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Poly(lactide)-starch matrix, blended with multi-functionalized graphene oxide, was synthesized by solution casting in this study. To improve its interface compatibility, the graphene oxide (GO) was grafted with maleic anhydride and subsequently modified by dodecyl amine. The chemical structure and morphology of functionalized GO (f-GO) were determined by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The crystallization property, surface wettability, morphology, thermal stability, and dynamic mechanical and aging resistance properties of the nanocomposite were determined. By XRD and morphological analysis, we observed the formation of well-dispersed nanocomposites. Thermo-gravimetric analysis revealed significant improvements in thermal stability. The isothermal and non-isothermal crystallization behavior of the PLA-starch-f-GO nanocomposites demonstrated that the f-GO that was added accelerated the heterogeneous nucleation of the nanocomposites. The surface hydrophobicity, UV-shielding capacity, and aging resistance properties of these nanocomposites were enhanced by the incorporation of the f-GO. The migration rate of plasticizer of the nanocomposites decreased compared with the group without f-GO. The storage modulus for these nanocomposites improved by dynamic mechanical analysis. These insights provide a strategy for constructing high-performance nanohybrids and broadening their application in the food packaging and pharmaceutical industries., (Copyright © 2019. Published by Elsevier B.V.)

Bionanocomposite film is composed of renewable materials such as polymer with the addition of nanofiller in the form of nanocrystal cellulose (NCC). Biopolymer serves as a matrix, while nanofiller is dispersed to improve the functional properties. NCC is a nanoparticle commonly used in the production of bioplastics, and the addition to nanocomposite film can enhance the mechanical and barrier properties. Therefore, this study aimed to determine the physio-chemical, mechanical, and permeability characteristics of elephant foot-yam starch-based nanocomposite films by adding different concentrations of NCC at 3, 5, and 7 wt.%. The experiment used elephant foot-yam starch, NCC, sorbitol, and carboxymethyl cellulose (CMC) as biopolymer, nanofiller, plasticizer, and stabilizer, respectively. The results showed that the optimum concentration was 7 wt.% NCC, showing tensile strength, elongation, WVTR, and thickness consistent with the Japanese Industrial Standard. NCC dispersion showed favorable water solubility and excellent biodegradability, yielding optimal SEM and FTI-R results. SEM analysis showed a well-dispersed structure, while FTI-R showed sharper spectra in specific functional groups. Moreover, XRD showed several diffraction peaks with strong intensity at 2θ = 17.12°(101̅), 22.75° (002), and 35.0° (040), confirming the presence of NCC in the film matrix. Based on the results, this nanocomposite had great potential to be developed into environmentally friendly packaging. [ABSTRACT FROM AUTHOR]

In the current study, taro starch was extracted and used for the encapsulation of probiotics to prolong their viability under stressed conditions. Taro starch and sodium alginate were used as wall materials for the encapsulation of Lactobacillus rhamnosus. Probiotic bacteria were encapsulated by the extrusion method, and obtained microbeads were subjected to various morphological, molecular, and structural characterization using Fourier transform infrared spectroscopy ;(FTIR), Scanning electron microscopy (SEM), and X-ray diffraction (XRD) technique. Furthermore, the viability of free and encapsulated probiotics was also accessed under simulated gastrointestinal conditions and in the food model (cheddar cheese). Average size microcapsules ranged from 6.16 ± 0.05 mm to 5.28 ± 0.03 mm. The encapsulation efficiency for taro and sodium alginate was recorded as 86.27% log CFU/g and 81.78% log CFU/g respectively. SEM micrographs exhibited entrapment of probiotics in wall materials. The surface of capsules was-irregular spherical structure FTIR spectra revealed broad characteristic peaks at 815 cm1, 1320 cm1, 1130 cm1, and ~ 1610 cm1. XRD images showed loss of crystalline structure following encapsulation. Higher probiotic viability was recorded under simulated gastrointestinal conditions for encapsulated probiotics compared to free probiotics. Likewise, a high probiotic count was observed in cheese fortified with encapsulated probiotics. Conclusively, taro starch wall material showed overall best results regarding the viability of probiotics under stressed conditions. [ABSTRACT FROM AUTHOR]

Summary: The current study investigates the comparison and quality characteristics of starches isolated from potatoes using different processing methods from three commercial varieties: Lady Rosetta, Asterix and Challenger, for the first time in Pakistan. The analysis of variance revealed that starch yield significantly (P < 0.05) depended on total solids, peeling (12.7%, 12.0% and 12.0%) and unpeeling (15.0%, 14.0% and 14.0%) of potatoes compared to potato varieties for Lady Rosetta, Challenger and Asterix, respectively. Moreover, pasting properties, protein content, redness and yellowness were increased in those starches isolated without peeling while carbohydrates and lightness were increased in peeled potato starches. Furthermore, Fourier‐transform infrared spectroscopy analysis revealed that protein (1200–1400 cm−1) was present in starch extracted without peeling. Besides, scanning electron microscopy analysis revealed oval‐shaped starch granules with no impurities in peeled potato starch. The findings suggest the suitability of peeling process for obtaining a high‐quality pure starch. [ABSTRACT FROM AUTHOR]

