Abstract:Carboxymethyl rice starch films were prepared from carboxymethyl rice starch (CMSr) treated with sodium hydroxide (NaOH) at 10–50% w/v. The objective of this research was to determine the effect of NaOH concentrations on morphology, mechanical properties, and water barrier properties of the CMSr films. The degree of substitution (DS) and morphology of native rice starch and CMSr powders were examined. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and differential scanning calorimetr… Show more
“…242 The microstructure of the starch-based film is not completely homogeneous, as can be seen through the scanning electron microscopy (SEM) technique in the mentioned works. [243][244][245][246][247][248][249] The cause of the film surface heterogeneity reported in the previous paragraph may be due to the difficulty in dissolving the starch granules in water (due to hydrogen bonds and large polymer chains). The dissolution step is carried out by heating the starch dispersion under moderate shear in excess of water, characterized by: hydration, swelling, birefringence loss and crystallinity of the starch chains.…”
Section: Starch: Generalities and Gelatinizationmentioning
confidence: 96%
“…242 The microstructure of the starch-based film is not completely homogeneous, as can be seen through the scanning electron microscopy (SEM) technique in the mentioned works. 243–249 Figure 4.Gelatinized native starch for the production of flexible films.…”
Section: Biodegradable Polymers Applied In Food Packagingmentioning
The limited degradation of synthetic polymers used in food packaging when discarded in the environment is a major concern for society. Therefore, industry and academia have sought to develop biodegradable and eco-friendly materials for single-use in packaging. An interesting alternative for the food industry is biodegradable polymeric films, which is why different biopolymers have been used in the production of sustainable packaging. It is worth mentioning that the use of biodegradable polymers is one of the most successful innovations in the industry to address issues related to the environment. Among the available raw materials, starch extracted from different renewable sources is very promising for this purpose, due to its abundance, low-cost compared to other polymers and ability to produce non-toxic films. However, when used alone, pure starch has many limitations, which can be overcome by developing a mixture with other polymers (polymer blends), preferably from renewable and biodegradable sources, such as poly(lactic acid) (PLA). In this context, the absence of literature reviews evidencing the results of the application of films in foods led us to write this article, given the importance of polymer blends produced with different types of starch (cassava, corn, pea, potato, rice and wheat) and the PLA matrix. According to the results, it is clear that polymer blends based on PLA/Starch for food packaging are very promising, already being part of the industries solutions, aiming to minimize the large volume of plastic waste of petrochemical origin discarded in nature. Obviously, as with any technology, more research is needed to further improve the performance of the films, and while much research has made great strides, there are still limitations that prevent the commercialization of these materials.
“…242 The microstructure of the starch-based film is not completely homogeneous, as can be seen through the scanning electron microscopy (SEM) technique in the mentioned works. [243][244][245][246][247][248][249] The cause of the film surface heterogeneity reported in the previous paragraph may be due to the difficulty in dissolving the starch granules in water (due to hydrogen bonds and large polymer chains). The dissolution step is carried out by heating the starch dispersion under moderate shear in excess of water, characterized by: hydration, swelling, birefringence loss and crystallinity of the starch chains.…”
Section: Starch: Generalities and Gelatinizationmentioning
confidence: 96%
“…242 The microstructure of the starch-based film is not completely homogeneous, as can be seen through the scanning electron microscopy (SEM) technique in the mentioned works. 243–249 Figure 4.Gelatinized native starch for the production of flexible films.…”
Section: Biodegradable Polymers Applied In Food Packagingmentioning
The limited degradation of synthetic polymers used in food packaging when discarded in the environment is a major concern for society. Therefore, industry and academia have sought to develop biodegradable and eco-friendly materials for single-use in packaging. An interesting alternative for the food industry is biodegradable polymeric films, which is why different biopolymers have been used in the production of sustainable packaging. It is worth mentioning that the use of biodegradable polymers is one of the most successful innovations in the industry to address issues related to the environment. Among the available raw materials, starch extracted from different renewable sources is very promising for this purpose, due to its abundance, low-cost compared to other polymers and ability to produce non-toxic films. However, when used alone, pure starch has many limitations, which can be overcome by developing a mixture with other polymers (polymer blends), preferably from renewable and biodegradable sources, such as poly(lactic acid) (PLA). In this context, the absence of literature reviews evidencing the results of the application of films in foods led us to write this article, given the importance of polymer blends produced with different types of starch (cassava, corn, pea, potato, rice and wheat) and the PLA matrix. According to the results, it is clear that polymer blends based on PLA/Starch for food packaging are very promising, already being part of the industries solutions, aiming to minimize the large volume of plastic waste of petrochemical origin discarded in nature. Obviously, as with any technology, more research is needed to further improve the performance of the films, and while much research has made great strides, there are still limitations that prevent the commercialization of these materials.
