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1.
Int J Biol Macromol ; 266(Pt 2): 131206, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38574919

RESUMO

In this study, cinnamic acid modified acid-ethanol hydrolyzed starch (CAES) with different degrees of substitution (DS) was fabricated to stabilize Pickering emulsions and probed their application for encapsulating curcumin (Cur). Successful preparation of CAES (with DS from 0.016 to 0.191) was confirmed by 1H NMR and FT-IR, and their physicochemical properties were characterized by XRD, SEM, and TGA. The biosafety evaluations and surface wettability confirmed the excellent safety and amphiphilic character of CAES. CAES-stabilized Pickering emulsion (CS-PE) exhibited different emulsion stability at different DS, with CS-PE (0.031) showing the highest stability. CLSM revealed that the CAES (0.031) formed a dense barrier on the surface of the oil droplets, preventing them from coalescing. The CS-PE (0.031) achieved effective encapsulation of Cur (up to 96.2 %). Compared with free Cur, CS-PE (0.031) exhibited better photochemical stability, higher free fatty acids (FFA) release, and enhanced bioaccessibility. These studies suggested that CAES may serve as a promising emulsifier for stabilizing Pickering emulsions to encapsulate and deliver hydrophobic bioactive compounds.

2.
Nanomaterials (Basel) ; 14(6)2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38535657

RESUMO

The encapsulation and the oxidative stability of cod liver fish oil (CLO) within coaxial electrosprayed (ethyl cellulose/CLO) core-(octenyl succinic anhydride, OSA-modified starch) shell, and monoaxial electrosprayed ethyl cellulose/CLO microcapsules were investigated. Core-shell (H-ECLO) and monoaxial (ECLO) electrosprayed microcapsules with an average diameter of 2.8 ± 1.8 µm, and 2.2 ± 1.4 µm, respectively, were produced. Confocal microscopy confirmed not only the core-shell structure of the H-ECLO microcapsules, but also the location of the CLO in the core. However, for the ECLO microcapsules, the CLO was distributed on the microcapsules' surface, as also confirmed by Raman spectroscopy. Atomic force microscopy showed that the average surface adhesion of the H-ECLO microcapsules was significantly lower (5.41 ± 0.31 nN) than ECLO microcapsules (18.18 ± 1.07 nN), while the H-ECLO microcapsules showed a remarkably higher Young's modulus (33.84 ± 4.36 MPa) than the ECLO microcapsules (6.64 ± 0.84 MPa). Differential scanning calorimetry results confirmed that the H-ECLO microcapsules enhanced the oxidative stability of encapsulated CLO by about 15 times, in comparison to non-encapsulated oil, mainly by preventing the presence of the fish oil at the surface of the microcapsules, while ECLO microcapsules enhanced the oxidative stability of CLO about 2.9 times due to the hydrophobic interactions of the oil and ethyl cellulose. Furthermore, the finite element method was also used to evaluate the electric field strength distribution, which was substantially higher in the vicinity of the collector and lower in the proximity of the nozzle when the coaxial electrospray process was employed in comparison to the monoaxial process.

3.
Food Chem ; 446: 138841, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38428082

RESUMO

Native starch has poor stability and usually requires modification to expand its industrial application range. Commonly used methods are physical, chemical, enzymatic and compound modification. Microwave radiation, as a kind of physical method, is promising due to its uniform energy radiation, greenness, safety, non-toxicity. It can meet the demand of consumers for safe food. Microwave-assisted modification with other methods can directly or indirectly affect the structure of starch granules to obtain modified starch with high degree of substitution and low viscosity, and the modification efficiency is greatly improved. This paper reviews the effect of microwave radiation on the physicochemical properties of starch, such as granule morphology, crystallization characteristics, and gelatinization characteristics, as well as the application of microwave radiation in starch modification and starch food processing. It provides theoretical references and suggestions for the research of microwave heating modified starch and the deep processing of starchy foods.


