Pure Starch Research Articles

Rheological and Textural Investigation to Design Film for Packaging from Potato Peel Waste

(1) Background: The recovery of potato waste for circular-economy purposes is a growing area of industrial research. This waste, rich in nutrients and potential for reuse, can be a valuable source of starch for packaging applications. Rheology plays a crucial role in characterizing film-forming solutions before casting. In this work, packaging film was prepared from potato waste using rheological information to formulate the film-forming solution. (2) Methods: To this aim, rheological measurements were carried out on starch/glycerol-only samples, and the data obtained were used to optimize the formulation from the waste. The polyphenol content of the peels was analyzed, and the resulting films were comprehensively characterized. This included assessments of color, extensibility, Fourier-transform infrared (FT-IR) spectroscopy, surface microscopy, and contact angle. (3) Results: Polyphenol-loaded films, suitable for packaging applications, were developed from potato waste. These films exhibited distinct properties compared to those made with pure starch, including an improved wettability of about 75° for the best sample and a high elastic modulus of about 36 MPa, which reduces the deformability but enhances the resistance against the stress. (4) Conclusions: Through rheological studies, we were able to design films from potato peel waste. These films demonstrated promising mechanical performance.

High-Resistant Starch Based on Amylopectin Cluster via Extrusion: From the Perspective of Chain-Length Distribution and Structural Formation.

Resistant starch (RS) has the advantage of reshaping gut microbiota for human metabolism and health, like glycemic control, weight loss, etc. Among them, RS3 prepared from pure starch is green and safe, but it is hard to achieve structural control. Here, we regulate the crystal structure of starch with different chain-length distributions (CLDs) via extrusion at low/high shearing levels. The change in CLDs in extruded starch was obtained, and their effects on the fine structure (Dm, dBragg, dLorentz, degree of order and double helix, degree of crystal) of RS and its physicochemical properties were investigated by SAXS, FTIR, XRD and 13C NMR analyses. The results showed that the RS content under a 250 r/min extrusion condition was the highest at 61.52%. Furthermore, the crystalline system induced by high amylopectin (amylose ≤ 4.78%) and a small amount of amylose (amylose ≥ 27.97%) was favorable for obtaining a high content of RS3-modified products under the extruding environment. The control of the moderate proportion of the A chains (DP 6-12) in the starch matrix was beneficial to the formation of RS.

An intensive exploration of plasticization, tensile, flexural and ecotoxicity of styrene-grafted thermoplastic starch (TPS) composite material

Thermoplastic starch (TPS) is a potential alternative to non-biodegradable plastics. Nevertheless, nice hydrophilicity, poor mechanical property and processability restrain use. Herein, pure corn starch was modified by styrene grafting, then, plasticized by glycerol to prepare TPS composite material. Later, plasticizing behavior, thermal-stability, mechanical property, ecotoxicity, etc. were explored. Main results reveal that styrene was successfully grafted to starch achieving a grafting yield (GY) as 45.58 wt% and grafting converted starch crystalline shape transformation from A to V. Glycerol plasticization furtherly altered crystalline structure and surface wettability. To native species, plasticization induced amorphization; to grafted species, it induced crystalline perfection. Compared to native species grafted starch displayed easier plasticization characteristic and better processability, elevated hydrophobicity and mechanical property. Herein, a glycerol content as 20 wt% is proper. From native to grafted TPS composite material tensile, flexural strengths and modulus were elevated from 8.9, 20.9 and 777–24.2, 56.5 and 1924 MPa. A more important issue is that styrene grafted TPS composite material composting products displayed no-visible ecotoxicity. Where, wheat and mung seeds germination rates and plant fresh and dry masses in systems containing 10 wt% previous TPS composting products are all higher than 90 % those of blank compositing systems, which is in line with EN 13432–2000 standard, non-toxic to environment. It seems via some level styrene grafting possessing nice mechanical property and non-visible ecotoxicity starch material can be prepared, possibly having a potential use in plastic industry in real, which is of great significance and attractive.

