Native Starch Films Research Articles

Effect of ultrasonically stimulated potato germination during soaking on the physicochemical properties of starch and its use in edible films

The aim of this work was to investigate the effects of ultrasonic treatment during soaking of potatoes on the physicochemical properties of starches obtained after 16 weeks of germination. The ultrasonic treatment showed a direct correlation between sprout length and ultrasonic time. The protein content decreased from 0.63 to 0.38 % and the fat content decreased significantly from 0.31 to 0.01 % after germination. The amylose content changed depending on the ultrasonic treatment, and increased from 36.27 to 40.92 % after 16 weeks of germination, which was related to the amylopectin debranching and the duration of the ultrasonic treatment. X-ray diffraction showed that the nanocrystals with hexagonal structure were not affected by the germination and the duration of ultrasonic treatment. Scanning electron microscopy showed that the surface of the starch granules was not affected by the enzymatic treatment.The sprouted potato starch resulted in films with better tensile strength and lower water vapor permeability (WVP) compared to the native potato starch films. In addition, the films produced with ultrasound stimulated potato starch exhibited better properties (high strength and low permeability), which is desirable when it comes to controlling moisture exchange between a food product and the surrounding atmosphere.

Intelligent films based on dual-modified starch and microencapsulated Aronia melanocarpa anthocyanins: Functionality, stability and application

This study aims to enhance the physical properties and color stability of anthocyanin-based intelligent starch films. Three dual-modified starches, namely crosslinked-oxidized starch (COS), acetylated distarch phosphate (ADSP), and hydroxypropyl distarch phosphate (HDSP), were utilized as film matrices. Aronia melanocarpa anthocyanins were incorporated through three different pre-treatments (free, spray-drying microencapsulation, and freeze-drying microencapsulation) to assess the prepared films' functionality, stability, and applicability. The results indicate that the ADSP film exhibited an approximately two-fold increase in elongation at break (EAB) compared to native starch film. Specifically, the ADSP film's water contact angle (WCA) reached 90°, demonstrating excellent flexibility and hydrophobicity. Scanning electron microscopy (SEM) revealed stronger interactions between anthocyanins and the film matrix after microencapsulation. Furthermore, after 30 days of exposure to 37 °C heat and light radiation, the freeze-dried anthocyanin-based intelligent film (FDA film) exhibited minimal fading, displaying the highest stability among the tested films. Notably, during beef freshness monitoring, the intelligent films underwent significant color changes as the beef deteriorated. In conclusion, the developed FDA film, with its outstanding stability and responsive pH characteristics, holds immense potential as a novel packaging material for food applications.

The effect of citric acid concentrations on the mechanical, thermal, and structural properties of starch edible films

SummaryThis study investigated the effects of citric acid on the properties of edible tapioca starch films plasticised with glycerol. These films were formed using 5% tapioca (w/w of water); 1%, 3%, 5%, 7% and 9% citric acid (w/w of starch); and 2.2% glycerol (w/w of water). Native starch films formed using 5% tapioca and 2.2% glycerol were used as the control. The properties tested included the degree of crosslinking, thermal stability, crystallinity and mechanical properties. These were evaluated using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR‐FTIR), X‐Ray diffraction (XRD), thermal gravimetric analysis (TGA) and tensile profile analysis (TPA). The FTIR results provided information about the nature of the crosslinking in the films, while TGA showed that increasing the citric acid concentration reduced the physical decomposition temperature of the materials. Films containing 9% citric acid had the highest degree of esterification and crosslinking, while those containing 7% citric acid had the lowest heat‐related weight loss that correlated with the degree of crosslinking. The weight loss among all six samples was the greatest in the temperature range 260 °C–350 °C where a total of 60% weight loss occurred. The XRD results showed that films containing 3% citric acid had the lowest crystallinity while the native starch films had the highest crystallinity. The TPA analyses showed that films containing 5% citric acid had the greatest influence on improving the tensile strength and elastic modulus, while also having the best impact on lowering the elongation. Tensile strength values recorded for films containing 0%, 1%, 3%, 5%, 7% and 9% citric acid were 5.327, 7.813, 8.688, 12.855, 14.549 and 11.614 MPa. Similarly, when citric acid concentration increased from 3% to 5%, the elastic modulus significantly increased from 831.058 to 2255.691 MPa. This study demonstrated that the physicochemical properties of tapioca starch‐based films could be modified by the incorporation of citric acid.