Assuntos
Micro-Ondas , Amido , Amido/química , Viscosidade , Cristalização , Manipulação de Alimentos
4.
Heliyon ; 10(6): e27453, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38509922

RESUMO

This study reviews the importance of resistant starch (RS) as the polymer of choice for biodegradable food packaging and highlights the RS types and modification methods for developing RS from native starch (NS). NS is used in packaging because of its vast availability, low cost and film forming capacity. However, application of starch is restricted due to its high moisture sensitivity and hydrophilic nature. The modification of NS into RS improves the film forming characteristics and extends the applications of starch into the formulation of packaging. The starch is blended with other bio-based polymers such as guar, konjac glucomannan, carrageenan, chitosan, xanthan gum and gelatin as well as active ingredients such as nanoparticles (NPs), plant extracts and essential oils to develop hybrid biodegradable packaging with reduced water vapor permeability (WVP), low gas transmission, enhanced antimicrobial activity and mechanical properties. Hybrid RS based active packaging is well known for its better film forming properties, crystalline structures, enhanced tensile strength, water resistance and thermal properties. This review concludes that RS, due to its better film forming ability and stability, can be utilized as polymer of choice in the formulation of biodegradable packaging.

5.
Int J Biol Macromol ; 259(Pt 1): 129173, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38181923

RESUMO

Modified starch was prepared from japonica starch (JS) by heat-moisture treatments (HMT). Under the same moisture content and HMT temperature, the effects of various HMT times on the structural, properties of JS and its in vitro digestibility properties were investigated. The results showed that adhesion occurred between the particles of japonica starch after the HMT, and there were depressions on the surface. The size of the JS particles increased, the short-range ordering and relative crystallinity of the HMT-modified starch increased and gradually decreased, reaching a peak of 36.51 % at 6 h, as the HMT time was extended. The pasting indexes of HMT-modified starch decreased and then increased with the increase of the HMT time; compared with JS, the thermal stability of HMT-modified starch increased while the pasting enthalpy decreased. All the HMT-modified starches were weakly gelatinous systems and pseudoplastic fluids. Following HMT, the amount of resistant starch (RS) and slowly digested starch (SDS) grew initially before declining. The amount of RS in HMT-modified starch peaked at 24.28 % when the HMT time was 6 h. The results of this research can serve as a theoretical foundation for the creation of modified japonica starch and its use in the food industry.


Assuntos
Temperatura Alta , Amido , Amido/química , Temperatura , Termodinâmica , Amido Resistente
6.
Int J Biol Macromol ; 259(Pt 2): 129230, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38184054

RESUMO

The ultrasonically processed Eugenol (EU) and Carvacrol (CAR) nanoemulsions (NE) were successfully optimized via response surface methodology (RSM) to achieve broad spectrum antimicrobial efficacy. These NE were prepared using 2 % (w/w) purity gum ultra (i.e., succinylated starch), 10 % (v/v) oil phase, 80 % (800 W) sonication power, and 10 min of processing time as determined via RSM. The second order Polynomial method was suitable to RSM with a co-efficient of determination >0.90 and a narrow polydispersity index (PDI) ranging 0.12-0.19. NE had small droplet sizes (135.5-160 nm) and low volatility at high temperatures. The EU & CAR entrapment and heat stability (300 °C) confirmed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Further, the volatility of EU & CAR NE was 18.18 ± 0.13 % and 12.29 ± 0.11 % respectively, being lower than that of bulk/unencapsulated EU & CAR (i.e., 23.48 ± 0.38 % and 19.11 ± 0.08 %) after 2 h at 90 °C. Interestingly, both EU & CAR NE showed sustained release behaviour till 48 h. Their digest could inhibit Salmonella typhimurium (S. typhimurium) via membrane disruption and access to cellular machinery as evident from SEM images. Furthermore, in-vivo bio-accessibility of EU & CAR in mice serum was up to 80 %. These cost-effective and short-processed EU/CAR NE have the potential as green preservatives for food industry.


Assuntos
Anti-Infecciosos , Cimenos , Eugenol , Animais , Camundongos , Eugenol/farmacologia , Eugenol/química , Salmonella typhimurium , Amido/química , Anti-Infecciosos/farmacologia , Emulsões
7.
Foods ; 13(2)2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38254604

RESUMO

Ensuring the stability of zein nanoparticles at different pH levels is crucial for their application as nanocarriers. In this study, octenyl succinic anhydride-modified starch (OSA-modified starch) was employed to enhance the stability of zein nanoparticles against different pH levels by forming complex nanoparticles with OSA-modified starch. The effect of preparation pH on the stability of the zein/OSA-modified starch nanoparticles was investigated. Sedimentation occurred in zein nanoparticles as the pH reached the isoelectric point. However, the stability of zein nanoparticles at various pH levels significantly improved after adding OSA-modified starch to form zein/OSA-modified starch nanoparticles regardless of whether they were prepared under acidic or alkaline pH conditions. Notably, the stability of zein/OSA-modified starch nanoparticles prepared at an acidic pH was higher than that of those prepared at an alkaline pH, thereby highlighting the critical role of the preparation pH for zein/OSA-modified starch in maintaining the stability of zein. The stable zein/OSA-modified starch nanoparticles developed in this study exhibit significant potential for use in delivery systems across various pH environments.

