Starch Surface Research Articles

The dissolution and bioavailability of curcumin reinforced by loading into porous starch under solvent evaporation.

Curcumin is a polyphenol with anti-inflammatory and antitumorigenic properties. However, its low water solubility and bioavailability limit its use. In this study, porous starch supplemented with a solvent evaporation process was demonstrated as a highly loaded vehicle for curcumin (17.82%) that could be efficiently solubilized over sustained periods. The migration of curcumin and its adsorption onto the surface of porous starch during solvent evaporation indicated that curcumin was deposited as amorphous globules in pores and encapsulated on the starch surface. The process was demonstrated to involve hydrogen bonding and hydrophobic interactions using infrared spectroscopy and particle dissociation experiments. Notably, the saturated solubility of curcumin in CU/PS in ionized water, ethanol, and acetic acid was 17.81×, 31.65×, and 26.53× greater than that of raw curcumin, respectively. In particular, it could slowly dissolve in simulated intestinal fluids and exhibited a higher cumulative dissociation (about 6 times that of raw curcumin). In vitro experiments using a colon adenocarcinoma cell line confirmed that curcumin loaded with porous starch enhanced cellular uptake and reduced IC50 of raw curcumin by 55 times. Thus, porous starch with a simple and efficient process provides new ideas for the design of drug delivery systems and is expected to inspire further development in reducing dosing intervals and maximizing therapeutic efficacy.

Magnetic field improvement of the germination of brown rice in the absence/presence of gibberellin: Changes in α-amylase activity and starch structural and physicochemical properties

Germination could improve the sensory and nutritional value of brown rice (BR), and magnetic field (MF) is considered as a promising technique for enhancing germination. However, the mechanism underlying MF-enhanced germination of BR remains unclear. Therefore, in this study, BR was exposed to MF (10 mT, 60 min, 25 °C), germinated in the absence/presence of gibberellin (GA) solution (20 mg/L, 30 °C) for 36 h, and subsequently the mechanism was explored by assessing germination index, endogenous GA content, relevant gene expression, α-amylase activity, and α-amylase action on rice starch. Results indicated that with MF treatment, the shoot and root length of BR increased by 10.4% and 22.9%, respectively. MF treatment upregulated the gene expression related to α-amylase by 0–110.2%, activated α-amylase by 11.0%, led to the hydrolysis of starch into more reducing sugars by 9.2% and thus provided additional energy for BR germination. Post-germination, pores appeared on BR starch surface, and there was a decrease in its relative crystallinity, pasting temperature, and enthalpy. Compared with MF, the combination of MF and GA treatments (GM) showed a more pronounced effect on germination, which further confirmed that MF might enhance BR germination by activating α-amylase through the GA pathway. Overall, this study extended the knowledge of MF-assisted germination, which provided a guidance for the applications of MF in food and agricultural industries.

Resolving differences in digestion features of cooked rice and wheat noodles: A view from starch multiscale structure

The staple foods play an important role in providing energy in the human daily diet. Wheat is the main staple food in northern China, rice in southern China, and the different staple food patterns between the north and south result in health disparities. Therefore, analyzing the differences in the digestion of staple foods are particularly important for understanding the digestive energy supply of staple foods. The firmer gel network structure, thicker crystalline lamellae, more V-type crystallites, higher degree of helical structure, and short-range order in cooked rice impeded the diffusion of amylase on the starch surface and inhibited the amylase-starch binding, leading to a lower rate of enzymatic hydrolysis of starch molecular chains and significantly higher content of RS than wheat noodles (P < 0.05). The different processing methods of cooked rice and wheat noodles influenced the multiscale structure of starch and thus the rate of digestion.

Effects of microwave treatment on structural and functional properties of germinated corn starch.

