Enhanced Water Absorption Research Articles

Thermo-responsive hydrogel with deep eutectic mixture co-monomer as drawing agent for forward osmosis

Deep eutectic mixture (DEM) and N-isopropylacrylamide (NIPAM) were co-polymerized as thermo-responsive P(NIPAM-co-DEM) hydrogel drawing agents for forward osmosis (FO). N-hexyl-N,N-dihydroxyethyl-N-methylammonium chloride–acrylic acid ([DHEA]Cl-AA) DEM is non-toxic and highly conductive due to its ionic (R4N+, Cl−) and hydrophilic (-OH, -C=O) groups. Addition of DEM at different contents (0–7.5 wt%) afforded P(NIPAM-co-DEM) with wide open pores as excellent water channels during water absorption. Their critical temperatures ranged Tc = 34.7–51.4 °C. At T < Tc, P(NIPAM-co-DEM) attained equilibrium swelling ratios = 32–43 (vs. 19 for PNIPAM), highlighting the advantage of DEM for enhanced water absorption. Heating the hydrogels at T > Tc resulted in 87.6–96 % dewatering efficiencies. Among the fabricated hydrogels, P(NIPAM-co-DEM) with 5 wt% DEM exhibited the highest water uptake and dewatering efficiency at moderate Tc. It achieved the highest FO water flux (initial Jv = 2.38 LMH in DI water feed). P(NIPAM-co-DEM) with 5 wt% DEM effectively and consistently desalinated low salinity water (2000 mg L−1 NaCl, Jv = 1.81 LMH) and treated domestic wastewater (Jv = 1.90 LMH) at T = 25 °C in cycled operations via efficient water recovery T = 45 °C and hydrogel drying via solar irradiation (1 kW m−2 for 1.5 h). Overall results demonstrate the potential of deep eutectic mixtures for the development of hydrogels as effective FO drawing agents.

Bifunctional Amphiphilic Nanospikes with Antifogging and Antibiofouling Properties.

Over the past few decades, extensive research efforts have been devoted to developing surfaces with unique functionalities, such as controlled wettability, antibiofouling, antifogging, and anti-icing behavior, for applications in a wide range of fields, including biomedical devices, optical instruments, microfluidics, and energy conservation and harvesting. However, many of the previously reported approaches have limitations with regard to eco-friendliness, multifunctionality, long-term stability and efficacy, and cost effectiveness. Herein, we propose a scalable bifunctional surface that simultaneously exhibits excellent antifogging and antibiofouling properties based on the synergistic integration of an eco-friendly and bio-friendly polyethylene glycol (PEG) hydrogel, oleamide (OA), and nanoscale architectures in a single flexible platform. We demonstrate that the PEG-OA-nanostructure hybrid exhibits excellent antifogging performance owing to its enhanced water absorption and spreading properties. We further show that the triple hybrid exhibits notable biofilm resistance without the use of toxic biocides or chemicals by integrating the "fouling-resistant" mechanism of the PEG hydrogel, the "fouling-release" mechanism of OA, and the "foulant-killing" mechanism of the nanostructures.

Durability and water absorption behaviour of rubberised concrete incorporating burnt clay brick powder

Rubberised concrete has suffered from reduced durability and water absorption performance compared to conventional concrete and its decreased durability is limiting its practical use. To reduce the inferior durability and water absorption performance of rubberised concrete, the inclusion of Burnt Clay Brick Powder (BCBP) partially replacing cement is considered. This paper captures the water absorption properties of rubberised concrete containing BCBP. Durability properties of rubberised concrete incorporating BCBP exposed to sea water and sulphuric acid were also evaluated in comparison with conventional concrete. Specimens were totally submerged in sulphuric acid and sea water in order to investigate the 90-days durability behaviour. These specimens were assessed in relation to strength, mass and diameter losses. Water absorption investigations illustrated that incorporating 5% BCBP in concrete enhanced water absorption performance compared to control concrete. The outcomes of durability tests showed that concrete mixes with 5% BCBP experienced the most excellent behaviour for both exposures. Moreover, the use of BCBP in rubberised concrete seemed to have protected rubberised concrete from experiencing substantial strength, diameter and mass losses. Eventually, the use of BCBP was suggested as a significant criterion that could achieve improved durability and water absorption properties of rubberised concrete.