8.
J Agric Food Chem ; 72(1): 590-603, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38133624

RESUMO

SBEIIb (Sobic.004G163700), SSSIIa (Sobic.010G093400), and GBSSI (Sobic.010G022600) genes that regulate starch synthesis in sorghum endosperm were transferred into Escherichia coli by transgenic technology. SBEIIb, SSSIIa, and GBSSI enzymes were separated and purified through a Ni column and analyzed by electrophoresis with molecular weights and activities of 91.57 84.57, and 66.89 kDa and 551 and 700 and 587 U/µL, respectively. Furthermore, they were applied to starch modification, yielding interesting findings: the A chain content increased from 25.79 to 89.55% for SBEIIb-treated waxy starch, while SSSIIa extended the A chain to form DPs of the B chain, with A chain content decreasing from 89.55 to 37.01%, whereas GBSSI was explicitly involved in the synthesis of B1 chain, with its content increasing from 9.59 to 48.45%. Modified starch was obtained, which could be accurately applied in various industries. For instance, we prepared a sample (containing 89.6% A chain content) with excellent antiaging and antidigestion properties through SBEIIb modification. Moreover, higher RS3 (34.25%) and SDS contents (15.75%) of starch were obtained through the joint modification of SBEIIb and SSSIIa. These findings provide valuable insights for developing sorghum starch synthesis-related enzymes and offer opportunities for improving starch properties through enzymatic approaches.


Assuntos
Sorghum , Amido , Sorghum/genética , Escherichia coli/genética , Amilopectina , Endosperma/química , Amilose/análise
9.
J Agric Food Chem ; 71(48): 19033-19044, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37997356

RESUMO

Starch-lipid-protein complexes are attracting increasing attention due to their unique structure and low enzymatic digestibility. However, the mechanisms underlying the formation of these ternary complexes, especially those with monoglycerides as the lipid component, remain unclear. In the present study, potato starch or octenyl succinic anhydride (OSA)-modified potato starch (OSAPS), various monoglycerides (MGs), and beta-lactoglobulin (ßLG) were used in model systems to characterize the formation, structure, and in vitro digestibility of the respective ternary complexes. Colorimetry and live/dead staining assays demonstrated that the OSAPS had good biocompatibility. Experimental data and molecular dynamics simulations showed that both unmodified potato starch and OSAPS formed starch-lipid-protein complexes with MGs and ßLG. Of the two types of starch, OSA formed a greater amount of the more stable type II V-crystallites in complexes, which had greater resistance to in vitro enzymic digestion. This study demonstrated for the first time that starch can interact with MGs and ßLG to form ternary complexes and that OSA esterification of starch promoted the formation of more complexes than unmodified starch.


Assuntos
Monoglicerídeos , Anidridos Succínicos , Anidridos Succínicos/química , Amido/química , Esterificação
10.
Food Sci Biotechnol ; 32(13): 1883-1891, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37781065

RESUMO

The O/W emulsions were prepared using perilla seed oil (PSO) dispersed in soy sauce (PSE) and in distilled water (PWE), respectively. Octenyl succinic anhydride-modified starch (OSA starch, 3 wt%) showed the most efficient emulsifying ability and its stabilities of emulsion and oxidation in PSE and PWE were studied at different storage periods (0, 4, and 8 weeks) and temperatures (4, 25, and 40 °C). Negligible change in droplet diameter of PSE was observed without coalescence or flocculation during storing for 8 weeks at 4 °C. The stabilizing ability of OSA-starch despite the high ionic strength of soy sauce is attributed to the starch backbone, which promotes steric repulsions between droplets. A lower oxidation degree was observed for PSE prepared than PWE and PSO under all storage conditions. Thus, the O/W emulsion prepared from PSO and soy sauce can be applied to the production of ω-3 fatty acid-enriched Asian-style emulsified products.