Measuring the germination index of corn, and gelatinization index, thermodynamic properties, long-range structure, short-range structure and particle morphology of corn starch, the study aimed to investigate the effects of different microwave (MW) treatment on the structural and functional properties of germinated corn starch. The results indicated that after appropriate MW treatment, the germination indices (germination rate, germination potential, sprout length and sprout weight) of germinated corn starch were improved after 7 days of germination. In addition, MW treatment also affected the structure of germinated corn starch. MW treatment could reduce the relative crystallinity of starch, but did not change the crystal type and the peak position of each absorption peak in Fourier transform infrared spectra. In addition, rapid visco-analysis and differential scanning calorimetry results showed, respectively, that MW treatment decreased the peak viscosity of germinated corn starch and increased the gelatinization temperature. Finally, MW treatment made the starch surface become rough, destroyed the starch particle structure and produced random cracks and voids. Overall, the present study proves that appropriate MW treatment is an effective measure for the modification of germinated corn starch, and provides a theoretical basis for the application of MW technology in germinated corn products. © 2024 Society of Chemical Industry.

Rapid preparation of anti-retrogradation starch by choline chloride based deep eutectic solvents: A comparative study

Legumes are a widespread and cheap source of starch. However, legume starches are prone to retrogradation in applications. Therefore, enhancing the resistance to retrogradation is important to ensure the quality of starch products. In this study, the effects of amines, alcohols, and carboxylic acids deep eutectic solvents (DESs) on the retrogradation properties of pea starch (PS) were investigated. The results showed that the starches treated with carboxylic acid DESs for only 30 min exhibited low paste viscosity, high paste clarity and anti-retrogradation. The carboxylic acid DESs treatment resulted in holes or cracks appearing on the starch surface, a decrease in molecular ordering, relative crystallinity, and amylose content. The thermal enthalpy of starch as well as the pasting viscosity were substantially reduced after the treatment. The paste clarity and the resistance to retrogradation were significantly improved. Conversely, the structure, pasting and retrogradation properties of starch treated with amine and alcohol DESs exhibited only slight differences compared to PS. The carboxylic acid DESs took a short time for the starch modification, and the modified starch paste with low viscosity, high clarity, and resistance to retrogradation. The study could provide an environmentally-friendly and cost-effective method for the preparation of starch with well anti-retrogradation properties.

Effect of salt and alkali on the viscoelastic behavior of noodle dough sheet with different wheat starch granule sizes

The underlying mechanisms of salt and alkali on the viscoelastic behaviors of noodle dough sheets with varied B/A-type starch ratios were investigated from water state, protein polymerization and conformation, and microstructure. The viscoelastic behaviors of dough sheets increased with increasing B/A-type starch ratio, regardless of the presence of salt and alkali, indicating the addition of salt and alkali did not change the effect law of starch granule size on dough viscoelasticity. The viscoelastic moduli of dough decreased in the presence of salt and alkali, and the effect was more obvious as the ratio of B/A-type starch decreased, which was mainly determined by the interactions of protein-protein, protein-starch, and starch-starch in dough systems. In the low ratio of B/A-type starch dough sheets, NaCl enhanced the non-covalent interactions and β-sheet structure, while alkali promoted the covalent cross-linking of protein. In the high ratio B/A-type starch dough samples, the big starch surface area provided by a high phase volume of starch granules led to the domination of starch-starch interactions over the protein phase, thus determining the viscoelastic behavior of dough. SEM images showed that NaCl caused the gluten to form a fibrous structure, while alkali induced a membrane-like and more closed structure. NaCl and alkali showed different influences on water distribution, molecular conformation, and network structure of dough sheets with varied B/A-type starch ratios and thus contributed to the different viscoelastic behaviors.

Pyro-dextrinization, acid hydrolysis, and cross-linking impacts on functional, pasting and structural properties of elephant foot yam starch

Underutilized plants represent valuable reservoirs of starch, urging the need for prominent exploration of these botanical resources. The effects of pyrodextrinization, acid hydrolysis and cross linking modification on the physico-chemical, functional, structural and pasting properties of elephant foot yam (Amorphophallus paeoniifolius) starches were studied. Yam starch was cross-linked using boric acid, which is for the preparation of cross-linked yam starch. The results suggested that cross linking modification significantly decreased moisture content (10.46–1.91 %), swelling power (3.71–1.69 %) and solubility (3.58–1.51 %) of yam starch. At the same time it significantly (P < 0.05) improved amylose content (13.89–18.04 %) of starch. Increase in degree of crystallinity of all modified starches was depicted from X-ray diffractogram. Decrease in viscosity profile of modified starches was observed using Rapid Visco Analyzer. The morphology of the starch granules presented surface fissures in case of acid, whereas smooth surface of native, pyrodextrinized and cross-linked starches were observed. This research has demonstrated that chemical alterations induce notable transformations in the inherently flexible starch polymer, thereby influencing its functional characteristics and structural features. The treatment which resulted in the most thermostable starch obtained in this study was cross-linked yam starch. The ultimate goal is to offer yam starch suitable for a wide range of applications across various industries, including both food and non-food sectors positively revealing its utmost applicability for food packaging industry to be utilized as a film or coating material (cross-linked starch), fat replacers/mimickers in low-fat starch based healthy foods (acid-hydrolyzed starch).

