showed higher molecular orientation and crystallinity. • The chains with DP between 9 and 24 and molecular orientation were the dominant factors. • Thermoplastic starch films showed a better tensile strength and water resistance. [ABSTRACT FROM AUTHOR]

To illustrate the correlations between molecular structures and the film-forming properties of thermoplastic starch from various botanical sources, starches from cereal, tuber and legume were modified by thermoplastic extrusion and the corresponding thermoplastic starch films were prepared including thermoplastic corn starch (TCS), thermoplastic rice starch (TRS), thermoplastic sweet potato starch (TSPS), thermoplastic cassava starch (TCAS) and thermoplastic pea starch (TPES) films. TPES film displayed a higher tensile strength (6.28 MPa) and stronger water resistance, such as lower water solubility (15.70 %), water absorption (42.35 %), and water vapor permeability (0.285 g·mm· h −1· m −2·kPa−1) due to higher contents of amylose and B 1 chains. TCAS showed a smoother and more amorphous film due to higher amylopectin content, resulting higher elongation at break and larger opacity. TCS film was the most transparent due to a compacter network and more ordered crystallinity structure, which was suit for the packaging of fresh vegetables and aquatic products, whereas TCAS film was the opaquest, which protected package foods from light such as meat products, etc. The outcome would provide an innovative theory to regulate accurately the functional properties of thermoplastic starch films for different food needs. • The structure-function relationship of thermoplastic starch films was studied. • TPES film with higher contents of amylose and B1 chains displayed a stiffer structure. • TPES film displayed a stronger water resistance with higher amylose content and B1 chains. • TCAS film with higher amylopectin showed a higher elongation at break and opacity. • TCS film was the most transparent due to more ordered crystallinity structure. [ABSTRACT FROM AUTHOR]

Waxy maize starch (WMS) was modified using sequential α-amylase and transglucosidase to create enzyme-treated waxy maize starch (EWMS) with higher branching degree and lower viscosity as an ideal healing agent. Self-healing properties of retrograded starch films with microcapsules containing WMS (WMC) and EWMS (EWMC) were investigated. The results indicated that EWMS-16 had the maximum branching degree of 21.88 % after transglucosidase treatment time of 16 h, and A chain of 12.89 %, B1 chain of 60.76 %, B2 chain of 18.82 % and B3 chain of 7.52 %. The particle sizes of EWMC ranged from 2.754 to 5.754 μm. The embedding rate of EWMC was 50.08 %. Compared to retrograded starch films with WMC, water vapor transmission coefficients of retrograded starch films with EWMC were lower, while tensile strength and elongation at break values of retrograded starch films were almost similar. Retrograded starch films with EWMC had higher healing efficiency of 58.33 % as compared to that Retrograded starch films retrograded starch films with WMC was 44.65 %. [ABSTRACT FROM AUTHOR]

To explore an effective and economic method to prepare higher contents of resistant starch (RS), different enzyme treatments including single pullulanase (PUL), commercial α-amylase (AA) or/and β-amylase (BA) with PUL, and malt endogenous amylase (MA) with PUL were used and the structural, physicochemical properties and digestibility of all modified starches (MS) were compared. All the enzyme-treated starches displayed a mixture of B and V-type diffraction patterns. The MA/PUL-MS showed higher V-type diffraction peak intensity as compared to other modified starches. Compared to the combination of commercial enzyme treatment, the combination of malt enzyme treatment led to higher apparent amylose contents (45.56%), RS content (53.93%) and thermal stability (302 °C), whereas it possessed lower solubility indices and predicted glycaemic index. The apparent viscosity and shear resistance of MA/PUL-MS were lower than that of AA/PUL-MS, whereas that of MA/PUL-MS was higher than that of BA/PUL-MS and BA/AA/PUL-MS. These findings would provide a theoretical and applicative basis to produce foods with lower GI in industrial production. • The effects of commercial or malt enzymes on maize starch properties were compared. • The malt enzyme treatment formed more amylose–lipid complexes. • Malt enzyme-modified starch had the highest RS content and lowest GI value. • Low-cost malt amylase can replace expensive commercial enzymes to prepare RS. [ABSTRACT FROM AUTHOR]

