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The storage substances of rice are critical factors that simultaneously affect grain yield and quality. Starch is the major component in the endosperm, directly affecting the seed yield as well as the cooking and eating quality of grains. Growing evidence suggests that some transcription factors are involved in regulating seed traits and starch biosynthesis. Here, we reveal the role of an NF-Y transcription factor gene, OsNF-YA8 , in regulation of seed traits and starch accumulation. OsNF-YA8 encodes a rice NF-YA protein containing the 166-amino acid. The RT-qPCR showed that OsNF-YA8 is expressed in roots, stems, leaves, flag leaves, and panicles, and dramatically increased in panicle during rice filling. Intracellular localization analysis showed that OsNF-YA8 is a nucleus-localized protein. In the OsNF-YA8 overexpression lines, rice grain length increased by 13.80–14.21 %, rice grain thickness decreased by 3.22–6.65 %, and the total starch content increased by 14.70–33.14 %. The overexpression of the OsNF-YA8 also decreased average starch granule size, and changed starch properties. Moreover, OsNF-YA8-overexpression up-regulated the expressions of genes involved in sucrose synthesis/transport and starch synthesis. By contrast, RNAi of OsNF-YA8 decreased the grain length, grain width, 1000 grain weight and starch content of rice seeds, and down-regulated the expressions of genes involved in sucrose synthesis/transport and starch synthesis. These results suggest that OsNF-YA8 enhances starch accumulation and confers seed traits by positively regulating starch biosynthesis in rice. The findings provide a new perspective on genetic improvement of crop agronomic traits and seed quality. [Display omitted] • OsNF-YA8 encodes a nucleus-localized protein with 166-amino acid. • The overexpression of the OsNF-YA8 confers seed improvement traits. • OsNF-YA8 promotes starch accumulation by positively regulates starch biosynthesis. • OsNF-YA8 impacts on rice grain size and physicochemical properties of starch grains. • OsNF-YA8 upregulates the expression of sucrose and starch synthesis-related genes. [ABSTRACT FROM AUTHOR]

Soluble starch synthase IIIa (SSIIIa) is a key enzyme involved in amylopectin biosynthesis in rice, and deficiency of SSIIIa results in high content of resistant starch, which is benefit to human health. However, little is known about metabolic differences and carbon re-allocation in the seeds of the indica rice ss3a mutant. We found that SSIIIa deficiency impaired the storage of starch, but increased the soluble sugars, free amino acids and lipids. By multi-omic analyses, we found inactivation of SSIIIa triggered carbon repartitioning by downregulating sucrose synthase , grain incomplete filling 1 , fructokinase and hexokinase (HK), and promoted the accumulation of soluble sugars. Meanwhile, the downregulation of HK and upregulation of plastidic phosphoglucomutase reduced the carbon flow through glycolysis and promoted glycogenesis. The downregulation of OsbZIP58 and the deleterious effect on ribosome formation might result in the reduction of storage protein synthesis and increased free amino acids content in ss3a. The higher levels of amylose and lipids could form more amylose-lipid complexes (starch phospholipids), resulting in a higher resistant starch content. Taken together, our study unraveled a functional cross talk between starch, protein and lipids in rice endosperm during seed development of ss3a , providing new insights for formation of high resistant starch in rice. [Display omitted] [ABSTRACT FROM AUTHOR]

A new dull grain rice mutant with low amylose content, designated lowac1 , has been isolated and characterized. To identify the causal mutation site, resequencing of the whole genome and analysis of a cleaved amplified polymorphic sequence (CAPS) marker were performed. Genotypes using the CAPS marker of the identified LowAC1 gene encoding an RNA recognition motif (RRM) protein were entirely consistent with low amylose phenotypes in BC 1 F 2 progeny. Moreover, the segregation of BC 1 F 2 population indicated that the low amylose phenotype was controlled by a single recessive gene. lowac1 involves a single-nucleotide polymorphism from G to A within the gene, resulting in the stop codon generation. The RRM protein deletion in the mutant seed specifically affected the splicing efficiency of Waxy b (Wx b ) in the 5′ splice site of intron 1, resulting in decreased protein levels of granule-bound starch synthase I (GBSSI) encoded by Wx b . Whereas, the RRM protein did not affect amylose content in Wx a of indica variety. Also, the mutation induced a little variation in the expression levels of some genes involved in starch biosynthesis. Particularly, expression levels of SBEIIb , PUL , and AGPL2 mRNAs in lowac1 mutant were approximately two times higher compared to the corresponding wild type (WT) genes. Aside from low amylose content, lowac1 seeds included an amylopectin structure reducing short chains compared to that of WT seeds. Overall, our data suggest that LowAC1 is a novel regulatory factor for starch synthesis in rice. • A novel low-amylose mutant generated by SNP in LowAC1 was isolated. • LowAC1 gene encodes an RNA recognition motif (RRM) protein. • The deletion of LowAC1 protein led to alternative splicing of the Waxy b gene. [ABSTRACT FROM AUTHOR]

Improving grain filling in the presernt farming systems is crucial where grain filling is a concern due to the extreme use of chemical fertilizers (CF). A field experiment was conducted at the experimental station of Guangxi University, China in 2019 to test the hypothesis that cattle manure (CM) and poultry manure (PM) combined with CF could improve rice grain filling rate, yield, biochemical and qualitative attributes. A total of six treatments, i.e., no fertilizer (T 1), 100% CF (T 2), 60% CM + 40% CF (T 3), 30% CM + 70% CF (T 4), 60% PM + 40% CF (T 5), and 30% PM + 70% CF (T 6) were used in this study. Results showed that the combined treatment T 6 increased starch metabolizing enzymes activity (SMEs), such as ADP-glucose phosphorylase (ADGPase) by 8 and 12%, soluble starch synthase (SSS) by 7 and 10%, granule bound starch synthesis (GBSS) by 7 and 9%, and starch branching enzyme (SBE) by 14 and 21% in the early and late seasons, respectively, compared with T 2. Similarly, higher rice grain yield, grain filling rate, starch, and amylose content were also recorded in combined treatments. In terms of seasons, higher activity of SMEs , grain starch, and amylose content was noted in the late-season compared to the early season. The increment in these traits was mainly attributed to a lower temperature in the late season during the grain filling period. Furthermore, our results suggested that an increment in starch accumulation and grain filling rate were mainly associated with the enhanced sink capacity by regulating key enzyme activities involved in Suc-to-starch conversion. In-addition, RT-qPCR analysis showed higher expression levels of AGPS2b, SSS1, GBSS1, and GBSE11b genes, which resultantly increased the activities of SMEs during the grain filling period under combined treatments. Linear regression analysis revealed that the activity of ADGPase, SSS, GBSS, and SBE were highly positively correlated with starch and amylose accumulation. Thus, we concluded that a combination of 30% N from PM or CM with 70% N from CF is a promising option in terms of improving rice grain yield and quality. Our study provides a sustainable fertilizer management strategy to enhance rice grain yield and quality at the lowest environmental cost. [ABSTRACT FROM AUTHOR]

