Short-range structure in (partially) crystalline potato starch determined with attenuated total reflectance Fourier-transform IR spectroscopy

Metabolic regulation mechanism of melatonin for reducing cadmium accumulation and improving quality in rice

Melatonin acts as a potential regulator of cadmium (Cd) tolerance in rice. However, its practical value in rice production remains unclear. To validate the hypothesis that melatonin affects Cd accumulation and rice quality, a series of experiments were conducted. The results showed that exogenous melatonin application was associated with reduced Cd accumulation (23-43%) in brown rice. Fourier transform infrared spectroscopy (FTIR) analysis showed that exogenous melatonin affected the rice protein secondary structure and starch short-range structure. Metabolomics based on LC-MS/MS revealed that exogenous melatonin altered the brown rice metabolic profile, decreased fatty acid metabolite content, but increased amino acid metabolite, citric acid, melatonin biosynthetic metabolite, and plant hormone contents. These findings indicate that exogenous melatonin can effectively reduced Cd accumulation and improve rice quality through metabolic network regulation, serving as an effective treatment for rice cultivated in Cd-contaminated soil.

Recent advances in the impact of gelatinization degree on starch: Structure, properties and applications

During home cooking or industrial food processing operations, starch granules usually undergo a process known as gelatinization. The starch gelatinization degree (DG) influences the structural organization and properties of starch, which in turn alters the physicochemical, organoleptic, and gastrointestinal properties of starchy foods. This review summarizes methods for measuring DG, as well as the impact of DG on the starch structure, properties, and applications. Enzymatic digestion, iodine colorimetry, and differential scanning calorimetry are the most common methods for evaluating the DG. As the DG increases, the structural organization of the molecules within starch granules is progressively disrupted, the particle size of the granules is altered due to swelling and then disruption, the crystallinity is decreased, the molecular weight is reduced, and the starch-lipid complexes are formed. The impact of DG on the starch structure and properties depends on the processing method, operating conditions, and starch source. The starch DG affects the quality of many foods, including baked goods, fried foods, alcoholic beverages, emulsified foods, and edible inks. Thus, a better understanding of the changes in starch structure and function caused by gelatinization could facilitate the development of foods with novel or improved properties.

Heat-moisture treatment of freshly harvested high-amylose maize kernels improves its starch thermal stability and enzymatic resistance

The objective of this work was to study the effects of heat-moisture treatment (HMT) of freshly harvested mature high-amylose maize (HAM) kernels on its starch structure, properties, and digestibility. Freshly harvested HAM kernels were sealed in Pyrex glass bottles and treated at 80 °C, 100 °C, or 120 °C. HMT of HAM kernels had no impact on its starch X-ray diffraction pattern but increased the relative crystallinity. This result together with the increased starch gelatinization temperatures and enthalpy change indicated starch molecules reorganization forming long-chain double-helical crystalline structure during HMT of HAM kernels. The aggregation of starch granules were observed after HMT, indicating interaction of starch granules and other components. This interaction and the high-temperature crystalline structure led to reductions in the starch digestibility, swelling power, solubility, and pasting viscosity of the HAM flours. Some starch granules remained intact and showed strong birefringence after the HAM flours were precooked at 100 °C for 20 min and followed by enzymatic hydrolysis, and the amount of undigested starch granules increased with increasing HMT temperatures. This result further supported that HMT of HAM kernels with high moisture level could increase the starch thermal stability and enzymatic resistance.

Sub-high amylose maize starch: an ideal substrate to generate starch with lower digestibility by fermentation of Qu

BACKGROUND

The fermentation of Qu (FQ) is a novel method to modify the properties of starch to expand its application and especially to increase the resistant starch (RS) content. Using waxy maize starch (WMS) as a fermentation substrate can increase the RS content significantly but it may be time consuming and not cost effective due to the almost negligible RS content of WMS. To solve this problem, we hypothesized that sub-high amylose starch (s-HAMS), with an amylose content close to 50% could be an ideal substrate for FQ.

RESULTS

The results showed that FQ did not change the shape and the particle size of starch granules, the gelatinization peak (Tp), or the conclusion temperature (Tc), but the slowly digested starch content declined. Rapidly digested starch content fluctuated during FQ and the amylose content decreased within 36 h and then increased. Within 24h, FQ significanlty increased these values: the RS content, relative crystallinity (RC), the ratio of FTIR absorbances at 1047/1022cm-1, the diffraction peak at 19.8° in X-ray diffraction (XRD), and the gelatinization onset temperature (To) increased significantly, within 24 h of FQ. However, after 24 h of fermentation, the RS content, RC, the ratio of FTIR absorbances at 1047/1022 cm-1, and gelatinization enthalpy (ΔH) decreased significantly.

CONCLUSION

Sub-high amylose starch is more suitable for FQ to produce low digestibility starch, and the increase in RS may be due to the formation of 'amylose-lipid' complexes (RS5). © 2024 Society of Chemical Industry.

Effect of fibers on starch structural changes during hydrothermal treatment: multiscale analyses, and evaluation of dilution effects on starch digestibility

BACKGROUND

Dietary fibers (DFs) may influence the structural, nutritional and techno-functional properties of starch within food systems. Moreover, DFs have favorable effects on the digestive system and potentially a lower glycemic index. These potential benefits may change depending on DF type. Starch processed in the presence of soluble and insoluble fibers can undergo different structural and functional changes, and the present study investigated the effects of short-chain and long-chain inulin and cellulose on the structural and digestive properties of wheat starch.

RESULTS

The combined use of differential scanning calorimetry, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) provided insights into the structural changes in starch and inulin at different levels. Short-chain and long-chain inulin had higher water retention capacity and a potential to limit starch gelatinization. The FTIR results revealed an interaction between starch and inulin. Scanning electron microscopy analysis showed morphological changes in starch and inulin after the hydrothermal treatment. Cellulose fiber was not affected by the hydrothermal treatment and had no influence on starch behavior. The structural differences observed through XRD, FTIR and scanning electron microscopy analyses between starch with and without inulin fibers did not significantly impact starch digestibility, except for the dilution effect caused by adding DFs.

CONCLUSION

The present study highlights the importance of utilizing different analytical tools to assess changes in food samples at different scales. Although short-chain and long-chain inulin could potentially limit starch gelatinization, the duration of the heat treatment (90 °C for 10 min) was sufficient to ensure complete starch gelatinization. The dilution effect caused by adding fibers was the primary reason for the effect on starch digestibility. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Combined effects of nitrogen and sulfur fertilizers on chemical composition, structure and physicochemical properties of buckwheat starch

Buckwheat starch has attracted worldwide attention in the food industry as a valuable raw material or food additive. Nitrogen (N) and sulfur (S) are two nutrients essential to ensure grain quality. This study investigated the combined application of N fertilizer (0, 45 and 90 kg N ha-1) and S fertilizer (0 and 45 kg SO3 ha-1) on the chemical composition, structure and physicochemical properties of buckwheat starch. The results showed that increasing the fertilizer application decreased amylose content and starch granule size but increased light transmittance, water solubility and swelling power. The stability of the absorption peak positions and the decrease in short-range order degree suggested that fertilization influenced the molecular structure of buckwheat starch. In addition, increases in viscosity and gelatinization enthalpy as well as decreases in gelatinization temperatures and dynamic rheological properties indicated changes in the processing characteristics and product quality of buckwheat-based foods.