The Effect of Starch Concentration on the Characteristics of Modified Purple Yam Starch Using the Precipitation Method

Purple yam starch-based edible film experienced high water vapor transmission rate. The use of composite starch using addition of modified starch of smaller size particles may decrease the rate. This study aimed to obtain starch concentrations that produced smallest size of modified starch, to produce composite starch for edible films and to determine the characteristics of edible films made out of native starch and edible films from composite starch (mixture of native starch and modified starch with the smallest size). This research was conducted in 2 stages: modification of purple yam starch by precipitation method and production of edible films from native starch and composite starch. This study was designed to produce modified starch using 5 levels of starch concentration (0,2%, 0,4%, 0,6%, 0,8%, and 1%) and 2 repetitions. The results showed that the treatment of 0,8% starch concentration produced the smallest particle size of starch (3,211 x 10,340 µm) up to (20,876 x 25,437 µm) with starch yield of 76,25%. Edible films made out composite starch have different characteristics than native starch alone. Edible films from composite starch produced higher thickness values ​​of 0.161 ± 0.007 mm, lower solubility 32,080 ± 4,671%, lower transparency of 10.644 ± 0.357% / mm and lower water vapor transmission rate (WVTR) of 24,701 ± 7,05 g / m2. hour and higher compressive strength 356,87 ± 7,38 gF than native starch edible films.

Fabrication and characterization of talipot starch-based biocomposite film using mucilages from different plant sources: A comparative study

Biocomposite films were prepared by formulating talipot starch with plant mucilage derived from shoeblack leaves, okra, and seeds of basil, fenugreek, and flax, which were identified as SBM-TSF, OKM-TSF, BSM-TSF, FGM-TSF, and FXM-TSF, respectively. The plant mucilages enhanced the crosslinking of the filmogenic solutions, which increased the film’s relative crystallinity. Upon topographical investigation, the biocomposite films exhibited the same compact and homogeneous structures as the native talipot starch film (NTSF), but with finer corrugations. When compared to NTSF, the addition of plant mucilage decreased the moisture content while increasing the thickness and opacity. SBM-TSF showed significantly reduced (p ≤ 0.05) solubility and water vapor permeability, indicating that increased crosslink formation in the film obstructed the water vapor passage. Among all the biocomposite films, the BSM-TSF had the greatest tensile strength, making it more resistant to stretching. Among the studied biocomposite films, SBM-TSF and BSM-TSF demonstrated improved thermal and biodegradation stability.

Synthesis, characterization, and in-vivo application of non-thermal plasma-modified talipot starch-Aloe vera gel biocomposite films for enhancing the shelf life of guava fruits

Modification of talipot starch by non-thermal plasma (NTP) treatment and addition of Aloe vera (AV) gel enhanced the crosslinking of filmogenic solution and improved biofilm properties. Both, NTP-modified talipot starch film (MTSF) and AV gel-incorporated modified talipot starch film (AV-MTSF) showed surface protuberances and roughness compared to native talipot starch film (NTSF) and AV gel-incorporated talipot starch film (AV-NTSF). The incorporation of AV gel increased the relative crystallinity and also altered the moisture content, thickness, and opacity of the films. AV-NTSF and AV-MTSF showed decreased water vapor and oxygen permeability, solubility, and elongation at break, and increased tensile strength compared to NTSF and MTSF. Furthermore, AV gel-incorporated films with comparatively good barrier properties showed enhanced control over the increase in pH and total soluble solids, reduced weight loss, firmness, titratable acidity, and ascorbic acid upon in-vivo guava coating application, which induced protectiveness against the desiccation and deterioration of guava fruits.

Enhancing the Mechanical Properties of Corn Starch Films for Sustainable Food Packaging by Optimizing Enzymatic Hydrolysis.