Enzymatic biocatalysis processes on the semicrystalline and morphological order of native cassava starches (Manihot esculenta)

Enzymatic biocatalysis has emerged as a green technology in starch modification with divergent results at the morphological level depending on the origin of the starch source. Therefore, various enzymatic biocatalysts were implemented to evaluate their effect on the morphological and semi-crystalline characteristics of native cassava starches. The degree of affinity of the biocatalysts and the conversion rate on native cassava starches were determined by kinetic parameters such as the Michaelis-Menten constant, whose results revealed the following order of affinity from highest to lowest: α-amylase, amyloglucosidase, pullulanase, and β-amylase. In addition, greater biocatalytic activity of α-amylase and β-amylase was evidenced on the amorphous zones of the polymer associated with the decrease in the amylose content and a significant increase in the degree of relative crystallinity. According to morphological analyses and XDR, the action of amyloglucosidase promoted exo-erosion phenomena and the appearance of lacerations on the granular surface of starch with the consequent decrease in the semicrystalline order. The pullulanase caused slightly eroded fragmented granules with greater biocatalytic activity on the crystalline lamellae, associated with a significant increase in the apparent amylose content. FTIR analysis in the 1,200-900 cm-1 region, corresponding to the starch fingerprint, allowed us to detect notable changes in the degree of molecular order after the enzymatic attack; this result was consistent with the degree of relative crystallinity estimated by X-ray diffraction. Likewise, the results allowed us to notice significant changes in the semi-crystalline order and morphological characteristics during the modification with α-amylase (AAM) and amyloglucosidase (AMG) associated with their greater affinity and preferential action on the amorphous structures located on the granular surface of native cassava starch.

Effects of cereal flour types and sourdough on dough physicochemical properties and steamed bread quality.

Coarse cereals have been promoted for their health benefits, and sourdough is used to improve their steamed bread sensory acceptance. However, grains vary in dough physiochemical properties and steamed bread-making performance. This study investigated the effects of yeast and sourdough fermentation on the biochemical, textural, and flavor properties of dough and steamed bread of eight grain types. Results indicated that sourdough dough had a lower pH and higher total titrable acidity compared with yeast group. The texture of sourdough-steamed bread was significantly improved with reduced hardness and enhanced springiness. Microstructure revealed that sourdough resulted in starch surface corrosion and less amylopectin recrystallization. Aldehydes, alcohols, and esters are more dominant in sourdough group than yeast group. Foxtail millet and sorghum steamed breads exhibited the highest performances in texture, flavor, and sensory evaluation. This could provide a theoretical basis for producing coarse cereal products with desirable quality.

Transglutaminase and protease: How starch granule-associated protein modification affects starch retrogradation

This study investigated the effects of transglutaminase (TG) and protease on starch granule-associated proteins and their impact on starch properties, especially retrogradation. TG incorporated storage protein onto the starch surface, while protease removed starch-granule associated proteins from it. Neither treatment altered the basic structural characteristics of starch such as its crystallinity or thermal properties, but could significantly affect swelling power, amylose leaching, and retrogradation. TG-treated wheat starch (WST) showed reduced swelling power (11.50) and amylose leaching (28.92 mg/g) compared with the control wheat starch (WSC) at 11.95 and 30.53 mg/g, respectively, suggesting a more stable structure. Conversely, protease-treated starch (WSP) exhibited increased swelling power at 12.47 and amylose leaching at 33.17 mg/g, suggesting a disintegration of starch granules. Both WSC and WST showed the same degree of retrogradation at the equilibrium state (a) at 0.06, whereas WSP, with a higher degree at 0.08, promoted retrogradation. The rate constant (k) for WST was lower (1.41 d−1) than that for WSC (2.37 d−1), indicating that TG treatment effectively inhibited retrogradation. These findings illustrated the distinct mechanisms through which TG and protease modify starch properties by acting on starch granule-associated proteins. This also highlighted the potential of TG and protease to control starch modifications for specific applications.