Texture characterization of 3D printed fibrous whey protein-starch composite emulsion gels as dysphagia food: A comparative study on starch type

Texture-modified, multi-nutrient composite foods are essential in clinical treatment for dysphagia individuals. Herein, fibrous whey protein-stabilized emulsion and different crystalline starches (wheat, corn, rice, potato, sweet potato, cassava, mung bean and pea) were used to structure composite emulsion gels (CEGs). These CEGs then underwent 3D printing to explore the feasibility of developing a dysphagia diet. The network of molded CEGs was mainly maintained by hydrophobic interactions and hydrogen bonds. Rice and cassava starches were better suited for structuring soft-textured CEGs. Compared with molded CEGs, 3D printing decreased hydrogen bonds and the compactness of the nano-aggregate structure within the gel system, forming a looser gel network and softening the CEGs. Interestingly, these effects were more pronounced for the CEGs with high initial hardness. This study provided new strategy to fabricate CEGs as dysphagia diet using fibrous whey protein and starch, and to design texture-modified foods for patients using 3D printing.

Study on the Effect of Sorghum Flour Particle Size on the Storage Quality of Leavened Pancakes

Pancakes prepared with sorghum flour possess a high nutritional value, yet their quality is unstable and prone to degradation during storage. This instability can be attributed to the particle size of coarse cereal powder, which significantly influences the quality of flour products during storage. In this study, changes in the quality of these pancakes, prepared with varying particle sizes of sorghum flour, were meticulously analyzed during cold storage using advanced instruments such as a texture analyzer, nuclear magnetic resonance spectrometer, differential scanning calorimeter, X-ray diffractometer, and Fourier transform infrared spectrometer. Findings revealed that the hardness of leavened pancakes significantly increased over time. After a refrigeration period of 7 days, the hardness of wheat flour leavened pancakes increased by 56.60%. However, with a decrease in the particle size of sorghum flour, the increase in hardness diminished, thereby delaying the aging process of the pancakes. As the storage duration was extended, moisture migration within the pancakes occurred, and the sorghum flour pancakes with a smaller particle size exhibited a reduced moisture change rate, indicating an enhanced water holding capacity. In comparison to their wheat flour counterparts, sorghum flour leavened pancakes exhibited a substantial reduction in retrogradation enthalpy and crystallinity. The inclusion of sorghum flour effectively inhibited amylopectin recrystallization, thus slowing down the aging process of the pancakes. This inhibitory effect was more evident with decreasing sorghum flour particle sizes. Fourier transform infrared data indicated no significant alterations in absorption peaks across various wavelengths during cold storage. Although starch short-range orderliness increased with storage time, the use of sorghum flour with smaller particles reduced the degree of short-range orderliness in starch molecules throughout the cold storage period. Sorghum flour with a smaller particle size can inhibit water migration and amylopectin recrystallization, which subsequently delays pancake aging and enhances its quality stability during storage.

Pre-dry heat treatment alters the structure and ultimate in vitro digestibility of wheat starch-lipids complex in hot-extrusion 3D printing

Herein, we proposed dry heat treatment (DHT) as a pre-treatment method for modifying printed materials, with a particular focus on its application in the control of starch-lipid interactions during hot-extrusion 3D printing (HE-3DP). The results showed that pre-DHT could promote the complexation of wheat starch (WS) and oleic acid (OA)/corn oil (CO) during HE-3DP and thus increase the resistant starch (RS) content. From the structural perspectives, pre-DHT could break starch molecular chains into lower relative molecular weight which enhanced the starch-lipids hydrophobic interactions to form the V-type crystalline structure during HE-3DP. Notably, pre-DHT could also induce the formation of complexed structure which was maintained during HE-3DP. Compared with CO, OA with linear hydrophobic chains was easier to enter the spiral cavity of starch to form more ordered structures, resulting in higher RS content of 27.48 %. Overall, the results could provide basic data for designing nutritional starchy food systems by HE-3DP.

Effects of different oil additives on water resistance of corn starch straws

To investigate the effect of oil additives on improving the water resistance of corn starch straws, corn oil (CO), soybean oil (SO), rapeseed oil (RO), peanut oil (PO), lard (LD) and coconut oil (CCO) were chosen and compared the structure and properties of starch straws with different oil additives. Corn starch straws (CS), and starch straws supplemented with CO, SO, RO, PO, LD and CCO were prepared by thermoplastic extrusion. The results showed that the incorporation of oils effectively enhanced the water resistance of starch straws such as water absorption, water solubility and water swelling performance. Meanwhile, the flexural strength of starch straws significantly increased. There was no significant linear relationship among starch chain length, oil unsaturation and straw performance. Among seven starch straws, S-SO had the strongest hydrogen bond interaction (3289 cm-1) and relaxation time (0.96 ms). The S-CO had the highest relative crystallinity (16.82 %) and degree of double helix (1.535), hence resulting in the lowest water absorption and solubility values, the highest flexural strength (23.43 MPa), the highest ΔT value (9.93 °C) and ΔH value (4.79 J/g). S-RO had the highest thermal transition temperatures.

New insights into how freeze-drying and cryo-milling affects the fine structure and digestibility of gelatinized starch

Freeze-drying (FD) and cryo-milling (CM) are common methods for preparing powder gelatinized starch samples. This study investigates the structural characterization of raw/gelatinized maize starches and digestibility after FD/CM processes to elucidate their effect on starch digestibility determination. Results showed that FD slightly increased digestibility, while higher initial glucose content in CM samples, especially for gelatinized samples. Only FD retained the granular morphology and relative crystallinity (RC), while gelatinized-FD decreased RC by 75%. CM decreased RC by 12%, while gelatinized-CM decreased it by 97%. Combined with short-range and chain structural results, FD tended to disrupt internal connected chains through volume stress, while CM cleaved glycosidic bonds in external chain. Stretched chains in gelatinized starch promoted the breakage of chains during shearing and their efficient binding with digestive enzymes. These findings would provide a basis for pre-treatment of powder samples and processes of starch- rich foods.

Value addition of mango kernel for development and characterization of starch with starch nanoparticles for packaging applications

The present research was conducted to explore the potential of mango kernel starch from the Chaunsa variety to develop starch and starch nanoparticles (SNPs) based films. The investigation included starch isolation from mango kernel followed by the preparation of SNPs by acid hydrolysis and a thorough examination of various physicochemical properties for film formation. The properties of SNPs were found to be distinctly different from those of native starch. SNPs exhibited an aggregated form with an irregular surface, whereas native starch had an oval and elongated shape with a smooth surface. X-ray diffraction (XRD) analysis confirmed that the starch type in SNPs was of the A-type. Additionally, the pasting properties of SNPs were minimal due to the acid hydrolysis process. SNP-based composite film was developed with (5 %) SNP concentration added. This successful incorporation of SNPs enhanced biodegradability, with complete degradation occurring within three weeks. Moreover, the composite films displayed increased burst strength, measuring 1303.51 ± 73.7 g, and lower water vapor transmission rates (WVTR) at (7.40 ± 0.50) × 10-3 g per square meter per second and reduced water solubility at 35.32 ± 3.0 %. This development represents a significant advancement in the field of eco-friendly packaging materials.

Short-range molecular order is the driving factor for starch digestibility and texture of alginate-encapsulated rice beads

BACKGROUND

Rice grain analogues with slow starch digestibility are commonly associated with an unsatisfactory texture, often leading to consumer dissatisfaction. Alginate encapsulation has been applied to reduce the digestibility of corn and potato starch. The fine molecular structures of rice starch can greatly determine its digestibility and texture. However, it remains unclear whether a combination of alginate encapsulation and varied starch molecular structures can be employed to create rice grain analogues that offer both slow starch digestibility and an appealing texture.