Development of polysaccharide bioplastic: Analysis of thermo-mechanical properties and different environmental implications

Despite the distinct benefits of plastics, the environmental impacts stemming from their production and accumulation in the environment have become a global concern. Therefore, the development of new technologies that mitigate these impacts is of notable importance. The present study aimed to evaluate the physicochemical properties of starch-xylan-based bioplastic, and to discuss the viability of this material in terms of applications and ecological impacts. Holocellulose, xylan, and α-cellulose were extracted from waste biomass and combined with starch for bioplastic production. Solubility in food simulants (3% acetic acid, and 90% ethanol) was performed for xylan and starch-based bioplastics. Bioplastic was evaluated to grow Aspergillus versicollor for xylanase production. The bioplastic was evaluated as a photoprotector with yeast exposed to UVC light-covered by the bioplastic for 2 h. Bioplastic disintegration was evaluated in different soil moistures and the disintegration on the surface of the compost. Liquid washes from soils exposed to bioplastic biodegradation were tested for Lactuca sativa seed germination/inhibition. Water from a local lake was exposed to bioplastic and microbial cell density modification was verified. Images of the surface of the bioplastics were obtained by scanning electron microscopy, and characterized by thermogravimetric and dynamic-mechanical analysis. The xylan addition in bioplastic led to a material with a 40–50% decreased ultraviolet light transmittance. An increase in xylan concentration reduced solubility in lipid food simulant solutions, with no fatty solubilization with 25% of xylan. It suggests potential applications in photoprotective and packaging contexts. The thermal degradation temperature of the pure starch bioplastic was 324 °C, and the addition of 10% (287 °C), 15% (286 °C), and 25% (296 °C) xylan (w/w) indicated a reduction in thermal resistance, possibly due to suboptimal interaction between polymer chains. The decrease in crystallinity in the compositions 10/90% (Xc = 20%), 15/85% xylan/starch (Xc = 21%) compared to 25/75% xylan/starch (Xc = 11%) also underscored the complexity of polymer interactions within the bioplastic matrix. Tensile strength of pure starch was 1.21 MPa, while the composition of 15/85% xylan/starch exhibited improved strength 2.99 MPa. Further investigation into the interaction between starch and xylan is warranted. Concerning the disintegration of the 25/75% xylan/starch formulation in the soil, the humidity of the soil matrix played a significant role. The disintegration occurred over 5 days and 16 days in compost (55% humidity) and soil (32.6% humidity), respectively. The results of phytotoxicity (Lactuca sativa seeds) and changes in the physicochemical and biological profile of water (smell, turbidity, phosphorus and nitrogen levels, pH, and bacterial and phytoplankton density/richness), in response to exposure to bioplastics, highlight the necessity of developing this biologically-based and biodegradable technology in concerns about potential environmental impacts. Furthermore, the present study introduces the approach of bioplastic waste recycling using enzyme production biotechnology. In line with the legitimacy of bioplastics as important materials for addressing the challenges posed by their non-biodegradable synthetic counterparts, the presented results broaden the discourse on the feasibility of this biologically based material, contributing to the development of a sustainable society.

Sustainable innovations in postharvest conservation of passion fruit

The study aimed to evaluate the post-harvest quality of sour passion fruit using carnauba wax, cassava starch, and avocado seed extract coatings. The experiments were conducted in randomized blocks with five replications and two fruits per experimental unit. Two coatings associated with biofungicide were used. The carnauba wax treatment consisted of Control: fruits coated with pure carnauba wax, Wax and Extract 1:1, Wax and Extract 1:3, and fruits coated with avocado seed extract solution. The cassava starch treatment consisted of Control: fruits coated with avocado seed extract solution, fruits coated with pure cassava starch, Starch and Extract 1:1, Starch and Extract 1:3, and subplots consisting of six periods: 00, 03, 06, 09, 12, 15 conservation days, for both experiments. Fresh matter mass loss, peel color, longitudinal and transversal diameter, fruit mass, peel mass, pulp mass, total soluble solids, total titratable acidity, ratio, and pH were evaluated. Coatings, individually or in combination, influenced physicochemical attributes, presenting more adequate values for peel thickness and citric acid percentage acid in the juice. The results highlight the influence of storage time on fruit characteristics, emphasizing the need to assess specific approaches to optimize post-harvest conservation.