Bactericidal effect of ultrasound on glutinous rice during soaking and its influence on physicochemical properties of starch and quality characteristics of sweet dumplings

The soaking process of glutinous rice allows the growth and reproduction of microorganisms, which can easily cause food safety problems. In this work, the effects of different ultrasonic powers (150 W, 300 W, 450 W, and 600 W) on the bactericidal effect of glutinous rice, the physicochemical properties of starch and the quality characteristics of sweet dumplings were studied. Compared with soaking for 0 and 2 h, sonication of glutinous rice after soaking for 4 h was more effective at reducing the number of microorganisms in soaked glutinous rice, and the bactericidal effect increased with increasing ultrasound intensity. After 30 min, the total number of bacteria decreased by 2.04 log CFU/g. Moreover, ultrasonic treatment destroys the grain structure of glutinous rice starch, resulting in the formation of dents and cracks on the starch surface, increasing the amylose content, improving its expansion, reducing its short-range order and relative crystallinity, and altering its gelatinization characteristics. In addition, ultrasonic treatment increased the soup transparency of sweet dumplings from 51.8 % to 63.95 %, reducing their hardness, chewiness and adhesiveness. In summary, ultrasonic treatment can not only effectively kill microorganisms in soaked glutinous rice but also improve the quality of glutinous rice dumplings by changing the physicochemical properties of glutinous rice starch. The results of this study provide theoretical support for the application of ultrasonic technology in glutinous rice food production.

The Effect of Maltose on Structural, Physicochemical, and Digestive Properties of Lentil Starch under Electron Beam Irradiation.

This study investigated the effects of electron beam irradiation (EBI) on the structural, physicochemical, and functional properties of lentil starch with varying maltose content. EBI did not significantly disrupt the starch's surface structure or cause amorphization of starch and maltose crystals, but it significantly reduced the intensity of starch's XRD peaks. The presence of maltose intensified internal growth ring damage, leading to more cross-link and rearrangement between short chains, improving short-range ordering of lentil starch and enhancing starch's solubility and thermal stability. Additionally, adding maltose that EBI then treats can lead to an increased content of slowly digestible starch in samples.

Effect of Lycium barbarum L. polysaccharides on the quality of potato chips under low temperature frying and the mechanism of its action

Consumers increasingly desire healthier low-fat snack options. In this study, potato starch served as the substrate, and varying quantities of Lycium barbarum L. polysaccharide (0, 1, 3, and 5 g/100 g) were added to formula potato chips (FPC). The effect of LBPs on the sensory qualities, oil content, microstructure, and starch properties of FPC-LBPs was examined. The results showed that LBPs resulted in enhanced acceptability, reduced oil content, increased RS content, lower straight-chain starch leaching, and a gradual increase in the composite index (CI) of polysaccharides and starch in FPC-LBPs. The FPC-1LBPs exhibited the highest acceptability compared with the control samples. As the quantity of LBPs increased, the pores and cracks in the FPC-LBPs gradually decreased, and a polysaccharide wrapping layer formed on the surface of starch, which was the primary cause of the decrease in the oil content. With an increase in LBPs addition, the long-range and short-range ordered structure of starch progressively increased, and the hydrogen bonding interaction between LBPs and starch gradually strengthened, resulting in thinner FPC-LBPs. The enthalpy change of starch gradually decreased owing to LBPs, which delayed the pasting of starch and increased the RS content.