RESULTS

For the first time, the present study constructed alginate-encapsulated rice beads (as a rice grain analogue). A wide range of starch digestion rates were found among alginate-encapsulated rice beads prepared with different rice varieties, and only certain rice varieties (e.g. Subei and Nanjing) were able to result in rice beads with slower starch digestibility than their parental rice kernels. More importantly, all rice beads showed a relatively softer texture compared to their parental rice kernels. Correlation analysis showed that starch digestion rate, hardness and stickiness were all positively correlated with the ratio of short-range amorphous regions in rice bead samples, as obtained from Fourier transform-infrared spectroscopy, but not with the relative crystallinity.

CONCLUSION

Collectively, these results suggest that rice beads with slower starch digestion rate and softer texture could be obtained by choosing rice varieties that develop more short-range ordered structure after cooking. © 2024 Society of Chemical Industry.

Replacement of Loops at the Entrance of the Active Pocket of Streptococcus thermophilus 4,6-α-Glucanotransferase Changes Its Catalytic Activity and Product Specificity

To explore the roles of loops around active pocket in the reuteran type 4,6-α-glucanotransferase (StGtfB) from S. thermophilus, they were individually or simultaneously replaced with those of an isomalto/maltopolysaccharides type 4,6-α-glucanotransferase from L. reuteri. StGtfB with the replaced loops A1, A2 (A1A2) and A1, A2, B (A1A2B), respectively, showed 1.41- and 0.83-fold activities of StGtfB. Two mutants reduced crystallinity and increased starch disorder at 2, 4, and 8 U/g more than StGtfB and increased DP ≤ 5 short branches of starch by 38.01% at 2 U/g, much more than StGtfB by 4.24%. A1A2B modified starches had the lowest retrogradation over 14 days. A1A2 modified starches had the highest percentage of slowly digestible fractions, ranging from 40.32% to 43.34%. StGtfB and its mutants bind substrates by hydrogen bonding and van der Waals forces at their nonidentical amino acid residues, suggesting that loop replacement leads to a different conformation and changes activity and product structure.

Molecular Basis of the Granular Characteristics of Small-Granule Starch: A Comparative Study

Small-granule starches (SGSs) have technological advantages over starches of conventional sizes for many applications. The study compared the granular characteristics of three SGSs (from amaranth, quinoa, and taro) with those of maize and potato starches and revealed their molecular basis. The results indicated that the supramolecular architecture of starch granules was not necessarily correlated with granule size. Acid hydrolysis of amaranth and quinoa starches was fast due to not only their small granule sizes but also the defects in the supramolecular structure, to which short external and internal chain lengths of amaranth and quinoa amylopectins contributed. By comparison, the granular architecture of taro starch granules was more stable partly due to the longer external chain length of taro amylopectin. Comparison of the molecular composition of branched subunits (released by using α-amylase of Bacillus amyloliquefaciens) in amylopectins and that in lintnerized starches suggested a significant heterogeneous degradation of amaranth and quinoa starches at supramolecular levels.

Potential of polyphenols from Ligustrum robustum (Rxob.) Blume on enhancing the quality of starchy food during frying

The increasing concerns about health have led to a growing demand for high-quality fried foods. The potential uses of Ligustrum robustum (Rxob.) Blume, a traditional tea in China, as natural additives to enhance the quality of starchy food during frying was studied. Results indicated that L. robustum polyphenols extract (LREs) could improve the quality of fried starchy food, according to the tests of color, moisture content, oil content, texture property, and volatile flavor. The in vitro digestion results demonstrated that LRE reduced the final glucose content from 11.35 ± 0.17 to 10.80 ± 0.70 mmol/L and increased the phenolic content of fried starch foods from 1.23 ± 0.04 to 3.76 ± 0.14 mg/g. The appearance and polarizing microscopy results showed that LRE promoted large starch bulges on the surface of fried starchy foods. Meanwhile, X-ray diffraction results showed that LRE increased the intensity of characteristic diffraction peak of fried starch with a range of 21.8%-28%, and Fourier transform infrared results showed that LRE reduced the damage to short-range order structure of starch caused by the frying process. In addition, LRE increased the aggregation of starch granules according to the SEM observation and decreased the enthalpy of starch gelatinization based on the differential scanning calorimetry results. The present results suggest that LREs have the potential to be utilized as a natural additive for regulating the quality of fried starchy food in food industries. PRACTICAL APPLICATION: The enhancement of L. robustum polyphenols on the quality of starchy food during frying was found, and its mechanisms were also explored. This work indicated that L. robustum might be used as a novel economic natural additive for producing high-quality fried foods.

Interactions between corn starch and lingonberry polyphenols and their effects on starch digestion and glucose transport

This study investigated the interaction mechanism between corn starch (CS) and lingonberry polyphenols (LBP) during starch gelatinization, focusing on their effects on starch structure and physicochemical properties. Moreover, it explored the effect of this interaction on starch digestion and glucose transport. The results indicated that LBP interacted non-covalently with CS during starch gelatinization, disrupted the short-range ordered structure of starch, decreased gelatinization enthalpy of starch, and formed a dense network structure. Furthermore, the incorporation of LBP remarkably reduced the digestibility of CS. In particular, the addition of 10 % LBP decreased the terminal digestibility (C∞) from 77.87 % to 60.43 % and increased the amount of resistant starch (RS) by 21.63 %. LBP was found to inhibit α-amylase and α-glucosidase in a mixed manner. Additionally, LBP inhibited glucose transport in Caco-2 cells following starch digestion. When 10 % LBP was added, there was a 34.17 % decrease in glucose transport compared with starch digestion without LBP. This study helps establish the foundation for the development of LBP-containing starch or starch-based healthy foods and provides new insights into the mechanism by which LBP lowers blood glucose.

Possible interaction between pectin and gluten alters the starch digestibility and texture of wheat bread

This study incorporated citrus pectin in wheat bread, aiming to develop breads with both desirable texture and slow starch digestibility. Results showed that starch digestibility in wheat bread decreased over the addition of pectin, and the maximum starch digested amount decreased by 6.6 % after the addition of 12 % pectin (wheat flour weight basis). The addition of pectin transferred part of the rapidly digestible starch into slowly digestible starch, and reduced the binding rate constant between slowly digestible starch and digestive enzymes, resulting in overall reduced starch digestibility. Furthermore, the addition of 4 % pectin contributed to the development of wheat bread with softer texture and increased specific volume. Mechanistically, the lowered starch digestibility of wheat bread after the pectin addition was due to (1) residual outermost swollen layer of starch granules, (2) protein and pectin interactions, and (3) increased short-range ordering of starch. This study, therefore, suggests that the addition of an appropriate amount of citrus pectin has the potential to develop bread with both a low glycemic index and desirable texture.

Suitability of Fourier transform infrared microscopy for the diagnosis of cystic echinococcosis in human tissue sections

Cystic echinococcosis (CE) is a global health concern caused by cestodes, posing diagnostic challenges due to nonspecific symptoms and inconclusive radiographic results. Diagnosis relies on histopathological evaluation of affected tissue, demanding comprehensive tools. In this retrospective case study, Fourier transform infrared microscopy was explored for detecting and identifying CE through biochemical changes in human tissue sections. Tissue samples from 11 confirmed CE patients were analyzed. Archived FFPE blocks were cut and stained, and then CE-positive unstained sections were examined using Fourier transform infrared microscopy post-deparaffinization. Results revealed the method's ability to distinguish echinococcus elements from human tissue, irrespective of organ type. This research showcases the potential of mid-infrared microscopy as a valuable diagnostic tool for CE, offering promise in enhancing diagnostic precision in the face of the disease's complexities.