Recent findings suggest that optimal application of nitrogen fertilizers can effectively improve the quality of proso millet (PM). Here, we aimed to investigate the pathways associated with starch synthesis and metabolism to elucidate the effect and molecular mechanisms of nitrogen fertilization in starch synthesis and properties in waxy and non-waxy PM varieties using transcriptomic techniques. Co-expression network analysis revealed that the regulation of starch synthesis and quality in PM by nitrogen fertilizer mainly occurred in the S2 and S3 stages during grain filling. Nitrogen fertilization inhibited glycolysis/gluconeogenesis and starch biosynthesis in grains, but increased starch degradation to maltose and dextrin and then to glucose. Moreover, nitrogen fertilization increased starch accumulation by upregulating the expression of SuS and malZ genes, thereby increasing the total starch content in grains. In contrast, nitrogen fertilization suppressed the expression of GBSS gene and decreased amylose content in PM grains, resulting in a relatively higher crystallinity, light transmittance, and breakdown viscosity in the two PM varieties. Overall, these results provided transcriptomics insights into the molecular mechanisms by which nitrogen fertilization regulates starch quality in PM, identified key genes that associated with the starch properties, and provided new insights into the quality cultivation of PM. [Display omitted] [ABSTRACT FROM AUTHOR]

Starch is the main component of crop grains. Jasmonate-ZIM domain (JAZ1), is a transcriptional repressor in the jasmonate signaling pathway, has been widely studied in plant development, and stresses responses. However, its function in crop starch biosynthesis remains unclear. In this study, the intrinsic relationship between TaJAZ1 and starch biosynthesis was studied using barley stripe mosaic virus-induced gene silencing (BSMV-VIGS) method. The results showed that, compared with the control, grain length, thousand kernel weight, contents of total starch and amylopectin were significantly increased in grains of BSMV- TaJAZ1 -silenced plants. And its starch ultrastructures, such as volume, surface area, relative crystallinity, and some viscosity parameters were also significantly changed in above grains. Moreover, the molecular mechanisms of TaJAZ1 involving starch biosynthesis were further explored by measuring the expression levels of starch synthesis-related genes. Results showed that TaJAZ1 gene silencing increased the expression of TaAGPS1 , TaAGPL1 , TaBEIIb and TaSSI and decreased TaGBSSI or TaSSIIIa , while their expressions were separately decreased or increased in TaJAZ1 transiently overexpression wheat plants. To conclude, these findings showed that TaJAZ1 involved starch synthesis by affecting the expression levels of six starch synthesis enzyme-related genes further changing the components, ultrastructures, and physicochemical properties of starch in wheat grain. • TaJAZ1 silencing increased grain starch contents. • TaJAZ1 silencing changed molecular and crystalline structures of starch. • TaJAZ1 silencing increased pasting properties of grain starch. • TaJAZ1 regulated the expression of starch synthesis-related genes. [ABSTRACT FROM AUTHOR]

Highlights • Waxy and non-waxy barley flours were selected for the extraction of starch nanoparticles. • Organic and alkali treatments were adopted to purify the barley waxy cultivar. • Nanoparticles with reduced mean diameter and thermal stability originated from waxy starch. • Amorphous nanoparticles derived from waxy and non-waxy barley starches were extracted. Abstract Waxy and non-waxy barley flours were selected as native material for the extraction, by acidic hydrolysis, of starch nanoparticles (NPs), with the main aim of evaluating how their different amylose/amylopectin ratio affected NPs structural characteristics. To this scope, two approaches based, respectively, on the use of NaCl/toluene (called organic treatment) and of sodium hydroxide solutions (called alkali treatment) were adopted in order to purify the waxy flours to give starch granules. Morphological investigations of waxy flour after alkali and organic treatments, before and after acetone washing, showed that the isolation methods of the starch did not affect the general morphologic characteristics of starch granules. The method found to provide the best outcomes in terms of thermal and morphological properties was also applied to purify the non-waxy barley. The results confirmed that waxy starch characterized by granules of smaller dimensions (WS) gave amorphous nanoparticles (WNP) with reduced mean diameter and thermal stability with respect to NPs obtained from non-waxy barley flour. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Waxy potato starch nanocrystals (SNCs) were modified by octenyl succinic acid. • Crystalline structure of SNCs preserved after the esterification. • Hydrophobicity of SNCs was controlled by adjusting octenyl succinic acid content. • Prominent compatibility and stability of SNCs in chloroform were exhibited. Abstract Waxy potato starch nanocrystals (SNCs) were successfully modified through esterification by using octenyl succinic anhydride (OSA) aiming to improve its hydrophobicity. The SNCs were characterized by using 1H nuclear magnetic resonance (1H NMR) spectroscopy, X-ray diffraction (XRD), Fourier transformation infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), dispersion experiments and scanning electron microscopy (SEM). The degree of substitution (DS) was determined by means of 1H NMR revealed the upward trend with the increase of OSA dosage. XRD displayed the un-changed crystalline structure of SNCs but relative slight decrease of crystallinity. FT-IR spectroscopy showed characteristic absorption of the ester carbonyl groups and carboxylate RCOO− enclosed to 1732 cm-1, 1572 cm-1 respectively in OSA-SNCs. XPS confirmed the introduction of long chain hydrocarbon. The hydrophobicity of the modified SNCs increased with the increase of applied OSA contents. Dispersion experiments revealed the prominent compatibility and stability of nanocrystals in chloroform and acetone. SEM micrographs showed the serious aggregation of OSA-SNCs composed of smaller blocklets with 200–800 nm in size. [ABSTRACT FROM AUTHOR]

Abstract In grapevine (Vitis vinifera L.) buds, the short day (SD)-photoperiod induces endodormancy and increases the level of ABA and the expression of ABA key biosynthesis genes, which suggests that ABA could be the mediator of the photoperiodic induction of endodormancy. In the present study, it was established that during the development of the endodormancy, the content of ABA and the accumulation of starch increased in parallel in the buds; however, these increases occurred after the buds were already in the state of endodormancy. Despite this finding the exogenous applications of ABA to single-bud cuttings increased the starch content and up-regulated the expression of starch synthesis genes (VvSS1 and VvSS3) and down-regulated the expression of sucrose metabolism genes, invertase (VvINV) and sucrose phosphate synthase (VvSUPS). In addition, the manipulation of the endogenous content of ABA in the grapevine buds by applications of hydrogen cyanamide and uniconazole- P , revealed that the depth of the endodormancy depends on the ABA levels. Taken together, the results indicate that the development of the endodormancy in grapevine buds is associated with the accumulation of starch and a shift in metabolism towards a storage metabolism; as ABA stimulates both processes, it must play an important role in the maintenance and release but not the induction of endodormancy in grapevine buds. [ABSTRACT FROM AUTHOR]

Abstract Although sweetpotato is an important crop worldwide, there has been almost no research on the occurrence of internal browning (IB) to date. In this study, we clarified the mechanism of occurrence of the disorder by using two types of cultivars with different IB susceptibility. In cells around the secondary vascular tissue, large size of starch grains accumulated in IB-susceptible cultivar compared with resistant one. Histochemical observation performed on cells around the secondary vascular tissues showed the presence of high levels of polyphenol oxidase activity, chlorogenic acid, and hydrogen peroxide in cells from the IB-affected regions in IB-susceptible cultivar. Likewise, high levels of starch content, hydrogen peroxide concentration, and polyphenol content were detected in the affected regions of IB-susceptible cultivar. In IB-susceptible cultivar, both the transcript levels of gens related starch and polyphenol biosynthesis were higher at an early stage of root maturation, while the levels in resistant cultivar were low at this stage and thereafter increased relatively more moderately. These observations suggest that the occurrence of IB disorder in sweetpotato largely depends on the morphology and timing of accumulated starch grain in cells around the secondary vascular tissues. Highlights • Intervarietal differences with respect to the severity of internal browning in sweetpotato were examined. • Active ROS generation and polyphenol biosynthesis were observed in cells from affected regions in susceptible cultivar compared with resistant one. • In susceptible cultivar, both the transcript levels of gens related starch and polyphenol biosynthesis were higher at an early stage of root maturation compared with resistant one. [ABSTRACT FROM AUTHOR]

