The assisting effects of ultrasound on the multiscale characteristics of heat-moisture treated starch from Agriophyllum squarrosum seeds

Preparation and evaluation of novel Agriophyllum squarrosum starch nanoparticles for encapsulation of lycopene with enhanced retention rate and bioactivity during simulated in-vitro digestion

In this study, we developed novel Agriophyllum squarrosum starch nanoparticles (ASSNPs) for the encapsulation of lycopene (LYC), aiming to enhance its stability and bioactivity under adverse environmental and digestive conditions. The small-granule starch extracted from A. squarrosum seeds was processed using ionic liquids (ILs) as an effective "green" solvent, followed by a systematic treatment involving ultrasonication and pullulanase to prepare the ASSNPs. The resulting nanoparticles exhibited small size, narrow particle size distribution, negative zeta potential, and high encapsulation efficiency of up to 64.3 %. The structures of ASSNPs were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and transmission electron microscopy. These analytical techniques confirmed the successful encapsulation of LYC and revealed increased intermolecular interactions. Stability and degradation experiments demonstrated that the retention of the LYC in the complexes was significantly higher than that of the unencapsulated LYC, highlighting the superior protective effects of ASSNPs on the storage and digestive stability of LYC. This research elucidated the structural features of the complex between ASSNPs and LYC, underscoring the potential of ASSNPs as a food-grade delivery system. This approach offers a sustainable method for enhancing the bioavailability of hydrophobic nutraceuticals.

Integrative approach to modifying banana starch: The role of physical treatment and polyphenol enrichment on physicochemical and digestive characteristics

This study assessed the effects of three physical methods-dielectric barrier discharge (DBD) plasma, ultrasound, and heat-moisture treatment-coupled with resveratrol enrichment, on the physicochemical and digestive properties of banana starch. The findings indicated that each physical treatment enhanced the complex index between starch and resveratrol. Scanning electron microscopy and X-ray diffraction analyses revealed that the inherent A-type crystallinity of the starch remained unchanged after modifications. Heat-moisture treatment induced the most profound alterations in the long-range and short-range order. While DBD plasma and ultrasound did not affect the granular morphology, heat-moisture treatment caused the most significant disruption. Furthermore, DBD plasma and ultrasound treatments significantly enhanced the solubility, gelatinization temperature, and viscoelastic properties of banana starch, while having a negligible effect on its digestibility. After heat-moisture treatment, banana starch exhibited significantly higher gelatinization temperatures (To = 72.13 °C, Tp = 82.56 °C, Tc = 83.69 °C) and a digestion rate of 82.37 %, compared to those observed with DBD plasma and ultrasound treatments, despite reduced solubility and viscoelasticity. Additionally, all three treatments improved the oil absorption capacity of the starch. The integration of resveratrol not only consolidated starch structure but also augmented its thermal stability and resistant starch content. These findings provide empirical support for modifying banana starch and expanding its application in food industry.

Influence of ultrasonication during soaking on water absorption and Softness characteristics in the cooking process of cowpea

Owing to the long duration of cooking legumes, which limits their consumption and utilization, soaking has been used to reduce cooking time, save energy consumption, and diminish their hardness. However, limited studies have reported the influence of cooking and soaking treatment along with ultrasonication on hydration, hardness, and cooking time reduction of legumes. Therefore, this study investigated the impact of cooking and soaking treatments on Dr. Saunder cowpea's water absorption, hardness, and cooking time reduction with and without ultrasonication. Samples of Dr. Saunder's cowpea were first soaked at 30 °C and 50 °C for 15 - 90 min (with and without ultrasonication), after which they were cooked at 100 °C and 121 °C for 15 - 120 min. The absorbed water and hardness of the tested samples under these treatments were measured. Hydration and softening behaviors were modeled from the obtained data using Ibarz-Augusto and first-order equations, respectively. Arrhenius equation was used to describe the kinetics of the hydration and softening process. Results showed that ultrasonic treatments accelerated water absorption and reduced the hardness of the samples; consequently, in a shorter time, using less energy will receive the desired hardness as the final product. The Ibartz-Augusto and first-order equations perfectively fit the sigmoidal and decaying exponential behavior of the absorbed water and hardness data with high prediction performance (R2 ≈ 1) marked by minimal error values. The deployment of ultrasonication and increased cooking temperature were observed to reduce the kinetic parameter (water absorption) and elevate the softening rates and activation energy (for hydration and softening). A synergy of the trio treatments reduced the total cooking duration from 120 min to 90 min (25 %), thus promoting the benefit of deploying ultrasonication to soften cowpeas and other seeds rapidly.