Enhancing starch functionality through synergistic modification via sequential treatments with cold plasma and electron beam irradiation

The impact of dual sequential modifications using radio-frequency (RF) plasma and electron beam irradiation (EBI) on starch properties was investigated and compared with single treatments within an irradiation dose range of 5-20 kGy. Regardless of sequence, dual treatments synergistically affected starch properties, increasing acidity, solubility, and paste clarity, while decreasing rheological features with increasing irradiation dose. The molecular weight distribution was also synergistically influenced. Amylopectin distribution broadened particularly below 10 kGy. Amylose narrowed its distribution across all irradiation doses. This was due to dominating EBI-induced degradation and molecular rearrangements from RF plasma. With the highest average radiation-chemical yield (G) and degradation rate constant (k) of (2.12 ± 0.14) × 10-6 mol·J-1 and (3.43 ± 0.23) × 10-4 kGy-1, respectively, upon RF plasma pre-treatment, amylose underwent random chain scission. In comparison to single treatments, dual modification caused minor alterations in spectral characteristics and crystal short-range order structure, along with increased granule aggregation and surface irregularities. The synergistic effect was dose-dependent, significant up to 10 kGy, irrespective of treatment sequence. The highest synergistic ratio was observed when RF plasma preceded irradiation, demonstrating the superior efficiency of plasma pre-treatment in combination with EBI. This synergy has the potential to lower costs and extend starch's technological uses by enhancing radiation sensitivity and reducing the irradiation dose.

Structural and physicochemical properties of rice starch from a variety with high resistant starch and low amylose content

Research on the physicochemical properties of rice-derived endo-sperm high resistant starch (RS) with low amylose content (AC) is limited. In this study, we evaluated the physicochemical characteristics of such a starch variety and revealed that the starch granules exhibit a smoother, more refined surface with distinct edges, increased compactness, higher order of surface, and fewer cavities compared to those of a low RS rice variety. The starch crystal was classified as an A-type, which may be connected to the high amylose-lipid complex content. The branched internal long chains (B2 + B3) were abundant, allowing for easy entanglement with other molecular chains and a compact structure. Differential scanning calorimetry revealed the need for high temperature and energy to disrupt the double helix structure within the crystallization region of starch. Furthermore, starch viscosity analysis revealed a high cold paste viscosity, consistency, and setback value, with recrystallization yielding a stable structure, increased viscosity, and enhanced hydrolysis resistance to enzymes.

The effect of heat moisture treatment times on physicochemical and digestibility properties of adzuki bean, pea, and white kidney bean flours and starches

The effects of heat moisture treatment (HMT) times on the physicochemical properties of three bean flours and their starch were analyzed. The colors of L*, b* and ΔE values increased significantly with time. The adzuki bean and pea flours showed better WAI and SP, and better gelation of starch at 2 h. The rheological properties of mixed HMT dough (3:7) exhibited the typical solid-like weak gel behavior. HMT had a significantly decreased on the pasting viscosity of bean flour starch with treated time. HMT caused the starch granules damage, but did not radically change the crystal type. FTIR results showed more proteins attached to the surface of starch granules, and the short-range molecular order decreased the DO at 2 h. In vitro digestibility inferred that RDS converted into SDS and RS. These results indicated that HMT significantly affected the digestibility and physicochemical properties of bean flours.

Synergistic modification of hot-melt extrusion and nobiletin on the multi-scale structures, interactions, thermal properties, and in vitro digestibility of rice starch

Background

Rice starch has high digestibility due to its large carbohydrate content. Synergistic modification of hot-melt extrusion (HME) and additives such as flavonoids, hydrocolloids, proteins, lipids, and other additives has the tendency to retard the rate of starch hydrolysis. Hence, the current investigation aimed to study the combined effect of the HME-assisted addition of nobiletin (NOB, 0, 2, 4, and 6%) on the multi-scale structures, interactions, thermal, and digestibility characteristics of rice starch.

Methods

The study employed density functional theory calculations and an infrared second derivative of an Fourier-transform infrared (FTIR) spectrometer to analyze the interactions between NOB and starch. The physicochemical properties of the starch extrudates were characterized by FTIR, 13C nuclear magnetic resonance, X-ray diffraction, and differential scanning calorimetry, while the digestibility was evaluated using an in vitro digestion model.

Results

HME was found to disrupt the crystalline structure, helix structure, short-ordered structure, and thermal properties of starch. The interaction between NOB and starch involved hydrophobic interactions and hydrogen bonds, effectively preventing the molecular chains of starch from interacting with each other and disrupting their double helix structure. The addition of NOB led to the formation of a highly single-helical V-type crystalline structure, along with the formation of ordered structural domains. Consequently, the combined treatment significantly enhanced the ordered structure and thermal stability of starch, thus effectively leading to an increase in resistant starch and slowly digestion starch.

Discussion

The study underscores that synergistic modification of HME and NOB holds promise for enhancing both the nutritional value and functional properties of rice starch. These findings offer valuable insights for developing high-quality rice starch products with broader applications.

Impact of soluble soybean polysaccharide on the gelatinization and retrogradation of corn starches with different amylose content

Polysaccharides have a significant impact on the physicochemical properties of starch, and the objective of this study was to examine the effect of incorporating soluble soybean polysaccharide (SSPS) on the gelatinization and retrogradation of corn starches (CS) with varying amylose content. In contrast to high-amylose corn starch (HACS), the degree of gelatinization of waxy corn starch (WCS) and normal corn starch (NCS) decreased with the addition of SSPS. The inclusion of SSPS resulted in reduced swelling power in all CS, and led to a decrease in gel hardness of the starches. The intermolecular forces between SSPS and CS were primarily hydrogen bonding, and a gel network structure was formed, thereby retarding the short-term and long-term retrogradation of CS. Scanning electron microscopy results revealed that the addition of SSPS in starches led to a loose network structure with larger poles and a reduced ordered structure after retrogradation, as observed from the cross-section of formed gels. These findings suggested that SSPS has great potential for applications in starchy foods, as it can effectively retard both gelatinization and retrogradation of starches.

A multihole nozzle controls recrystallization of high-moisture extruded maize starches: Effect of cooling die temperature

Hot extrusion is utilized for starch modification due to its high mechanical input and product output. Amylose recrystallization commences and primarily depends on intermolecular interactions after conventional extrusion. Hence, the design of a new component based on the existed extrusion system was aimed at facilitating molecular aggregation, potentially accelerating starch recrystallization. In this study, a nozzle sheet comprising 89 holes was integrated into the cooling die. The impact of the multihole nozzle on the structure and in vitro digestibility of extruded maize starches after retrogradation was examined at varying cooling die temperatures. The results showed that the nozzle-assembled extrusion system operated effectively without additional mechanical or yield losses. At 50 °C, the crystallinity of nozzle-produced starch was approximately 70 % higher than that of conventionally extruded starch, predominantly owing to the B-type allomorph of the amylose double helix. Recrystallized amylopectin was also found in these nozzle-produced starches, indicating that multihole nozzle-induced uniaxial elongational flow resulted in the rapid starch crystallization. The increased formation of recrystallized amylose led to improved molecular order in starch structures while reducing their digestibility. These findings revealed a new approach to improve starch crystallinity by incorporating a nozzle sheet in the extrusion process.