“…CLCMRS, on the other hand, was dispersible in unheated water and formed a continuous entangled phase which, upon casting on the Teflon plate and dried in a hot-air oven, yielded an intact, flexible film even without the addition of a plasticizer (Figure 2B). Carboxymethyl starches derived from several starch sources were previously reported to possess a film-forming property [27][28][29], partly because the hydrophilic carboxymethyl groups acting as hydrogen bond disruptors which increased the intermolecular spacing between starch chains, a mechanism mimicking that of a plasticizer [18]. The additional cross-linking reaction, which produced CLCMRS, improved the swelling and disintegrating properties while exerting little or no effect on the film-forming ability.…”
Section: Preparation and Properties Of Crosslinked Carboxymethyl Rice...mentioning
Crosslinked carboxymethyl rice starch (CLCMRS), prepared via dual modifications of native rice starch (NRS) with chloroacetic acid and sodium trimetaphosphate, was employed to facilitate the disintegration of hydroxypropylmethylcellulose (HPMC) orodispersible films (ODFs), with or without the addition of glycerol. Fabricated by using the solvent casting method, the composite films, with the HPMC--LCMRS ratios of 9:1, 7:1, 5:1 and 4:1, were then subjected to physicochemical and mechanical evaluations, including weight, thickness, moisture content and moisture absorption, swelling index, transparency, folding endurance, scanning electron microscopy, Fourier transform infrared spectroscopy, tensile strength, elongation at break, and Young’s modulus, as well as the determination of disintegration time by using the Petri dish method (PDM) and slide frame and bead method (SFM). The results showed that HPMC-CLCMRS composite films exhibited good film integrity, uniformity, and transparency with up to 20% CLCMRS incorporation (4:1 ratio). Non-plasticized composite films showed no significant changes in the average weight, thickness, density, folding endurance (96–122), tensile strength (2.01–2.13 MPa) and Young’s modulus (10.28–11.59 MPa) compared to HPMC film (135, 2.24 MPa, 10.67 MPa, respectively). On the other hand, the moisture content and moisture absorption were slightly higher, whereas the elongation at break (EAB; 4.31–5.09%) and the transparency (4.73–6.18) were slightly lowered from that of the HPMC film (6.03% and 7.03%, respectively). With the addition of glycerol as a plasticizer, the average weight and film thickness increased, and the density decreased. The folding endurance was improved (to >300), while the transparency remained in the acceptable range. Although the tensile strength of most composite films decreased (0.66–1.75 MPa), they all exhibited improved flexibility (EAB 7.27–11.07%) while retaining structural integrity. The disintegration times of most composite films (PDM 109–331, SFM 70–214 s) were lower than those of HPMC film (PDM 345, SFM 229 s). In conclusion, the incorporation of CLCMRS significantly improved the disintegration time of the composite films whereas it did not affect or only slightly affected the physicochemical and mechanical characteristics of the films. The 5:1 and 4:1 HPMC:CLCMRS composite films, in particular, showed promising potential application as a film base for the manufacturing of orodispersible film dosage forms.
“…Sodium hydroxide is commonly used to dissolve starch as part of the starch modification process. It reacts with the hydroxyl groups in the starch molecule and become an alkoxide [14][15][16]. Therefore, it is expected that the addition of sodium hydroxide will aid in the precipitation during the production of these glutinous rice flour nanoparticles.…”
In this work, nanorod particles were synthesized from a locally available source, glutinous rice flour, using sodium hydroxide (NaOH) through a simple precipitation process. The synthesized nanofillers were then presented as an alternative organic filler for dental impression application to support the making of a diagnostic and working model. Dynamic Light Scattering, Scanning Electron Microscope, Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Energy Dispersive Spectroscopy, Thermogravimetric Analysis, and Differential Scanning Colorimeter were used to characterize the fillers. The particle size measurement, morphology interaction, and composition of glutinous rice flour nanorod particles were also investigated. The cell viability using 3T3L1 cells was assessed to determine the safety of nanorod particles using the MTT assay and trypan blue solution. All treated samples exhibit a change in particle morphology from polyhedral to rod. We observed a decrease in crystallinity, dehydration, and gelatinization temperature. Its functional group interacting with sodium hydroxide also changes slightly after size reduction. The samples treated with 3000 centrifugation speed without surfactant addition showed changes from the control sample's 3931.71 nm to the smallest average width particle size of 73.26 nm with an average length of 865.15 nm. All of the treated samples with NaOH and NaOH-surfactant additions met the non-cytotoxicity acceptance criteria in the range of 73.54-99.58%, according to the cell viability results. The incorporation of 15 wt% of the synthesized nanorod fillers resulted in a 20 µm continuous line as the impression materials specimen, yielding a satisfactory detail reproduction test result. In conclusion, nanorod particles with biocompatible properties have been successfully manufactured and can potentially be used in the future as an alternative dental impression filler materials.
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