Starch Particles Research Articles

A starch digestion model considering intrinsic granular properties

Starch particle digestion is an important topic in food digestion research. This study has developed a diffusion-reaction model to characterize hindered enzyme diffusion and substrate hydrolysis on the surface and in the interior of porous starch particles. A moving boundary numerical method is applied to account for particle shrinkage caused by surface reaction. This model has been proven to predict the digestion rate of various starch particles of different sizes. The parameter estimation procedure quantifies the properties that are hard to measure by experimental techniques, i.e., diameter, reactive area, and proportion of pores accessible for enzyme as well as susceptibility of starch to enzyme. This work formulates a quantitative procedure for identifying the particle digestion pattern (i.e., outside-in or inside-out) by resorting to the developed model. Computational experiments indicate that in addition to internal architecture, particle size has a significant effect on the digestion pattern.

Enhancement of γ-Aminobutyric Acid and the Characteristics of Nutrition and Function in White Quinoa through Ultrasound Stress at the Pre-Germination Stage.

The global production of quinoa has been increasing in recent years. In plant-based foods, ultrasound stress has received increasing attention, owing to its ability to enhance the production of primary and secondary metabolites. We studied the effects of ultrasonic stress at the pre-germination stage on the γ-aminobutyric acid (GABA) accumulation and characteristics of nutrition and function in quinoa. The results showed that ultrasonic conditions of 100 W for 4 min promoted an increase in GABA content by 9.15-fold, to 162.47 ± 6.69 mg/100 g·DW, compared to that of untreated quinoa, through promoting a 10.2% and 71.9% increase in the water absorption and glutamate decarboxylase activity of quinoa, respectively. Meanwhile, compared to untreated quinoa, ultrasonic stress at the pre-germination stage enhanced the total phenolic, total flavonoid, and total saponin contents of quinoa by 10.2%, 33.6%, and 90.7%, to 3.29 mg GA/g·DW, 104.0 mg RE/100 g·DW, and 7.13 mg/g, respectively, without decreasing its basic nutritional quality. Ultrasonic stress caused fissures on the surface of quinoa starch particles. Additionally, germination under ultrasonic stress increased the n3 polyunsaturated fatty acids by 14.4%. Furthermore, ultrasonic stress at the pre-germination stage promoted the scavenging of 2,2-diphenyl1-picrylhydrazyl radicals and inhibitions of α-amylase, α-glucosidase, and pancreatic lipase by 14.4%, 14.9%, 24.6%, and 20.0% in vitro, compared to untreated quinoa. The results indicated that the quinoa sprouted via ultrasonic stress could represent a promising method through which to develop nutritionally balanced whole grains rich in GABA, with hypoglycemic and hypolipidemic activities, which could provide theoretical support for the development of functional whole-grain foods based on quinoa.

Extraction process, physicochemical properties, and digestive performance of red yeast rice starch.

In the present study, taking red yeast rice (RYR) as the raw material, the optimum extraction process of RYR starch was investigated through a single-factor experiment and the Box-Behnken design: The liquid-to-solid ratio was 5mL/g, the concentration of sodium hydroxide solution was 0.075mol/L, and the extraction time was 3.1h. Under these extraction conditions, the extraction rate of starch reached 90.077%. To explore the influence of solid-state fermentation on RYR starch, three different fermentation stages of RYR starch, raw rice starch, semi-gelatinized rice starch, and RYR starch were used as test materials to determine the changes in the physicochemical properties and glycemic index (GI) values of RYR starch during solid-state fermentation. The results showed that with the advancement of the RYR solid-state fermentation process, the starch particle size gradually increased, the light transmittance gradually decreased, and the solubility and swelling power significantly increased. In addition, the amylose content of starch gradually increased, whereas the amylopectin content gradually decreased; the content of fast digestible starch and slow digestible starch decreased, whereas the content of resistant starch increased. In parallel, during solid-state fermentation, the hydrolysis index significantly decreased, and the GI values also decreased. In summary, solid-state fermentation reduced the digestibility of RYR starch. These results provide a theoretical basis for the structural and physicochemical properties of RYR starch and lay a foundation for its subsequent application and expansion of RYR starch.