Effect of curdlan addition and thermal sterilization on the structural and properties of rice starch gel

This study delves into the effects of curdlan integration and thermal sterilization on the rheological properties, structure, and quality attributes of concentrated rice starch gel. Acting as a heat-set polysaccharide, curdlan established a dual-network gel structure with rice starch gel, displaying strong interactions with rice starch, as confirmed by confocal laser scanning microscopy and Fourier-transform infrared spectroscopy. The addition of curdlan expedited the gel formation of rice starch, yielding a denser gel structure. Consequently, this enhanced G′, solid-like behavior, textural properties, and cooking quality while reducing frequency-dependence. Given the cooling-induced gelation behavior of pure rice starch, thermal treatment disrupted inter-chain hydrogen bonding, compromising the structural integrity of the gel. This disruption manifested in a softer texture and diminished mechanical properties and cooking quality. Notably, this decline in mechanical properties and cooking quality of rice starch gel was markedly ameliorated with the incorporation of curdlan, particularly at a content of ≥1.0 %. Compared with pure RS, 1.0 % CD inclusion showed a reduction in cooking breakage rate by 30.69 % and an increase in hardness by 38.04 %. This work provides valuable insights for the advancement of fresh starch gel-based foods that exhibit exceptional quality and an extended shelf life.

Novel starch–tungsten (VI) oxide biocomposites: Preparation, characterization, and comparisons between experimental and theoretical photon attenuation coefficients

This study synthesized biocomposites containing starch and WO3 at varying ratios of 10 %, 20 %, 30 %, 40 %, and 50 % and assessed their thermal and radiation-shielding properties. These biocomposites were characterized using Fourier-transform infrared spectroscopy, X-ray diffraction (XRD) analysis, particle-size distribution assessments, scanning electron microscopy–energy dispersive X-ray spectroscopy, and thermogravimetric analysis–differential thermogravimetry measurements. Furthermore, the linear attenuation coefficients of the biocomposites were experimentally measured using an NaI(Tl) gamma spectrometry system and theoretically computed using XCOM and GAMOS simulations for comparisons. The XRD and particle-size distribution profiles of the WO3.2H2O powder, respectively, demonstrated evident diffraction peaks and favorable pore-size distributions. Morphological characterizations revealed that the WO3 particles were homogeneously dispersed throughout the starch matrix without any agglomeration. Comparisons of the thermal degradation rates revealed that the pure starch and starch +50%WO3 biocomposite began decomposing at approximately 200°Cand 300 °C, respectively, indicating that increasing WO3 proportions enhanced thermal stability. Furthermore, the starch +50%WO3 biocomposite demonstrated the highest experimental linear attenuation coefficient, with a value of 0.2510 ± 0.0848 cm−1 at a gamma energy of 662 keV. Meanwhile, XCOM and GAMOS simulations revealed theoretical attenuation coefficients of 0.1229 and 0.1213 cm−1 for pure starch and 0.2202 cm−1 and 0.2178 cm−1 for the starch +50%WO3 biocomposite at 662 keV, respectively.

Different effects of pea protein on the properties and structures of starch gel at low and high solid concentrations

In the context of starch–protein composite gels, the influence of protein on gel formation significantly shapes the textural attributes of starch gels, leading to distinct outcomes. This study aimed to evaluate how different ratios of pea protein (PP) affect the properties and structures of starch–protein composite gels at low (10 wt%) and high (40 wt%) solid concentrations. The addition of PP had opposite effects on the two gels. Compared to the pure starch gel, the low-concentration composite gel (LCG) with 20 % PP experienced a 48.90 ± 0.33 % reduction in hardness, and the storage modulus (G′) decreased from 14,100 Pa to 5250 Pa, indicating a softening effect of PP on LCG. Conversely, the hardness of the high-concentration composite gel (HCG) with 20 % PP exhibited a 62.19 ± 0.03 % increase in hardness, and G′ increased from 12,100 Pa to 41,700 Pa, highlighting the enhancing effect of PP on HCG. SEM and fluorescence microscopy images showed that PP induced uneven network sizes in LCG, while HCG with a PP content of 20 %, PP, together with starch, formed a three-dimensional network. This study provides valuable insights and guidance for the design and production of protein-enriched starch gel products with different textural properties.