Herein, a multistage induced electric field (IEF) combined with a continuous-flow reactor was utilized to assist the acid hydrolysis of corn, potato, and waxy corn starch for avoiding plate corrosion and heavy metal leakage. It was found that adding IEF stages was beneficial to improve the hydrolysis efficiency. Treating potato, corn, and waxy corn starch via continuous-flow IEF increased the reducing sugar contents up to 78.76 %, 57.86 %, and 66.18 %, respectively. The electrical conductivity of starch grew with the reaction stages, while starch yield demonstrated the opposite trend. Treated starch had higher solubility and gelatinization peak temperature than native starch, with the gelatinization enthalpy showing fluctuations. Meanwhile, the swelling power decreased as the number of IEF stages was increased. Observations of Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy indicated that the treated starch became more ordered, and crystalline regions were destroyed to various degrees with pores forming on particle surfaces. These variations could be attributed to acid hydrolysis and IEF. [ABSTRACT FROM AUTHOR]

• Innovative contactless thermal effect on starch hydrolysis was investigated. • Starch acidolysis solution acts as the coils of a transformer for heating treatment. • Innovative inner heating method accelerated corn starch acid hydrolysis. • The treated starch had increased solubility and swelling power. • Thermal effect of induced electric field altered the physicochemical properties of starch. Growing attention has been focused on modifications of starch using electric field, but electrode corrosion and metal contamination remain unavoidable during the process. To solve these problems, the magneto-induced electric field was used to assist corn starch hydrolysis due to its thermal effect. Results indicated that the method accelerated corn starch acid hydrolysis and decreased the treatment time. The reducing sugar content increased to 0.59 g/L after a 60 s treatment, which was 353.44 % higher than the 20 s treatment, while the average degree of polymerization reached a minimum. The treated starch showed increased solubility and swelling power, as well as decreased freeze-thaw stability. X-ray diffraction, fourier transform infrared spectroscopy, and scanning electron microscopy results suggested that the physicochemical changes of corn starch were due to the thermal effect of the induced electric field. This study is expected to provide an important basis for applying new electric field hydrolysis technology to starch modification. [ABSTRACT FROM AUTHOR]

To study correlation between interfacial adhesion and properties of corn starch/corn stalk cellulose (CSC) biodegradable straws, the interfacial adhesion and functional properties of the starch-based straws with different cellulose contents were analyzed and compared. The results showed that the starch/CSC straw with 1 % CSC (SC1) had the highest interfacial adhesion between starch and cellulose, resulting in higher mechanical properties and water resistance. Compared to starch/CSC straw with 0 % CSC, water absorption rate of SC1 decreased by 13.0 % (4 °C, 1 h) and 18.4 % (25 °C, 1 h), respectively. The fracture strength and fracture deformation increased by 47.8 % and 59.6 %, respectively. The strength increased by 3.93 (4 °C, 30 min) and 1.53 (25 °C, 30 min) times after soaking, respectively. The soil degradation rate of SC1 was 89.5 % on the 20th day and thermal degradation rate was 79.6 % at 600 °C. The SC1 with better properties (soil degradability, water resistant and mechanical properties) was as economical as paper straw. [Display omitted] • 1 % CSC addition resulted in better interfacial adhesion between starch and CSC. • Mechanical properties and water resistance were improved by interfacial adhesion. • Interfacial adhesion is formed by hydrogen bonds and mechanical interlocks. • The performances of starch/CSC straws with 1 % CSC were better than paper straws. [ABSTRACT FROM AUTHOR]

This study aimed to improve the effect of moderate electric field (MEF) treatment on the structural and physicochemical properties of maize starch by adding 1-butyl-3-methylimidazolium chloride ([bmim]Cl). Starch (20%, w/v) was mixed with [bmim]Cl solution (0, 30%, 50%, and 70%, w/w), and then electro-treated (5 V/cm, 50 Hz) at 60 °C for 10 min. As the [bmim]Cl concentration increased, the electro-induced disintegration of starch granules was enhanced due to the intensified Joule heat and decreased pH of reaction bulk. After electro-treated in 70% w/w [bmim]Cl, a transparent solution of starch was observed and the recovered starch tended to dissolve rather than swell in water. Compared with water-bath heating, MEF caused more destruction in the granular and crystal structure, increased the particle size, decreased the pasting viscosity, and reduced the gelatinization enthalpy and thermostability of starch. The obtained results could provide guidance for the application of electro-based techniques in starch modification. [Display omitted] • Moderate electric field (MEF) intensified the destruction of maize starch in [bmim]Cl. • The intensification was improved with increasing concentration of [bmim]Cl. • Starch granules were disintegrated by MEF treatment in 70% w /w [bmim]Cl. • Starch tended to dissolve rather than swell after MEF treatment in 70% w/w [bmim]Cl. [ABSTRACT FROM AUTHOR]