Physicochemical, Antioxidant, Starch Digestibility, and Sensory Properties of Wheat Bread Fortified with Taiwanese Cocoa Bean Shells.

The effects of replacing 5-25% of wheat flour (WF) with Taiwanese cocoa bean shells (CBSs) on the physicochemical, antioxidant, starch digestion, and sensory properties of the bread were studied. The lead (0.18) and cadmium (0.77) contents (mg/kg) of the CBSs were below the Codex Alimentarius specifications for cocoa powder. Ochratoxin A and aflatoxins (B1, B2, G1, and G2) were not detected in the CBSs. The CBSs were rich in dietary fiber (42.9%) and bioactive components and showed good antioxidant capacity. The ash, fat, protein, dietary fiber, crumb a* and c*, hardness, chewiness, total phenols, and antioxidant activities of the bread increased with an increasing CBSs level. The starch hydrolysis rate (45.1-36.49%) of the CBS breads at 180 min was lower than that of the control (49.6%). The predicted glycemic index of the bread (CBS20 and CBS25) with 20-25% of the WF replaced with CBSs was classified as a medium-GI food using white bread as a reference. In the nine-point hedonic test, the overall preference scores were highest for control (6.8) and CBS breads, where CBSs replaced 5-10% of WF, with scores of 7.2 and 6.7. CBS20 supplemented with an additional 20-30% water improved its volume, specific volume, and staling rate, but the overall liking score (6.5-7.2) was not significantly different from the control (p > 0.05). Overall, partially replacing wheat flour with CBSs in the production of baked bread can result in a new medium-GI value food containing more dietary fiber, bioactive compounds, and enhanced antioxidant capacity.

Moderate regulation of wheat B-starch ratio: Improvement of molecular structure, spatial conformation, aggregation behavior of reconstituted fermented doughs and its processing suitability.

Aiming to investigate the changes and effects of different particle sizes of wheat A/B starch during dough fermentation, the present study reconstituted A/B starch fractions in ratios of 100:0, 75:25, 50:50, 25:75, and 0:100, further blended with gluten and subjected to slight (20 min), medium (30 min), and high (60 min) fermentation processes by yeasts. Results showed that fermentation gas production promoted gluten network extension, inducing starch granule exposure and dough surface roughness. Also, fermentation fractured protein intermolecular disulfide bonds and decreased α-helix and ß-folded structure content, contributing to GMP, LPP, and SPP content decreases. Moreover, moderately increasing the B-starch ratio in the dough can improve gluten network stability, continuity, and air-holding capacity. The 25A-75B steam bread exhibited optimal processing suitability (better morphology, texture, and quality) due to its higher GMP and polymer protein content with lower free sulfhydryl and monomeric protein content. Further, conformational relationships indicated the key indicators influencing dough products' properties were free sulfhydryl content, GMP content, protein molecular weight distribution, and secondary structure. The obtained findings contributed to understanding the effect of wheat starch granule size distribution on dough processing behavior, and future targeted breeding for wheat cultivars with high B-starch content for improved fermentation pasta product qualities.

Sequential effects of autoclaved heat treatment and electron beam irradiation on acorn starch: Multiscale structural differences and related mechanisms.

In this study, the differences in the modification effects and related mechanisms of different times (20 and 40 min) of autoclaved heat (AH) treatment and different doses (2 and 4 kGy) of electron beam irradiation (EBI) in different sequences of effects on acorn starch were investigated. The results showed that both AH and EBI reduced the amylose content (22.70 to 19.59%) and enthalpy (10.28 to 1.84%) of starch but increased the resistant starch content (53.69 to 64.11%). AH treatment made the crystalline regions of the residual starch granules denser, which was resistant to the action of amylase enzymes. EBI degraded the long chain of starch, which increased the solubility. Notably, EBI pretreatment improves the reactive sites by inducing depolymerization and disorder in starch internal structure, thus increasing the modification extent of AH-modified starch, forming starch with lower viscosity, better hydration, and digestibility resistance, therefore being used as an ingredient for functional foods.

Enhanced B-type starch granules proportion modulates starch-gluten interactions during the thermal processing of reconstituted doughs.