The objective of this study was to investigate the effects of enzymatic hydrolysis using α-amylase from Bacillus amyloliquefaciens on the mechanical properties of starch-based films. The process parameters of enzymatic hydrolysis and the degree of hydrolysis (DH) were optimized using a Box-Behnken design (BBD) and response surface methodology (RSM). The mechanical properties of the resulting hydrolyzed corn starch films (tensile strain at break, tensile stress at break, and Young's modulus) were evaluated. The results showed that the optimum DH for hydrolyzed corn starch films to achieve improved mechanical properties of the film-forming solutions was achieved at a corn starch to water ratio of 1:2.8, an enzyme to substrate ratio of 357 U/g, and an incubation temperature of 48 °C. Under the optimized conditions, the hydrolyzed corn starch film had a higher water absorption index of 2.32 ± 0.112% compared to the native corn starch film (control) of 0.81 ± 0.352%. The hydrolyzed corn starch films were more transparent than the control sample, with a light transmission of 78.5 ± 0.121% per mm. Fourier-transformed infrared spectroscopy (FTIR) analysis showed that the enzymatically hydrolyzed corn starch films had a more compact and solid structure in terms of molecular bonds, and the contact angle was also higher, at 79.21 ± 0.171° for this sample. The control sample had a higher melting point than the hydrolyzed corn starch film, as indicated by the significant difference in the temperature of the first endothermic event between the two films. The atomic force microscopy (AFM) characterization of the hydrolyzed corn starch film showed intermediate surface roughness. A comparison of the data from the two samples showed that the hydrolyzed corn starch film had better mechanical properties than the control sample, with a greater change in the storage modulus over a wider temperature range and higher values for the loss modulus and tan delta, indicating that the hydrolyzed corn starch film had better energy dissipation properties, as shown by thermal analysis. The improved mechanical properties of the resulting film of hydrolyzed corn starch were attributed to the enzymatic hydrolysis process, which breaks the starch molecules into smaller units, resulting in increased chain flexibility, improved film-forming ability, and stronger intermolecular bonds.

The impact of heat‐moisture treatment and pre‐gelatinization on functional, mechanical, and barrier properties of basmati rice starch films

Background and Objectives This study investigated the effect of heat-moisture treatment (HMT) and pre-gelatinization (PG) on the physical, mechanical, barrier, and optical features of films based on starch extracted from the Pakistani well-known variety “Basmati rice.” The thermal disintegration of granules was indicated by Scanning Electron Micrographs for HMT film. Findings The results of the study showed that the solubility of films in water was reduced in the following sequence: Pre-gelatinized rice starch film (33.66%) > Native rice starch (NRS) film (30.42%) > Heat moisture-treated rice starch (HMTRS) film (26.90%). The lowest water-soluble HMTRS film showed increased water transfer resistance and both treatments (HMT and PG) reduced water vapor permeability values of NRS from 2.49 × 10−10 to 1.25 × 10−10 g−1 s−1 Pa−1 and 1.34 × 10−10 g−1 s−1 Pa−1, respectively. Conclusions HMT induced structural deviations that impact higher changes in color parameters and reduced transparency while both modified films had higher elongation at break than NRS films, but PG films had lower TS as compared to the HMT and NRS films. Significance and Novelty The lower water vapor permeability of HMT films makes them suitable for packaging moisture-sensitive food products, while PG films can find use in the packaging of products that are sensitive to light.

Octenyl succinylated potato starch-based film reinforced by honey-bee products: Structural and functional properties

Edible films were developed from native or octenyl succinylated potato starches and extracts from the following honey-bee products: multifloral honey, buckwheat honey, bee-pollen, bee-bread or propolis. Pasting and rheology properties of film-forming suspensions as well as structural characteristic and physical properties of the produced films were studied. The results showed that esterified starch and the honey-bee extracts (HBE) changed film properties in a different way, depending on the type of the extract. The pasting and rheological properties were improved as a result of both starch esterification and incorporation of the HBE. The FTIR-ATR spectroscopy of films indicated that some molecular interactions between the starch and the HBE may have occurred. The films made from the esterified starch showed significantly lower tensile strength, elasticity, thermal transition parameters (enthalpy - ΔH and onset - To, peak - Tp, end - Te temperatures), as well as higher swelling as compared to the native starch films. All films were characterized by a high structural integrity, however films based on esterified starch and reinforced with HBE exhibited a rough and folding surface. Bee-bread and propolis extracts seem to be the most promising HBE for production of films due to the ability to reduce solubility and thermal transition parameters as well as to improve mechanical properties of the films.