Enhancing fresh pear preservation with UV-blocking film coatings based on κ-carrageenan, cassava starch, and copper oxide particles

Renewable material packs have been an alternative to traditional petroleum-based products. Thus, this work aimed to develop an active and biodegradable coating based on κ-carrageenan/starch containing copper oxide particles (CuOPs) for fresh pears. The composite material was extensively characterized. Digital images of the coatings suggested stable and highly transparent materials. The composites presented handleability and flexibility. However, only the κ75 films prepared at 75:25 κ-carrageenan/starch weight ratio containing 0, 1, 1.5, and 2% (wt/wt) of CuOPs concerning the polysaccharide content demonstrated applicability as surface coatings for fresh pears. The water vapor permeation, tensile strength, and elongation at the break ranged from 1.14 × 10−10 to 1.59 × 10−10 Pa⋅m2·s−1, 26.19–101.67 MPa, and 6.73 to 17.05 wt%, respectively. Micrographs showed composite films with slight roughness and homogenous surfaces exhibiting hydrophilic characteristics supported by water contact angle measurements (between 71 and 84°). The films were durable for approximately 90 min in an aqueous solution, with the ability to expand their mass up to 3847% (sample κ75-0). The materials were tested as coatings on fresh pears under consumption conditions. The film κ75-2 conserved the fruit for consumption over 30 days, supporting better results than the commercial poly (vinyl chloride) pack. The composite material based on κ-carrageenan/starch containing CuOPs, especially the κ75-2 composite at 2.0% (wt/wt) of CuOPs, can be applied as a surface coating for fresh pears.

Numerical analysis of charge characteristics of electrostatic chute for edible powder

AbstractThe influence of physical parameters on the charge characteristics of food powder in the process of electrostatic chute transportation was studied to provide technical support for the electrostatic elimination of food powder in the process of conveying and packaging. Taking edible powder as the research object, firstly, the particle model was established, and the three‐dimensional model of electrostatic chute was imported into EDEM software to calibrate the parameters of particles with different particle size distribution, different water content and different chute materials. Then the chute transport simulation was carried out on the calibrated edible powder to analyze the variation law of the average charge‐mass ratio of the powder. The electrostatic chute test platform was built to complete the relevant tests. The simulation study found that the average charge‐mass ratio between wheat flour with water content of 10%, 12%, 14%, 16%, and 18% and 304 stainless steel chute is 7.024, 7.01, 6.838, 6.55, and 5.932 nC/g, respectively. The average charge‐mass ratio in contact with PVC chute is 5.622, 4.808, 4.766, 4.412, and 4.768 nC/g; The average charge‐mass ratio between wheat starch with the same moisture content and 304 stainless steel chute is 2.984, 2.468, 2.254, 2.248, and 2.078 nC/g, and the average charge‐mass ratio between wheat starch and PVC chute is 2.522, 2.152, 1.962, 1.371, and 2.026 nC/g. When the water content is the same (10%–18%), the static friction Angle of powder and chute is negatively related to the charge of wheat flour and wheat starch in the static chute. The higher the water content of wheat flour and wheat starch (10%–16%), the worse the chargability. The charge characteristics of wheat flour with large grain size distribution range are higher than those of wheat starch with small grain size distribution range. The results of electrostatic chute test and simulation are consistent, which verifies the correctness of the simulation results. The research results provide certain reference for the electrostatic elimination in the process of food powder conveying and packaging.Practical ApplicationIn this paper, EDEM is used to establish the particle parameter model of food powder, and the parameters of wheat starch and wheat flour particles are calibrated through the combination of experiment and simulation, and electrostatic chain‐simulation experiments are carried out. By obtaining the average charge‐mass ratio change of powder's charge characteristics under different influencing factors, the corresponding electrostatic influence rule of powder is found. The influence of physical property parameters on the charge characteristics of food powder in the process of electrostatic chute transportation was studied to provide technical support for electrostatic elimination in the process of food powder transportation and packaging.

Enhancing the Physicochemical Attributes of Dough and Noodles through the Incorporation of Bacillus vallismortis Laccase.