Abstract Background Starch is the most important carbohydrate source of plant species. Both amylose and amylopectin are components of starch whose content and structures contribute to its unique properties used in food processing and industrial applications. Cassava (Manihot esculenta Crantz) is a starchy root crop used as a staple food for human consumption in tropical and sub-tropical regions, as well as in numerous industrial applications. Starch biosynthesis is controlled by various isoforms of several enzymes which are expressed during root development, and considerable effort has been made in understanding the mechanisms of starch biosynthesis and regulation. The improvement of cassava starch for both consumption and the starch industry has been a major goal of breeders. Scope and approach The review summarizes the identification of genes and enzymes involved in starch biosynthesis and the mechanisms of gene regulation in cassava. Quantitative trait loci (QTLs) and candidate genes associated with the important quality traits and mutations affecting starch physicochemical properties are also summarized. Key findings and conclusions A total of 45 genes participating in starch biosynthesis in cassava including ADPG pyrophosphorylase (AGPase), granule bound starch synthase (GBSS), starch synthase (SS), starch branching enzyme (SBE), de-branching enzyme (DBE) and glucan, water dikinase (GWD) have been identified and their functions have been characterized. A total of 110 QTLs for starch content and pasting properties have been identified. These genes and QTLs will contribute to the improvement of starch quality by current biotechnologies, such as transgenic breeding and molecular marker assisted selection. Highlights • Cassava starch quality depends on how starch is biosynthesized. • Identification and function of 43 isoforms in starch biosynthesis are summarized. • Forty seven QTLs for starch content and 63 for pasting properties have been reported. • Mutations affecting starch properties have been identified. • Molecular breeding can be conducted for starch quality improvement in cassava. [ABSTRACT FROM AUTHOR]

Abstract A novel nano fluorescent starch, starch-bearing 3-epoxypropoxy fluorescein (ST-EF) was developed by a simple method. First, 3-epoxypropoxy fluorescein (EF) was prepared via a nucleophilic substitution reaction between fluorescein and epichlorohydrin. Then, ST-EF was synthesized via a ring-opening reaction to attach fluorescein to native cassava starch chains. The degree of substitution (DS) of ST-EF was determined by ultraviolet-visible spectrophotometry. The 1H nuclear magnetic resonance (NMR) spectroscopy, elemental analysis, fourier transformed infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscope (TEM), dynamic laser scattering (DLS), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to characterize ST-EF. Fluorescent properties of ST-EF in water were studied. The results showed that the nano fluorescent starch shows strong fluorescence as fluorescein, and can be used as a fluorescent polymer in various applications, especially in biomedicine. [ABSTRACT FROM AUTHOR]

Abstract Starch digestibility is the dominant factor affecting the nutrition of starchy food. Starch with different digestibility can be obtained through tailoring the starch multi-scale structures by controlling the crop growth period. Here, the multi-scale structure and digestibility of cassava starch obtained from different cassava growth periods were investigated, and the structure-digestibility relationships were revealed. The results indicated that the cassava starch synthesized during different growth periods showed differences in digestibility. The combined total content of slowly digestible starch (SDS) and resistant starch (RS) was highest at the growth period of 7 months, and the individual content of SDS and RS was highest at the growth periods of 10 and 11 months, respectively. The multi-scale structure changes during different growth periods demonstrated that smaller weight-average molecular molar mass, larger molecular density, more ordered short-range structure, and thinner amorphous lamellae decreased starch digestion, while higher amylose content and B 2 chain ratio, longer average chain length, thicker crystalline lamellae, and repeated semicrystalline lamellae contributed the formation of RS fractions. Hence, specific starch structures can be tailored by simply controlling the growth period for obtaining slow and resistant digestible cassava starch to improve its nutritional value. Highlights • Slowly digestible starch (SDS) and resistant starch (RS) changed with growth period. • SDS and RS reached peaks at growth periods of 10 and 11 months, respectively. • Specific starch structures can be tailored by controlling crop growth period. • A growth period-related structure-digestibility relationship of starch was proposed. • Starch with desired digestibility can be obtained at specific crop growth periods. [ABSTRACT FROM AUTHOR]

Lotus (Nelumbo nucifera Gaertn.) is one of the most important aquatic vegetables in China, which is rich in starch and is important sources of energy for livings. Potassium fertilizer has important effects on physiological characteristics, yield and quality of lotus rhizomes. However, the relationship between starch and potassium fertilizer remains unclear. Here, we investigated the relationship between starch quality and potassium fertilizer. Compared with the treatment without potassium fertilizer (CK), the total starch content, amylose content, and amylopectin content of potassium fertilizer treatment 30 kg/667 m2 (K30) were significantly increased. RNA-seq showed that K30 induces more than 2000 differentially expressed genes (DEGs), which mainly enriched in biosynthesis of starch and sucrose metabolism, secondary metabolites, photosynthesis. Meanwhile, K30 significantly promoted the expression of most of key genes and transcription factors involved in the regulation of starch synthesis. We identified a NF-YB transcription factor NnNF-YB1, induced by potassium fertilizer could activate the expression of NnGBSSII by directly bind to its promoter. Transient overexpression of NnNF-YB1 resulted in the increase of total starch, amylose and amylopectin content in rhizomes of lotus. NnNF-YB1 positively regulated the expression of NnGBSSII and plays an important role in starch synthesis under potassium fertilizer treatment. Collectively, our study provides a reference for fertilizer application in lotus production. At the same time, we revealed a new mechanism of potassium fertilizer increasing starch content and improving the quality of starch in rhizomes. • The optimal potassium fertilizer concentration in lotus is 30 kg/666.7 m2 (K30). • K30 promoted the yield and starch content of rhizomes. • Potassium fertilizer induced NnNF-YB1 to regulate starch synthesis of lotus. • Transient overexpression of NnNF-YB1 increases the yield and content of starch. • NnNF-YB1 bound to the promotor of NnGBSS and promote its activity. [ABSTRACT FROM AUTHOR]

The aim of the present investigation was to study the in vitro mineral dialyzability of pasta made with white and whole-grain flours obtained from two genotypes (Klein Guerrero and Baguette Premium 11) with different mineral contents. Pasta samples were made from white flour (FP), and whole grain flour from cyclonic mill (WFAP) and blade mill (WFBP). Mineral content and in vitro digestion were determined on all samples to study starch variation and mineral dialyzability. Whole-grain pasta contained significantly higher amounts of minerals than FP, since bran and embryo are richer in minerals than endosperm. In addition to the low content of mineral composition observed in FP, the dialyzability of some minerals (Cu, Fe, Mg and Zn) was higher than whole-grain pasta even when the percentage of starch hydrolyzed after intestinal digestion was higher than FP. These results can also be useful for developing wheat-based products rich in the desired minerals. [ABSTRACT FROM AUTHOR]