11.
Int J Biol Macromol ; 253(Pt 8): 127543, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37866555

RESUMO

Lotus (Nelumbo nucifera G.) rhizomes are an under-utilized and sustainable starch source that constitutes up to 20 % starch. The review mainly focused on the extraction methods of starch, the chemical composition of LRS, and techno-functional characteristics such as swelling power, solubility, in vitro digestibility, pasting property, and gelatinization is highlighted in LRS review. Lotus rhizome starch (LRS) is also used as a water retention agent, thickening, gelling, stabilizing, and filling in food and non-food applications. Native starch has limited functional characteristics in food applications so by modifying the starch, functional characteristics are enhanced. Single and dual treatment processes are available to enhance microstructural properties, resistant starch, techno-functional, morphological, and, film-forming properties. Compared with other starch sources, there is a lack of systematic information on the LRS. Many industries are interested in developing food products based on starch such as nanoparticles, hydrogels, edible films, and many others. Additionally, there are several recommendations to improve the applications in the food industry. Finally, we provide an outlook on the future possibility of LRS.


Assuntos
Lotus , Nelumbo , Amido/química , Nelumbo/química , Rizoma/química , Lotus/química , Solubilidade
12.
Carbohydr Polym ; 322: 121331, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37839843

RESUMO

This study aimed to investigate how the types and order of modifications influence the structure and physicochemical characteristics of modified porous starch. The work focuses on the encapsulation of essential oil in hydrophobic microcapsules embedded in sodium alginate hydrogels. FTIR spectra indicated successful esterification of starch with OSA. 1047:1022 cm-1 and 1022:995 cm-1 band ratios of FTIR spectra revealed increased crystallinity due to enzymatic modification, supported by XRD patterns. Porous-OSA (PO) starch had 1.5 times higher degree of substitution (DS) than OSA-porous (OP) starch, confirmed by the intense peak at 0.85 ppm in 1H NMR spectra. SEM images displayed larger particles and smaller pore diameter in OP compared to PO and porous starch, indicating amylolytic enzyme inhibition by OSA. Loading efficiency (LE) showed no significant difference between OP and PO microcapsules (≈70 %), both significantly higher other starch microcapsules. OP and PO microcapsules exhibited sustained release, with enhanced antibacterial activity. Alginate hydrogels preserved about 60 % antioxidant and 90 % antibacterial activities of SEO against 2 h of UV radiation. These findings suggest that the order of modification could not affect the functional properties of final microcapsules. Additionally, the importance of alginate hydrogels as the protective and second wall material was disclosed.


Assuntos
Óleos Voláteis , Satureja , Hidrogéis , Alginatos/química , Cápsulas , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Amido/química , Antibacterianos/farmacologia
13.
Heliyon ; 9(9): e19581, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37809979

RESUMO

Potatoes are among the leading staple crops due to nutritional value and high demand. The undersized and damaged potatoes are considered low grade and mainly dumped as a waste or used in animal feed. The study aimed to extract starch from low grade potatoes, its modification to improve the starch properties and formulation of gluten free cookies using modified starch (MS). The starch was extracted from low-grade potatoes of three varieties known as Asterix, Kruda and Mosaic, using the water steeping method. The native starch (NS) was modified using lintnerization and repetitive autoclaving. MS contains high amylose content which is associated with health benefits. NS and MS were characterized for amylose content, color attributes, granular morphology, water solubility index (WSI), water absorption index (WAI), thermogravimetric analysis (TGA) and Fourier transform infrared spectrometer (FTIR) analysis. Gluten-free cookies were formulated by adding potato NS and MS. The cookies were characterized by sensory evaluation, proximate and textural analysis. The starch yield extracted from three different varieties of potatoes i.e. Asterix, Kruda, Mosaic was 11.53%, 11.32% and 11.24%, respectively. The amylose content of potato starch was significantly (p < 0.05) increased for all varieties (33.61-37.74%) after modification of NS, which was in the range of 25.71-26.60% for different potato varieties. The granules of MS were observed as amorphous structures in comparison to NS granules with smooth surfaces. The addition of MS significantly (p < 0.05) decreased the hardness of the cookies in comparison to NS. Overall, no significant difference was observed in the sensory attributes of control, NS and MS containing cookies. Therefore, in comparison to other dietary fibers, MS can be used as a functional ingredient in food products without compromising the texture and sensory attributes.