Innovative plasticization technique for talc-powder reinforced wheat-starch biomass composite plastics with enhanced mechanical strength

N-methyl-morpholine-N-oxide (NMMO) was initially created as a plasticizer for starch to produce thermoplastic wheat starch. Subsequently, talc powder was used as a reinforcing filler to enhance the mechanical strength of thermoplastic biomass-based composite plastics. The chemical structure, crystal structure, and microscopic morphology were analyzed using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Additionally, the thermal properties were explored through thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The hydrated NMMO plasticizer demonstrated an outstanding plasticizing effect on starch, resulting in a composite with remarkable mechanical properties. In fact, the pure thermoplastic wheat starch plasticized with hydrated NMMO exhibited the highest mechanical strength recorded so far, with a tensile strength of up to 9.4 MPa. In addition, talcum powder displayed a noticeable reinforcing effect. When the talcum powder content reached 30 wt%, the targeted composite achieved a tensile strength of 20.5 MPa and a Young's modulus of 177.9 MPa. These values were 118 % and 48 % higher, respectively, than those of the pure thermoplastic starch sample. This innovative plasticizing method opens up a new avenue for the development of high-mechanical-strength thermoplastic biomass-based composite plastics with promising potential applications.

Effect of Soy Protein Isolate on Pasting, Rheological, and Textural Attributes of Potato Starch

AbstractThe effects of different concentrations of soy protein isolate (SPI) on the functional, rheological, pasting, and structural properties of potato starch (PS) are investigated. The water and oil absorption capacity (OAC) of PS‐SPI mix increased significantly with the addition of SPI. Gel strength, peak, final, breakdown, and setback viscosity of PS decreases, whereas the pasting temperature increases with an increase in SPI fraction. Both the Herschel–Bulkley and power law model are found to equally fit in steady state rheology. The PS‐SPI blend exhibits pseudoplastic behavior. The addition of SPI decreases the storage (G′) and loss modulus (G″). SPI also lowers the flow stress values in the amplitude sweep test. Frequency sweep confirms the formation of weak gel formation in PS‐SPI blend by exhibiting a lower value of G′ and G″ than the pure starch. The microstructure of composite gel appears less dense with greater pore size than starch gel. The hardness of the SPI‐PS blend gel decreases from 6.76 to 0.85 N when the SPI content is increased from 0% to 50%. Fourier transform infrared (FTIR) confirms that no chemical groups are formed or destroyed during the composite gel‐making process.

Investigation of physio-mechanical, antioxidant and antimicrobial properties of starch–zinc oxide nanoparticles active films reinforced with Ferula gummosa Boiss essential oil

The production of surface compounds coated with active substances has gained significant attention in recent years. This study investigated the physical, mechanical, antioxidant, and antimicrobial properties of a composite made of starch and zinc oxide nanoparticles (ZnO NPs) containing various concentrations of Ferula gummosa essential oil (0.5%, 1%, and 1.5%). The addition of ZnO NPs improved the thickness, mechanical and microbial properties, and reduced the water vapor permeability of the starch active film. The addition of F. gummosa essential oil to the starch nanocomposite decreased the water vapor permeability from 6.25 to 5.63 g mm−2 d−1 kPa−1, but this decrease was significant only at the concentration of 1.5% of essential oils (p < 0.05). Adding 1.5% of F. gummosa essential oil to starch nanocomposite led to a decrease in Tensile Strength value, while an increase in Elongation at Break values was observed. The results of the antimicrobial activity of the nanocomposite revealed that the pure starch film did not show any lack of growth zone. The addition of ZnO NPs to the starch matrix resulted in antimicrobial activity on both studied bacteria (Staphylococcus aureus and Escherichia coli). The highest antimicrobial activity was observed in the starch/ZnO NPs film containing 1.5% essential oil with an inhibition zone of 340 mm2 on S. aureus. Antioxidant activity increased significantly with increasing concentration of F. gummosa essential oil (P < 0.05). The film containing 1.5% essential oil had the highest (50.5%) antioxidant activity. Coating also improved the chemical characteristics of fish fillet. In conclusion, the starch nanocomposite containing ZnO NPs and F. gummosa essential oil has the potential to be used in the aquatic packaging industry.