Enhanced water absorption of tissue paper by cross-linking cellulose with poly(vinyl alcohol)

Tissue paper was the only paper grade whose consumption increased during 2020 in Europe. In a highly competitive context, this work explores a strategy based on bisacrylamide cross-linkers and poly(vinyl alcohol) (PVA), seeking to enhance the water uptake of pulps for tissue paper and the key properties of the resulting tissue sheets: water absorption capacity, capillarity, softness, porosity, and strength. For that, α-cellulose from cotton and a kraft hardwood pulp, in parallel, were reacted with N,N’-methylenebisacrylamide, both in the absence and in the presence of PVA. The water desorption rate of the modified polymers was monitored. Pulp blends were then mixed with a conventional softwood pulp (30%) to prepare laboratory tissue paper sheets (20 g m–2). For cotton cellulose, cross-linking with PVA more than doubled the water uptake, up to 7.3 g/g. A significant enhancement was also obtained in the case of pulps, up to 9.6 g/g, and in the case of paper, to 11.9 g/g. This improvement was consistent with a drastic increase in porosity, and it was not detrimental to paper strength.Graphical

Limbal Bio-Engineered Tissue Employing 3D Nanofiber-Aerogel Scaffold to Facilitate LSCs Growth and Migration.

Constrained by the existing scaffold inability to mimic limbal niche, limbal bio-engineered tissue constructed in vitro is challenging to be widely used in clinical practice. Here, a 3D nanofiber-aerogel scaffold is fabricated by employing thermal cross-linking electrospinned film polycaprolactone (PCL) and gelatin (GEL) as the precursor. Benefiting from the cross-linked (160°C, vacuum) structure, the homogenized and lyophilized 3D nanofiber-aerogel scaffold with preferable mechanical strength is capable of refraining the volume collapse in humid vitro. Intriguingly, compared with traditional electrospinning scaffolds, the authors' 3D nanofiber-aerogel scaffolds possess enhanced water absorption (1100-1300%), controllable aperture (50-100µm), and excellent biocompatibility (optical density value, 0.953± 0.021). The well-matched aperture and nanostructure of the scaffolds with cells enable the construction of limbal bio-engineered tissue. It is foreseen that the proposed general method can be extended to various aerogels, providing new opportunities for the development of novel limbal bio-engineered tissue.

Superior Unidirectional Water Transport and Mechanically Stable 3D Orthogonal Woven Fabric for Human Body Moisture and Thermal Management.

Unidirectional water transport performance is vital for maintaining human thermal and wet comfort in the field of garment materials. In this work, a 3D orthogonal woven fabric (3DOWF) with excellent one-way transport capacity and mechanical properties is developed via 3D weaving and plasma treatment. The 3DOWF consists of polyester yarns (first layer), cotton yarns (second layer), and viscose yarns (third layer) with successively enhanced water absorption capacity. This allows droplets to penetrate spontaneously from the hydrophobic layer to the hydrophilic layer but not vice versa. Moreover, the Coolmax yarn with the core suction effect in the Z-direction and the plasma-treated polyester of the 3DOWF are shown to efficiently speed up the water transport process. In particular, the water penetration rate of the 3DOWF reaches 25µl s-1 . In turn, the surface temperature after water absorption is increased by 2.6°C compared with the cotton fabric, while the tensile strengths in the weft and warp directions of the 3DOWF are 49.62 and 18MPa, respectively. These values represent the best insulation and mechanical characteristics thus far reported among unidirectional water transport fabrics. Therefore, the 3DOWF has great potential for use in watchbands, backpack belts, insoles, and other functional textiles.

