Quaternization of cassava starch and determination of antimicrobial activity against bacteria and coronavirus.

This study describes the novel development of quaternized cassava starch (Q-CS) with antimicrobial and antiviral properties, particularly effective against the MHV-3 coronavirus. The preparation of Q-CS involved the reaction of cassava starch (CS) with glycidyltrimethylammonium chloride (GTMAC) in an alkaline solution. Q-CS physicochemical properties were determined by FTIR, NMR, elemental analysis, zeta potential, TGA, and moisture sorption. FTIR and NMR spectra confirmed the introduction of cationic groups in the CS structure. The elemental analysis revealed a degree of substitution (DS) of 0.552 of the cationic reagent on the hydroxyl groups of CS. Furthermore, Q-CS exhibited a positive zeta potential value (+28.6 ± 0.60 mV) attributed to the high positive charge density shown by the quaternary ammonium groups. Q-CS demonstrated lower thermal stability and higher moisture sorption compared to CS. The antimicrobial activity of Q-CS was confirmed against Escherichia coli (MIC = 0.156 mg mL-1) and Staphylococcus aureus (MIC = 0.312 mg mL-1), along with a remarkable ability to inactivate 99% of MHV-3 coronavirus after only 1 min of direct contact. Additionally, Q-CS showed high cell viability (close to 100%) and minimal cytotoxicity effects, guaranteeing its safe use. Therefore, these findings indicate the potential use of Q-CS as a raw material for antiseptic biomaterials.

Valorization of a by-product of the yerba mate industry by assembling with cassava starch adhesive for packaging material production.

Yerba mate industrial processing produces tons of powder as a by-product, this yerba mate powder (YMP) is an excellent source of biomass to develop biodegradable materials. Cassava starch modified with 1,2,3,4-butane tetracarboxylic acid (BA) in the presence of sodium propionate as a catalyst is an eco-friendly option to obtain bioadhesives. This work aimed to develop sustainable laminates from starch-based adhesives and yerba mate powder and to study their physico-chemical, structural, and mechanical properties. Blends of bioadhesive and YMP were prepared (1:1, adhesive:YMP). Monolayer materials were obtained by thermo-compression and later assembled with adhesive to obtain bilayer laminates. Bioadhesive was able to bind the yerba mate by-product fibers, as evidenced by SEM microstructure analysis, the interactions of adhesive:substrate were elucidated by ATR-FTIR and supported by chemometrics analysis. The incorporation of the catalyst decreased the rugosity of materials and their mechanical performance was improved by the action of both acid concentration and catalyst presence, requiring higher energy for puncture. Thus, it was feasible to obtain mono and bilayer laminates as an eco-compatible alternative for the design of sustainable tray-like materials based on the industrial by-product of yerba mate.

Investigating the evolution of the fine structure in cassava starch during growth and its correlation with gelatinization performance.

The evolution of the starch fine structure during growth and its impact on the gelatinization behavior of cassava starch (CS) was investigated by isolating starch from South China 6068 (SC6068) cassava harvested from the 4th to 9th growth period. During growth, the short-range ordered structure, crystallinity as well as particle size distribution of starch were increased. Meanwhile, the starch molecular size and amylopectin (AP) proportion increased, while the proportion of amylose (AM) exhibited a decreasing tendency. The chains of short-AM (X ~ 100-1000) were mainly significantly reduced, whereas the short and medium-AP chains (X ~ 6-24) had the most increment in AP. The solubility, thermal stability, shear resistance, and retrogradation resistance of starch were enhanced after gelatinized under the influence of the results mentioned above. This study presented a deeper insight into the variation of starch fine structure during growth and its influence on gelatinization behavior, which would provide a theoretical basis for starch industrial applications.

Physical properties and in-vitro gastrointestinal digestion of oil-in-water emulsions stabilized by single- and dual-modified cassava starches with cross-linking and octenylsuccinylation.