Abstract Waterlogging is one of the most common abiotic stress types in wheat production in many rainy areas of the world. Two locally widely grown winter wheat (Triticum aestivum L. cv Yumai 34 and Yangmai 9) were subjected to post-anthesis waterlogging in a pot experiment to investigate the impacts of waterlogging on the starch synthesis and the physiochemical properties. Post-anthesis waterlogging significantly decreased grain weight and affected the content of starch components. Waterlogging down-regulated the activity and expression of genes encoding soluble starch synthase [SSS (EC 2.4.1.21)], while up-regulated those of the granule bound starch synthase I [GBSSI (EC:2.4.1.242)]. This further resulted in decreased amylopectin content and increased amylose content. Waterlogging also caused a reduction in the number of starch granules, while increased the mean diameter of starch granules in mature grains, which was mainly due to an increase in the volume frequency percent of the A-type starch granules. Waterlogging also lowered the peak viscosity and trough viscosity of starch, but did not affect the breakdown viscosity and peak time. We concluded that the modified expressions of the starch synthase encoding genes were responsible for the changed size distribution of starch granules, which finally affected the starch pasting properties of wheat growing under post-anthesis waterlogging conditions. Highlights • Waterlogging down-regulated the activity and expression of gene encoding the SSS, while up-regulated those of GBSSI. • Waterlogging decreased amylopectin content while increased amylose content. • Waterlogging reduced the number of starch granules, while increased the mean diameter of starch granules in mature grains. • Waterlogging affected the starch pasting properties of wheat grain. [ABSTRACT FROM AUTHOR]

Polymer flooding in HPHT reservoirs using modified biopolymers and their composites acquire incremental attention nowadays. Some literature reported about limitations of native starch through enhanced oil recovery applications regarding bacterial degradation, thermal and ionic stability under severe reservoir environment. In the present study, functionalization of the starch biopolymer with thiol derivative then oxidation of thiol to sulfonic acid by environmentally friendly oxidants has been prepared and confirmed, after that starch derivative copolymerized with vinyl-containing monomers by free radical/redox emulsion polymerization in presence of silica seeds. Spectroscopic characterization and structure determination carried out by different spectroscopic techniques comprising FTIR, 1 H NMR, while particles size measured through DLS and TEM, and thermal analysis determined by TGA analysis. Evaluation of the prepared composite as a novel enhanced oil recovery (EOR) candidate as well as the precursors conducted at simulated reservoir condition, where the oil recovery factor and water cut percentage calculated relevant to injected pore volume. The flooding data indicate that the prepared starch functionalized sulfonic acid co-imidazolium/silica composite is favorable for enhanced oil recovery applications as it can withstand high temperature and salinity conditions and the recovery factor reaches 39% of residual oil saturation. [ABSTRACT FROM AUTHOR]

A thermo and pH dual-responsive starch (TPDS) was successfully synthesized by etherification, in which butyl glycidyl ether (BGE) was used as the hydrophobic reagent followed by addition of 2-chloro-4, 6-diglycino-[1,3,5]-triazine (CDT) groups. The obtained materials were characterized by Fourier transform–infrared spectroscopy (FTIR), 1 H nuclear magnetic resonance ( 1 H NMR) and elemental analysis to confirm the structure and the average substitution degree of BGE and CDT on starch molecule. It was observed that the lower critical solution temperature (LCST) of the TPDS could be modulated from 31 °C to 47 °C by increasing pH of the solution. The effects of pH and the concentration of such materials on the energy-saving performance of TPDS which could be potentially used as smart windows were investigated by UV-vis-NIR spectrophotometry. The solar modulating ability (△T sol ) and the luminous transmittance (△T lum ) of the sample were 40.1% and 47.1% when 10 g/L TPDS was chosen at pH 3. The results indicate that TPDS exhibits excellent optical performance with a controllable LCST, which shows great potential for the application as a smart window. [ABSTRACT FROM AUTHOR]

Starch is a natural biopolymer that subjected to various chemical modifications through different industrial applications. Molecular structure of starch allow its grafting with different vinyl monomers in the presence of crosslinking agents to synthesize cross-linked hydrogels, which used in enhanced oil recovery (EOR) applications, water shutoff and drag reduction. Application of native starch in the field of petroleum reservoirs as a flooding agent suffer from some limitations concerned with microbial degradation, thermal and salinity resistance under harsh petroleum reservoir conditions. In the current research, we stated the synthesis of acryloylated starch then it's grafting with poly (Acrylamide/Vinylmethacrylate/1-Vinyl-2-pyrrolidone) terpolymer in presence of dimethylphenylvinylsilane through emulsification polymerization. Characterization and structure determination occur by different spectroscopic techniques as stated throughout the manuscript. Rheological and solution properties carried out as a function of shear rate, salinity and temperature at simulated reservoir conditions. Flooding tests carried out through linear-dimensional sandstone model at simulated reservoir conditions, and recovered oil amount calculated on volumetric basis. The obtained results indicate that the prepared starch-g-terpolymer can tolerate to severe flooding conditions of high temperature and salinity, moreover it can increase recovery factor up to 49% of residual oil saturation so considered as a promised EOR candidate. [ABSTRACT FROM AUTHOR]

The aim of this work was to isolate starch from different parts of rye grain by a traditional and newly developed enzymatic method, and to compare the physical, chemical and molecular properties of isolated starches, especially focusing on susceptibility to resistant starch (RS) formation. Enzymatic treatment provided a high yield of starch which differed in granularity depending on the parts of grain used for isolation. A share of extreme size granules in starches have a strong impact on swelling and pasting properties. The differences could be explained by molecular properties of starch fractions in the examination of which HPSEC with post-column derivatization was especially helpful showing higher dispersity and molar mass of amylose in starches obtained by the enzymatic method. The derivatized SEC profiles of RS have not been reported earlier. Starches isolated by enzymatic method with a high share of small starch granules were less susceptible to a RS formation. [ABSTRACT FROM AUTHOR]

Aim The purpose of this study was to develop a novel thiolated starch polymer with improved mucoadhesive properties by conjugation of cysteamine to starch as a natural polymer of restricted mucoadhesive properties. Methods Aldehyde substructures were integrated into starch via oxidative cleavage of vicinal diols by increasing amounts of sodium periodate followed by covalent attachment of cysteamine to oxidized starch via reductive amination. Thiol groups were quantified via Ellman’s reaction and their impact on mucoadhesion was analyzed by rheological investigations, the rotating cylinder method and tensile studies on porcine mucosa. Results The total amount of immobilized thiol groups revealed a correlation between degree of oxidation and thiolation. Modified starch demonstrated an up to 1.66-fold increase in water uptake in comparison to native starch. Modification of starch resulted in greatly improved cohesive properties and improvement in mucoadhesion. Rheological investigations revealed a 2- to 4-fold rise in viscosity of mucus. Tensile studies revealed a linear correlation between degree of oxidation/thiolation and enhancement of maximum detachment force and total work adhesion. Conclusion In terms of these results, thiolated starch is a new, promising, polymer in the field of mucoadhesive drug delivery systems. [ABSTRACT FROM AUTHOR]

Wheat is one of the most important crops globally, and its grain is mainly used for human food, accounting for 20% of the total dietary calories. It is also used as animal feed and as a raw material for a variety of non-food and non-feed industrial products such as a feedstock for the production of bioethanol. Starch is the major constituent of a wheat grain, as a result, it is considered as a critical determinant of wheat yield and quality. The amount and composition of starch deposited in wheat grains is controlled primarily by sucrose transport from source tissues to the grain and its conversion to starch. Therefore, elucidation of the molecular mechanisms regulating these physiological processes provides important opportunities to improve wheat starch yield and quality through biotechnological approaches. This review comprehensively discusses the current understanding of the molecular aspects of sucrose transport and sucrose-to-starch metabolism in wheat grains. It also highlights the advances and prospects of starch biotechnology in wheat. [ABSTRACT FROM AUTHOR]