Antimicrobial agents in dental restorative materials: Effect on long-term drug release and material properties.

The present study reports on the long-term drug release and mechanical properties of bioactive dental filling materials based on chlorhexidine diacetate (CHX) or octinidine (di)hydrochloride (ODH) incorporated in a composite based on dimethacrylates or an ormocer. CHX or ODH were added to a nano-hybrid ormocer (O) and a nano-hybrid composite (C) with the amount of 2wt% to achieve four matrix-drug combinations: O-CHX, O-ODH, C-CHX, and C-ODH. Drug extraction and release were measured using high-performance liquid chromatography with diode-array detection (HPLC-DAD), while drug distribution was assessed by using energy dispersive X-ray spectroscopy (EDX). Drug release in water at 37°C was observed over 87 d. To determine the material properties, the water absorption, water solubility, flexural strength and hardness were measured and compared to the reference materials. Persistent drug release over 87 d was observed for both ODH-based systems and both ormocer-systems, with the longest duration of activity seen for the O-ODH combination. Persistent drug release was achieved via the loosening of the polymer network indicated via decreasing polymerization enthalpies, enhanced water absorption, and water solubility. As a consequence, the flexural strengths of the materials were reduced. However, surface hardness was hardly reduced. ODH seems to be more adequate than CHX for the design of bioactive dental filling materials based on nano-hybrid ormocer and composites.

Effects of silane coupling agent modifications of hollow glass microspheres on syntactic foams with epoxy matrix

A syntactic foam was prepared from an epoxy resin matrix and modified hollow glass microsphere fillers. Modification by silane coupling agents with different molecular structures was analyzed, and the optimal content of the silane coupling agent was determined. The results demonstrated that all silane coupling agents enhanced the adhesion between the hollow glass microspheres and epoxy resin matrix, resulting in enhanced water absorption, compressive performance, tensile performance, and bending performance compared to those prepared using unmodified hollow glass microspheres. Among silane coupling agents with different end groups, the one with a sulfhydryl end group exhibited optimal modification for hollow glass microspheres. Among the silane coupling agents with different backbone structures, the one with silanol groups exhibited the optimal modification of hollow glass microspheres. Additionally, the performance of the syntactic foams was optimal when 6% of the silanol-containing coupling agent was used. The results demonstrated that syntactic foams prepared with hollow glass microspheres modified by silane coupling agents exhibited improvements in water absorption, compressive performance, tensile performance, and bending performance, compared with those prepared using unmodified hollow glass microspheres. Among silane coupling agents with different end structures, the one with a sulfhydryl group as end group showed the best modification effect on hollow glass microspheres. The water absorption was 0.35%, the compressive strength was 62.15 MPa, the tensile strength was 40.15 MPa, and the bending strength was 53.17 MPa. Among silane coupling agents with different backbone structures, the one with silanol groupsbonds showed the best results. Its compressive strength was up to 64.15 MPa, the tensile strength was 35.47 MPa, and the bending strength was 53.99 MPa.

Radio-frequency (RF) room temperature plasma treatment of sweet basil seeds (Ocimum basilicum L.) for germination potential enhancement by immaculation