The different modified cassava starches (MCS) obtained by either single or dual modifications with cross-linking (CL) and octenylsuccinylation (OS), including 2%CL, 3%OS, 2%CL-3%OS, and 3%OS-2%CL, were used to stabilize soybean oil-in-water emulsions (oil content 10% (w/w)) at a concentration of 4.5% (w/w) compared to native cassava starch (NCS) and their physical properties and in-vitro gastrointestinal digestion were investigated. The emulsions stabilized with NCS and 2%CL-MCS had larger oil droplet sizes, higher viscosity, and lower negative charge than the emulsions stabilized by single- or dual-MCS with 3%OS. All MCS-stabilized emulsions showed a higher emulsion stability against creaming than the NCS-stabilized emulsion. Under a simulated gastrointestinal tract, all 3%OS-MCS promoted droplet flocculation, while the less ionic NCS and the 2%CL-MCS showed a decrease in droplet size after passing through the mouth and stomach stages. The lipid digestion rate of emulsions stabilized with different MCS and NCS followed the following order: 3%OS >2%CL-3%OS > 3%OS-2%CL > 2%CL > NCS. The NCS- and 2%CL-stabilized emulsions had a lower lipid digestion rate, possibly due to the larger droplet sizes and higher viscosity of the initial emulsions, which delays access of lipase enzymes to lipid droplet surfaces, compared to all 3%OS-MCS-stabilized emulsions.

Preparation of porous superabsorbent particles based on starch by supercritical CO2 drying and its water absorption mechanism.

The slow water-absorption speed of starch-based superabsorbent resin (St-SAP) limits its application. In this study, porous St-SAP (P-St-SAP) was prepared by inverse suspension polymerization and supercritical CO2 drying, the aim is to provide a preparation method of fast absorbent resin. The P-St-SAP at 33 % starch content had an interpenetrating porous structure with macropores, mesopores and micropores, and the surface area, pore volume and average pore diameter were 32.06 m2·g-1, 0.116 cm3·g-1 and 21.6 nm, respectively. The water-absorption process included rapid-section, medium-section and slow-section, according with internal diffusion, double-constant and quasi second-order kinetic models, respectively. In the initial 30 s, a water-absorption speed of 262.6 g·g-1·min-1 in distilled water was much higher than some previous research results, and the equilibrium absorption value of 517.9 g·g-1 in distilled water and 72.9 g·g-1 in 0.9 % saline was better than that of non-porous St-SAP at similar starch content. Moreover, at the same stage the percentage of saline absorption ratio to equilibrium absorption value was 1.0- 2.0 times higher than that of distilled water. These research results indicate that the P-St-SAP has fast water-absorption speed and good salt resistance, which will have greater application prospects in sanitary materials, building concrete pouring, and flood control blocking piping.

Multivapor-Responsive Controlled Actuation of Starch-Based Soft Actuators.

Multivapor-responsive biocompatible soft actuators have immense potential for applications in soft robotics and medical technology. We report fast, fully reversible, and multivapor-responsive controlled actuation of a pure cassava-starch-based film. Notably, this starch-based actuator sustains its actuated state for over 60 min with a continuous supply of water vapor. The durability of the film and repeatability of the actuation performance have been established upon subjecting the film to more than 1400 actuation cycles in the presence of water vapor. The starch-based actuators exhibit intriguing antagonistic actuation characteristics when exposed to different solvent vapors. In particular, they bend upward in response to water vapor and downward when exposed to ethanol vapor. This fascinating behavior opens up new possibilities for controlling the magnitude and direction of actuation by manipulating the ratio of water to ethanol in the binary solution. Additionally, the control of the bending axis of the starch-based actuator, when exposed to water vapor, is achieved by imprinting-orientated patterns on the surface of the starch film. The effect of microstructure, postsynthesis annealing, and pH of the starch solution on the actuation performance of the starch film is studied in detail. Our starch-based actuator can lift 10 times its own weight upon exposure to ethanol vapor. It can generate force ∼4.2 mN upon exposure to water vapor. To illustrate the vast potential of our cassava-starch-based actuators, we have showcased various proof-of-concept applications, ranging from biomimicry to crawling robots, locomotion near perspiring human skin, bidirectional electric switches, ventilation in the presence of toxic vapors, and smart lifting systems. These applications significantly broaden the practical uses of these starch-based actuators in the field of soft robotics.