Background Native starches have limited applications and are commonly modified for desired properties. There has been increasing demand for physically and non-chemically modified starches from the market as consumers prefer “natural and healthy” food products. Among various physical means, electric field based techniques have been gaining a research focus for starch modifications during the last few years. Another trend is to produce modified starches using cleaner process. Electric fields of certain conditions can facilitate the “cleaner production” of food and industrial ingredients. Scope and approach This mini-review summarises the modifications of starches from different botanical sources by the electric field based techniques. The techniques are based on pulsed electric field, induced electric field, moderate electric field, and ohmic heating. Physicochemical properties, granular and molecular structures, applications of starch as affected by the electric field based modifications are reviewed. Structure-function relationships of starch as affected by the electric fields are discussed. Impact of electric fields on food systems rich in starch (e.g., flour) is also reviewed. Research gaps to better utilize these techniques for starch modifications are suggested. Key findings and conclusions Different electric field based methods greatly modify the starch physicochemical properties to different extents. Factors affecting the outcomes of the modifications include the starch type and concentrations, electrical conductivity, and electric field type, strength, and duration. Starch modification processes such as hydrolysis and substitutions can be efficiently optimized by applying electric fields. The functionalities of food systems rich in starch can also be modified by these techniques. It becomes evident that electric field based techniques have potential to be used in starch modifications to create a range of functionalities and to help meet the ever-rising market of clean label ingredients. [ABSTRACT FROM AUTHOR]

Starch blends is an alternative method for achieving new technological properties, avoiding the use of chemical, modifications. Starches from pea (PS), rice (RS) and arracacha (AS) were mixed in different ratios utilizing simplex-centroid design, in order to evaluate the impact of these combinations on thermal, pasting and structural properties. It was established a maximum limit of 100% and minimum of 0% for each of the studied starches. Differential scanning calorimetry analysis show an increase on gelatinization temperatures ( T o , T p and T c ), when elevated RS concentrations. Furthermore, these parameters decreased with higher AS ratios. Thermogravimetric curves exhibited three characteristic mass losses. Stability increase was evidenced during dehydration in the interaction between starches, showing additive behavior between the studied samples. It was showed through viscoamilograms (RVA) an increase in peak viscosity, related to high AS ratios. The mixtures application was fundamental for the detection of synergistic or additive effects among the starches. [ABSTRACT FROM AUTHOR]

Industrial biotechnology aims to produce bulk chemicals including polymeric materials and biofuels based on bioprocessing sustainable agriculture products such as starch, fatty acids and/or cellulose. However, traditional bioprocesses require bioreactors made of stainless steel, complicated sterilization, difficult and expensive separation procedures as well as well-trained engineers that are able to conduct bioprocessing under sterile conditions, reducing the competitiveness of the bio-products. Amid the continuous low petroleum price, next generation industrial biotechnology (NGIB) allows bioprocessing to be conducted under unsterile (open) conditions using ceramic, cement or plastic bioreactors in a continuous way, it should be an energy, water and substrate saving technology with convenient operation procedure. NGIB also requires less capital investment and reduces demand on highly trained engineers. The foundation for the simplified NGIB is microorganisms that resist contaminations by other microbes, one of the examples is rapid growing halophilic bacteria inoculated under high salt concentration and alkali pH. They have been engineered to produce multiple products in various scales. [ABSTRACT FROM AUTHOR]

As well-documented inhibitors of starch digestive enzymes, dietary phenolics are less known for the ability to modify starch structures and functionality. This study aimed to characterize changes in starch structures by complexing individual phenolic acids with maize amylopectin and potato starch respectively, and to determine pasting properties and digestibility of the resulting complexes. FTIR-ATR results confirmed (995/1022 and 1047/1022 cm −1 /cm −1 ) reduced crystallinity in short-range order of both starches, which were likely caused by a decrease in moisture content and/or by attenuation of molecular interactions in both crystalline and amorphous lamellas. Measurements of apparent amylose content and amylose leaching discovered formation of amylose-like structures in amylopectin and V-type amylose in potato starch. These structural changes were negatively associated with pasting temperature, peak viscosity, hot paste viscosity and cold paste viscosity. Digestibility was modestly lower for starch-phenolic acid complexes than for native starch and starch-phenolic acids mixtures. More interestingly, a small fraction of phenolic acids remained bound to starch molecules after pasting of starch-phenolic acid complexes, suggesting bound phenolic acids as a potential factor inhibiting starch hydrolysis. [ABSTRACT FROM AUTHOR]

Corn starch was modified with amino acid by heat-moisture treatment (HMT) to investigate the formation of slowly digestible starch (SDS). SDS content in native corn starch and heat-moisture treated corn starch were 17.91% and 4.35% respectively, while the maximum SDS content in amino acid-heat treated starches (HMT-amino acid) reached 41.07%. HMT-Lys displayed reduced birefringence brightness at the periphery, while for HMT-Asp, a weaker birefringence region was observed but without apparent Maltese crosses. HMT-amino acid showed higher gelatinization temperature and lower gelatinization enthalpy. After HMT, relative crystallinity of amino acid-heat treated starches decreased. The lower ΔH and the lowest relative crystallinity had the highest SDS content (41.07%). The results indicated that structural changes of corn starch mixed with amino acid by HMT significantly affected the digestibility. [ABSTRACT FROM AUTHOR]

The recent trends in microalgal cultures are focused on the biorefinery of the biomass components. Some of them are not completely valorised, for example starch. Since there is a wide market for starch products in food and non-food industries, the exploitation of microalgal starch fractions could improve the economic sustainability of microalgae production. In this perspective, the optimization of nitrogen and carbon source uptake for starch accumulation is a critical point for reducing the nitrogen requirement footprint and to increase CO 2 capture. In this study, four robust microalgal strains, already known as starch-accumulating strain, were investigated: Chlorella sorokiniana , Scenedesmus vacuolatus , Dunaliella tertiolecta , and Tetraselmis chuii. C. sorokiniana was selected as the best starch producer in the biorefinery context, and the role nitrogen and CO 2 concentration had on the starch production was investigated. For light irradiance of 300 μmol m −2 s −1 the optimal nitrogen concentration for growth and starch accumulation resulted 32 mg L −1 . The CO 2 concentration clearly does not influence the starch accumulation, but concentrations distant from 2% negatively influence microalgal growth, affecting the final starch productivity. The biomass composition during the batch growth of C. sorokiniana was also analysed in order to explicitly characterise the dynamic of starch accumulation during the different growth phases. Protein content decreased during N-depletion, carbohydrates were mainly produced during the early N-depletion, followed by the accumulation of lipids in the late depletion. [ABSTRACT FROM AUTHOR]

A comparative experiment about the production of starch nanocrystals (SNCs) with/without glucoamylase enzymatic pretreatment by sulfate acid hydrolysis from waxy potato starch (WPS) was employed in the present study. The research focused on the enhancement of the preparation efficiency while improving the dispersion of SNCs at the same time. The enzymatic pretreatment resulted in the decrease of acid hydrolysis duration. The minimum size and best dispersibility of nanocrystals was obtained after 5 days of hydrolysis. X-ray diffraction confirmed the increase of crystallinity (from 33% to 50.8%) and the polymorphic transitions (B–A) for nanocrystals harvested at day 5. The structure of nanocrystals was characterized by FT-IR, which suggested the presence of sulfate ester on the surface of SNCs. Zeta potential and size distribution revealed the prominent stability and dispersibility of nanocrystals at pH 7.0. SEM and TEM revealed that SNCs had square shapes with particle sizes ranging from 50 to 100 nm. [ABSTRACT FROM AUTHOR]