This work investigated structure-properties changes of reconstituted wheat A/B starch doughs under different ratios during dynamic thermal processing. Results indicated that a change in spatial conformation and aggregation structure of the starch-gluten system was induced with heating (30 °C-86 °C). Moderately increased B starch ratio can effectively fill the gluten network and improve starch-protein interactions, which promotes the free sulfhydryl group oxidation and results in the formation of more glutenin macropolymer; this contributes to a higher degree of cross-linking and stability to the gluten network matrix. This improvement is enhanced as the heating temperature is increased. Notably, the B starch ratio requires to be controlled within a suitable range (≤ 75%) to avoid aggregation and accumulation on the gluten matrix triggered by its excess. This work may provide insights and optimization for clarifying the on-demand regulation strategy of A/B starch in dough processing.

Impact of flaxseed gum on the aggregate structure, pasting properties, and rheological behavior of waxy rice starch.

This study examines the effects of flaxseed gum (FG) on the aggregate structure, pasting and rheological properties of waxy rice starch (WRS). Results display an increase in the ordered molecular structure (R1047/1024), relative crystallinity (RC), compactness (α), and microphase heterogeneity (ε, density degree of nanoaggregates, from 3.52 to 4.23) for WRS-FG complexes. These suggested FG facilitated the development of more organized molecular and crystalline structures of WRS, accompanied by the formation of ordered nanoaggregates with higher density (i.e., nano-aggregation structure). Also, FG addition resulted in the formation of enhanced gel network structure characterized by thicker layer walls and more uniform pores. These structural transformations contributed to a rise in gelatinization temperature (To, from 56.90 °C to 62.10 °C) and enthalpy (ΔH), as well as alterations in paste viscosities (PV, from 1285.00 mPa·s to 1734.00 mPa·s), and the rigidity of network structure (e.g., decreased loss tangent). These results indicate that FG could effectively regulate the techno-functional properties of WRS by rationally controlling the starch intrinsic structures of starch. And this study may improve the pasting and gelling properties of starch, thus driving the development of high-quality starchy foods and prolonging their shelf life, especially for glutinous rice flour products.

Effect of electron beam irradiation pretreatment and different fatty acid types on the formation, structural characteristics and functional properties of starch-lipid complexes.

The effects of different electron beam irradiation doses (2, 4, 8 KGy) and various types of fatty acids (lauric acid, stearic acid, and oleic acid) on the formation, structure, physicochemical properties, and digestibility of starch-lipid complex were investigated. The complexing index of the complexes was higher than 85 %, indicating that the three fatty acids could easily form complexes with starch. With the increase of electron beam irradiation dose, the complexing index increased first and then decreased. The highest complexing index was lauric acid (97.12 %), stearic acid (96.80 %), and oleic acid (97.51 %) at 2 KGy radiation dose, respectively. Moreover, the microstructure, crystal structure, thermal stability, rheological properties, and starch solubility were analyzed. In vitro digestibility tests showed that adding fatty acids could reduce the content of hydrolyzed starch, among which the resistant starch content of the starch-oleic acid complex was the highest (54.26 %). The lower dose of electron beam irradiation could decrease the digestibility of starch and increase the content of resistant starch.

Insights into the hierarchical structure and physicochemical properties of starch isolated from fermented dough.

Understanding the hierarchical structure and physicochemical properties of starch isolated from fermented dough with different times (0-120 min) is valuable for improving the quality of fermented dough-based products. The results indicate that fermentation disrupted the starch granule surface and decreased the average particle size from 19.72 µm to 18.45 µm. Short-term fermentation (< 60 min) disrupted the crystalline, lamellar, short-range ordered molecular and helical structures of starch, while long-term fermentation (60-120 min) elevated the ordered degree of these structures. For example, relative crystallinity and double helix contents increased from 23.7 % to 26.8 % and 34.4 % to 37.2 %, respectively. During short-term fermentation, the structural amorphization facilitated interactions between starch molecular chains and water molecules, which increased the peak viscosity from 275.4 to 320.6 mPa·s and the swelling power from 7.99 to 8.52 g/g. In contrast, starches extracted from long-term fermented dough displayed the opposite results. Interestingly, the hardness and springiness of starch gels gradually decreased as fermentation time increased. These findings extend our understanding of the starch structure-property relationship during varied fermentation stages, potentially benefiting the production of better-fermented foods.

Improvement of sorghum-wheat blended flours by E-beam irradiation: Physicochemical properties, rheological behavior, microstructure, and quality properties.