Utilization of solid residue from hydrothermal liquefaction of breadfruit pulp for the production of bio-briquette using cassava starch as binder.

The generation of agro-waste as a result of increase in agro and food processing activities is on the increase due to rapid increase in human population. Hence the need to eliminate these waste by converting them into a useful product or energy source. This work presents the use of bio-char from hydrothermal liquefaction of breadfruit pulp to produce bio-briquettes with cassava starch as a binder. The response surface method using design expert was used to design the experiment with particle size, press pressure and binder dosage as factors, to determine the parameter combination that will produce briquettes of high energy density. The briquette with the highest calorific value 26.75 MJ/kg was produced at the parameter combination of 450 mm-6 particle size, 5 MPa press pressure, and 20 % binder dosage. The ultimate analysis carried on the produced briquette gave carbon, hydrogen, nitrogen and sulphur content of 47.22 %, 3.88 %, 0.69 %, and 0.42 % respectively, with oxygen content of 4.79 % by percentage mass difference. While the proximate analysis gave moisture, ash, volatile matter, and fixed carbon content of 7.8 %, 3.9 %, 43.7 %, and 44.6 % respectively. Other characterization test carried out gave combustion rate of 4.5 g/min, ignition time of 3.5 min, density of 0.86 g/cm3, compressive strength of 8.31 N/mm2, shatter index of 0.89, and hydrophobicity of 61.3 %. These findings shows that briquettes produced with bio-char from HTL of breadfruit pulp can be used as solid fuel for domestic and mini-industrial heating purposes, as well as eliminate waste from processing of breadfruit.

Natural fermentation of potato (Solanum tuberosum L.) starch: Effect of cultivar, amylose content, and drying method on expansion, chemical and morphological properties.

Natural fermentation with sun-drying is a modification that promotes the expansion capacity of starch, and its effects on potato starch have not been reported so far. The aim of this study was to evaluate the effects of the amylose content of potato (Solanum tuberosum L.) starches and natural fermentation followed by oven or sun drying on its properties. Cassava starch was also used a control. Native and fermented starches were evaluated based on their chemical composition, amylose, carboxyl and carbonyl content as well as their thermal, pasty, and morphological properties. The fermentation water was evaluated by pH and titratable acidity to control the process. Puffed balls were prepared to evaluate expandability, mass loss, porosity and texture. The fermentation intensity was greater for potato and cassava starch with low-amylose content than for potato starch with higher amylose content. In addition, the acidity of the fermentation water increased faster with cassava starch than with potato starches. The fermented potato starches with the highest amylose content had low acidity and low expansion capacity compared to the fermented potato and cassava starches with low-amylose content. Fermentation and sun-drying of low-amylose potato and cassava starches increased the expansion and reduced the hardness of the puffed balls.

Preparation and characterization of glyceryl stearate/cassava starch composite for wax therapy.

Glyceryl stearate and cassava starch (CS) composites were prepared by an esterification process. Formulations containing starch at various concentrations were prepared, being 1, 1.5, 3, 5, 10, 15, 20, and 30 % by weight, respectively. The characteristics of pH, moisture content, FTIR, melting point, latent heat, thermal energy storage, and specific heat capacity of composites were elucidated. The optimal formulation contained 1 % w/w CS, this indicated that the composite was able to maintain its temperature for 9.4 ± 0.5 min, with a melting temperature of 51.9 ± 0.3 °C, solidification temperature of 36.1 ± 1.6 °C, latent heat of fusion of 120 ± 10 J/g, and latent heat of solidification of 126 ± 3 J/g, and specific heat capacity of 2.6 ± 0.2 J/g.K. New bonds were formed in the composite structure of glyceryl stearate and CS at these levels. The composite had a pH that was safe for contact with human skin and a moisture content that could be kept stable for a prolonged time. The innovation and the advantages of a composite materials: 1. The main components are derived from natural materials. 2. Costs effective 3. Sustainability 4. Safety, and 5. Efficacy. Therefore, composites have a high potential as are replacement for paraffin wax bath therapy.