Modification of starch digestibility and phenolic bioaccessibility in phenolic-rich flours by physical treatments with ferulic acid followed by vacuum oven and freeze-drying

Consumer demand for healthy snack products has led to increased efforts to modify glycemic responses of these products. The formation of starch-ferulic acid (FA) complexes through acidified water steeping leads to an increase in RS content and reduction of glycemic responses in animal models. However, the application of these methodologies to commercially relevant phenolic-rich flours (black rice, BR; purple maize, PM) and their impacts on starch digestibility and phenolic bioaccessbility remain unclear. Using an acidified water steeping method previously reported in pure starch, potato starch (PS), BR and PM flour slurries were prepared with FA at a 20:1 and 8:1 ratio in HCl-acidified water (pH 2). The steeping process reduced phenolic content (∼75%) and increased starch digestibility. Ferulic acid loading capacity on PS (22–124 mg/g starch) was greater than for PM and BR flours (8–40 mg/g starch). Ferulic acid bioaccessibility decreased with an increase in its amount in PS and flours. Steeping enhances cyanidin 3-O-glucoside bioaccessibility, while addition of FA decreases its bioaccessibility. The increase in starch digestibility of phenolic-rich flours after steeping with and without FA can be attributed to the limited loading capacity of FA and loss of native phenolics during the steeping process.

Evaluation of Starch-Garlic Husk Polymeric Composites through Mechanical, Thermal, and Thermo-Mechanical Tests.

The present work evaluates the influence of different properties of composite materials from natural sources. Films were prepared using the evaporative casting technique from corn starch reinforced with a waste material such as garlic husk (GH), using glycerin as a plasticizer. The results of the syntheses carried out demonstrated the synergy between these materials. In the morphological analysis, the compatibility and adequate dispersion of the reinforcer in the matrix were confirmed. Using Fourier transform infrared spectroscopy (FTIR), the interaction and formation of bonds between the matrix and the reinforcer were confirmed by the presence of some signals such as S-S and C-S. Similarly, thermogravimetric analysis (TGA) revealed that even at low concentrations, GH can slightly increase the decomposition temperature. Finally, from the results of dynamic mechanical analysis (DMA), it was possible to identify that the storage modulus increases significantly, up to 115%, compared to pure starch, especially at low concentrations of the reinforcer.

Improving water resistance and mechanical properties of starch-based films by incorporating microcrystalline cellulose in a dynamic network structure

The widespread use of starch-based films is hindered by inadequate tensile strength and high water sensitivity. To address these limitations, a novel starch film with a dynamic network structure was produced via the dehydration-condensation reaction of N, N′-methylene diacrylamide (MBA) and microcrystalline cellulose (MCC). The improvement in mechanical properties was enhanced by the incorporation of MCC, which was achieved through intermolecular hydrogen bonding and chemical crosslinking. To verify the interactions among MCC, MBA, and starch, x-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR), and x-ray diffraction (XRD) were conducted. The results established the predicted interactions. The dynamic network structure of the film reduced the water absorption capacity (WAC) of starch and MCC hydroxyl groups, as confirmed by differential scanning calorimeter (DSC) and dynamic mechanical thermal analysis (DMTA). These analyses showed a restriction in the mobility of starch chains, resulting in a higher glass transition temperature (Tg) of 69.26 °C. The modified starch films exhibited excellent potential for packaging applications, demonstrating a higher contact angle (CA) of 89.63°, the lowest WAC of 4.73 g/g, and the lowest water vapor transmission rate (WVTR) of 13.13 g/m2/d, along with improved mechanical properties and identical light transmittance compared to pure starch films.