Starches isolated from buckwheat and potato were subject to different doses of irradiation at 0, 5, 10, 15 and 20 kGy. Native and irradiated starch samples were evaluated for their physicochemical and functional properties to assess the effect of gamma irradiation. Apparent amylose content decreased significantly from 26.84% to 22.12% and 27.01 to 16.11% for buckwheat and potato starch respectively as the dose increased. A significant decrease was observed in pH, swelling power and syneresis as the dose increased for both buckwheat and potato starch. pH decreased from 5.20 to 3.81 and 5.81 to 3.95 for buckwheat and potato starch, respectively. Carboxyl content, freeze thaw stability, water and oil absorption capacity and transmittance showed increasing trend with increasing irradiation dose. Carboxyl content increased from 0% to 0.23% and 0–0.22% for buckwheat and potato starch, respectively. [ABSTRACT FROM AUTHOR]

Effects of gamma irradiation on the physicochemical, rheological and thermal properties of the buckwheat and oat starch were studied. Results revealed that the transition temperature and enthalpy of gelatinization of starch decreased with increase in irradiation dose. Pasting properties (peak, trough, setback, pasting temperature and final viscosity) of both the starches were decreased by gamma irradiation. Gamma irradiation also resulted in the reduction in the per cent crystallinity of the starches. Apparent amylose content and swelling index decreased with increase in dose. However, solubility index was increased by gamma irradiation. No surface fissures were seen in irradiated starches. FTIR spectra pattern did not change by gamma irradiation. [ABSTRACT FROM AUTHOR]

The selected thermal and rheological properties of pumpkin starches were compared with values evaluated for corn and potato starch. The pumpkin starches had lower pasting temperatures (by near 3 °C and 24 °C than potato or corn starch respectively), the peak viscosity (nearly 2300 mPa s lower than potato starch) and higher final viscosities (by 80–120 mPa s than those for potato starch and by 1700 mPa s in relation to corn starch). The thermal profile of pumpkin starches examined by the DSC method were quite similar to those of potato starch but lower than those of corn. The retrogradation degree of pumpkin starch was lower by 5–26% than that for corn or potato starches. The thermal treatment of starches led to the formation of radicals. Pumpkin starches were less susceptible to the formation of radicals than potato starch and had less about 0.3–1.3 × 10 15 radicals/g than potato starch. [ABSTRACT FROM AUTHOR]

Since their discovery over 100 years ago cyclodextrins (CDs) have been the subject of numerous scientific publications. In 2016 alone CDs were the subject of over 2200 research articles published in peer-reviewed journals and mentioned in over 2300 patents and patent applications, many of which were on pharmaceutical applications. Natural CDs and their derivatives are used as enabling pharmaceutical excipients that enhance aqueous solubility of poorly soluble drugs, increase drug permeability through biological membranes and improve drug bioavailability. Unlike conventional penetration enhancers, their hydrophilic structure and high molecular weight prevents them from penetrate into lipophilic membranes leaving biological membranes intact. The natural CDs and some of their derivatives have monographs in pharmacopeias and are also commonly used as food additives and in toiletry products. CDs form inclusion complexes with lipophilic moieties of hydrophobic drugs. Furthermore, CDs are able to form non-inclusion complexes and self-assembled aggregates; small and large complex aggregates with micellar-like structures that can enhance drug solubility. Excipients commonly used in pharmaceutical formulations may have additive or inhibiting effect on the CD solubilization. Here various methods used to investigate CD aggregate formation are reviewed as well as techniques that are used to increase the solubilizing effects of CDs; methods that enhance the apparent intrinsic solubility of drugs and/or the complexation efficacy and decrease the amount of CD needed to develop CD-containing pharmaceutical formulations. It will be explained how too much or too little CD can hamper drug bioavailability, and the role of CDs in solid dosage forms and parenteral formulations, and examples given on how CDs can enhance drug delivery after ocular, nasal and pulmonary administration. [ABSTRACT FROM AUTHOR]

Waxy maize starch was mechanically treated with a planetary ball mill. X-ray diffraction analysis was employed to determine the optimal ball milling time. After ball milling, the pretreated starch was hydrolyzed with H 2 SO 4 . The hydrolysates were obtained and their relative crystallinity, morphology, and particle size were estimated by X-ray diffraction analysis, atomic force microscopy, and nanoparticle size analyzer, respectively. The results revealed that it is possible to obtain starch nanocrystals (SNCs) after a combination of ball milling and 3 days of H 2 SO 4 hydrolysis with a yield of 19.3 wt% with a shape similar to those acquired by the conventional procedure after 5 days of sulfuric acid hydrolysis, with a yield of 15.8 wt%. Round-edge SNCs with an average diameter of approximately 31 nm were observed. The results revealed that by controlling some parameters, certain mechanical processing methods considered unsuitable could also be applied to the preparation of SNCs. [ABSTRACT FROM AUTHOR]

Starch is an emerging polymer in biomedical research area due to its ease of availability, low- cost and biological values. Starch polymer has been used as powder and film in applications such as tissue engineering and hemostatic application. Starch in fibrous form is very difficult to produce due to the branched amylopectin structure. With the advent of electrospinning fibrous form of starch is attempted by various researchers. The present paper reports comprehensive review of attempts made on electrospinning of starch and its potential applications in biomedical and tissue engineering. [ABSTRACT FROM AUTHOR]

Interest in use of resistant starch and maltooligosaccharides as functional foods and biopreservatives has grown in recent years. In this research, a novel debranching enzyme IsoM from Corallococcus sp. strain EGB was identified and expressed in P. pastoris GS115. Sequence alignments showed that IsoM was typical isoamylase with the specific activity up to 70,600 U/mg, which belongs to glycoside hydrolase family 13 (GH 13). Enzymatic reaction pattern demonstrated that IsoM has high debranching efficiency against α-1,6-glycosidic bond of branched starch, and exhibited no activity towards α-1,4-glycosidic bond. The potential application of IsoM in starch processing was determined. IsoM was a potential candidate for the production of RS (70.9%) from raw starch, which was comparable with the commercial pullulanase (Promozyme ® D2). IsoM also improved the maltohexaose yield in combination with maltohexaose-producing α-amylase AmyM (KM114206), the maltohexaose yield was improved by 63.3% compared with 21.9% improvement of Promozyme ® D2. The results of RS production and combination with other amylases suggesting that IsoM is a potential candidate for the efficient conversion of starch. [ABSTRACT FROM AUTHOR]

Starches were isolated from adzuki bean ( Vigna angularis L.) and edible kudzu ( Pueraria thomsonii Benth) and investigated for their physico-chemical, morphological, pasting, crystallinity, thermal and FT-IR spectroscopic characteristics. Statistical analysis of physico-chemical and functional characteristics showed significant ( p < 0.05) difference between isolated starches from adzuki bean and edible kudzu. The XRD pattern of starches from adzuki bean and edible kudzu showed A-type with reflections (2 θ ) at 15.0°, 17.03°, 17.89°, 23.18°and 15.12°, 17.03°, 17.77°, 23.3°, respectively. The starch granules from adzuki bean were smooth, round, oval to kidney or irregular while those of edible kudzu starch were spherical, hemispherical and polygonal. Edible kudzu starch exhibited high pasting temperature, gelatinization temperatures, enthalpy and less pasting parameters as compared to starch from adzuki bean. Peaks in FT-IR spectra of both starches shown its carbohydrate nature. Starch from adzuki bean showed high swelling power and solubility as compared to edible kudzu, and enhanced the swelling power and solubility of isolated starches with the temperature raised from 50 °C and 90 °C. Finally, this work offers data for the application of starches isolated from adzuki bean and edible kudzu that would be applicable for both food and non-food industries. [ABSTRACT FROM AUTHOR]