Encapsulation of HaCaT Secretome for Enhanced Wound Healing Capacity on Human Dermal Fibroblasts.

In the epidermal and dermal layers of the skin, diverse cell types are reconstituted during the wound healing process. Delays or failures in wound healing are a major issue in skin therapy because they prevent the normal structure and function of wounded tissue from being restored, resulting in ulceration or other skin abnormalities. Human immortalized keratinocytes (HaCAT) cells are a spontaneously immortalized human keratinocyte cell line capable of secreting many bioactive chemicals (a secretome) that stimulate skin cell proliferation, rejuvenation, and regeneration. In this study, the HaCaT secretome was encapsulated with polyesters such as poly (lactic-co-glycolic acid) (PLGA) and cassava starch in an effort to maximize its potential. According to the estimated mechanism of the HaCaT secretome, all treatments were conducted on immortalized dermal fibroblast cell lines, a model of wound healing. Encapsulation of HaCaT secretome and cassava starch enhanced the effectiveness of cell proliferation, migration, and anti-aging. On the other hand, the levels of reactive oxygen species (ROS) were lowered, activating antioxidants in immortalized dermal fibroblast cells. The HaCaT secretome induced in a dose-dependent manner the expression of antioxidant-associated genes, including SOD, CAT, and GPX. Six cytokines, including CCL2 and MCP-1, influenced immunoregulatory and inflammatory processes in cultured HaCAT cells. HaCaT secretome encapsulated in cassava starch can reduce ROS buildup by boosting antioxidant to stimulate wound healing. Hence, the HaCaT secretome may have a new chance in the cosmetics business to develop components for wound prevention and healing.

Antioxidant Edible Films Based on Pear Juice and Pregelatinized Cassava Starch: Effect of the Carbohydrate Profile at Different Degrees of Pear Ripeness.

Edible films based on fruit and vegetable purees combined with different food-grade biopolymeric binding agents (e.g., pectin, gelatin, starch, sodium alginate) are recognized as interesting packaging materials that benefit from the physical, mechanical, and barrier properties of biopolymers as well as the sensory and nutritional properties of purees. In the current contribution, edible antioxidant films based on pear juice and pregelatinized cassava starch were developed. In particular, the suitability of using pregelatinized cassava starch for the non-thermal production of these novel edible films was evaluated. In addition, the effects on the films' properties derived from the use of pear juice instead of the complete puree, from the content of juice used, and from the carbohydrate composition associated with the ripening of pears were all studied. The produced films were characterized in terms of their total polyphenol content, water sensitivity, and water barrier, optical, mechanical and antioxidant properties. Results showed that the use of pear juice leads to films with enhanced transparency compared with puree-based films, and that juice concentration and carbohydrate composition associated with the degree of fruit ripeness strongly govern the films' properties. Furthermore, the addition of pregelatinized cassava starch at room temperature discloses a significant and favorable impact on the cohesiveness, lightness, water resistance, and adhesiveness of the pear-juice-based films, which is mainly attributed to the effective interactions established between the starch macromolecules and the juice components.

Effect of Lithium Salts on the Properties of Cassava Starch Solid Biopolymer Electrolytes.