A comparison of the physicochemical properties, digestibility, and expression patterns of starch-related genes of two supersweet corn hybrids (F1) and their parents

The quality difference of corn largely depends on parental selection. Herein, the structure, digestive characteristics, and expression patterns of starch-related genes of two supersweet maize hybrids and their parents were studied. The structural analysis revealed that the starch of supersweet corn is round or oval, and the particles are smaller compared to those of normal corn. Hybridization changed the grain morphology, crystal, and helical structure of starch. Parents had a significantly different influence on supersweet corn. Notably, hybridization improved the setback value and digestibility of Shantian1500F1 and Shantian2000F1 compared to that of the parents. ZmBEI, ZmPHOH, and ZmAGPL2 genes had a consistent high expression throughout the whole grain formation phase. The results of this study expand our understanding of the breeding of supersweet corn hybrids and the effect of parents on the new strand. These results provide a useful reference for further breeding and studies of supersweet corn for starch production in corn.

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

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

Heat moisture treatment and ultrasound-induced hydrothermal wheat starch modification: Techno-functional, microstructural and quality 3D printed characteristics

In this study, the effect of hydrothermal process, ultrasound and combined freezing-ultrasound process on the physical and structural characteristics of wheat starch (Triticum aestivum) was investigated. Two heat-moisture treatments for 2 h (HMT2) and 4 h (HMT4), high-intensity, high-frequency ultrasound under two treatment times (10 to 20 min) (UT10 and UT20) as pre-treatment and sonication after freezing as post-treatment (FUT) on wheat starch suspension was applied. The modifications of starch crystallinity, chemical bonds of starch treated, morphology, thermal, swelling, pasting, and physicochemical characteristics were evaluated. Finally, the starches treated under these conditions were used as ink for a 3D printer, and the characteristics of the printed product were evaluated. The results demonstrate that heat-moisture modified starch increased swelling and size of granules and lowered syneresis values. Sonication promoted molecular depolymerization and reduction of starch swelling and crystallinity. Combined treatment (Sonication and freezing) showed higher peak apparent viscosity during gelatinization and pasting, and the FUT starch-based hydrogels showed the best printability (better ability to stack layers on top of each other and build the desired 3D shape), indicating better reproducibility of this ink. These results showed that FUT is a suitable process for improving the synergy and properties of wheat starch-based hydrogels, which are suitable as inks for use in 3D printers.

Effect of superheated steam treatment on enzyme inactivation, morphostructural, physicochemical and digestion properties of sand rice (Agriophyllum squarrosum) flour

The lipase (LA) and peroxidase (POD) activities, as well as morphological structure, physicochemical and digestion properties of sand rice flour (SRF) treated with superheated steam (SS), were investigated. SS treatment at 165 °C completely deactivated LA and resulted in a 98% deactivation of POD activities in SRF. This treatment also intensified gelatinization, induced noticeable color alterations, and decreased pasting viscosities. Furthermore, there was a moderate reduction in crystal structure, lamellar structure, and short-range ordered structure, with a pronounced reduction at temperatures exceeding 170 °C. These alterations significantly impacted SRF digestibility, leading to increased levels of rapidly digestible starch (RDS) and resistant starch (RS), with the highest RS content achieved at 165 °C. The effectiveness of SS treatment depends on temperature, with 165 °C being able to stabilize SRF with moderate changes in color and structure. These findings will provide a scientific foundation for SS applicated in SRF stabilization and modification.