Effect of starch granule size on the properties of dough and the oil absorption of fried potato crisps

Starch is a key element in fried potato crisps, however, the effect of starch granule size on oil absorption of the product have yet to be fully investigated. The study explored the impact of starch granule size on both the dough characteristics and oil absorption in potato crisps. The dough composed of small-sized potato granules showed more compact and uniform network system. Additionally, X-ray Microscope analysis showed that potato crisps prepared with small-sized potato granules had limited matrix expansion and fewer pores, cracks, and voids. The small-sized potato and small-sized wheat starches granule addition crisps displayed a significantly greater average cell thickness (52.05 and 53.44 μm) than other samples, while exhibiting notably lower average porosity (61.37 % and 60.28 %) compared to other samples. Results revealed that potato crisps with medium and small potato granules had 12.91 % and 21.92 % lower oil content than those containing large potato starch. Potato crisps with B-type wheat starch showed 16.36 % less oil absorption than those with A-type wheat starch. Small-sized starches significantly influence the dough structure and contribute to the reduction of oil absorption in fried products. The generated insights may provide monitoring indexes for cultivating potato varieties with low oil absorption.

Purple rice starch in wheat: Effect on retrogradation dependent on addition amount

While individual starch types may not possess the ideal gelatinization and retrogradation properties for specific applications, the amalgamation of multiple starch varieties might bestow desirable physicochemical properties upon resulting starch-based products. This study explored the impact of incorporating purple rice starch (PRS), as a novel starch variant (up to 15 % PRS), on the gelatinization and retrogradation (within 14 days) of regular wheat starch (WS). Rheological and texture assessments demonstrated that the introduction of PRS diminished the viscoelasticity and hardness of fresh WS paste. Additionally, in the case of retrograded WS pastes stored at 4 °C for 1-14 days, the incorporation of 10 % or 15 % PRS effectively retarded the reduction in transparency and significantly reduced hardness, retrogradation degree, the ratio of absorbance at 1047/1017 cm-1, and relative crystallinity. Notably, 10 % PRS results in a more pronounced effect. Conversely, 5 % PRS induced an opposing impact on retrograded WS post-storage. Moreover, scanning electron microscopy revealed that as the proportion of PRS increased, the microstructure of gelatinized WS-PRS closely resembled that of pure PRS. In conclusion, the diverse effects of varying PRS proportions on WS alter the texture and characteristics of starch-based foods, underscoring the potential of starch blending for improved applications.

Effects of cooking methods on the physical properties and in vitro digestibility of starch isolated from Chinese yam

The objective of this study was to compare the structural and functional attributes of Chinese yam starches obtained via different domestic cooking methods. Cooking changed the crystalline type from the C type to the CB type, and disrupted the short- and long-range molecular order of Chinese yam starch. The average chain length of amylopectin in BOS (boiling starch) was the smallest at 22.78, while RWS had the longest average chain length, reaching 24.24. These alterations in molecular structure resulted in variations in functional properties such as solubility, swelling power (SP), pasting characteristics, and rheological properties. Among these alterations, boiling was the most effective method for increasing the water-binding capacity and SP of starch. Specifically, its water holding capacity was 2.12 times that of RWS. In vitro digestion experiments indicated that BOS has a higher digestion rate (k = 0.0272 min-1) and lower RDS (rapidly digestible starch), which may be related to its amylopectin chain length distribution. This study can guide us to utilize yam starch through suitable cooking methods, which is relevant for the processing and application of Chinese yam starch.

V-type granular starches prepared by maize starches with different amylose contents: An investigation in structure, physicochemical properties and digestibility

V-type granular starches (VGSs) were prepared via an ethanol-alkaline (EA) method using maize starch with different amylose contents, specifically, high amylose (HAM), normal maize starch (MS), and waxy maize starch (WS). The X-ray diffraction pattern of the native starch was completely transformed into a V-type pattern after the EA treatment, indicating a structural change in the starch granules. The VGSs prepared by HAM had highest relative crystallinity (31.8°), while the VGSs prepared by WS showed amorphous diffraction pattern. Excessive NaOH, however, would disrupt the formation of V-type structures and cause granular shape rupture. The quantity of double-helical structures, particularly those formed by amylopectin at the starch granules' periphery, significantly decreased. Conversely, single-helical structures formed by amylose increased. A notable rise in the relative crystallinity of V crystals. Four VGS samples, characterized by granular integrity, were chosen for the next investigation of physicochemical and digestive properties. VGS prepared from HAM exhibited higher granular integrity, lower cold-water swelling extent (59.0 and 161.0 cP), improved thermal stability (the value of breakdown as lower as 57.67 and 186.67 cP), and higher resistance to digestion (RS content was up to 10.38 % and 9.00 % higher than 5.86 % and 5.66 % of VGS prepared from WS and MS). The results confirmed that amylose content has a substantial impact on the microstructural and physicochemical properties of VGSs.

Structural and Rheological Characterization of Vegetable Crispbread Enriched with Legume Purée

Crispbread is gaining popularity as a healthy snack or bread substitute. This is a lightweight dry type of flat food that stays fresh for a very long time due to its lack of water and usually contains different types of grain flour, including gluten-containing wheat or rye flour. The incorporation of legume purée into crispbread represents an innovative approach to enhancing the nutritional profile and taste of the product. The rheological properties of various legume purées (chickpea, white bean, black bean, and red bean) mixed with citrus pectin were examined, revealing significant differences in fluid behavior and viscosity. Crispbread formulations were analyzed for water content and activity, color, structure, FT-IR spectra, water vapor adsorption isotherms, and sensory evaluation. The results showed the possibility of obtaining crispbread based on the purée of legumes and citrus pectin. Crispbread enriched with red bean purée exhibited low water activity (0.156) and water content (3.16%), along with a continuous porous structure, and received the highest sensory evaluation score among the products. These findings can be treated as a basis for the development of other innovative recipes and combinations using legumes.

Structural characteristics, digestion properties, fermentation properties, and biological activities of butyrylated starch: A review

Butyrylated starch is produced by the esterification of hydroxyl groups in starch with butyryl groups, which improves the structural diversity of starch and expands its function and biological activity. The paper summarizes the structural properties and digestive properties, fermentation properties, and biological activities of butyrylated starch and describes the conformational relationships generated by the butyryl groups to reveal the underlying mechanisms. The butyryl groups replace the hydroxyl groups in starch and break the hydrogen bonds, which consequently changes the molecular, crystal, and granular structures of starch, while the starch structure also affects the distribution of the butyryl groups. Binding to the butyryl groups gives starch efficacy in resisting digestion, lowering the glycaemic index, releasing butyric acid in the colon, and regulating intestinal flora and metabolites. Relationships between starch structural parameters and butyric acid production and intestinal flora were also concluded to provide guidance for the rational design of butyrylated starch to improve efficacy. Moreover, based on its digestive and fermentation properties, butyrylated starch has exhibited good therapeutic efficacy for intestinal diseases, diabetes, polycystic ovary syndrome, and chronic restraint stress-induced abnormalities. This review provides a valuable reference for butyrylated starch advancement and utilization.