Starch nanoparticles (StNPs) were previously prepared using severe mechanical, physical and/or chemical conditions that takes too long time to produce a little yield of uncontrolled large size of StNP. The current work presents a new technique for the synthesis of StNPs based on the combination between sodium hydroxide and glycerol in aqueous medium during the synthesis process while the precipitation of the StNPs is performed under homogenization at ambient conditions. The new technique is based on three assumptions: 1) the dual impact of sodium hydroxide and glycerol on the swelling and gelatinization of starch as a pre-stage of the synthesis of (StNPs1), 2) the dual impact of glycerol and cooking of starch on the swelling and gelatinization of starch as a pre-stage of the formation of (StNPs2), and 3) the precipitation under homogenization at ambient conditions and its effect on breaking the H- bonds of the starch molecule in both StNPs1 and StNPs2. The importance of this technique arises from the ease of the process, the eco-friendly chemicals and the combination between the mechanical and chemical processes. NS (native starch), StNPs1 and StNPs2 were characterized using FTIR, XRD, TGA and TEM. TEM of StNPs1 showed a well-defined round particles uniformly distributed with size of about 62.5 nm. StNPs2 showed a non-specific shape starch particles. [ABSTRACT FROM AUTHOR]

Functional interactions of plastidial phosphorylase (Pho1) and starch branching enzymes (BEs) from the developing rice endosperm are the focus of this study. In the presence of both Pho1 and BE, the same branched primer molecule is elongated and further branched almost simultaneously even at very low glucan concentrations present in the purified enzyme preparations. By contrast, in the absence of any BE, glucans are not, to any significant extent, elongated by Pho1. Based on our in vitro data, in the developing rice endosperm, Pho1 appears to be weakly associated with any of the BE isozymes. By using fluorophore-labeled malto-oligosaccharides, we identified maltose as the smallest possible primer for elongation by Pho1. Linear dextrins act as carbohydrate substrates for BEs. By functionally interacting with a BE, Pho1 performs two essential functions during the initiation of starch biosynthesis in the rice endosperm: First, it elongates maltodextrins up to a degree of polymerization of at least 60. Second, by closely interacting with BEs, Pho1 is able to elongate branched glucans efficiently and thereby synthesizes branched carbohydrates essential for the initiation of amylopectin biosynthesis. [ABSTRACT FROM AUTHOR]

The present work investigates the synergistic impact of glucoamylase and ultrasound on starch hydrolysis. The extent of starch hydrolysis at different reaction parameters (ultrasonic intensity, temperature, reaction time) was analyzed. The hydrolysis extent increased with the reaction time and reached a maximum value under ultrasonic intensity of 7.20 W/mL at 10 min. Ultrasound did not alter the optimum enzymatic temperature but speeded up the thermal inactivation of glucoamylase. The evaluation of enzymatic kinetics and starch degradation kinetics indicated a promotion of the reaction rate and enzyme-substrate affinity. According to the thermodynamic results, sonoenzymolysis reactions require less energy than enzymolysis reactions. The measurement of molecular weight, solubility, thermal properties, and structures of the substrates revealed that sonoenzymolysis reaction generated greater impacts on starch properties. The molecular weight and radii of gyration decreased by 80.19% and 90.05% respectively while the starch solubility improved by 136.50%. [ABSTRACT FROM AUTHOR]

In a marine green starch-producing microalga Tetraselmis subcordiformis , the role of starch phosphorylase (SP) in the starch biosynthesis was disclosed by characterizing the enzyme properties and activity variations during the starch accumulation process. TsSP4, a SP isoform accounting for the major SP activity in T. subcordiformis , was unique to be active in a monomer form with a molecular weight of approximately 110 kDa. It resembled one of the chloroplast-located SPs (PhoA) in Chlamydomonas reinhardtii with a similarity of 63.3% in sequence, though it possessed the typical L78/80 domain found in the plastidial SPs (Pho1) of higher plants that was absent in PhoA. TsSP4 exhibited moderate sensitivity to ADP-Glc inhibition and had a high activity for longer-chain linear maltooligosacchride (MOS) and amylopectin against highly branched glycogen as the substrates. TsSP4 had 2-fold higher affinity for Glc-1-P in the synthetic direction than for Pi in the phosphorolytic direction, and the catalytic constant k cat for Glc-1-P was 2-fold of that for Pi. Collectively, TsSP4 preferred synthetic rather than phosphorolytic direction. TsSP4 could elongate MOSs even initially with Pi alone in the absence of Glc-1-P, which further supported its synthetic role in the starch biosynthesis. TsSP4 displayed increased activities in the developing and mature stage of starch biosynthesis under nitrogen-starvation conditions, indicating its possible contribution to the amylopectin amplification. [ABSTRACT FROM AUTHOR]

From the view of multi-scale structures of hydroxypropyl starch (HPS)/carbon nanotube (CNT) nanocomposite films, the film physicochemical properties were affected by comprehensive factors including molecular interaction, short range molecular conformation, crystalline structure and aggregated structure. The less original HPS hydrogen bonding that was broken, less decreased order of HPS short range molecular conformation, lower film crystallinity and larger size of micro-ordered regions contributed to higher tensile strength and Young’s modulus of the film with CNT content of 0.5% (g/g, CNT in HPS). The higher film overall crystallinity and larger size of micro-ordered regions of the film with CNT content of 0.05%–0.3% compared with those of control contributed to better film barrier property. The addition of CNT with the content of 0.05%–0.5% broke the original HPS hydrogen bonding and decreased the order of starch short range molecular conformation, which counteracted the positive effect of CNT on the thermal stability of the material, thus thermal degradation temperature of these nanocomposite films did not increase. But the sharp increase of film crystallinity increased film thermal degradation temperature. This study provided a better understanding of film physicochemical properties changes which guides to rational design of starch-based nanocomposite films for packaging and coating application. [ABSTRACT FROM AUTHOR]

Gowé is an acidic beverage obtained after simultaneous saccharification and fermentation (SSF) of sorghum. A previous paper focused on modeling the growth of lactic acid bacteria during gowé processing. This paper focuses on modeling starch amylolysis to build an aggregated SSF model. The activity of α-amylase was modeled as a function of temperature and pH, and the hydrolysis rates of both native and soluble starch were modeled via a Michaelis-Menten equation taking into account the maltose and glucose inhibition constants. The robustness of the parameter estimators was ensured by step by step identification in sets of experiments conducted with different proportions of native and gelatinized starch by modifying the pre-cooking temperature. The aggregated model was validated on experimental data and showed that both the pre-cooking and fermentation parameters, particularly temperature, are significant levers for controlling not only acid and sugar contents but also the expected viscosity of the final product. This generic approach could be used as a tool to optimize the sanitary and sensory quality of fermentation of other starchy products. [ABSTRACT FROM AUTHOR]