This study evaluates the effect of lithium salts on the structural, electrochemical, and thermal properties of cassava starch solid biopolymer electrolytes (SBPEs). Films of SBPEs were synthesized using plasticizing agents and lithium salts (LiCl, Li2SO4, and CF3LiSO3) via thermochemical method. The SBPEs with lithium salts exhibited characteristic FTIR bands starch, with slight variations in the vibration oxygen-related functional groups compared to salt-free biopolymer spectra. The RCOH/COC index (short-range crystallinity) was higher in the films synthesized without lithium salt and the lowest value was established in the films synthesized with Li2SO4. Thermal degradation involved dehydration between 40 to 110 °C and molecular decomposition between 245 to 335 °C. Degradation temperatures were close when synthesized with salts but differed in films without lithium salt. DSC revealed two endothermic processes: one around 65 °C linked to crystalline structure changes and the second at approximately 271 °C associated with glucose ring decomposition. The electrochemical behavior of the SBPEs varied with the salts used, resulting in differences in the potential and current of peaks from the redox processes and its conductivity, presenting the lowest value (8.42 × 10-5 S cm-1) in the SBPE films without salt and highest value (9.54 × 10-3 S cm-1) in the films with Li2SO4. It was concluded that the type of lithium salt used in SBPEs synthesis affected their properties. SBPEs with lithium triflate showed higher molecular ordering, thermal stability, and lower redox potentials in electrochemical processes.

Optimization of the Processing Conditions for the Production of a Gluten-Free Bread from Sour Cassava Starch (Manihot esculenta) and Some Legumes (Arachis hypogaea, Vigna unguiculata, and Glycine max).

BACKGROUND: Sour cassava starch is used as an alternative to wheat flour in breadmaking. However, its nutritional and technological properties are limited. To remedy this, the use of legumes has proved to be very successful. Thus, the present study aimed to determine the optimal condition for the production of bread made from sour cassava starch, peanut, cowpea and soybean flour. METHODS: The I-optimal design was employed to obtain an optimal proportion of the mixture with the variables sour cassava starch, cowpea, soy and peanut flour. The responses evaluated were overall acceptability, specific volume and protein content. RESULTS: It resulted that the incorporation of sour cassava starch positively influenced the volume but negatively influenced the protein content and overall acceptability. While the addition of legumes increased protein content and overall consumer acceptability, the specific volume was reduced. The optimal proportions of sour cassava starch, cowpea, soybean and peanut flour were 64.11%, 18.92%, 0% and 16.96%, respectively. Under this condition, it led to a desirability of 1, specific volume of 1.35, overall acceptability of 6.13, protein content of 9.72%, carbohydrate content of 67.89%, fat content of 9.39%, fiber content of 2.10% and ash content of 1.04%. CONCLUSIONS: The findings suggest that cowpea and peanut can be used for the improvement of the technological, nutritional and sensory properties of sour cassava starch bread and thus increase its consumption and application in the food processing industry.

Relation between Conventional and Starch-Assisted ASP Injection and Impact of Crystallinity on Flood Formation.

Alkaline-surfactant-polymer (ASP) flooding, a recognized method for oil recovery, encounters limited use due to its expense. In addition, ASP's best composition and injection sequence still remains uncertain today. This study explores conventional ASP flooding using PT SPR Langgak's special surfactants, simulating Langgak oilfield conditions in Sumatra, Indonesia. By comparing the outcomes of this flooding technique with that of starch-assisted ASP performed in another study, the benefits of adding starch nanoparticles to flooding are evident. Nano-starch ASP increased oil recovery by 18.37%, 10.76%, and 10.37% for the three configurations investigated in this study. Water flooding preceded ASP flooding, and flooding operations were carried out at 60 °C. This study employed sodium hydroxide (NaOH), sodium carbonate (Na2CO3), and specialized surfactants from PT SPR. The adopted polymer is solely hydrolyzed polyacrylamide (HPAM) at 2000 ppm. Starch nanoparticles underwent comprehensive characterization and focused more on charge stability. Purple yam nanoparticles (PYNPs) exhibited remarkable stability at -36.33 mV, unlike cassava starch nanoparticles (CSNPs') at -10.68 mV and HPAM's at -27.13 mV. Surface properties affect interactions with fluids and rocks. Crystallinity, a crucial characterization, was assessed using Origin software 2019b. CSNPs showed 24.15% crystallinity, surpassing PYNPs' 20.68%. Higher crystallinity benefits CSNPs' thermal stability. The amorphous behavior found in PYNPs makes them less suitable if applied in harsh reservoirs. This research correlated with prior findings, reinforcing starch nanoparticles' role in enhancing oil recovery. In summary, this study highlighted conventional ASP flooding using HPAM as the sole polymer and compared it with three formations that used two starch nanoparticles included with HPAM, assessing their impact on charge stability, crystallinity, and recovery rate to emphasize their importance in the oil recovery industry. Starch nanoparticles' benefits and limitations guided further investigation in this study.