Ocimum basilicum L. is an antiviral and immunity boosting medicinal plant and culinary herb. Potential use of sweet basils in COVID 19 prevention and management is making its demand rise. This study is aimed at germination potential enhancement of sweet basil seeds. Reported study is evidenced with scientific data of radio-frequency cold plasma treatment using Ar + O2 feed gas. O. basilicum seeds, placed inside the rotating glass bottle, were directly exposed to RF (13.56 MHz) plasma produced in Ar + O2 feed gas. Seed treatment was done using RF source power (60 W, 150 W, 240 W), process pressure (0.2 mbar, 0.4 mbar, 0.6 mbar), and treatment time (5 min, 10 min, 15 min) at different combinations. Results show that, the most efficient treatment provide up to ∼89 % of the germination percentage which is an enhancement by 32.3 % from the control. SEM images revealed slight shrinkage in the seed size with eroded appearance over the seed. Enhancement of lipid peroxidation, show that oxidation of seed coat may propagate internally. Water imbibition analysis, of the treated seeds, was carried out for 2−12 hours. Further analysis of seed weight, on every one hour, after soaking shows enhanced water absorption capability except the treatment at 240 W, 0.6 mbar and 15 min. Plasma treatment enhanced carbohydrate content and protein content which is reported to be due to increased primary metabolism. Whereas, increased activity of secondary metabolism results in the enhancement of enzymatic (catalase) and non-enzymatic antioxidants (proline). Vital growth parameters, such as SVI I and SVI II, got amplified by 37 % and 133 % respectively after treatment. Ameliorative effects of plasma treatment are found highly significant with a positive and significant correlation value (p < 0.01) between germination percentages, SVI I, SVI II, carbohydrate, protein and proline show their interrelationship. Ar + O2 plasma treatment is found to bring forth significant changes in the O. basilicum seeds which eventually enhanced the germination potential and it could be a very promising technology for the medicinal crop.

Chemical and Physical Characterization of Sorghum Milling Fractions and Sorghum Whole Meal Flours Obtained via Stone or Roller Milling.

Due to climate change sorghum might gain widespread in the Western countries, as the grain is adapted to hot climate. Additionally sorghum contains a notable amount of health-promoting nutrients. However, Western countries do not have a long history of sorghum consumption, and thus little experience in processing it. Milling systems in these areas were mostly developed for wheat or rye milling. In the present work, the effectiveness of sorghum milling when using a stone and a roller milling system (pilot scale) was investigated as well as its impact on the chemical and physical properties of the obtained flour fractions and whole-grain flours. Results showed that both milling systems could be successfully adapted to producing chemically and physically distinct flour and bran fractions from the small sorghum kernels. Fractions with increased bran material that contained higher amounts of ash, protein, fat, total dietary fiber, and total phenolic content but less starch, showed enhanced water absorption indices and water solubility indices. Interestingly, no significant difference was found in the ash and fat content of the different fractions obtained from stone milling. Overall, the study provided information on the production and composition of distinct flour fractions, which offer a wider range of future food applications.

Stability and Influence of Storage Conditions on Nanofibrous Film Containing Tooth Whitening Agent.

Carbamide peroxide (CP), a tooth whitening agent, is chemically unstable. The present study explores stability enhancement of CP by loading in a nanofibrous film (CP-F) composed of polyvinyl alcohol/polyvinylpyrrolidone/silica mixture, using an electrospinning technique. Kept at a temperature range of 60–80 °C for 6 h, CP in CP-F showed significantly higher stability than that in a polymer solution and in water, respectively. Degradation of CP in CP-F could be described by the first order kinetics with the predicted half-life by the Arrhenius equation of approximately 6.52 years. Physicochemical properties of CP-F after long-term storage for 12 months at different temperatures and relative humidity (RH) were investigated using scanning electron microscopy, X-ray diffractometry, differential scanning calorimetry, and Fourier transform infrared spectroscopy. It was found that high temperature and high humidity (45 °C/75% RH) could enhance water absorption and destruction of the nanofibrous structure of CP-F. Interestingly, kept at 25 °C/30% RH, the nanofibrous structure of CP-F was not damaged, and exhibited no water absorption. Moreover, the remaining CP, the mechanical properties, and the adhesive properties of CP-F were not significantly changed in this storage condition. It is concluded that the developed CP-F and a suitable storage condition can significantly improve CP stability.