The application of poly(dimethyldiallylammonium chloride) in poly(butylene adipate‐co‐terephthalate)/starch composites

AbstractAntimicrobial degradable materials are pivotal in enhancing food safety, mitigating plastic pollution, and advancing sustainable development. In this study, poly(diallyldimethylammonium chloride) (PDMDAAC) was initially anchored to the starch surface (PMS) and utilized as a filler. Subsequently, poly(butylene adipate‐co‐terephthalate) (PBAT)/PMS composites with antimicrobial properties were successfully prepared by melt blending. The results showed that the introduction of PMS filler can improve the mechanical and antimicrobial properties of PBAT. Compared with pure PBAT, the tensile strength and modulus of PBAT/10PMS composites were enhanced by 25% and 29%, respectively. In addition, the prepared PBAT/PMS composites exhibited excellent antimicrobial activity against Escherichia coli when the PMS filler content reached 10 wt% or even higher. Therefore, an antimicrobial biodegradable composite was successfully prepared using a facile blending method in this study.

Interfacial kinetics reveal enzymatic resistance mechanisms behind granular starch with smooth surfaces

Heterogeneous (interfacial) enzyme catalyzed hydrolysis of starch granules occurs in various biological systems, including plants, animal/human digestion, and microorganisms. Factors such as granular size, surface area, pores, and smoothness play crucial roles in influencing this process. However, limited understanding persists regarding the high enzymatic resistance of starch granules with smooth surfaces. In this study, we investigated the hydrolysis mechanism of glucoamylase (GA) on three different types of starch granules with smooth surfaces, extracted from Curcuma zedoaria (zedoary) rhizomes, Solanum tuberosum (potato) tubers, and Manihot esculenta (tapioca or cassava) roots. We compared the Langmuir adsorption, interfacial kinetics, and the multi-level structure of the three starches. Our data demonstrate that the lower enzymatic resistance observed in tapioca starch stems from the higher density of enzymatic attack sites (kinΓmax) recognized by GA on tapioca starch (1.0 nmol/g) compared to potato (0.6 nmol/g) and zedoary (0.3 nmol/g) starch granules. The high kinΓmax for tapioca starch was significantly influenced by its relatively lower B-type crystallinity, which is disrupted by the presence of short fa chains (degree of polymerization (DP) < 12) and long amylose chains. Furthermore, the relatively higher proportion of longer chains (fb1 and fb2 chains) on the surface of tapioca starch also contributed to higher kinΓmax for GA, resulting in lower enzymatic resistance. These findings enhance our understanding of how the structure of starch granules affects enzymatic catalysis, particularly in granular starches with smooth surfaces devoid of pores. Such insights are crucial for elucidating the digestion and utilization of starch granules.

Oxidised porous starch carrier for caffeine delivery: preparation, characterisation, and in vitro release

SummaryThis work established an oxidised porous starch carrier system for the administration of caffeine by selectively oxidising the main hydroxyl groups at the C6 positions of porous starch to carboxyl groups using 2,2,6,6‐tetramethylpiperidoxyl (TEMPO) oxidation. The loading capacity and encapsulation efficiency of oxidised porous starch on caffeine rose as the oxidation degree (0%–90%) increased, increasing by 4.66 and 4.95 times, respectively, at 90% oxidation. The crystallinity of porous starch diminished after TEMPO oxidation, while the crystalline caffeine transferred into an amorphous state when loaded onto oxidised porous starch. Following oxidation, the absolute value of porous starch surface potential rose, enabling the granules avoided aggregation. Caffeine formed tighter bonds with oxidised porous starch in acidic conditions due to the dissociation of carboxyl groups, which lead to a peak loading capacity (8.02%) of oxidised porous starch with 90% oxidation at pH 4. Electrostatic interactions and hydrogen bonds were the driving forces. Long‐term gastrointestinal release of caffeine was achieved utilising oxidised porous starch as carriers.

Spatially selective catalysis of OSA starch for preparation of Pickering emulsions with high emulsification properties

The traditional strategies of chemical catalysis and biocatalysis for producing octenyl succinic anhydride modified starch can only randomly graft hydrophobic groups on the surface of starch, resulting in unsatisfactory emulsification performance. In this work, a lipase-inorganic hybrid catalytic system with multi-scale flower like structure is designed and applied to spatially selective catalytic preparation of ocenyl succinic anhydride modified starch. With the appropriate floral morphology and petal density, lipases distributed in the “flower center” can selectively catalyze the grafting of hydrophobic groups in a spatial manner, the hydrophobic groups are concentrated on one side of starch particles. The obtaining OSA starch exhibits excellent emulsifying property, and the pickering emulsion has good protective effect on the embedded curcumin. This work provides a direction for the development of high-performance starch-based emulsifiers for the food and pharmaceutical industries, which is of great significance for improving the preparation and emulsification theory research of modified starch.