To enhance the processing suitability of blended flours, this study used 4 kGy E-beam irradiated (EBI) sorghum flour in different ratios blended with wheat flour and further verified the improvement mechanism of the processed products under the optimal ratios. The results suggested that the EBI can mitigate the deterioration of the blend flour farinograph properties while enhancing the gas release during dough fermentation. Under the same addition ratio, the irradiated blend flours showed higher expansion height, gas release, cavitation time, and gas retention coefficient than the control flours. Also, irradiated blend flours retained a gluten network at a higher addition rate (20 %). Moreover, the irradiated blend flours were optimized at 10 % as its pasting and thermal properties were improved. Notably, this ameliorating effect promotes a decrease in hardness and chewiness and an increase in cohesion of the bread cores, presenting better textural attributes and delaying the aging rate during storage. The findings are instructive for applying EBI technology in the manufacture and quality improvement of mixed grain breads and open a new research avenue for processing sorghum staple foods.

Investigation of the role of sodium chloride on wheat starch multi-structure, physicochemical and digestibility properties during X-ray irradiation.

In this paper, different NaCl content was added to wheat starch and then subjected to X-ray irradiation to investigate the effect of salt on starch modification by irradiation. The results showed that the degradation of wheat starch intensified with the increase in irradiation dose. When irradiated at the same dose, wheat starch with sodium chloride produced shorter chains, lower molecular weight and amylose content, and higher crystallinity, solubility, and resistant starch than wheat starch without sodium chloride. The energy generated by X-rays dissociating sodium chloride caused damage to the glycoside bonds of the starch molecule. With a further increase in the mass fraction of NaCl, the hydrogen bonds of the starch molecules were broken, and the double helix structure was depolymerized, which exacerbated the extent of irradiation-modified wheat starch. At the same time, starch molecules will be rearranged to form a more stable structure.

Adequately increasing the wheat B-starch ratio can improve the structure-properties of dough during freeze-thaw cycles: Mechanisms and conformational relations.

To reveal the influence of wheat starch particle size distribution on frozen dough quality, this study reconstituted A/B starch according to 100:0, 75:25, 50:50, 25:75 and 0:100 and prepared reconstituted dough by compounding with gluten proteins. Further, the freeze-thaw cycle of 1, 3, and 9 times for reconstituted dough was performed to investigate its ratio-regulatory role of A- and B-starch. The results showed that the freeze-thaw cycle induced gluten network breakage and starch granule exposure in doughs mainly by disrupting disulfide and hydrogen bonds between gluten protein molecules and upsetting their secondary structures, leading to a reduction in GMP and polymer protein content and an increase in freezing water content. Moreover, a moderate increase (25-50 %) in the B-starch proportion can minimize gluten protein deterioration by freeze-thaw cycles. However, excessive B-starch amounts (75-100 %) can also adversely affect gluten structure. The prepared dumpling wrappers under the 50A-50B ratio showed optimal steaming loss rate, hardness, and chewiness during the freeze-thaw cycle. Correlation analysis indicated that the B-starch ratio and its filling pattern improved dough freeze-thaw deterioration primarily by affecting dough-free sulfhydryl content, protein molecular weight distribution, secondary structure, and ΔH. The results may provide insights and guidelines for product development and storage for frozen pasta.

Electron beam irradiation-assisted prepare pea starch nanocrystals and characterization of their molecular structure, physicochemical and rheological properties.

Electron beam irradiation (EBI) is an environmentally friendly physical modification technology. In this study, pea starch nanocrystals (SNC) were prepared by EBI-assisted pretreatment, and investigated the effects of EBI on the multiscale structure and physicochemical properties of SNC. EBI-assisted pretreatment didn't change the particle morphology, crystalline type and FT-IR spectra of SNC. However, EBI-SNC's relative crystallinity and short-range orderliness index (R1047/1022) significantly increased with increasing irradiation dose (5 KGy-20 KGy). In addition, EBI-assisted pretreatment caused the long chains of SNC's amylopectin to break into short chains. Moreover, EBI-assisted treatment significantly reduced the mean size, molecular weight, apparent amylose content, swelling power and SDS + RS content of SNC, while increasing the solubility, zeta potential and RDS content. Furthermore, the flow properties of the EBI-SNC samples were increased. The results show that EBI effectively changed the structural and functional properties of SNC, and the excellent functional properties are expected to broaden the application range of SNC.

Effect of electron beam irradiation on granular cold-water swelling chestnut starch: Improvement of cold-water solubility, multiscale structure, and rheological properties.

In this study, granular cold-water swelling (GCWS) starch was prepared from chestnut starch by ethanol-alkali method, after which it was further modified by electron beam irradiation (EBI) technique to investigate the effect of EBI on GCWS chestnut starch. It was shown that the alcohol-alkali treatment disrupted the starch double helix structure and the starch crystalline form had been changed from "C" to "V" type. On this basis, EBI continued to act on the disrupted starch chains and further cleaved the long chains into short chains, which significantly improved the solubility of starch to 90.08 % in cold water at a 24 kGy irradiation dose. Therefore, this study can broaden the application scope of starch and provide new ideas for GCWS starch applications in food and water-soluble pharmaceutical industries.