Insight into the nutritional, physicochemical, functional, antioxidative properties and in vitro gastrointestinal digestibility of selected Thai rice: Comparative and multivariate studies

Nutritional, physicochemical, functional, antioxidative and digestion properties of brown and white rice flours from four Thai rice varieties (Luangpatue, upland rice, RD43, and Hommali) were investigated and compared. Due to differences in grain color, the color parameters of flours varied significantly. Protein, fat, ash, carbohydrate, and moisture content, total dietary fiber, and calories of these rice flours were 6.94-10.21%, 1.68-3.16%. 0.554-1.442%, 71.20-79.68%, 9.79-10.53%, 1.07-3.64%, and 350.82-362.73 kcal/100g, respectively. RD43 brown rice (18.4%) and Luangpatue white rice (26.5%) respectively exhibited the lowest and highest amylose content. Luangpatue rice flours also showed higher swelling power, setback value, final viscosity, and thermal properties than other varieties. The variations in hydration properties and oil absorption index were noticeable among these rice flours. In addition, the highest level of total phenolic content and antioxidant activity led to the lowest estimated glycemic index (eGI = 62.92) found in upland brown rice. It was confirmed by the multivariate analysis results. This study reported the diverse physicochemical properties and composition-property relationships of two kinds of flours from four rice varieties collected from Thailand for the first time. It exhibited possible capabilities for the development of various rice-based products that promote health based on their characteristics on industrial scale.

Physicochemical, Quality and Flavor Characteristics of Starch Noodles with Auricularia cornea var. Li. Powder

Auricularia cornea var. Li., as an edible mushroom rich in various nutrients, could be widely used in noodle food. This study aimed to investigate the effect of Auricularia cornea var. Li. (AU) powder on the gel properties, structure and quality of starch noodles. Taking the sample without adding AU powder as a control, the addition of AU powder enhanced the peak viscosity, trough viscosity, final viscosity, breakdown, setback, peak time, gelatinization temperature, G' (storage modulus) and G'' (loss modulus). Meanwhile, the incorporation of AU powder significantly enhanced the stability of the starch gel structure and contributed to a more ordered microstructure also promoting the short-term aging of starch paste. In vitro digestion results displayed lower rapid digestibility (21.68%) but higher resistant starch content (26.58%) with the addition of AU powder and increased breaking rate, cooking loss, swelling index and a* and b* values. However, it decreased dry matter content and L*, particularly the reducing sugar content significantly increased to 4.01% (p < 0.05), and the total amino acid content rose to 349.91 mg/g. The GC-IMS library identified 51 VOCs, and the OPLS-DA model classified 18 VOCs (VIP > 1). Overall, the findings indicate that starch noodles with the addition of AU powder may provide greater nutritional quality, gel stability and starch antidigestibility.

Comparative analysis of multi-angle structural alterations and cold-water solubility of kudzu starch modifications using different methods

Kudzu, a plant known for its medicinal value and health benefits, is typically consumed in the form of starch. However, the use of native kudzu starch is limited by its high pasting temperature and low solubility, leading to a poor consumer experience. In this study, kudzu starch was treated using six modification techniques: ball milling, extrusion puffing, alcoholic-alkaline, urea-alkaline, pullulanase, and extrusion puffing-pullulanase. The results of the Fourier transform infrared spectrum showed that the intensity ratio of 1047/1022 cm-1 for the modified starches (1.02-1.21) was lower than that of the native kudzu starch (1.22). The relative crystallinity of modified kudzu starch significantly decreased, especially after ball milling, extrusion puffing, and alcoholic-alkaline treatment. Furthermore, scanning electron microscopy and confocal laser scanning microscopy revealed significant changes in the granular structures of the modified starches. After modification, the pasting temperature of kudzu starch decreased (except for the urea-alkaline treatment), and the apparent viscosity of kudzu starch decreased from 517.95 Pa·s to 0.47 Pa·s. The cold-water solubility of extrusion-puffing and extrusion puffing-pullulanase modified kudzu starch was >70 %, which was significantly higher than that of the native starch (0.11 %). These findings establish a theoretical basis for the potential development of instant kudzu powder.

Effect of solution on starch structure: New separation approach of amylopectin fraction from gelatinized native corn starch

The complete dissolution of starch without degradation are necessary prerequisites for starch fractionation to obtain amylose or amylopectin (AP). With the recent, continuous progress in finding efficient and eco-friendly starch-dissolving solutions, applying new solvents for starch fractionation is important. In this study, the effects of dimethyl sulfoxide (DMSO), NaOH, and CaCl2 solutions on starch structure and AP product parameters during starch fractionation were compared with respect to the starch deconstruction effect. This study proved that the CaCl2 solution could effectively dissolve corn starch (50 °C, solubility of 98.96 %), and promote the regeneration of starch into uniform and fine particles. Furthermore, the three solvents (DMSO, NaOH, and CaCl2) changed the crystal structure of corn starch, but they were all non-derivatizing solvents. The effect of the CaCl2 solution on the molecular structure of corn starch was the least significant of the three solvents. Finally, the extraction rate of AP from the CaCl2 solution reached 69.45 %. In conclusion, this study presents a novel and effective method for AP extraction.

Insight into the dynamic molecular mechanism underlying the endogenous polyphenols inhibiting the in vitro starch digestion of highland barley noodles

Highland barley is a type of grain with slow-digesting characteristics. It is worth exploring the impact of non-starch components on starch digestion. In this study, four varieties of highland barley were used to investigate the impacts of endogenous polyphenols (EP) on the relationship between starch structure, physicochemical properties, and the time course digestibility of highland barley noodles. The results showed that EP removal decreased the proportion of long-chain amylopectin and disrupted the crystalline structure, while increasing the short-range ordered structure in the residue. Significant correlations indicated that these structural changes make starch more susceptible to thermal degradation and digestion, causing a 12.60%-52.00% increase in rapidly digestible starch (RDS) and a 12.70%-25.22% decrease in resistant starch (RS). These results revealed the internal factors that affect the slow digestion characteristics of highland barley noodles from the perspective of EP and provide important reference values for a slow digestion diet.

Effect of different screw speeds on the structure and properties of starch straws

To illustrate the action mechanism of screw speed on the performance of starch-based straws during the extrusion process, starch-based straws at different screw speeds were prepared using a twin-screw extruder and the structures and characteristics were compared. The results indicated that as screw speeds improved from 3 Hz to 13 Hz, the A chain of amylopectin increased from 25.47 % to 28.87 %, and the B3 chain decreased from 6.34 % to 3.47 %. The absorption peak of hydroxyl group shifted from 3296 cm-1 to 3280 cm-1. The relative crystallinity reduced from 13.49 % to 9.89 % and the gelatinization enthalpy decreased from 3.5 J/g to 0.2 J/g. The performance of starch straws did not increase linearly with increasing screw speeds. The starch straw produced at screw speed of 7 Hz had the largest amylose content, the highest gelatinization temperature, the minimum bending strength, and the lowest water absorption rate in hot water (80 °C). Screw speed had a remarkable impact on the mechanical strength, toughness and hydrophobicity of starch-based straws. This study revealed the mechanism of screw speed on the mechanical strength and water resistance of starch straws in the thermoplastic extrusion process and created the theoretical basis for the industrial production of starch-based straws.

Sodium caseinate medium promotes the in vitro digestion of starch: An insight into the macromolecular crowding effect

The macromolecular crowding effects of polysaccharides can alter the activity of digestive enzymes; however, whether protein crowding affects the digestive properties of starch remains unknown. Herein, the interaction of sodium caseinate (NaCas) with starch and pig pancreas α-amylase (PPA) and their effects on enzyme activity and starch digestion were studied. NaCas delayed gelatinization and reduced the leaching amount of amylose and increased the relative content of easily digestible starch. The ratio of the ordered structure (α-helix and β-sheet) to disordered structure (β-turns) of PPA increased with NaCas concentration, indicating that NaCas maintained the conformational stability of the enzyme and thereby accelerated the rate of enzymatic hydrolysis. This study demonstrates the detailed mechanism of NaCas-induced enhancement of starch digestibility and suggests a nonnegligible macromolecular crowding effect should be considered when evaluating the function of food macromolecules.