This investigation examined how the Bacillus vallismortis laccase (rBVL-MRL522) influenced the physicochemical characteristics, structural attributes, and functional capabilities of both dough and noodles. Incorporating rBVL-MRL522 (1 U/g) did not lead to a substantial change in the water absorption of wheat flour. However, the introduction of rBVL-MRL522 caused a significant elongation in the formation time of wheat flour dough, extending it by 88.9%, and also resulted in a 50% increase in the stabilization duration of wheat flour dough. Furthermore, adding rBVL-MRL522 led to a proportional rise in both the elastic and viscous moduli (G'' of the dough, signifying that r-BVL (rBVL-MRL522) has a beneficial effect on the gluten strength of the dough. Integrating rBVL-MRL522 promoted the consolidation of the gluten-based cross-linked structure within the dough, decreasing the size of starch particles and, more evenly, the dispersion of these starch particles. In the noodle processing, adding rBVL-MRL522 at a rate of 1 U/g raised the L* value of the noodles by 2.34 units compared to the noodles prepared without the inclusion of rBVL-MRL522. Using a greater amount of rBVL-MRL522 (2 U/g) substantially increased the hardness of the noodles by 51.31%. Additionally, rBVL-MRL522 showed a noteworthy enhancement in the elasticity, cohesiveness, and chewiness of the noodles. In conclusion, rBVL-MRL522 promoted the cross-linking gluten, leading to a more extensive and condensed three-dimensional network structure in raw and cooked noodles. As a result, this study offers valuable insights into the environmentally friendly processing of dough and associated products.

Tuning Blood-Material Interactions to Generate Versatile Hemostatic Powders and Gels.

Polymer-based hemostatic materials/devices have been increasingly exploited for versatile clinical scenarios, while there is an urgent needto reveal the rational design/facile approach for procoagulant surfaces through regulating blood-material interactions. In this work, degradable powders (PLPS) and thermoresponsive gels (F127-PLPS) are readily developed as promising hemostatic materials for versatile clinical applications, through tuning blood-material interactions with optimized grafting of cationic polylysine: the former is facilely prepared by conjugating polylysine onto porous starch particle, while F127-PLPS is prepared by the simple mixture of PLPS and commercial thermosensitive polymer. In vitro and in vivo results demonstrate that PLPS2 with the optimal-/medium content of polylysine grafts achieve the superior hemostatic performance. The underlying procoagulant mechanism of PLPS2 surface is revealed as the selective fibrinogen adsorption among the competitive plasma-protein-adsorption process, which is the foundation of other blood-material interactions. Moreover, in vitro results confirm the achieved procoagulant surface of F127-PLPS through optimal PLPS2 loading. Together with the tunable thermoresponsiveness, F127-PLPS exhibits outstanding hemostatic utilization in both femoral-artery-injury and renal-artery-embolization models. The work thereby pioneers an appealing approach for generating versatile polymer-based hemostatic materials/devices.

Edible Carrageenan Films Reinforced with Starch and Nanocellulose: Development and Characterization

Currently, from the sustainable development point of view, edible films are used as potential substitutes for plastics in food packaging, but their properties still have limitations and require further improvement. In this work, novel edible carrageenan films reinforced with starch granules and nanocellulose were developed and investigated for application as a bio-based food packaging system. The nanocellulose was used to improve film mechanical properties. Aloe vera gel was incorporated for antibacterial properties. Glycerol and sesame oil were added as plasticizers into the nanocomposite film to improve flexibility and moisture resistance. The interactions between charged polysaccharide functional groups were confirmed by FTIR spectroscopy. The migration of starch particles on the upper film surface resulting in increased surface roughness was demonstrated by scanning electron and atomic force microscopy methods. Thermogravimetric analysis showed that all films were stable up to 200 °C. The increase in nanocellulose content in films offered improved mechanical properties and surface hydrophilicity (confirmed by measurements of contact angle and mechanical properties). The film with a carrageenan/starch ratio of 1.5:1, 2.5 mL of nanocellulose and 0.5 mL of glycerol was chosen as the optimal. It demonstrated water vapor permeability of 6.4 × 10−10 g/(s m Pa), oil permeability of 2%, water solubility of 42%, and moisture absorption of 29%. This film is promising as a biodegradable edible food packaging material for fruits and vegetables to avoid plastic.