14.
Sci Total Environ ; 904: 166787, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37666335

RESUMO

Microplastics (MPs) pose a potential risk to aquatic ecosystems, and there is a growing demand to alleviate the contamination of MPs. Here, we introduce cationic-modified starch (CS) as an eco-friendly bio-coagulant for removing MPs from water. CS with varying degrees of substitution was synthesized and characterized, and its performance in removing MPs was evaluated under different MP sizes, types, and aging, as well as various water conditions. The results indicated that CS efficiently removed MPs, achieving an average removal rate of 65.33 % for polystyrene particles, with higher removal rates for larger, high-density, and aged MPs. The efficiency of CS remained consistent across a wide range of water pH values, but was significantly reduced in the presence of kaolin clay or/and humic acid. The removal efficiency of CS for MPs was enhanced by the non-ionic surfactant, Tween 20, but inhibited by the anionic surfactant, cetyltrimethylammonium bromide. In addition, CS could concurrently remove both MPs and phenanthrene, as a typical water contaminant. Moreover, the applicability of CS was demonstrated in natural water samples from the Ecological Demonstration Zone of the Yangtze River Delta, China, with an average removal rate of 60.13 ± 3.15 %. Taken together, this study offers an environmentally friendly and cost-effective approach for the removal of MPs from water, demonstrating CS has significant application potential as a sustainable solution to mitigate microplastic pollution.

15.
J Oleo Sci ; 72(9): 811-818, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37574285

RESUMO

This study highlights the use of red palm oil (RPO) as an alternative to dairy fat in a hard ice cream sample in the presence of different stabilizers; maltodextrin (MALTOD) and modified starch (MSTARCH). No stabilizer was added in the control sample (CO), while the different ratios of RPO to each stabilizer were 4:1, 3:2, and 2:3, coded as MALTOD1, MALTOD2, MALTOD3 for maltodextrin, and MSTARCH1, MSTARCH2, and MSTARCH3 for modified starch, respectively. These samples were compared regarding overrun, physical, and sensory properties. For MALTOD, sample MALTOD3 had the highest overrun (49.31±13.78%), while MALTOD2 had the highest viscosity (7.90±0.03 Pa.s) and hardness (1.09±0.07 kg), and MALTOD1 had the lowest melting properties (61.10±0.20%). For MSTARCH, sample MSTARCH1 had the highest hardness (3.39±0.07 kg), MSTARCH2 had the highest overrun (67.64±2.27%), and MSTARCH3 had the highest viscosity (8.19±0.24 Pa.s) and the lowest melting properties (39.83±0.20%). Samples MALTOD3 and MSTARCH1 were selected for comparison with commercial samples in terms of sensory acceptance and preference. There was no significant difference (p > 0.05) between the sensory acceptability of MALTOD3 and MSTARCH1. However, both samples received a significantly lower (p < 0.05) ranking than the commercial samples in terms of appearance, texture, flavour, meltability, and overall acceptance. Future studies are recommended to improve the RPO-based ice cream sample, particularly in terms of its sensory properties.


Assuntos
Sorvetes , Amido , Óleo de Palmeira , Polissacarídeos
16.
Polymers (Basel) ; 15(16)2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37631544

RESUMO

Biodegradable starch-based polymers were developed by melt-blending modified thermoplastic starch (MTPS) with poly(butylene succinate) (PBS) blended with epoxy resin (Er). A modified thermoplastic starch blend with chlorhexidine gluconate (MTPSCh) was prepared by melt-blending cassava starch with glycerol and chlorhexidine gluconate (CHG) 1.0% wt. The Er was melt-blended with PBS (PBSE) at concentrations of 0.50%, 1.0%, 2.5%, and 5.0% (wt%/wt%). The mechanical properties, water resistance, and morphology of the MTPSCh/PBSE blends were investigated. The MTPSCh/PBSE2.5% blend showed an improvement in tensile strength (8.1 MPa) and elongation at break (86%) compared to the TPSCh/PBS blend (2.6 MPa and 53%, respectively). In addition, water contact angle measurements indicated an increase in the hydrophobicity of the MTPSCh/PBSE blends. Thermogravimetric analysis showed an improvement in thermal stability when PBS was added to the MTPSCh blends. Fourier transform infrared spectroscopy data confirmed a new reaction between the amino groups of CHG in MTPSCh and the epoxy groups of Er in PBSE, which improved the interfacial adhesion of the MTPSCh/PBSE blends. This reaction improved the mechanical properties, water resistance, morphology, and thermal stability of the TPSCh/PBSE blends.