Stabilization and release of thymol in pre-formed V-type starch: A comparative study with traditional method

Recently, pre-formed V-type starch has become popular as a versatile carrier in encapsulation systems of containing starch-guest inclusion complexes (ICs). However, the differences in stabilizing and dissociating guests between ICs prepared by either the traditional method or the pre-formed "empty" helix method have not yet been elucidated. Here, starch-thymol ICs were prepared using the traditional high temperature-water method and the pre-formed method, covering different complexation temperatures and solvents, to compare the loading capacity, crystalline structure, thermal stability, and release properties. The highest content of thymol in ICs prepared by the pre-formed and the traditional method was 74.2 and 65.3 mg/g, respectively. Different from ICs prepared by the traditional method (V7-type crystal), ICs prepared by the pre-formed method mostly exhibited a V6a structure with larger crystallinities and a better short-range ordered structure. ICs prepared at 90 °C were type II complexes and efficiently protected thymol from rapid heat loss. A slow release was observed in both cases: about 45 % and 75 % of thymol were released from ICs prepared by the pre-formed and traditional methods, respectively, after two weeks of storage at 25 °C.

Effects of polyol and surfactant plasticisers on lyophilised rice starch wafers for buccal drug delivery

Rice starch is a promising biopolymer for buccal formulations but typical oven drying may promote starch retrogradation that affects mechanical properties. Hence, lyophilisation was proposed here to improve starch product's stability. This study aims to investigate the effects of plasticisers (sorbitol and Tween® 80, T80) on the characteristics and drug release profiles of lyophilised rice starch wafers incorporated with propranolol hydrochloride. The wafers were prepared by lyophilising starch mixture (5%w/v) with plasticiser (0.2 and 0.3 g/g) and drug (10, 20, 30%w/w). Control wafers exhibited loose layers with rough wrinkled surface. Sorbitol resulted in a dense structure with higher puncture strength (PS) but lower water absorption capacity (WAC) while T80 loosened the flakes that reduced PS and increased WAC. Drug inclusion decreased PS and increased WAC of unplasticised wafers. T80-plasticised wafers with drug had a lower PS and higher WAC than sorbitol-plasticised wafers. Particularly, T80-plasticised wafers achieved outstandingly high PS and the lowest WAC at 30%w/w drug. Drug dissolution of wafers relied mainly on the drug crystallinity and WAC at 10 and 30%w/w drug. Plasticisers reduced and increased drug dissolution at 10 and 20%w/w drug, respectively. This study highlights the potential of lyophilisation in preparing rice starch wafers for buccal delivery.

Understanding resistant-starch formation during drying high-amylose maize kernels

Interests in using high-amylose maize (HAM) flour and starch for low glycemic index foods continue to grow. The objective of this work was to understand resistant-starch formation during drying the HAM kernels. Freshly harvested HAM kernels with 28.2 % initial moisture were subjected to sun drying (~30 °C) or hot-air drying at 50 °C, 70 °C, 90 °C, or 110 °C. The enzymatic digestibility of HAM flour decreased from 63.6 % to 41.1 % as the drying temperature increased from 30 °C to 110 °C. The swelling power, solubility, and overall viscosity of HAM flours milled from kernels dried at 110 °C decreased, whereas the peak and conclusion gelatinization temperatures, enthalpy change, and relative crystallinity increased compared to those of flours from kernels dried at 30 °C, 50 °C, 70 °C, and 90 °C. Light microscopic and scanning electron microscopic images showed that starch granule aggregation in HAM flour increased with increasing drying-temperatures. The aggregates remained after 16 h enzymatic hydrolysis of cooked HAM flours. These results suggested that the increase of enzymatic resistance of HAM flour resulted from the formation of high temperature-resistant ordered structures in starch granules and the starch aggregates less accessible to enzymatic hydrolysis.

Effects of oat β-glucan on the retrogradation behavior of rice starch and its potential mechanism

In this study, to minimize the quality deterioration caused by the retrogradation of starch-based food, the effect and mechanism of oat β-glucan (OG) on the retrogradation of rice starch was investigated. OG effectively decreased storage modulus (G'), syneresis, and retrogradation enthalpy, indicating the inhibition of short-term and long-term retrogradation of rice starch. The competition for water molecules between the OG and rice starch resulted in partial swelling of the starch granules, consequently reducing particle size, lowering amylose leaching, and decreasing the proportion of short-amylose chains. The microstructure characterization showed that the OG-treated rice starch group (ST-OG) exhibited a smoother and denser surface. Particularly, no notable alterations were observed in the structure of the ST-OG sample during storage, owing to the improved water-holding capacity of starch gel and reduced proportion of free water caused by OG. Furthermore, the ordered structure results confirmed the occurrence of hydrogen bonding between OG and rice starch, which hindered the rearrangement of starch molecules. Therefore, OG is an effective natural additive for controlling the retrogradation of starch-based foods.

Carboxymethyl Starch Films as Enteric Coatings: Processing and Mechanistic Insights

This study proposes the application of carboxymethyl starch derivatives as tablet coatings affording gastro-protection. Carboxymethyl starch (CMS) films were obtained by casting of aqueous filmogenic starch solutions with or without plasticizers and their structural organization was followed using Fourier transform infrared (FTIR), Thermogravimetric analysis (TGA), X-ray diffraction (XRD). Together with data from mechanical tests (tensile strength, elongation, Young's modulus) the results were used to select filmogenic formulations adapted for coatings of tablets. The behaviour of these films was evaluated in simulated gastric and intestinal fluids. The effect of plasticizers (glycerol and sorbitol) on the starch organization, on the rate of drying of the films and on the water vapor absorption was also analyzed. Various types of starch have been compared and the best results were found with high amylose starch (HAS) that was carboxymethylated in an aqueous phase to obtain carboxymethyl high amylose starch (CMHAS). The CMHAS coating solutions containing sorbitol or glycerol as plasticizers have been applied with an industrial pan coater and the final tablets exhibited a good gastro-resistance (up to 2h) in simulated gastric fluid followed by disintegration in simulated intestinal fluid (SIF). The CMHAS derivatives present a high potential as coatings for nutraceutical and pharmaceutical solid dosage forms.

Effect of starch and protein on eating quality of japonica rice in Yangtze River Delta

This study examined four types of japonica rice from Yangtze River Delta, categorized based on amylose content (AC) and protein content (PC): high AC with high PC, high AC with low PC, low AC with high PC, and low AC with low PC. It systematically explored the effect of starch, protein and their interactions on eating quality of japonica rice. Rheological analysis revealed that increased amylose, long chains amylopectin or protein levels during cooking strengthen starch-protein interactions (hydrogen bonding), forming a firm gel network. Scanning electron microscopy showed that increased amylose, long chains amylopectin or protein levels made protein and starch more stable in combination during cooking, limiting starch structure cleavage. Therefore, the eating quality of high AC in similar PC japonica rice and high PC in similar AC japonica rice were poor. Further, correlation and random-forest analysis (RFA) identified amylose as the most influential factor in starch-protein interactions affecting rice eating quality, followed by amylopectin and protein. RFA also revealed that in high AC japonica rice, the interactions of Fb3 and albumin with amylose were more conducive to forming good eating quality. In low AC japonica rice, the interactions of Fb2 and prolamin with amylose were more beneficial.