Tailoring the physicochemical properties of starch: impact of integrated ultrasonic and ethanol pretreatment on the oil uptake of infrared fried ginkgo seeds

BACKGROUND

The structural changes of starch would have a more crucial impact on oil absorption and quality changes in starch-rich fruits and vegetables during frying process with enhanced heat transfer (such as infrared frying). In the present study, the influence of integrated ultrasonic and ethanol (US + ethanol) pretreatment on oil uptake in infrared fried (IF) ginkgo seeds was evaluated regarding modifications in the physicochemical properties of starch. The pretreatment was performed with ultrasonic (40 kHz, 300 W) and ethanol osmotic (95%, v/v) treatment individually or integrated for 40 min.

RESULTS

The mass transfer in the pretreatment was facilitated by combined ultrasound and ethanol. The swelling power, solubility, and gelatinization degree of starch was significantly increased. Low-frequency-NMR curves and images revealed that the bound water fraction in ginkgo seeds was increased and the water distribution was homogenized. The results of Fourier transform-infrared spectrum and differential scanning calorimeter revealed that the crystalline regions of starch were reduced and the thermal enthalpy was decreased after US + ethanol pretreatment. The total, surface and structural oil content in IF ginkgo seeds with US + ethanol pretreatment was reduced by 29.10%, 34.52% and 29.73%, respectively. The US + ethanol pretreatment led to a thinner crust layer with increased porosity and smaller-sized pores in the IF ginkgo seeds as observed by stereo microscopy and scanning electron microscopy.

CONCLUSION

The changes in structural and physicochemical properties of starch by combined ultrasound and ethanol affect the crust ratio and pore characteristics in fried high-starch fruits and vegetables, thereby reducing oil absorption. © 2024 Society of Chemical Industry.

Improvement of resistant starch content and thermal-stability of starch-linoleic acid complex: An attempt application in extruded recombinant rice

The utilization of resistant starch in food industry is restricted due to its susceptibility to thermal degradation. This work aimed to address this issue by preparing a starch-linoleic acid complex (RS5) via extrusion method combined with heat moisture treatment, obtaining VII-type crystal (melting temperature ∼110 °C). The complex obtained through an 8-hour heat moisture treatment exhibited a high RS content of 46.7 %. The glycemic index (pGI) values predicted by two different methods for this complex were 54.5 and 64.2. The complex was further processed into recombinant rice, which exhibited similar textural properties to commercial rice products after cooking. Notably, the recombinant rice maintained an anti-enzyme structure (VII-type complex) as evidenced by its significant resistant starch content of 38.1 %, the lowest pGI values of 59.6 and 72.5. These findings could serve as a useful reference to aid in developing low glycemic index foods based on starch.

Effect of endogenous protein and lipid removal on the physicochemical and digestion properties of sand rice (Agriophyllum squarrosum) flour

The study investigated the effect of removing protein and/or lipid on the physicochemical characteristics and digestibility of sand rice flour (SRF). Morphological images showed that protein removal had a greater impact on exposing starch granules, while lipids acted as an adhesive. The treatment altered starch content in SRF samples, leading to increased starch crystallinity, denser semi-crystalline region, lower onset gelatinization temperature (To), higher peak viscosity and gelatinization enthalpy (ΔH), where Protein removal showed a more pronounced effect on altering physicochemical properties compared to lipid removal. The research revealed a positive correlation between rapidly digestible starch (RDS), maximum degree of starch hydrolysis (C∞), digestion rate constant (k) values and 1047/1022 cm-1 ratio, showing a strong connection between short-range structure and starch digestibility. The presence of endogenous proteins and lipids in SRF hinder digestion by restricting starch swelling and gelatinization, and physically obstructing enzyme-starch interaction. Lipids had a greater impact on starch digestibility than proteins, possibly due to their higher efficacy in reducing digestibility, higher lipid content with greater potential to form starch-lipid complexes. This study provides valuable insights into the interaction between starch and proteins/lipids in the sand rice seed matrix, enhancing its applicability in functional and nutritional food products.