• Sodium dodecyl sulfate (SDS) can balance the grafted percent and latex dispersion. • Moderate SDS shows significant promotion on grafted reaction. • SDS improve the dispersion of monomers (VAc) by decreasing the interfacial tension. • The surfactant can change the structure of starch chain. Graft copolymerization is a challenging step in preparation of starch-based adhesive due to the complexity and instantaneity. A combination of both experimental and simulation methodology has been employed to investigate the process at microscopic level. Through a series of characterizations of adhesives and copolymers with different SDS (sodium dodecyl sulfate) contents, 2% (w/w, 2g SDS/100 g starch) SDS demonstrated outstanding balance between the starch grafted percentage and interfacial properties. The coarse-grain molecular dynamics (CGMD) was utilized to reveal the molecular distribution and migratory mechanisms during the reaction by calculating radius distribution function (RDF) and mean square displacement (MSD). Starch chains covering the monomers surface was found to exhibit longer radius of gyration (Rg). Furthermore, the interfacial models were constructed in this study, and interfacial tension between water and VAc beads was calculated to confirm the improvement in interfacial properties and the rationality of simulation with the addition of SDS. [ABSTRACT FROM AUTHOR]

Highlights • Five adhesives and cured films with different nano-TiO 2 mass ratio were investigated. • Nano-TiO 2 showed improvement on the bonding strength and viscosity of adhesive. • Nana-TiO 2 enhanced the structure of grafted starch chain by embedding. • Moderate dispersion of nano-TiO 2 greatly promoted the film-forming properties. • There is branched network structure in adhesive film. Abstract The nano-TiO 2 was utilized to improve the bonding performance, structure stability and film-forming properties of renewable starch-based wood adhesive. The results showed that 4% nano-TiO 2 (nano-TiO 2 :starch, w;w) resulted in 6.5 MPa of shear strength and 6437 Pa.s of viscosity. The thermal stability was measured by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Additionally, low-field nuclear magnetic resonance (NMR) and rheological results exhibited the enhancement of nano-TiO 2 on the pseudoplasticity and structure which determined the state and migration of water. Besides, the structural characterization of copolymer was analyzed via fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD). Furthermore, the film-forming property was evaluated by small angle X-ray scattering (SAXS) and dynamic mechanical analysis (DMA). The morphological structures of adhesive were observed by scanning electron microscopy (SEM). In conclusion, the 4% nano-TiO 2 (nano-TiO 2 :starch, w;w) can be employed to prepare starch-based wood adhesives with superior properties for wood application. [ABSTRACT FROM AUTHOR]

It is proposed that the interfacial compatibility of starch-based adhesives could be improved by sodium dodecylsulfate (SDS). The preparation of starch suspension with high concentration and molecular dynamics simulation were designed according to the adhesive preparation. The results showed that SDS without absorption competition expanded the molecular space and improved the starch dispersion. Additionally, the thickest interfacial layer was formed on starch containing 2% SDS due to the deeper immersion of SDS. Excessive SDS facilitated the supramolecular assembly, leading to the formation of starch colloid. SDS decreased the interfacial tension between the starch and different polarity matrix. Our simulated results accorded with the experimental results and presented the starch structure at the atomic level. Owing to the inhibition on molecular interaction of starch, SDS promoted the starch extensibility and flexibility. Moreover, three different contact forms (tail, head, and inclusion) between the starch and SDS were also presented in this work. This study is fundamental to establishing the relationship between macromolecular behaviors and product performance. The interaction mechanism between sodium dodecylsulfate (SDS) and starch molecules revealed by combining experiments and computer simulation. Unlabelled Image • Surfactant addition could improve starch dispersion at high concentration. • 2% SDS widened the interfacial layer with electric fluctuation of starch. • The behavior transformation would occur in high SDS concentration. • Molecular configuration was investigated by computer simulation in detail. [ABSTRACT FROM AUTHOR]

In this study, oxidized sucrose is employed to crosslink corn starch at 100, 110, and 120 °C. The cross‐linked starch is analyzed by Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (1H NMR) spectroscopy. The X‐ray diffraction (XRD) analysis reveals that cross‐linked starch exhibits a "V" crystal structure after modification. Thermogravimetric (TG) analysis demonstrates that the destruction of the crystal structure increases the thermoplasticity of the starch. A decrease in the viscosity of the cross‐linked starch using a Rapid Visco Analyzer (RVA) is noted. However, compared with native starch, the swelling power of cross‐linked starch shows a negative correlation with treatment temperature. Furthermore, the cross‐linked starch that is treated at 100 °C experiences a fivefold increase in both swelling ratio and water binding capacity, compared with native starch. Additionally, low‐field nuclear magnetic resonance (low‐field NMR) analysis verifies the excellent hydrophilic properties of the cross‐linked starch. The oxidized sucrose‐modified starch (OSMS) is an alternative for improving starch‐based products, potentially in turn guiding further advancements in the pharmaceutical and food industries. [ABSTRACT FROM AUTHOR]