Research on corn starch and black bean protein isolate interactions during gelatinization and their effects on physicochemical properties of the blends

The interaction between starch and protein during food processing is crucial for controlling food quality. This study aims to understand the interactions between corn starch and black bean protein isolate (BBPI) at various gelatinization phases and their effects on the physicochemical properties of the blends. BBPI reduced the rheological properties of the corn starch/BBPI mixed system during gelatinization, increasing light transmittance and gelatinization temperature, while decreasing total viscosity and enthalpy change. The changes in starch and protein microstructure during gelatinization indicated that BBPI adhered to the starch particle surface or partially penetrated the swollen starch particles. Fourier transform infrared spectroscopy (FT-IR) revealed that BBPI decreased the number of hydrogen bonds within starch, with no newly formed functional groups in the mixed system. Furthermore, BBPI reduced the composite relative crystallinity (RC). The effect of protein addition on water migration in the mixed system demonstrates that protein and starch compete for water during gelatinization, preventing water molecules from diffusing into starch particles.

Effect of Eurotium cristatum on Saccharification Efficiency, Microorganisms in Mold Culture, and Liquor Flavor during Wuliangye Liquor Production

AbstractSaccharification fermentation is a very important technique for Chinese baijiu, which effects its yield and flavor. Eurotium cristatum has the ability to trigger saccharification, but has not been applied to the saccharification fermentation in Chinese baijiu. In this study, E. cristatum is added to the mold culture for the co‐fermentation of Wuliangye liquor to verify whether it enhances the saccharification efficiency. Starch from mold culture is analyzed to infer the effect. Microorganisms in the mold culture and liquor flavor substances are also evaluated. Results show that reducing sugar in the fermented grains reaches the maximum value of 40 g/100 g when 8 mL of E. cristatum suspension is added to 100 g of mold culture. Co‐fermentation using E. cristatum increases the amylose content, decreases the molecular weight, and forms irregular starch particles and an evident crystal structure of starch from the mold culture. These phenomena in starch molecules correspond to the mechanism by which E. cristatum enhances saccharification efficiency. What is more, E. cristatum also improves the growth of the original microorganisms in the mold culture, thereby benefitting the flavor of Wuliangye liquor. Therefore, it shows promise for application in saccharification fermentation of Wuliangye liquor.

The impact of acid rain on cadmium phytoremediation in sunflower (Helianthus annuus L.)

Sunflower is an ideal crop for phytoremediation of cadmium-contaminated farmland, as it brings economic benefits while conducting soil remediation. Due to industrial emissions and car exhaust, Cd contaminated areas are often accompanied by acid rain. However, the impact of acid rain on the Cd remediation capacity of sunflowers and its potential influencing factors are unclear. An experiment was manipulated to elucidate the effects of Cd concentration (0,10,50,100 μmol/L) and acid rain (pH 4.0) on the phytoremediation ability of sunflowers, in which the properties of them were explored. The results indicated that Cd stress is the main factor affecting the growth of sunflowers. Without AR, Cd treatment decreased sunflower biomass by 67.5–85.6%. Under AR, Cd treatment decreased sunflower biomass 53.9–86.4%. Compared without AR, the relative chlorophyll content with AR increased by 22.3–23.1%, while the YII with AR decreased by 6.5–20.0%. There was an interaction between acid rain and Cd stress on antioxidant enzyme activity. With AR, CAT activity at 0 μmol/L Cd treatment increased by 25.6%, compared without AR. Whether there is acid rain or not, the POD and SOD activities were increased at 10, 50 μmol/L Cd treatment, but they were decreased at 100 μmol/L Cd treatment. Among them, acid rain exacerbated the impact of POD activity (decreased by 31.4%) at 100 μmol/L Cd treatment and SOD activity (decreased by 15.1%) at 50 μmol/L Cd treatment, compared without AR. In this experiment, the phytoremediation capacity of sunflowers mainly depended on the concentration of Ca in the leaves and their antioxidant capacity. Acid rain enhanced 77.5% the total Cd accumulation at 10 μmol/L Cd treatment, compared without AR. Acid rain exacerbated the damage of Cd to the chloroplast structure of sunflowers, and reduced the accumulation of starch particles. The study findings may be useful for improving the phytoremediation of Cd-contaminated soil.