Combined effect of heat moisture and ultrasound treatment on the physicochemical, thermal and structural properties of new variety of purple rice starch

The advantages of physically modifying starch are evident: minimal environmental impact, no by-products, and straightforward control. The impact of dual modification on starch properties is contingent upon modification conditions and starch type. Herein, we subjected purple rice starch (PRS) to heat-moisture treatment (HMT, 110 °C, 4 h) with varying moisture content, ultrasound treatment (UT, 50 Hz, 30 min) with different ultrasonic power, and a combination of HMT and UT. Our findings reveal that UT following HMT dispersed starch granules initially aggregated by HMT and resulted in a rougher granule surface. Rheological analysis showcased a synergistic effect of HMT and UT, enhancing the fluidity of PRS and reinforcing its resistance to deformation in paste form. The absorbance ratio R1047/1015 indicates that increased moisture content during HMT and high ultrasound power for UT reduced the short-range order degree (1.69). However, the combined HMT-UT exhibited an increased R1047/1015 (1.38-1.64) compared to HMT alone (1.29-1.45), likely due to short-chain rearrangement. Notably, the A-type structure of PRS remained unaltered, but overall crystallinity significantly decreased (23.01 %-28.56 %), consistent with DSC results. In summary, physical modifications exerted significant effects on PRS, shedding light on the mechanisms governing the transformation of structural properties during HMT-UT.

Physicochemical properties of ultrasound-pretreated pea starch and its inclusion complexes with lauric acid

Ultrasound is a promising green technology for modifying starch. The influence of ultrasound pretreatment (UPT) at diverse temperatures on the morphology and molecular structure of pea starch and its ability to form inclusion complexes with lipids were investigated. After UPT at each temperature, the starch granules retained an unchanged crystalline structure but exhibited notable changes in short-range molecular order and molecular structure. In comparison with the samples treated at 0 and 20 °C, pea starch subjected to UPT at 40 °C had a significantly (P ≤ 0.05) higher complexing index with lauric acid (LA) and the starch-LA inclusion complex exhibited a higher enthalpy change, relative crystallinity, and resistant starch content. These differences were attributed to the higher temperature causing changes in the disruption points of starch chains and an enlargement in the molecular weight of linear chains. These results may promote the utilization of ultrasound for effective starch modification.

Exploring the influence mechanism of water grinding on the gel properties of corn starch based on changes in its structure and properties

BACKGROUND

At present, most studies have focused on the preparation of modified starches by dry grinding. As an excellent starch plasticizer, water might enhance the action of grinding on the structure of starch granules, and water grinding might improve the gel properties of starch. Therefore, this article explored the influence mechanism of water grinding on the gel properties of corn starch based on the changes in its structure and properties.

RESULTS

The results showed that water grinding could make water enter the starch granules and hydrate the starch molecules, and the starch gelatinized after water grinding for 20 min. Thus, water enhanced the action of grinding on the structure of the starch granules. Under the plasticization and grinding action of water grinding, the mechanochemical effect of the starch granules occurred. When the starch was in the aggregation stage (7.5-10 min), the crystallinity of the starch increased, and the starch molecules rearranged into a more stable structure, which increased apparent viscosity (η), elastic modulus (G') and viscous modulus (G″) of the starch gels.

CONCLUSION

Therefore, appropriate water grinding (10 min) contributed to increasing the viscoelasticity of starch gels. This study provided a theoretical foundation for research on improving the properties of starch by mechanical modification in future. © 2023 Society of Chemical Industry.

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.

Study of unripe and inferior banana flours pre-gelatinized by four different physical methods