Encapsulation is a widely used method to preserve core material from environmental influences and for controlled release of the core material. Here, we demonstrate a fast and facile method to prepare such core-shell microgranules by encapsulating starch with nanometric silica particles using spray drying. The virgin spray dried powder contained silica at shell and starch at the core. The powder granules were pyrolyzed to convert the virgin encapsulated starch granules into carbon-silica core-shell microgranules. The mesoscopic structure of the synthesized microgranules was probed by electron microscopy, scattering techniques and infrared spectroscopy. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) pretreatment has emerged as a promising technology toward environmentally benign conversion of lignocellulosic residues into high value cellulosic fiber as sustainable raw material for biocomposite fabrication. This study presents a comparison of ILs-assisted pretreatment of oil palm fronds (OPF) fiber with dilute acid, alkaline, and hot compressed water pretreatments on the mechanical and thermal properties of their fabricated thermo-molded biocomposites with thermoplastic starch as a biopolymer binder. A comparison of energy consumption for ILs pretreatment with other pretreatment methods was also performed and the comparative impact of ILs pretreatment on OPF fiber was investigated by lignocellulosic composition, crystallinity and thermal stability analysis for untreated and all pretreated fibers. Results indicate that ILs pretreatment is superior in terms of delignification of OPF and produces cellulose rich fiber (CRF) with 48–50% reduced crystallinity as compared to those of acidic, alkaline, and hot water pretreated fibers. However, the flexural strength of the IL [emim][dep] treated composite (13.8 MPa) was significantly improved over that of untreated composite with value of 5.3 MPa, but was slightly higher than acidic and hot water pretreatments which were 13.5 MPa and 10.8 MPa, respectively. ILs pretreatment consumed about 0.5–2.0 folds more energy per kg of OPF residue as compared to other methods. In the premises of the present findings, we believe that ILs-based pretreatment could be a new, clean and promising alternative processing approach for conversion of a wide variety of agro-based lignocellulosic waste materials into cellulose-rich fibers for manufacturing of engineered biocomposite panels. [ABSTRACT FROM AUTHOR]

Maize is an important food crop and industrial material owing to its high starch content. However, the mechanism of starch synthesis is not fully elucidated, especially with regard to the expression and regulation of starch synthetic genes. The APETALA2/Ethylene Responsive Factor (AP2/ERF) family plays a crucial role in various biological processes via regulating gene expression. In this study, the ZmEREB94 gene was identified through co-expression analysis. Bioinformatics analysis confirmed that ZmEREB94 belongs to the AP2/ERF family. Expression pattern analysis showed that this protein is strongly expressed in the maize endosperm. A ZmEREB94-GFP fusion protein was localized in the nuclei of onion epidermal cells, and ZmEREB94 showed strong transcriptional activation activity, which indicated that this protein is a transcription factor. In addition, yeast-one hybrid assays and transient expression in maize endosperm showed that ZmEREB94 could directly bind to the ZmSSI promoter and indirectly regulate ZmSh2 and ZmGBSSI expression. Our results revealed that ZmEREB94 might act as a key regulator of starch synthesis in maize. [ABSTRACT FROM AUTHOR]

Microbial amylases are used to produce ethanol, glucose and can be applied in textiles products, detergents and other industries. This study aimed to determine the best carbon source concentration to induce the amylase production by A. japonicus , and its purification and biochemical characterization. For that, this fungus was cultivated in Khanna medium, pH 5.5, for 4 days, at 25 °C, in static condition, supplemented with potato starch and maltose in different concentrations. The fungal crude enzymatic extract was purified in a unique elution in DEAE-cellulose column and the molecular mass was determined as 72 kDa. The optimum temperature and pH was 65 °C and 5.0, respectively. Amylase remained 75% of its activity after one hour at 50 °C and was stable in the pH range 3.0–7.0. The analysis of the end-products by thin layer chromatography showed only glucose formation, which characterizes the purified enzyme as a glucoamylase. Amylopectin was the best substrate for the enzyme assay and Mn +2 and Pb +2 were good glucoamylase activators. This activation, in addition to the biochemical characteristics are important results for future biotechnological applications of this glucoamylase in the recycling and deinking process by the paper industries. [ABSTRACT FROM AUTHOR]

Four novel starch derivatives modified with quaternary phosphonium salts were designed and successfully synthesized, including trimethylphosphonium acetyl starch chloride, tributylphosphonium acetyl starch chloride, tricyclohexylphosphonium acetyl starch chloride, triphenylphosphonium acetyl starch chloride, and characterized by FTIR, UV, 1 H NMR, 13 C NMR, and 31 P NMR spectra. Their antifungal activities against four kinds of phytopathogens were evaluated using the radial growth assay and minimum inhibitory concentration procedure. The fungicidal assessment revealed that the synthesized starch derivatives had superior antifungal activity compared with starch. Especially, the inhibitory indices of triphenylphosphonium acetyl starch chloride against these four kinds of plant pathogens were higher than 70% at 1.0 mg/mL. The results indicated that quaternary phosphonium groups should be high-efficiency antifungal function groups, and meanwhile longer alkyl chain lengths or the stronger electron-withdrawing groups were responsible for enhanced antifungal versatility and efficacy. The cytotoxicity of starch and starch derivatives bearing quaternary phosphonium salts was evaluated in vitro on HEK-293T cells. As novel quaternary phosphonium functionalized starch derivatives could be prepared efficiently and exhibited superduper antifungal activity, this synthetic strategy might provide an effective way and notion to prepare novel antifungal biomaterials. [ABSTRACT FROM AUTHOR]

In this study a systematic investigation of the temperature effect on the interactions between Pluronic F127 and hydroxypropylated oxidised potato starch by surface tension titrations and quartz crystal microbalance (QCM) analysis is presented. The binary mixture examined was subjected to 20 °C and 30 °C and the results indicated no presence of binary complexes at the lower temperature. However, at elevated temperature, an ability for inclusion complex formation was detected by the here used independent techniques. The formed inclusion complexes at 30 °C are presumably a product of hydrophobic interaction between Pluronic F127 and starch, where starch acts as a host molecule and Pluronic F127 due to its increased hydrophobicity is the guest molecule in this complex. [ABSTRACT FROM AUTHOR]

Four novel 1,2,3-triazolium-functionalized starch derivatives were synthesized by N -alkylating the precursor starch derivatives with 1,2,3-triazole with iodomethane based on cuprous-catalyzed azide-alkyne cycloaddition (CuAAC). The detailed structural characterization was investigated by means of FTIR, UV-vis, 1 H NMR, and 13 C NMR spectra. The antifungal activities of starch derivatives against Colletotrichum lagenarium , Fusarium oxysporum , and Watermelon fusarium , were then assayed by hypha measurement in vitro . The fungicidal assessment revealed that compared with starch and starch derivatives with 1,2,3-triazole, 1,2,3-triazolium-functionalized starch derivatives displayed tremendously enhanced antifungal activity. Especially, the inhibitory indices of 6-(4-hydroxymethyl-3-methyl-1,2,3-triazolium-1-yl)-6-deoxy starch iodine (2a) with against the tested plant threatening fungi attained 70% above at 1.0 mg/mL. It was also found that their antifungal activity profiles were dependent on the variation in alkyl chain length. As novel 1,2,3-triazolium-functionalized starch derivatives could be prepared efficiently and exhibited superduper antifungal activity, this synthetic strategy might provide an effective way and notion to prepare novel antifungal biomaterials. [ABSTRACT FROM AUTHOR]