The construction of whey protein-coated OSA debranched starch particles used for curcumin steady-state delivery and pH-sensitive sustained release

In this study, we successfully prepared Octenyl succinic anhydride debranched starch particles (OSADBSP) and whey protein–coated OSADBSP (WP-OSADBSP) for loading curcumin (Cur) through ethanol precipitation and electrostatic interaction. Compared with the low encapsulation efficiency (EE) (29.50%) obtained by OSADBSP synchronous encapsulation, the encapsulation rate of Cur-loading WP-OSADBSP (WP-Cur-OSADBSP) increased to more than 78%, and when the ethanol settlement ratio was 1:2.5 (10 mL of short amylose solution was dropped into 25 mL of Cur-ethanol solution), the EE was higher (92.04%). The addition of whey protein could increase the DPPH (2, 2-Diphenyl-1-picrylhydrazyl) free radical scavenging rate of OSADBSP-Cur from 24.02% to 62.42%. All of the WP-Cur-OSADBSP (1:1, 1:1.5, 1:2, 1:2.5, 1:3) exhibited sustained release of curcumin, the percentage of the Cur release in the gastric ranges was from 4.34% to 5.65%, and the percentage of the Cur release in the intestine ranges was from 24.91% to 32.07%. The results exhibited that WP-Cur-OSADBSP could be an effective delivery method for curcumin to improve its stability, antioxidant and bioavailability.

Ultrasound-assisted separation of wheat flour: Enhancing the degree of separation and characterization analysis

A novel ultrasound-assisted separation (UAS) method was proposed to enhance the efficiency of gluten starch and wheat separation. Factor experiments were conducted to optimize UAS conditions. The results showed that the highest yield of gluten and starch was obtained under probe-type ultrasonic power, temperature, and time of 500 W, 35 °C, and 15 min, respectively. Compared to non-ultrasonic separation, dry basis yield and purity of gluten increased by 0.56% and 10.96%, while A-starch yield and purity increased by 21.75% and 5.56%. Additionally, UAS improved the color and the concentration of particle size distribution for gluten and starch. UAS did not affect gluten molecular weight and disrupt starch structure, but resulted in a denser structure of gluten network and caused more starch particles to be exposed. The viscoelasticity of gluten and starch separately increased and reduced with UAS, implying ultrasound aids in the dispersion of both starch and proteins.

Comparative study on the in vitro digestion of different lipids in starch-based Pickering emulsions

Starch-based Pickering stabilizer has attracted more attentions due to its health-friendly attribute. Lipid digestion in Pickering emulsion is the key to its delivery ability for active substances. Herein, in vitro oral-gastric-intestinal digestions of Pickering emulsions stabilized by starch particles with different oil phases (e.g., coconut, corn, olive, and sunflower oils) were investigated. The highest rate of lipid digestion was coconut oil (25.71 %), followed by olive (12.64 %), corn (11.16 %), and sunflower (8.99 %) oils. The lipid digestibility was influenced by saturation of fatty acids: coconut (91.41 %)>olive (16.58 %)>corn (14.63 %)>sunflower (10.85 %) oils. The increase of starch concentration (0.5 % – 4.0 %, w/w) had positive effects, while the increase of oil fraction (25 % – 70 %, v/v) had negative impacts on free fatty acid release due to the formation of different initial droplet sizes. The microstructures observed using confocal laser scanning microscope indicated that starch-based Pickering emulsion possessed super stability against oral and gastric digestions, which made it a superior delivery system for lipophilic active substances under severe gastric environment. These results may promote the design of functional food emulsions stabilized by starch particles which can regulate digestion of triglycerides.

Heat-Induced Actuator Fibers: Starch-Containing Biopolyamide Composites for Functional Textiles.