Hydrothermal processes and simultaneous enzymatic hydrolysis in the production of modified cassava starches with porous-surfaces.

The amylolytic action of α-amylase and amyloglucosidase has been directly implemented in native cassava starches for the formation of cassava microporous granules with unsatisfactory results, however, its incidence in hydrothermally treated granules has never been evaluated. The effect of hydrothermal processes and simultaneous enzymatic hydrolysis on the physicochemical, morphological and structural properties of native cassava starch was evaluated. Native cassava starch presented a rigid, smooth surface, and was exempt from porosities, whereas hydrothermal processes altered the semicrystalline order and increasing the size and number of pores and increasing the size (4.11 ± 0.09 nm) and volume of pores (0.82 ± 0.00 cm3/g × 10-3). The hydrothermal action followed by enzymatic processes with α-amylase and amyloglucosidase, augmented the processes of internal degradation (endo-erosion) and pore widening (exo-erosion), improving the hydrophilic properties compared to the hydrothermal treatment. Likewise, the hydrothermally process followed by enzymatic hydrolysis for 24 h (HPS + EMS-24) increased the degradation of the amorphous lamellae, consistent with a significant decrease in amylose content. This same dual treatment increased the pore size at 17.68 ± 0.13 nm relative to the native counterpart; therefore, they are considered an effective method in the development of modified cassava starches with porous surfaces.

Catalytic Conversion of Carbohydrates into 5-Hydroxymethylfurfural by Phosphotungstic Acid Encapsulated in MIL-101 (Cr, Sn) Catalyst in Deep Eutectic Solvents.

Herein, we report the synthesis of bimetal-organic frameworks (BMOFs) with both Brønsted and Lewis acidities, in which phosphotungstic acid (PTA) was encapsulated in BMOFs. It is efficient in converting starch to 5-hydroxymethyl-furfural (HMF) in deep eutectic solvents (DESs) such as choline chloride and formic acid. The highest yield of HMF (37.94%) was obtained using P0.5/BMOFs1.0 to catalyze starch in a mixed solvent system comprising DESs and ethyl acetate (EAC) (v/v; 2:3) at 180 °C and a reaction time of 10 min. Employing a DES as a cocatalyst and solvent reduced the use of organic solvents. The catalyst showed adequate reusability, and the HMF yield only decreased by 2.88% after six cycles of reuse compared with that of the initial catalyst. This study demonstrates the application potential of BMOFs in the conversion of biomass to useful molecules with commercial and/or research value.

Influence of kepok banana bunch as new cellulose source on thermal, mechanical, and biodegradability properties of Thai cassava starch/polyvinyl alcohol hybrid-based bioplastic.

Bioplastics were developed to overcome environmental problems that are difficult to decompose in the environment. This study analyzes Thai cassava starch-based bioplastics' tensile strength, biodegradability, moisture absorption, and thermal stability. This study used Thai cassava starch and polyvinyl alcohol (PVA) as matrices, whereas Kepok banana bunch cellulose was employed as a filler. The ratios between starch and cellulose are 10:0 (S1), 9:1 (S2), 8:2 (S3), 7:3 (S4), and 6:4 (S5), while PVA was set constant. The tensile test showed the S4 sample's highest tensile strength of 6.26 MPa, a strain of 3.85%, and a modulus of elasticity of 166 MPa. After 15 days, the maximum soil degradation rate in the S1 sample was 27.9%. The lowest moisture absorption was found in the S5 sample at 8.43%. The highest thermal stability was observed in S4 (316.8°C). This result was significant in reducing the production of plastic waste for environmental remediation.

Preparation and Characterization of Cellulose Nanocrystals from Bamboos and Their Application in Cassava Starch-Based Film.