Potential Use of Oil Palm Fronds for Papermaking and Application as Molded Pulp Trays for Fresh Product under Simulated Cold Chain Logistics

ABSTRACT Waste paper from newsprint, a key feedstock for molded pulp trays, is globally deficient due to digital shifts. Hence, the alternative fiber source needs to be explored. The potential use of fiber from oil palm fronds for protective packaging under humid conditions was studied. Fibers were isolated from petioles by sulfate pulping with 30.72% yield. The high α-cellulose content (38%) showed valuable for papermaking. Runkle’s ratio (0.63), rigidity coefficient (38.46), and slenderness value (100) suggested that the paper would have excellent mechanical properties. Under cold chain logistics, packaging must withstand high humidity and low temperature (90%RH, 12°C). Addition of 1.4% cationic starch and 0.5% AKD significantly enhanced water absorption resistance from 59 to 23250 sec and improved the burst (6.68%) and tensile index (26.47%). The molded pulp trays fabricated from 70% sized frond fibers and 30% OCC fiber provided 7.71% higher compressive strength than neat OCC tray. All physical properties indicated that the as-prepared trays have potential use for protective material. A simulation with green apple demonstrated that the trays were impractical for use with soft-skinned fruit as the dense and rough surface of the packaging. Further study to evaluate cushioning performance for harder skin fruit is, therefore, necessary.

Green giant-a tiny chloroplast genome with mighty power to produce high-value proteins: history and phylogeny.

SummaryFree‐living cyanobacteria were entrapped by eukaryotic cells ~2 billion years ago, ultimately giving rise to chloroplasts. After a century of debate, the presence of chloroplast DNA was demonstrated in the 1960s. The first chloroplast genomes were sequenced in the 1980s, followed by ~100 vegetable, fruit, cereal, beverage, oil and starch/sugar crop chloroplast genomes in the past three decades. Foreign genes were expressed in isolated chloroplasts or intact plant cells in the late 1980s and stably integrated into chloroplast genomes, with typically maternal inheritance shown in the 1990s. Since then, chloroplast genomes conferred the highest reported levels of tolerance or resistance to biotic or abiotic stress. Although launching products with agronomic traits in important crops using this concept has been elusive, commercial products developed include enzymes used in everyday life from processing fruit juice, to enhancing water absorption of cotton fibre or removal of stains as laundry detergents and in dye removal in the textile industry. Plastid genome sequences have revealed the framework of green plant phylogeny as well as the intricate history of plastid genome transfer events to other eukaryotes. Discordant historical signals among plastid genes suggest possible variable constraints across the plastome and further understanding and mitigation of these constraints may yield new opportunities for bioengineering. In this review, we trace the evolutionary history of chloroplasts, status of autonomy and recent advances in products developed for everyday use or those advanced to the clinic, including treatment of COVID‐19 patients and SARS‐CoV‐2 vaccine.

A biological magnetic nano-hydrogel based on basil seed mucilage: study of swelling ratio and drug delivery

Basil seed with mucilage shell contains carbohydrates (BSG) which can be extracted to produce natural hydrogel compatible with the human body. In this study, a magnetic natural hydrogel was synthesized by copolymerization between the double bonds of vinyl-modified Fe3O4/SiO2 nanoparticles, methacrylic acid (MA) as a monomer, ethylene glycol dimethacrylate (EGDMA) as a crosslinker monomer, and vinylated BSG through free radical addition polymerization for delivery of naproxen (NPX) as a model drug. The product of each reaction step was identified by FTIR technique and the morphology of nanoparticles and magnetic nano-hydrogels was investigated using the SEM technique. SEM image analysis of dry magnetic hydrogels shows the existence of a porous structure with pore size in the range of 100–300 nm. The porosity of the hydrogels used in drug delivery systems can be useful in producing a large surface area, enhancing water absorption, and facilitating drug release. The swelling behavior of nano-hydrogels, a significant feature for drug delivery systems, was investigated at different pHs in buffer solutions. Also, drug loading and delivery experiments were performed by monitoring the concentration of loaded and released NPX by absorption at 245 nm on a UV–Vis spectrophotometer. The cumulative release behavior of hydrogels was investigated and the in vitro NPX release was achieved in the range of 98% at pH 7.4 after 24 h.