Starch-Based Polysaccharide Systems with Bioactive Substances: Physicochemical and Wettability Characteristics.

Polysaccharide-based systems have very good emulsifying and stabilizing properties, and starch plays a leading role. Their modifications should add new quality features to the product to such an extent that preserves the structure-forming properties of native starch. The aim of this manuscript was to examine the physicochemical characteristics of the combinations of starch with phospholipids or lysozymes and determine the effect of starch modification (surface hydrophobization or biological additives) and preparation temperature (before and after gelatinization). Changes in electrokinetic potential (zeta), effective diameter, and size distribution as a function of time were analyzed using the dynamic light scattering and microelectrophoresis techniques. The wettability of starch-coated glass plates before and after modification was checked by the advancing and receding contact angle measurements, as well as the angle hysteresis, using the settle drop method as a complement to profilometry and FTIR. It can be generalized that starch dispersions are more stable than analogous n-alkane/starch emulsions at room and physiological temperatures. On the other hand, the contact angle hysteresis values usually decrease with temperature increase, pointing to a more homogeneous surface, and the hydrophobization effect decreases vs. the thickness of the substrate. Surface hydrophobization of starch carried out using an n-alkane film does not change its bulk properties and leads to improvement of its mechanical and functional properties. The obtained specific starch-based hybrid systems, characterized in detail by switchable wettability, give the possibility to determine the energetic state of the starch surface and understand the strength and specificity of interactions with substances of different polarities in biological processes and their applicability for multidirectional use.

Potential use of Thai mango (Mangifera indica Linn. cultivar Chok-Anan) seed porous starch for retention of aroma compounds from coffee extract

This study aimed to extract and modify the properties of the starch from Thai mango seeds (cultivar Chok-Anan). The porous starch samples were obtained using enzymatic treatment and its potential to retain aroma compounds from coffee extract was evaluated. The physicochemical properties, structure characteristics, porosity characteristics and adsorption quantity of starches were also determined. The retention of coffee aroma compounds was investigated through combining starch or porous starch with odorants, and storing the mixtures at room temperature for 7 and 14 days, respectively. The chemical properties of aroma compounds as well as starch surface properties were observed to affect the retention of aroma compounds upon storage. Additionally, 2-furanmethanol, d-limonene and maltol were selected to be the primary target compounds to assess the retention of odorants. This study observed a noticeable decrease in d-limonene content throughout the storage period. On the contrary, after 14 days of storage, the porous starch exhibited high retention of hydroxy compounds including 2-furanmethanol and maltol. However, after prolonged storage their ability to retain 2-furanmethanol and maltol slightly decreased. Therefore, the porous starch derived from mango seeds exhibited the potential to retain coffee aroma compounds and could be a desirable green adsorbent for food and cosmetic industries.

Formation of small-granule starch oleogels based on capillary force: Impact of starch surface lipids on lubrication performance

Starch granule oleogels were prepared and their rheological properties were precisely tuned using the capillary bridging phenomenon. The addition of a small amount of water to an oily suspension of starch granules can lead to starch granule bridging and network formation, transitioning it from a fluid-like to a gel-like state. Small-granule starches with high specific surface area and interfacial area exhibited a greater number of liquid bridges and stronger starch granules interactions, making them more prone to forming structurally stable oleogel systems. By increasing the content of water and starch granule, the starch oleogels exhibited three distinct structural states: pendular state (water ≤ 3.28 %, starch ≤ 17.85 %), pendular bridging network (water: 4.92 %, starch: 24.59 %), and capillary aggregates (water ≥ 6.56 %, starch > 24.59 %). Furthermore, the influence of starch granule surface lipids on the lubrication performance of the oleogel system was investigated. Surface roughness increased after extraction of surface lipids, and the friction coefficient also showed a significant increase. Overall, capillary suspension system can potentially be used to design novel fat food products, and our findings have established the correlation between starch granule surface properties and sensory perception in food, providing valuable insights for adjusting the oral processing characteristics of food.