Comparison of Properties of Films Prepared from Potato Starch Modified by Annealing and Heat–Moisture Treatment

AbstractThis study modified potato starches using hydrothermal treatment, i.e., annealing (ANN) and heatmoisture treatment (HMT). ANN in the ratio (1:2) of potato starch and water at 60 °C is performed for a day. For HMT, native starch is exposed to 110 °C maintained at 20% moisture content (M.C.) for 8 h. Potato bio‐films (native and modified) are prepared by solution casting method using glycerol as a plasticizer. The properties of native and modified starches along with developed films are evaluated. HMT‐modified starches showed lower solubility (10.5%), lower swelling power (21.2 g g−1), lower freeze‐thaw stability, and exhibited non‐Newtonian fluid behavior. Films produced from HMT starch have decreased solubility (13.57%), WVP (0.20 g mm m−2 h−1 kPa−1), and enhanced mechanical properties (7.62 MPa tensile strength, elongation of 11.36%, and seal strength 4.06 MPa) compared to annealed and native starch films. ANN starch increased the elongation (9.36%) with lower solubility (17.31%) and WVP (0.65 g mm m−2 h−1 kPa−1) of the starch films compared to the native starch. Also, the result shows that the potato starch‐based films biodegraded within 15 days. The developed biodegradable packaging films could meet various packaging requirements using physically modified potato starch which has better film forming properties and is also eco‐friendly.

Morphological and thermo-mechanical characterization of sweet potato starch based nanocomposites reinforced with barley starch nanoparticles.

The aim of present study was to develop and characterize the biodegradable sweet potato starch-based nanocomposite films reinforced with barley starch nanoparticles (SNP). Sweet potato starch-based films with varying concentrations of barley SNP (5-25% w/w) were manufactured by adopting solution casting method using glycerol as a plasticizer. The morphology, thickness, transparency, water solubility, water vapor transmission rate (WVTR), tensile strength, elongation at break and thermal stability properties of nanocomposite films were evaluated. The results showed that the incorporation of barley SNP led to a significant increase in tensile strength from 2.63 (control film) to 8.98MPa (nanocomposite with 15% (w/w) SNP). Compared with the native starch film, the surface of the nanocomposite films became more rough and uneven with the increasing concentration of nanofillers. High concentration of SNP (upto 25%, w/w) significantly decreased the transparency and WVTR, and water solubility (upto 20%, w/w) of nanocomposite films. The WVTR decreased from 3294.53 to 349.06g/m2/24h. In addition, the thermal stability of nanocomposites got improved after incorporation of SNP into starch-film matrix.

Production and Properties of Native Potato Starch-Coated Urea

This work is dedicated to researching the possibilities of using starch coating for slow-release fertilizers. Urea was used as nitrogen containing component, because it is the most suitable for the production of slow-release nitrogen fertilizers and has the highest concentration of nitrogen – 46.6 %. During the studies, native potato starch film was prepared and its stability was evaluated, subsequently, urea was coated with starch film/coating and the influence on properties of fertilizer granules (hygroscopicity and strength) was evaluated. Single and/or multiple layered films were formed during the coating process and the influence of coating thickness on urea solubility was researched. It was found that the mechanical properties of urea with double coating change quite insignificantly while coating reduces the solubility of urea by more than 20 %.

Impact of starch nanocrystals on the physicochemical, thermal and structural characteristics of starch-based films

The incorporation of starch nanocrystals (SNCs) in starch films can be a way of increasing their applicability. Therefore, the objective of this study was to develop SNCs from rice and potato starch and apply them in films of native rice starch and hydrolyzed rice starch in order to observe the effect of these nanomaterials on the films’ properties. The SNCs were produced by hydrolysis for 5 and 7 days and characterized. The films were produced by the casting technique and the SNCs were added at concentrations of 0.1% and 0.3%. The films were characterized in terms of physicochemical, thermal and structural properties. The SNCs showed solubility above 70% while the control starches had solubility around 20%. The addition of SNCs increased the crystallinity of all films produced. The addition of 0.1% rice SNCs to native starch films reduced water vapor permeability by 64% compared to the control. The incorporation of 0.1% potato SNCs reduced the solubility to 14%. The application of 0.3% rice SNCs and 0.1% potato SNCs in native starch and hydrolyzed starch films reduced the surface roughness and fracture, making these films more cohesive. Therefore, SNCs act as a structural reinforcing agent, improving several properties of the films.