Cellulose from different species of bamboo (Thyrsostachys siamesi Gamble, Dendrocalamus sericeus Munro (DSM), Bambusa logispatha, and Bambusa sp.) was converted to cellulose nanocrystals (CNCs) by a chemical-mechanical method. First, bamboo fibers were pre-treated (removal of lignin and hemicellulose) to obtain cellulose. Next, the cellulose was hydrolyzed with sulfuric acid using ultrasonication to obtain CNCs. The diameters of CNCs are in the range of 11-375 nm. The CNCs from DSM showed the highest yield and crystallinity, which was chosen in the film fabrication. The plasticized cassava starch-based films with various amounts (0-0.6 g) of CNCs (from DSM) were prepared and characterized. As the number of CNCs in cassava starch-based films increased, water solubility and the water vapor permeability of CNCs decreased. In addition, the atomic force microscope of the nanocomposite films showed that CNC particles were dispersed uniformly on the surface of cassava starch-based film at 0.2 and 0.4 g content. However, the number of CNCs at 0.6 g resulted in more CNC agglomeration in cassava starch-based films. The 0.4 g CNC in cassava starch-based film was found to have the highest tensile strength (4.2 MPa). Cassava starch-incorporated CNCs from bamboo film can be applied as a biodegradable packaging material.

Tailor-made starch-based adhesives chemically modified with NaOH:urea and their applications on a cellulosic substrate.

Adhesives formulated with native starches have high viscosity, low solids content, poor bond strength and stability due to the starch retrogradation. To overcome this problem, a strategy is the starch treatment with NaOH solution combined with urea, capable of intercalating in the polymeric chains of starch. The aims of this work were to develop adhesives based on chemically modified cassava starch with different NaOH:urea ratios and to study in depth the effect induced by the addition of different concentrations of alkali and urea in the adhesive capacity of formulations that determine their subsequent application in paper-based packaging. Firmness and consistency of the adhesive increased for the 1:1 ratio while it decreased for the NaOH:urea 2:1 ratio, suggesting that the hydrolysis of polymer chains occurred. Additionally, adhesives prepared with 15 % starch maintaining NaOH:urea ratios of 0.5:1: and 1:1 exhibited the highest stress values. ATR-FTIR studies supported the results obtained. It was possible to obtain formulations with different adhesive properties with applications in paper-based packaging. From the analysis of the studied parameters, the combination of 15 % w/w cassava starch with a ratio of NaOH:urea 1:1 allows obtaining adhesives with adequate consistency and adhesive capacity which remain stable during the adhesive storage.

Characterization and qualitative evaluation of cassava starch-chitosan edible food wrap enriched with culinary leaf powders for eco-friendly food packaging applications.

Cassava starch-based edible food wraps were prepared by incorporating leaf powder from Indian curry leaf and Malabar bay leaf, reinforced with different (0.2, 0.4, 0.6, 0.8) wt.% of chitosan. Eleven combinations of films were prepared and their sensory acceptability, physical properties, Fourier-transform infrared spectroscopic (FTIR) spectrum, and scanning electron microscopy (SEM) image, were evaluated. The thickness of the films ranged from 0.198 ± 0.12 to 0.372 ± 0.27 mm. Tensile strength was reported to be the highest (40.71 ± 1.21 MPa) in the curry leaf powder incorporated sample. Maximum elongation at break was reported by bay leaf powder incorporated (5.8 ± 1.59%) sample. The Young's modulus values were observed to be increasing along with the concentration of chitosan. Maximum seal strength values were reported by curry leaf powder incorporated film with 0.8% chitosan (2.93 ± 0.22 N/mm). The leaf powder incorporated samples reported a higher flavonoid content compared to the control. The color analysis (L*, a*, b*) of the films was identical to the natural leaf color. The SEM images indicated a rough texture for the leaf powder incorporated films. The FTIR evaluation confirmed the presence of the respective functional groups. The statistical evaluation done by statistical package for social sciences software showed that all the data were significantly different (P ≤ 0.05.). The study demonstrated the potential of incorporation of leaf powder and chitosan to enhance the properties of starch-based edible packaging.