Effects of Mould Temperature on Rice Bran-Based Bioplastics Obtained by Injection Moulding

The high production rate of conventional plastics and their low degradability result in severe environmental problems, such as plastic accumulation and some other related consequences. One alternative to these materials is the production of oil-free bioplastics, based on wastes from the agro-food industry, which are biodegradable. Not only is rice bran an abundant and non-expensive waste, but it is also attractive due to its high protein and starch content, which can be used as macromolecules for bioplastic production. The objective of this work was to develop rice-bran-based bioplastics by injection moulding. For this purpose, this raw material was mixed with a plasticizer (glycerol), analysing the effect of three mould temperatures (100, 130 and 150 °C) on the mechanical and microstructural properties and water absorption capacity of the final matrices. The obtained results show that rice bran is a suitable raw material for the development of bioplastics whose properties are strongly influenced by the processing conditions. Thus, higher temperatures produce stiffer and more resistant materials (Young’s modulus improves from 12 ± 7 MPa to 23 ± 6 and 33 ± 6 MPa when the temperature increases from 100 to 130 and 150 °C, respectively); however, these materials are highly compact and, consequently, their water absorption capacity diminishes. On the other hand, although lower mould temperatures lead to materials with lower mechanical properties, they exhibit a less compact structure, resulting in enhanced water absorption capacity.

Effect of Psyllium Husk, Bran, and Raw Wheat Germ Addition on the Rheological Characteristics of Arabic (Pita) Bread Dough.

Arabic bread (khubuz) made from white flour is the staple food in the Arabic countries but has now become popular all over the world. A different approach of producing high fiber bread with improved quality can be produced using white flour with added mill fractions, but the addition of mill fractions has been shown to adversely affect the dough characteristics. Therefore, the effect of adding mill fractions on the rheological characteristics of dough was investigated using Brabender Farinograph and Extensograph with the major objective of eliminating their deleterious effects on dough quality, mainly by using psyllium husk, and also reported as an excellent source of soluble dietary fiber. Addition of fine bran, coarse bran, and raw wheat germ decreased the extensibility and resistance to extension and area under curve, lower dough stability, but enhanced water absorption and peak time. Addition of psyllium husk, though reduced the extensibility, but did not affect the area under the curve adversely, thus overcame some of the negative effects on rheological characteristics of the white flour dough. It was concluded that the use of psyllium husk will evidently help the bakers to produce nutritious and acceptable quality Arabic bread.

Cellulose Nanofibrils from Sugarcane Bagasse as a Reinforcing Element in Polyvinyl Alcohol Composite Films for Food Packaging

ABSTRACT Due to a high aspect ratio and enhanced mechanical strength, cellulose nanofibrils can be used as reinforcing elements in biocomposite films. In this study, cellulose nanofibrils were isolated from sugarcane bagasse using TEMPO-mediated oxidation and used to reinforce polyvinyl alcohol (PVA) films. The carboxyl group content, functional groups, crystallinity, thermal properties, and morphology of the nanofibrils were investigated. The influence of TOCNF content on the transmittance, swelling, and tensile strength of PVA-TOCNF films were investigated by varying the TOCNF content of PVA films. The fibrils had a carboxyl content of 12.2 ± 0.6 mg/g CE due to the presence of carboxylic groups, an increased degree of crystallinity, and highly porous nanofibrils with lengths between 150 nm and 600 nm. Incorporation of the isolated fiber on PVA films increased the swelling capacity, tensile strength, and UV absorption but a decrease in the solubility of the composite. An increase in the TOCNF content increased the tensile strength of the films with the highest tensile strength of 6.6 ± 2.2 kPa being observed when the TOCNF content was 30%. The improvement in films properties implies that the films can be used as a packaging material due to enhanced water absorption and light-barrier properties.