Structural analysis of potato starch transformation during high-energy ball-milling: Oxygen and humidity content effects

High Energy Ball-Milling (HEBM) modifies starchs' granule morphology, physicochemical properties, and chemical structure. However, understanding how the HEBM changes the starch chemical structure is necessary to control these modifications. Therefore, this study aimed to investigate the changes in potato starch's long- and short-range molecular order during HEBM at different environmental conditions such as oxygen (Air) and humidity content. Due to the correlation between the starch modification and the energy supplied (Esupp) by the HEBM, Burgio's equation was used to calculate this energy. The starch transformation was followed by X-ray diffraction, Fourier Transform-Infrared Spectroscopy, and Raman spectroscopy. A Principal Component Analysis (PCA) was conducted to reduce the HEBM variables. PAC analysis demonstrated that the different oxygen-humidity conditions do not affect the HEBM of potato starch. Based on the starch chemical structure transformation correlated with Esupp during HEBM, four stages were observed: orientation, modification, mechanolysis, and over-destruction. It was identified for the first time that at low milling energy (<1.5 kJ/g, orientation stage), the glycosidic rings change their orientation, and starch-water interaction increases while the starch's organization reduces. Ergo, the potato starch could be more susceptible to chemical modifications during the first two stages.

Preparation of starch-palmitic acid complexes by three different starches: A comparative study using the method of heating treatment and autoclaving treatment

Recent research emphasizes the growing importance of starch-lipid complexes due to their anti-digestibility ability, prompting a need to explore the impact of different starch sources and preparation methods on their properties. In this study, starch-palmitic acid (PA) complexes were prepared by three different starches including Tartary buckwheat starch (TBS), potato starch (PTS), and pea starch (PS) by heating treatment (HT) and autoclaving treatment (AT), respectively, and their physicochemical property and in vitro digestibility were systematically compared. The formation of the starch-PA complex was confirmed through various characterization techniques, including scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, and X-ray diffraction. Among the complexes, the PTS-PA complex exhibited the highest complexation index over 80 %, while the PS-PA complex had the lowest rapid digestible starch content (56.49-59.42 %). Additionally, the complexes prepared by AT exhibited higher resistant starch content (41.95-32.46 %) than those prepared by HT (31.42-32.49 %), while the complexes prepared by HT held better freeze-thaw stability and hydration ability than those prepared by AT. This study highlights the important role of starch sources in the physicochemical and digestibility properties of starch-lipid complex and the potential application of AT in the preparation of novel resistant starch.

Including protein hydrolysates during thermal processing mitigates the starch digestion of resulted starch-based binary matrix

Staple foods with starch and protein components are usually consumed after thermal processing. To date, how including protein hydrolysates (with varied hydrolysis degrees) tailors the structure and digestion features of starch-based matrix with thermal processing has not yet been sufficiently understood. Here, corn starch (CS), soy protein isolate (SPI), and soy protein isolate hydrolysates (SPIH) with different hydrolysis time (5-60 min) were used to prepare starch-based binary matrices. With the addition of SPI or SPIH during thermal processing, the resultant binary systems exhibited higher thermal stability (breakdown visibility was increased by 1.9-10.8 times), denser networks, and fewer short-range orders (R995/1022 was decreased by up to 15.3 %). These structural changes allowed an inhibited starch digestion within the binary system, especially with increased SPI or SPIH content. Compared with CS, the content of resistant starch (RS) for CS-SPI binary complex (10:3 w/w) increased from 9.89 % to 16.69 %. Compared to SPI, SPIH inclusion displayed a stronger inhibitory effect on starch digestion since the reduced molecule size of SPIH probably enhanced its interplays with starch or amylase. For instance, the 10:3 w/w starch-SPIH 60 binary matrix possessed the highest RS content (19.07 %).

Influence of the structure and physicochemical properties of OSA modified highland barley starch based on ball milling assisted treatment

This study aimed to investigate the influence of ball milling assisted treatment on the degree of substitution of octenyl succinic anhydride (OSA) modified highland barley starch (HBS) and on the physicochemical properties and structure of HBS. Scanning electron microscopy (SEM) findings showed that with the increasing of ball milling time, the surface morphology of OSA modified HBS became rougher and rougher and the particle morphology and crystal structure were damaged. When the pretreatment time of ball milling was 40 min, the degree of substitution of OSA modified HBS was 1.32 times higher than that of the conventional modification method. In addition, the longer the ball milling assistant, the longer the short-range ordering of the OSA modified HBS significantly decreased, and the relative crystallinity decreased (from 16.68 % to 7.93 %), leading to a decrease in thermal stability too. However, it greatly enhanced the aging resistance and flowability. In terms of emulsification properties, the emulsification properties of OSA modified HBS increased from 60.67 % to 75.67 %. Therefore, the HBS with better freeze-thaw stability and higher degree of substitution can be prepared by ball milling pretreatment and OSA modification, which provides technical support for further development of starch resources.

Effect of ethanol, phytic acid and citric acid treatment on the physicochemical and heavy metal adsorption properties of corn starch

Corn starch dispersions were heated with ethanol (E) and reacted with phytic acid (E-PA), citric acid (E-CA), and a mixture of phytic and citric acid (E-PACA) under dry-heating to prepare heavy metal adsorbents. Microscopy images indicated that ethanol treatment induced the formation of porous structures on the surface; furthermore, treatment with phytic and citric acid induced indentations, pores, and irregular structures in E-PA, E-CA, and E-PACA starches. Phytic and citric acid were retained in the starch molecules through ester bonds with the phosphate and carboxyl groups, respectively. Starch esterification by phytic and citric acid induced a loss of crystallinity, high water absorption capacity, and low solubility. E-PACA starch exhibited more efficient Cu2+ adsorption (38.13 mg/g) than native, E, E-PA, and E-CA starches (0.11, 0.49, 2.05, and 36.23 mg/g, respectively). Thus, modification with ethanol, phytic acid and citric acid can be applied to prepare natural starch-based heavy metal adsorbents.

Effect of structural characteristics of resistant starch prepared by various methods on microbial community and fermentative products

Resistant starch (RS) has been extensively studied because of its beneficial effects on gut microbiota. In this study, four RSs obtained through various preparation processes were utilized for in vitro fermentation, and their structural characteristics before and after fermentation were determined using chromatography, Fourier infrared spectroscopy, and scanning electron microscopy (SEM). It was observed that these RSs can be classified into two categories based on their fermentation and structural features. The autoclaving RS (ARS) and extruding RS (ERS) were classified as Class I Microbiome Community (MC-I), characterized by a higher proportion of butyrate and its producers, including unclassified_g_Megasphaera and Megasphaera elsdenii. While microwaving RS (MRS) and ultrasound RS (URS) belonged to Class II Microbiome Community (MC-II), marked by a higher proportion of acetate and its producer, Bifidobacterium pseudocatenulatum DSM 20438. MC-I had a lower molecular weight, shorter chain length, more chains with degree of polymerization (DP) 36-100, and a more ordered structure than MC-II. Furthermore, SEM observations revealed distinct degradation patterns between MC-I and MC-II, which may be attributed to their surface structural characteristics. These findings imply that the preparation methods employed for RS can determine its multilevel structural characteristics, and consequently influence its physiological properties.