17.
Polymers (Basel) ; 15(13)2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37447580

RESUMO

Starch is a readily available and abundant source of biological raw materials and is widely used in the food, medical, and textile industries. However, native starch with insufficient functionality limits its utilization in the above applications; therefore, it is modified through various physical, chemical, enzymatic, genetic and multiple modifications. This review summarized the relationship between structural changes and functional properties of starch subjected to different modified methods, including hydrothermal treatment, microwave, pre-gelatinization, ball milling, ultrasonication, radiation, high hydrostatic pressure, supercritical CO2, oxidation, etherification, esterification, acid hydrolysis, enzymatic modification, genetic modification, and their combined modifications. A better understanding of these features has the potential to lead to starch-based products with targeted structures and optimized properties for specific applications.

18.
Food Chem ; 429: 136748, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37467669

RESUMO

High internal phase Pickering emulsions (HIPPEs) stabilized using modified starch nanoparticles (SNPs) were studied as a delivery system for ferulic acid (FA). The quinoa (Q, 153 nm) and maize (M, 221 nm) SNPs were prepared by sono-precipitation and modified with nonenyl succinic anhydride (NSA) and octenyl succinic acid (OSA). The FA-encapsulated HIPPEs obtained showed neither coalescence nor Ostwald ripening, as reflected by emulsion index and droplet size measurements. Confocal laser scanning microscopy revealed FA entrapped droplets surrounded by the SNPs layer. The rheological measurements confirmed strong network formation and long-term stability. In vitro studies (pH 7.4, 96 h) showed sustained release of FA from the gel network. After 15 days, the encapsulation efficiencies for HIPPEs stabilized with both NSA and OSA modified QSNPs and MSNPs were close to 99%. The results showed that FA could be feasibly encapsulated in HIPPEs stabilized using modified SNPs.


Assuntos
Chenopodium quinoa , Nanopartículas , Emulsões , Anidridos Succínicos , Zea mays , Tamanho da Partícula , Amido
19.
Carbohydr Polym ; 316: 120975, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37321705

RESUMO

Blends of polylactic acid (PLA) and thermoplastic starch (TS) with and without chemical modification were obtained by melt extrusion and used to obtain non-woven fabrics by melt-blowing for the first time. Different TS were obtained by reactive extrusion from native cassava, oxidized, maleated, and dual modified (oxidized and maleated) starch. The chemical modification of starch decreases the difference in viscosity and favors blending, resulting in more homogeneous morphologies, unlike the blends with unmodified TS, which displayed a visible phase separation with large TS droplets. The dual modified starch showed a synergistic effect to process TS by melt-blowing. Regarding non-woven fabrics, values in diameter (2.5-82.1 µm), thickness (0.4-0.6 mm), and grammage (49.9-103.8 g/m2) were explained due to differences in viscosity of the components, and to the fact that during melt the hot air preferentially stretches and thins the areas without large droplets of TS. Moreover, plasticized starch acts as a flow modifier. The porosity of the fibers increased with the addition of TS. Further studies and optimization of blends with low contents of TS and type starch modification will be necessary to completely understand these systems with very complex behavior to obtain non-woven fabrics with improved properties and application.


Assuntos
Poliésteres , Amido , Amido/química , Poliésteres/química , Têxteis , Viscosidade
20.
Foods ; 12(9)2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-37174411

RESUMO

Ethanolic extracts of propolis and bee honey contain substances beneficial to human health. Mixtures of wall materials were compared in spray-drying microencapsulation of ethanolic extracts of propolis and bee honey rich in bioactive compounds. Maltodextrin and tara gum were used to obtain microencapsulates A, and modified native potato starch and tara gum were used for microencapsulates B. High values of phenolic compounds, flavonoids, and antioxidant capacity were obtained in microcapsules A and B, and the results obtained in terms of encapsulation efficiency, yield, hygroscopicity, solubility, moisture, Aw, bulk density, and color were typical of the spray-drying process. On the other hand, spherical and elliptical microparticles of sizes between 7.83 and 53.7 µm with light and medium stability were observed. Thermogravimetric properties were similar in both microencapsulates; total organic carbon, SEM-EDS, and FTIR analyses corroborated the encapsulation. X-ray diffractogram exhibited amorphous structures, and the release kinetics of phenolic compounds presented high values from 8.13 to 12.58 mg GAE/g between 7 and 13 h. Finally, modified potato starch is a better encapsulant than maltodextrin because it has better core protection and controlled release of the encapsulated bioactive compounds.

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