The potential exploitation of the Malay-red apple (Syzygium malaccense) seed as source of a phosphorylated starch

This work presents the characterization of a novel naturally phosphorylated starch extracted from an unconventional and non-utilized source, the seeds of the stone fruit Syzygium malaccense. The morphology and chemical characteristics of the extracted starch were examined by scanning electron microscopy, FTIR, 1H/13C/31P NMR and 13C-CP/MAS-NMR, HPAEC-PAD chromatography, XRD, DSC, and RVA. The extraction yielded a highly pure starch (95.6 %) with an average granule size of 13 μm. The analysis of the starch components revealed an amylose content of 28.1 % and a predominance (65 %) of B-chains (B1–B3 65 %) in the amylopectin, as shown through HPAEC-PAD chromatography. The X-ray diffractogram was compatible with B-type starch, which was confirmed by the deconvolution of the C1 peak in the 13C-CP/MAS-NMR. X-Ray diffractogram also showed that S. malaccense has 28.5 % of crystallinity. DSC analysis showed values of 82.6 °C and −12.41 J g−1 for Tc and ΔH, respectively, which is compatible with a highly ordered starch granule structure. The values observed for peak (4678 mPa•s), trough (3055 mPa•s), and final viscosity (6526 mPa•s) indicated that S. malaccense may be used as a thickener in hot food.

Multi-scale investigation of the heat-induced transformation of starch in model dough and starch systems

Our study investigated the impacts of starch botanical origin (tapioca versus wheat starch) and gluten addition on the water distribution and hydrothermal changes of starch in model dough systems compared to their pure starch counterparts. In it, we employed a combination of time-domain nuclear magnetic resonance (TD-NMR), wide angle X-ray diffraction (WAXD), solid state nuclear magnetic resonance (ssNMR) at variable temperature (VT) and differential scanning calorimetry (DSC) measurements. The results showed that at intermediate hydration levels, water ingress into starch granules, increase in glucan chain mobility, and dissociation of double helices (DH) of amylopectin occurred at lower temperatures than crystallite loss of order and melting. The inhibitory effect of gluten on wheat starch hydrothermal changes was explained by a higher water adsorption capacity of gluten compared to starch at this hydration level (50%, wb). However this effect was shown to be influenced by starch botanical origin, tapioca-based systems showing no hindrance effect of gluten on starch-water interaction. The study also provides additional evidence for the sensitivity and detection scales of the different techniques at 50% water content.

Preparation of porous-structured flat potato starch noodles with gelatin for shortening cooking time

Although dried flat starch noodles have been widely popular in Asian countries, the problem of long rehydration time needs to be solved. In this study, dried flat potato starch noodles with porous structure were constructed by adding gelatin to shorten the cooking time. Compared with pure flat potato starch noodles, the rehydration time of the dried flat potato starch noodles supplemented with 15% gelatin was reduced by 50.38%, from 11.75 ± 0.18 min to 5.83 ± 0.21 min. The results of scanning electron microscopy showed that the pore number of dried flat potato starch noodles increased with an increase in gelatin concentration, and the average diameter of pores ranged from 80.56 μm to 273.64 μm. The results of small-angle X-ray scattering showed that the mass fractal dimension value decreased from 1.769 (control noodles) to 1.308 (noodles with 20% gelatin), indicating that the starch aggregate structure was loosened due to the addition of gelatin. This loose structure was conducive to the diffusion of water in the cooking process of dried flat potato starch noodles. These findings indicated that the addition of gelatin, especially at the appropriate concentration, is effective in improving the cooking quality of noodles.