Characterization and properties of singly and dually modified hydrogen peroxide oxidized and glutaraldehyde crosslinked biodegradable starch films

Poor properties of native cassava starch film such as low mechanical properties and high water uptake are the limitations of biodegradable starch films. Dual modification is an alternative way to improve the properties. Characteristics and properties of oxidized, crosslinked and dually modified starch films by hydrogen peroxide oxidation and glutaraldehyde crosslinking were examined. Sequence of the dual modification was also studied. All starch films were prepared by casting technique using glycerol plasticizer. The oxidation and crosslinking of modified starch were confirmed by carbonyl and carboxyl contents as well as degree of crosslinking. The lowest and highest molecular weights of the modified starch were observed for the oxidized starch and crosslinked starch, respectively. Moreover, swelling power and moisture absorption of dually modified starch films was clearly lower than those of singly modified films. Additionally, both good stiffness and extensibility was also obtained from the dually modified films especially for the crosslinked-oxidized film. Moreover, thermal property and biodegradability were also determined.

Effect of dual-modified cassava starches on intelligent packaging films containing red cabbage extracts

This study aimed to develop intelligent packaging films possessing pH-sensitive and mechanical stability for cassava starch-based substrates using red cabbage extracts by a simple casting technique. It also investigated the effect of native and different dual-modified [oxidized hydroxypropyl starch, acetylated distarch phosphate (ADSP), and oxidized-acetylated starch] cassava starches on the morphological, physical, and pH-sensitive properties of intelligent films. Dual-modified cassava starch films presented better transparency, water-resistance, water vapor barrier ability and tensile strength than native cassava starch films. Scanning electron microscopy observation revealed the compactness of the films was improved by the modification. The addition of new groups was confirmed after the dual-modification of cassava starch in the films by infrared spectroscopy. The ADSP films had the best thermal stability compared to the other three films. Notably, all films produced intense naked-eye detectable colorimetric response to pH variation (2-12) and volatile ammonia, and exhibited different color reversibility properties. Anionic cassava starch formed stable complexes with anthocyanins through electrostatic interactions and hydrogen bonding, thus enhancing the stability of anthocyanins. Therefore, cassava starch-based films have promising potential for applications in intelligent food packaging.

Barnyard millet starch cross-linked at varying levels by sodium trimetaphosphate (STMP): Film forming, physico-chemical, pasting and thermal properties

Sodium trimetaphosphate (STMP) at different levels (1, 3 and 5%) was used to prepare cross-linked (CL) barnyard millet starch. The starches were studied for their physicochemical, pasting, steady shear rheological and thermal properties. Further, films were formulated from these starches and assessed for their functional and mechanical behavior. Amylose content of native starch (15%) decreased upon cross-linking (7.86–9.65%). CL starches had lower swelling power (SP) and solubility than native starch. CL starches showed lower peak (7049–9649 mPa.s), breakdown viscosities (BV) (1073–3172 mPa.s) but higher pasting temperature (PT) (79.7–80.8 °C) than native starch. Pasting properties were more affected for CL (5%) starch. Steady shear properties revealed lower yield stress (σo) values of CL starch pastes (1.39–2.37 Pa) than native starch paste (15.40 Pa). Flow behavior index was <1 for native and CL starches, thereby indicating their shear thinning behavior. Cross-linking increased gelatinization temperature, but decreased the enthalpy of gelatinization (ΔHgel) values. CL starch films exhibited lower water vapor permeability (WVP) and higher tensile strength (TS) and solubility than native starch films. CL (5%) starch film exhibited the lowest WVP (1.28 g.m/Pa.s.m2) and the highest TS (13.12 MPa) among films.