This study introduces the development of a thermally responsive shape-morphing fabric using low-melting-point polyamide shape memory actuators. To facilitate the blending of biomaterials, we report the synthesis and characterization of a biopolyamide with a relatively low melting point. Additionally, we present a straightforward and solvent-free method for the compatibilization of starch particles with the synthesized biopolyamide, aiming to enhance the sustainability of polyamide and customize the actuation temperature. Subsequently, homogeneous dispersion of up to 70 wt % compatibilized starch particles into the matrix is achieved. The resulting composites exhibit excellent mechanical properties comparable to those reported for soft and tough materials, making them well suited for textile integration. Furthermore, cyclic thermomechanical tests were conducted to evaluate the shape memory and shape recovery of both plain polyamide and composites. The results confirmed their remarkable shape recovery properties. To demonstrate the potential application of biocomposites in textiles, a heat-responsive fabric was created using thermoresponsive shape memory polymer actuators composed of a biocomposite containing 50 wt % compatibilized starch. This fabric demonstrates the ability to repeatedly undergo significant heat-induced deformations by opening and closing pores, thereby exposing hidden functionalities through heat stimulation. This innovative approach provides a convenient pathway for designing heat-responsive textiles, adding value to state-of-the-art smart textiles.

Preparation, Characterization, and Utilization of Crosslinked and Dual‐Modified Banana Starch for Stabilizing Pickering Emulsion

AbstractThe effect of sodium trimetaphosphate (STMP, 1%–3%), STMP + dry heat (STMP‐DH, at 180 °C for 60 min), and octenyl succinic anhydride (OSA, 3%) on functional, structural, morphological, and thermo‐rheological properties of banana starch is studied. Similar Fourier‐transform infrared (FTIR) and X‐ray diffraction (XRD) patterns of modified starches indicate minor structural changes; however, the degree of crystallinity significantly of native starch (26.88%) reduces after crosslinking (16.32%) and dual modification (13.91%). The native granules are flattened, elongated, oval‐ellipsoidal, and compact granules, whereas STMP starches have smoother surfaces than STMP‐DH starches. Due to changes in structure and functional groups, swelling and solubility of granules decrease, which depreciate the viscosity curve during cooking. In addition, pasting temperature elevates after STMP modification (76.3–83.1 °C) and remains comparable after STMP‐DH (76.3–75.1 °C). The rheological analysis shows that native starch gel has more shear‐thinning behavior and dominant elastic component than modified starches. The modified edible starch particles are successfully used to stabilize oil‐in‐water Pickering emulsion. The 2% and 3% STMP starches show better storage stability comparable to 3% OSA starch for up to 30 days. However, the loss in functional groups and amphiphilic properties of STMP‐DH results in creaming and an inability to perform as desired.

Development of Biodegradable Thermosetting Plastic Using Dialdehyde Pineapple Stem Starch.

Starch extracted from pineapple stem waste underwent an environmentally friendly modification process characterized by low-energy consumption. This process resulted in the creation of dialdehyde pineapple stem starch featuring varying aldehyde contents ranging from 10% to 90%. Leveraging these dialdehyde starches, thermosetting plastics were meticulously developed by incorporating glycerol as a plasticizer. Concurrently, unmodified pineapple stem starch was employed as a control to produce thermoplastic material under identical conditions. The objective of streamlining the processing steps was pursued by adopting a direct hot compression molding technique. This enabled the transformation of starch powders into plastic sheets without the need for water-based gelatinization. Consequently, the dialdehyde starch-based thermosetting plastics exhibited exceptional mechanical properties, boasting a modulus within the range of 1862 MPa to 2000 MPa and a strength of 15 MPa to 42 MPa. Notably, their stretchability remained relatively modest, spanning from 0.8% to 2.4%. Comparatively, these properties significantly outperformed the thermoplastic counterpart derived from unmodified starch. Tailoring the mechanical performance of the thermosetting plastics was achieved by manipulating the glycerol content, ranging from 30% to 50%. Phase morphologies of the thermoset starch unveiled a uniformly distributed microstructure without any observable starch particles. This stood in contrast to the heterogeneous structure exhibited by the thermoplastic derived from unmodified starch. X-ray diffraction patterns indicated the absence of a crystalline structure within the thermosets, likely attributed to the establishment of a crosslinked structure. The resultant network formation in the thermosets directly correlated with enhanced water resistance. Remarkably, the thermosetting starch originating from pineapple stem starch demonstrated continued biodegradability following a soil burial test, albeit at a notably slower rate when compared to its thermoplastic counterpart. These findings hold the potential to pave the way for the utilization of starch-based products, thereby replacing non-biodegradable petroleum-based materials and contributing to the creation of more enduring and sustainable commodities.