Structural, rheological, pasting, and digestive properties of wheat A-starch: Effect of outshell removal combined with annealing.

Wheat A- starch was subjected to single and combined CaCl2 and annealing (ANN) treatments. The influence of the treatment on wheat A- starch's structural, rheological, pasting, and digestive characteristics were studied. The results indicated that the application of CaCl2 treatment caused the removal of the outer layer of wheat A-starch, disrupted the integrity of the growth ring structure, and lowered the molecular weight of amylopectin and relative crystallinity. Meanwhile, the application of outshell removal combined with ANN treatment led to significant damage to the starch granules, resulting in a marked reduction in relative crystallinity, as well as the molecular weight of amylopectin and amylose. However, no changes were found in the non-Newtonian pseudoplastic behavior of starch after single or combined treatments. Furthermore, the combination of outshell removal and annealing treatment resulted in a decreased peak viscosity as well as trough viscosity of starch. Moreover, long-time ANN treatment had the potential to improve the resistant starch (RS) content of deshell starch.

The role and mechanism of electron beam irradiation in glutaric anhydride esterified proso millet starch: Multi-scale structure and physicochemical properties.

To investigate the effect of electron beam irradiation (EBI) pretreatment on the multiscale structure and physicochemical properties of esterified starch, this study used EBI pretreatment to prepare glutaric anhydride (GA) esterified proso millet starch. GA starch did not show the corresponding distinct thermodynamics peaks. However, it had a high pasting viscosity and transparency (57.46-74.25 %). EBI pretreatment increased the degree of glutaric acid esterification (0.0284-0.0560) and changed its structure and physicochemical properties. EBI pretreatment disrupted its short-range ordering structure, reducing the crystallinity, molecular weight and pasting viscosity of glutaric acid esterified starch. Moreover, it produced more short chains and increased the transparency (84.28-93.11 %) of glutaric acid esterified starch. This study could offer a rationale for using EBI pretreatment technology to maximize the functional properties of GA modified starch and enlarge its implementation in modified starch.

Wheat starch particle size distribution regulates the dynamic transition behavior of gluten at different stages of dough mixing.

This study investigated the morphology distribution, molecular structure, and aggregative properties variation of gluten protein during dough mixing stage and interpreted the interaction between starch with different sizes and protein. Research results indicated that mixing process induced glutenin macropolymer depolymerization, and promoted the monomeric protein conversion into the polymeric protein. Appropriate mixing (9 min) enhanced the interaction between wheat starch with different particle sizes and gluten protein. Confocal laser scanning microscopy images showed that a moderate increase in B-starch content in the dough system contributed to forming a more continuous, dense, and ordered gluten network. The 50A-50B and 25A-75B doughs mixed for 9 min exhibited a dense gluten network, and the arrangement of A-/B-starch granules and gluten was tight and ordered. The addition of B-starch increased α-helixes, ß-turns, and random coil structure. Farinographic properties indicated that 25A-75B composite flour had the highest dough stability time and the lowest degree of softening. The 25A-75B noodle displayed maximum hardness, cohesiveness, chewiness, and tensile strength. The correlation analysis indicated that starch particle size distribution could influence noodle quality by changing the gluten network. The paper can provide theoretical support for regulating dough characteristics by adjusting the starch granule size distribution.

Influence of pre- or post-electron beam irradiation on heat-moisture treated maize starch for multiscale structure, physicochemical properties and digestibility.

Electron beam irradiation (EBI) as a green technological method for starch modification can generate starch-based materials with new functions. This study modified maize starch by heat-moisture treatment (HMT) for 1 h and 3 h, and EBI with various intensities (5 kGy and 10 kGy), and their effects of treatment sequence on the multiscale structure, physicochemical properties and in vitro digestibility were investigated. EBI or HMT alone did not change the granule morphology and crystalline type, but reduced the crystallinity and molecular weight and increased the resistant starch content. HMT alone had no significant effect on the solubility of starch, while EBI led to a considerable increase in the solubility of maize starch. The combined treatment of EBI and HMT aggravated apparent viscosity reduction, and the HMT starch pretreated with EBI had a smaller molecular weight and lower viscosity. In contrast, post-EBI samples had higher solubility and RS content. Primarily, it has excellent potential for producing low-viscosity and high-solubility starch foods.