Physicochemical and Rheological Properties of Cross‐Linked Litchi Kernel Starch and Its Application in Development of Bio‐Films

AbstractIn this study, starch from a non‐conventional source, that is, litchi is extracted and cross‐linked (CL) with varying concentrations (1%, 3%, and 5%) of sodium trimetaphosphate (STMP). The starches are characterized for their physicochemical, pasting, rheological, and thermal properties. Bio‐films are also prepared from these starches and analyzed for selected barrier and mechanical properties. The results indicate that an increase in cross linking agent concentration resulted in a significant decrease in amylose content, swelling power (SP), and solubility of starches. Peak viscosity (PV) and breakdown viscosity (BV) of CL starches are lower in comparison to native starch. Steady shear properties reveal that magnitudes of yield stress (σo) and consistency index (K) decrease upon increase in the concentration of cross linking reagent. CL starches exhibit significantly (p &lt; 0.05) higher transition temperatures than native starch. Native starch film shows water solubility of 43.66% while for films from CL starches, the values ranged between 35.12 and 41.53%. Significant (p &lt; 0.05) reduction in water vapor permeability (WVP) values of CL starch films (1.24–1.52 g m Pa−1 s−1 m−2) is observed in comparison to native (2.32 g m Pa−1 s−1 m−2) starch films. Cross linking significantly improves tensile strength (TS) of films, however, films elongation is lower (14.71–17.97%) than native starch film (19.88%).

Study on enhanced mechanical, barrier and optical properties of chemically modified mango kernel starch films

The main aim of this study was to chemically modify mango kernel starch (MKS) and assess its impact on packaging film properties. MKS exhibited limited application due to low solubility, retrogradation, higher gelatinization temperature and hydrophilicity. These limitations could be effectually overcome by integrating modifications to native starch. Chemical modifications of MKS were performed by oxidation and benzylation with a low degree of substitution. X‐ray diffractogram presented A‐type pattern of crystal structure which was in accordance to endosperm starch. Fourier‐transform infrared (FTIR) spectra of the native and modified starch samples exhibited strong bands in the regions corresponding to OH and CH stretching. Additionally, absorption bands were found in the regions for carbonyl and aromatic phenyl vibrations signifying the substitution of functional groups within native starch. Modified starch films presented increased lightness L* representing that the films were lighter in colour than native film. Tensile strength (TS) of modified films was found to increase more than twice that of native starch film. Starch recrystallization was interrupted by oxidation thereby preventing retrogradation. Benzylation lowered the water vapour permeability by 58% and improved UV absorption by 80% when compared with native film.

Development of Bioplastic Films from γ − Irradiated Kithul (Caryota urens) Starch; Morphological, Crystalline, Barrier, and Mechanical Characterization

AbstractImportant properties of bioplastic film made from γ − irradiated kithul starch such as crystalline, morphological, mechanical, and barrier properties are studied. The films are made from native and irradiated kithul starch using the casting method. Relative crystallinity is higher for the film made from irradiated kithul starch. The film made from 100 kGy irradiated starch shows the highest relative crystallinity (2.26%) among the starch films. The film prepared from irradiated kithul starch exhibits lower water vapor permeability (WVP). The solubility of film made from irradiated starch decrease with an increase in irradiation dose. Irradiation of starch cause higher surface compactness, which decrease the oxygen permeability of the films. The decrease in WVP and oxygen permeability indicates the improved barrier properties of films made from irradiated starch. Mechanical properties increase in films made from irradiated kithul starch. Moreover, it shows lower surface roughness as compared with native starch film. The research reveals that films made from γ − irradiated kithul starch exhibited better mechanical and barrier properties due to their higher crystallinity and surface homogeneity.

Modified starch with bis(2-hydroxyethyl) terephthalate: synthesis, characterization and elaboration of films

Banana starch was modified with B bis(2-hydroxyethyl) terephthalate and its instrumental characterization allowed to propose a chemical structure. In the carbon 6 (C6) of the starch the modification reaction was carried out. The morphology of starch changes due to its chemical modification. The modified starch showed a lower crystallinity and thermal stability, compared to the native starch favoring its film formation. The electrical conductivity of the modified starch films was 2.7 times higher than that for the native starch film. The aqueous hydrolysis of the modified starch films was carried out obtaining a degradation of 77% in a determined time. Modified starch films present different mechanical properties compared to native starch film. These results have high application potential to be used in PET degradation products.