Actuation and self-sensing performance of soft polymer actuator skin using polyelectrolyte attached terpolymer

In this study, a soft polymer actuator skin is developed for stable actuation and generation of self-sensing voltage using electrolytes (NaCl, LiCl, ionic liquid) at room temperature (RT) that can be utilized for soft robotics and wearable voltage generation devices in the humid condition of the human body, respectively. We have developed poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) P(VDF-TrFE-CTFE) (terpolymer)/polyvinyl pyrrolidone (PVP)/polystyrene sulfonic acid (PSSA) based ionic polymer-metal nanocomposites (IPMNC) actuator skin for steady actuation at DC and AC voltage without back-relaxation and self-sensing behavior with various electrolytes. The terpolymer (terpolymer/PVP/PSSA) ionic polymer (IP) showed a large number of pores that enhanced water absorption, low Young's modulus, and high tensile strain than that of the PVDF copolymer (P(VDF-TrFE)/PVP/PSSA) and PVDF (PVDF/PVP/PSSA) IPs. The high porosity of terpolymer IP is responsible for stable actuation and self-sensing behavior of terpolymer IPMNC as compared to those of the PVDF copolymer and PVDF IPMNC. The terpolymer IPMNC generates the high sensing voltage with the pouring of the various electrolytes and sustains signals up to 1000s, which implies the self-diffusion of ions near the electrode of the IPMNC at RT. Our proposed soft polymer actuator skin could be utilized for wearable energy harvesting.

Breaking combinational dormancy of Rhus javanica L. seeds in South Korea: Effect of mechanical scarification and cold-moist stratification

Seeds with combinational dormancy have both physical (PY) and physiological (PD) dormancy. Chemical scarification and cold-moist stratification alleviate PY and PD, respectively. Therefore, we tested the effectiveness of mechanical scarification and cold-moist stratification for the release of combinational dormancy in Rhus javanica seeds to minimize the possibility of any internal damage and determine the optimal germination conditions. Mechanical scarification by a brushing machine and cold-moist stratification for 12 weeks weakened the pericarp and improved water absorption and percent germination. Prolonging mechanical scarification for up to 20 min further improved water absorption and percent germination; however, there was no significant difference in germination after 20 min (64.9%) and 40 min (63.1%) of mechanical scarification. The removal of blister-like structures in nontreated seeds by mechanical scarification enhanced water absorption. Further, cracks between the two inner pericarp cell-layers improved water absorption. Combined mechanical scarification (20 min) and cold-moist stratification (12 weeks) effectively broke combinational dormancy of R. javanica seeds and, therefore, comprise a suitable treatment for seed germination.

Effect of curdlan on the quality of frozen-cooked noodles during frozen storage

Frozen-cooked noodles (FCN) and its components undergo quality changes during frozen storage, such as reduced textural and cooking qualities, weakened gluten network, and damaged starch properties; thus, storage condition is a critical factor affecting the final quality of FCN. In this study, in view of the thermoirreversible high-strength gel property (at ≥ 80 °C) of curdlan, strong hydrophilicity, and freeze-thawed stability of high-strength gel prepared from curdlan powder, the effect of curdlan on the quality of FCN during frozen storage was first evaluated. The results showed that curdlan was effective in reducing cooking loss, enhancing water absorption, and improving textural properties of FCN; the improving effect presented a trend of first increasing and then decreasing with the amount of increasing curdlan (0.1%–0.9%); and the addition of 0.5% curdlan was most effective in improving the quality of FCN. Thermal gravimetric analysis indicated that curdlan enhanced thermal stability of FCN, implying curdlan could strengthen the gluten network. Meanwhile, structural observations revealed that, during frozen storage, FCN with added curdlan exhibited a more continuous and compact gluten network accompanied with more uniform and smaller ice crystals. Thus, curdlan is desirable to be used as a novel gum in FCN to provide specific functionality and minimize the negative effect of frozen storage. This study provides new insights into the quality improvement of FCN and further expands the application potential of curdlan in food industry.