Mechanical properties and water resistance improvement of thermoplastic modified starch, carboxymethyl cellulose, and zinc oxide nanometal particles by reactive blending

Novel biodegradable thermoplastic starch (TPS) with high mechanical properties and water resistance was developed using reactive blending technique. Effect of zinc oxide (ZnO) addition to TPS properties and reaction was investigated. Thermoplastic modified starch (TPMS) was prepared by melt-mixing modified starch with glycerol 70/30%wt/wt. Carboxy methyl cellulose (CMC) 5%wt was incorporated with modified starch, glycerol, and zinc oxide (ZnO) 0–5 %wt. Fourier-transform infrared (FTIR) spectroscopy analysis confirmed the formation of the carboxyl anion (OZn) between the –COO− of CMC and the free Zn+ ion of ZnO. The tensile strength of the TPMS/CMC/ZnO blend increased 7 time with ZnO 5 % (14 MPa) addition compared to TPMS (2 MPa). The color (∆E) of TPMS/CMC/ZnO differed notably at high ZnO concentrations (1–5 %wt). The TPMS/CMC blend displayed a smooth fracture surface due to the miscibility of the materials. Small particles of ZnO dispersed finely in the TPMS matrix and increased the interfacial tension and water contact angle of the blends. The miscibility of TPS with CMC and the occurrence of ionic interactions of –COO− of CMC and –OH of starch with the Zn+ ion as physical crosslinking were indicated to improve the mechanical properties and water resistance of the blends.

Modulation of the self-assembly kinetics and digestibility of type 3 resistant starch particles by co-crystallization with amino acid.

The effect of eight different l-amino acids (L-AA) on type-3 resistant starch particles (rSPs) derived from short chain glucan (SCG) was investigated. The L-AA were categorized based on their charge and polarity. The results reveal that positively charged L-AA, such as lysine and arginine, decreased the nucleation and growth rate of rSPs, while non-charged L-AA have negligible effects. Negatively charged L-AA, such as glutamic acid and aspartic acid, had a significant impact on the morphology and crystallinity of the rSPs, resulting in particle size of around 3μm and crystallinity of around 35%. This implies that charged L-AA influence the arrangement of SCG double helices in the particles. Furthermore, the complexation of SCG with charged L-AA reduced the level of RS in rSPs, indicating that L-AA could be useful in modulating the physical properties and digestibility of rSPs.

Effect of continuous instant pressure drop treatment on the rheological properties and volatile flavor compounds of whole highland barley flour

Continuous instant pressure drop (CIPD) treatment effectively reduces microbial contamination in whole highland barley flour (WHBF). Base on it, this study further investigated its effects on flour properties (especially rheological properties) and volatile compounds (VOCs) profile of WHBF, and compared it with that of ultraviolet-C (UV-C), ozone and hot air (HA) treatments. The results showed that the damaged starch content (6.0%) of CIPD-treated WHBF was increased, leading to a rough surface and partial aggregation of starch particle, thereby increasing the particle size (18.06 μm of D10, 261.46 μm of D50 and 534.44 μm of D90). Besides, CIPD treatment exerted a positive influence on the structure and rheological properties of WHBF, including an elevation in pasting temperature and viscosity. Notably, CIPD-treated WHBF exhibited higher storage modulus and loss modulus compared to the other three groups of sterilization treatments, contributing to the formulation of a better-defined and stable gel strength (tan δ = 0.38). UV-C and ozone, as cold sterilization techniques, also induced alterations in specific characteristics of WHBF. UV-C treatment led to changes in WHBF's crystallinity, while ozone treatment caused modifications in the secondary protein structure of WHBF. A total of 68 VOCs were identified in raw WHBF (including 3 acids, 19 alcohols, 25 aldehydes, 1 alkene, 8 esters, 2 ethers, 3 furans, and 7 ketones). The maximum flavor-contributing VOC in CIPD-treated WHBF remained dimethyl sulfide monomer (cabbage aroma), consistent with the raw WHBF. Conversely, in HA-treated WHBF, the maximum flavor-contributing VOC shifted to 2-furanmethanethiol monomer (roasted coffee aroma), altering the initial flavor presentation. These findings will provide strong support for the application of CIPD technology in the powdery foods industry.