This study aimed to prepare the pre-gelatinized banana flours and compare the effects of four physical treatment methods (autoclaving, microwave, ultrasound, and heat-moisture) on the digestive and structural characteristics of unripe and inferior banana flours. After the four physical treatments, the resistant starch (RS) content values of unripe and inferior banana flours were decreased from 96.85% (RS2) to 28.99-48.37% (RS2 + RS3), while C∞ and k values were increased from 5.90% and 0.039 min^-1 to 56.22-74.58% and 0.040-0.059 min^-1, respectively. The gelatinization enthalpy (ΔHg) and I_1047/1022 ratio (short-range ordered crystalline structures) were decreased from 15.19 J/g and 1.0139 to 12.01-13.72 J/g, 0.9275-0.9811, respectively. The relative crystallinity decreased from 36.25% to 21.69-26.30%, and the XRD patterns of ultrasound (UT) and heat-moisture (HMT) treatment flours maintained the C-type, but those samples pre-gelatinized by autoclave (AT) and microwave (MT) treatment were changed to C + V-type, and heat-moisture (HMT) treatment was changed to A-type. The surface of pre-gelatinized samples was rough, and MT and HMT showed large amorphous holes. The above changes in structure further confirmed the results of digestibility. According to the experimental results, UT was more suitable for processing unripe and inferior banana flours as UT had a higher RS content and thermal gelatinization temperatures, a lower degree and rate of hydrolysis, and a more crystalline structure. The study can provide a theoretical basis for developing and utilizing unripe and inferior banana flours.

Effects of Heat-Moisture Treatment on the Digestibility and Physicochemical Properties of Waxy and Normal Potato Starches

Heat-moisture treatment (HMT) is a safe, environmentally friendly starch modification method that reduces the digestibility of starch and changes its physicochemical properties while maintaining its granular state. Normal potato starch (NPS) and waxy potato starch (WPS) were subjected to HMT at different temperatures. Due to erosion by high-temperature water vapor, both starches developed indentations and cracks after HMT. Changes were not evident in the amylose content since the interaction between the starch molecules affected the complexation of amylose and iodine. HMT increased pasting temperature of NPS from 64.37 °C to 91.25 °C and WPS from 68.06 °C to 74.44 °C. The peak viscosity of NPS decreased from 504 BU to 105 BU and WPS decreased from 384 BU to 334 BU. The crystallinity of NPS decreased from 33.0% to 24.6% and WPS decreased from 35.4% to 29.5%. While the enthalpy values of the NPS declined from 15.74 (J/g) to 6.75 (J/g) and WPS declined from 14.68 (J/g) to 8.31 (J/g) at 120 °C. The solubility and swelling power of NPS decreased while that of WPS increased at 95 °C. Due to the lack of amylose in WPS, at the same HMT processing temperature, the reduction in peak viscosity of treated WPS compared to that of native starch was smaller than that of NPS. The resistant starch (RS) content of NPS after HMT at 120 °C was 73.0%. The slowly digestible starch (SDS) content of WPS after HMT at 110 °C was 37.6%.

Effect of Heat–Moisture Treatment on the Physicochemical Properties, Structure, Morphology, and Starch Digestibility of Highland Barley (Hordeum vulgare L. var. nudum Hook. f) Flour

This study modified native highland barley (HB) flour by heat–moisture treatment (HMT) at different temperatures (90, 110, and 130 °C) and moisture contents (15%, 25%, and 35%). The effects of the treatment on the pasting, thermal, rheological, structural, and morphological properties of the native and HMT HB flour were evaluated. The results showed that HMT at 90 °C and 25% moisture content induced the highest pasting viscosity (3626–5147 cPa) and final viscosity (3734–5384 cPa). In all conditions HMT increased gelatinization temperature (T_o, 55.77–73.72 °C; T_p, 60.47–80.69 °C; T_c, 66.16–91.71 °C) but decreased gelatinization enthalpy (6.41–0.43 J/g) in the HMT HB flour compared with that in the native HB flour. The HB flour treated at 15% moisture content had a higher storage modulus and loss modulus than native HB flour, indicating that HMT (moisture content, 15%, 25%, and 35%) favored the strengthening of the HB flour gels. X-ray diffraction and Fourier-transform infrared spectroscopy results showed that HMT HB flour retained the characteristics of an A-type crystal structure with an increased orderly structure of starch, while the relative crystallinity could be increased from 28.52% to 41.32%. The aggregation of starch granules and the denaturation of proteins were observed after HMT, with additional breakage of the starch granule surface as the moisture content increased. HMT could increase the resistant starch content from 24.77% to 33.40%, but it also led to an increase in the rapidly digestible starch content to 85.30% with the increase in moisture content and heating temperature. These results might promote the application of HMT technology in modifying HB flour.