Multiscale structure-property relationships of oxidized wheat starch prepared assisted with electron beam irradiation.

In this study, two promising eco-friendly modification techniques, electron beam (EB) irradiation and hydrogen peroxide (H2O2) oxidation, were used to prepare oxidized wheat starch. Neither irradiation nor oxidation changed starch granule morphology, crystalline pattern, and Fourier transform infrared spectra pattern. Nevertheless, EB irradiation decreased the crystallinity and the absorbance ratios of 1047/1022 cm-1 (R1047/1022), but oxidized starch exhibited the opposite results. Both irradiation and oxidation treatments reduced the amylopectin molecular weight (Mw), pasting viscosities, and gelatinization temperatures, while increasing the amylose Mw, solubility and paste clarity. Notably, EB irradiation pretreatment dramatically elevated the carboxyl content of oxidized starch. In addition, irradiated-oxidized starches displayed higher solubility, paste clarity, and lower pasting viscosities than single oxidized starches. The main reason was that EB irradiation preferentially attacks the starch granules, degrades the starch molecules, and depolymerizes the starch chains. Therefore, this green method of irradiation-assisted oxidation of starch is promising and may promote the appropriate application of modified wheat starch.

Pheophorbide-a as a Light-Triggered Liposomal Switch: For the Controlled Release of Alpinia galanga (A. galanga) Essential Oil and Its Stability, Antioxidant, and Antibacterial Activity Assessment.

In this study, Alpinia galanga essential oil liposomes (EO-Lip) were prepared with soybean lecithin and cholesterol as wall materials. A light-responsive liposome (EO-PLip) was designed for the controlled release of A. galanga oil based on the light-responsive properties of Pheophorbide-a. The dependence of Pheophorbide-a on illumination time was proved by UV spectroscopy. Characterization techniques such as UV spectroscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy demonstrated that the essential oils were successfully encapsulated in liposomes. Moreover, the particle size of EO-PLip was 166.30 nm, the polydispersity index was 0.22, the zeta potential was -49.50 mV, and the encapsulation efficiency was 30.83%. Both EO-Lip and EO-Plip have high sustained-release effects on essential oil and showed light-responsive release characteristics under infrared stimulation. The prepared liposomes had good storage stability at 4 °C for 28 d. EO-PLip showed excellent transient antioxidant and bacteriostatic properties based on the ability to respond to light and slow release. This EO-PLip provided a platform for essential oils and might be used as a potent and controllable solution.

Investigating the effects of pre- and post-electron beam treatment on the multiscale structure and physicochemical properties of dry-heated buckwheat starch.

This study presents the effects of dry heat (DH) assisted by pre-and post-electron beam (EB) treatment on buckwheat starch's multiscale structural, physicochemical, and digestive properties. The granule integrity and crystal shape were not affected by the investigated treatments. However, DH and EB treatments decreased amylose content, crystallinity, molecular weight, swelling power, thermal transition temperatures and gelatinization enthalpy while increasing solubility and the content of A chain, B1 chain, and resistant starch. EB application to DH starch promoted subsequent structural changes and enhanced starch properties compared to samples DH-processed alone. In addition, EB-induced starch chain depolymerization and structural rearrangement had sequential effects. EB pre-treatment reduced DH starch's amylose content, molecular weight, and swelling power while enhancing the content of A- chain, rapidly digestible starch, and resistant starch compared with EB post-treatment. This innovative study provides a theoretical basis for the potential applicability of EB irradiation in modifying the properties of DH starch.

Effects of various microwave intensities collaborated with different cold plasma duration time on structural, physicochemical, and digestive properties of lotus root starch.

Lotus root starch was treated with single and combined microwave (300 and 700 W) and cold plasma (60, 90, and 120 s) treatments. Effects of treatments on multi-structural, physicochemical, and digestive properties of lotus root starch were investigated. The results revealed that a combination of cold plasma and microwave treatments significantly affected the morphology of starch granules and reduced the relative crystallinity of starch compared with a single treatment. However, no changes were found in the chemical functional groups of starch after single or combined treatments. Additionally, the amylose content, amylopectin branch chain length distribution, solubility, and swelling power of the starch significantly varied depending on cold plasma treatment duration and microwave power. Furthermore, the treated starch showed lower peak viscosity and higher pasting temperature than the native one. Moreover, the resistant starch content significantly decreased as cold plasma treatment was prolonged and microwave power increased.