The anti-digestibility mechanism of soy protein isolate hydrolysate on natural starches with different crystal types

The effects of soy protein isolate hydrolysate (SPIH) on the physicochemical properties and digestive characteristics of three starch types (wheat, potato, and pea) were investigated. Fourier-transform infrared spectroscopy and molecular dynamics simulations showed that hydrogen bonds were the driving force of the interaction between SPIH and starch. Furthermore, the SPIH was predicted to preferentially bind to the terminal region of starch using molecular dynamics simulations. Compared to pure starch, adding 20 % SPIH to wheat starch, potato starch, and pea starch, the content of resistant starch increased by 39.71 %, 125.66 % and 37.83 %, respectively. Both the radial distribution function (RDF) and low field-nuclear magnetic resonance (LF-NMR) showed that SPIH reduced the flow of water molecules in starch, indicating that SPIH competed with starch for water molecules. Multiple characterization experiments and molecular dynamics simulations confirmed that the anti-digestibility mechanism of SPIH on natural starches with different crystal types could be attributed to the interaction between starch and SPIH, which decreased the catalytic efficiency of amylase. This study clarified the anti-digestibility mechanism of SPIH on natural starches, which provides new insights into the production of low-glycemic index foods for the diabetic population.

Thermoplastic starch biocomposites reinforced with hemp shives obtained via extrusion

Biodegradable and sustainable materials are becoming increasingly important in response to environmental concerns associated with traditional petroleum-based plastics. The objective of this study was to assess the feasibility and efficiency of incorporating hemp shives as a filler in thermoplastic wheat starch, aimed at promoting environmental sustainability and reducing reliance on non-renewable resources. The biocomposites, prepared by extrusion, consisted of pure starch, different hemp shives concentrations (10%, 20%, 30%, 40%, 50%, and 70%), with water and glycerol as plasticizers. The results revealed that the incorporation of shives notably enhanced the mechanical properties of the biocomposite, reaching an optimal performance at 40% shives concentration (resulting in a maximum tensile strength of 11.5 MPa and Young’s modulus of 1621 MPa). In this concentration, ESEM images unveiled robust adhesion between hemp shives and the matrix, indicating starch penetration into the shives' parenchymatous cells. At higher concentrations, however, the resulted high pressures during extrusion collapsed the shive cells, impairing their adhesion with starch and reducing the biocomposite strength. The hemp shives addition reduced the water uptake, thereby enhancing the dimensional stability. Conclusively, this study offers pivotal insights into the development and characteristics of starch/hemp shives biocomposites, with structure-process-properties relationships, suggesting their potential applicability in the creation of eco-friendly packaging materials and small objects, presenting a viable alternative to traditional materials.

A synthesis of post‐esterified oxidized starch accompanied with physicochemical property analysis and esterification reaction condition optimization

AbstractEsterification is a normal method for starch modification while reaction condition is not clear. Here, pure corn starch and vinyl acetate were chosen for starch esterification. Reaction conditions involving esterifying agent content, pH, reaction time and temperature were explored. Dess‐Martin periodinane (DMP) pretreatment was adopted to accelerate esterification. Main results reveal that a content of 30 wt% vinyl acetate, pH = 9, time as 1 h and temperature as 45°C is an optimized condition for vinyl acetate esterification and DMP oxidization can enhance it. After modification, variations in microstructure, surface morphology and macroscopic properties such as viscosity, transparency, adhesion property were explored by FT‐IR, XRD, SEM, TGA, UV–Vis, viscosity, and slushing experiments. Main results reveal that after esterification carbonyl groups were introduced, lattice plane occurred expansion, surface morphology was destroyed, water absorption capacity, viscosity, and gelatinization temperature decreased while transparency, thermal‐stability and adhesion property increased. DMP treatment enhanced the previous variations. It seems via a middle‐level DMP pretreatment and vinyl acetate esterification starch solution viscosity and gelatinization temperature decreased greatly while transparency and adhesion force increased greatly, possibly having a potential use in textile industry. For instance, using as slurry its manufacture cost can be decreased with decreased energy consumption, economical.