Improving resistant starch content of cassava starch by pulsed electric field-assisted esterification.

This study aims to investigate the effect of pulsed electric field (PEF) assisted OSA esterification treatment on the multi-scale structure and digestive properties of cassava starch and structure-digestion relationships. The degree of substitution (DS) of starch dually modified at 1.5-4.5 kV/cm was 37.6-55.3 % higher than that of starch modified by the conventional method. Compared with native starch, the resistant starch (RS) content of esterified starch treated with 3 kV/cm significantly increased by 17.13 %, whereas that of starch produced by the conventional method increased by only 5.91 %. Furthermore, assisted esterification at low electric fields (1.5-3 kV/cm) promotes ester carbonyl grafting on the surface of starch granules, increases steric hindrance and promotes the rearrangement of the amorphous regions of starch, which increases the density of the double-helical structure. These structural changes slow down starch digestion and increase the RS content. Therefore, this study presents a potential method for increasing the RS content of starch products using PEF to achieve the desired digestibility.

Mechanism of Yiqi Huoxue Huatan recipe in the treatment of coronary atherosclerotic disease through network pharmacology and experiments.

In recent years, with population aging and economic development, morbidity and mortality of atherosclerotic cardiovascular disease associated with atherosclerosis (AS) have gradually increased. In this study, a combination of network pharmacology and experimental verification was used to systematically explore the action mechanism of Yiqi Huoxue Huatan Recipe (YHHR) in the treatment of coronary atherosclerotic heart disease (CAD). We searched and screened the active ingredients of Coptis chinensis, Astragalus membranaceus, Salvia miltiorrhiza, and Hirudo. We also searched multiple databases for related target genes corresponding to the compounds and CAD. STRING was used to construct the protein-protein interaction (PPI) network of genes. Metascape was used to perform gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis for common targets to analyze the main pathways, and finally, the molecular docking and main possible pathways were verified by experimental studies. Firstly, a total of 1480 predicted target points were obtained through the Swiss Target Prediction database. After screening, merging, and deleting duplicate values, a total of 768 targets were obtained. Secondly, "Coronary atherosclerotic heart disease" was searched in databases such as the OMIM, GeneCards, and TTD. 1844 disease-related targets were obtained. Among PPI network diagram of YHHR-CAD, SRC had the highest degree value, followed by AKT1, TP53, hsp90aa1 and mapk3. The KEGG pathway bubble diagram was drawn using Chiplot, the Signal pathways such as NF kappa B signaling pathway, Lipid and AS, and Apelin signaling pathway are closely related to the occurrence of CAD. The PCR and Western blot methods were used to detect the expression of NF-κB p65. When compared with that in the model group, the expression of NF-κB p65mRNA decreased in the low-concentration YHHR group, with P < .05, while the expression of NF-κB p65mRNA decreased significantly in the high-concentration YHHR group, with P < .01. On the other hand, when compared with that in the model group, the expression of NF-κB p65 decreased in the low-concentration YHHR group, but was not statistically significant, while the expression of NF-κB p65 was significant in the high-concentration YHHR group, and has statistical significance with P < .05. YHHR has been shown to resist inflammation and AS through the SRC/NF-κB signaling pathway.

Enhanced encapsulation of lutein using soy protein isolate nanoparticles prepared by pulsed electric field and pH shifting treatment.

In this study, soy protein isolate (SPI) was modified by a pulsed electric field (PEF) combined with pH shifting treatment (10 kV/cm, pH 11) to prepare SPI nanoparticles (PSPI11) for efficient loading of lutein. The results showed that when the mass ratio of SPI to lutein was 25:1, the encapsulation efficiency of lutein in PSPI11 increased from 54% to 77%, and the loading capacity increased by 41% compared to the original SPI. The formed SPI-lutein composite nanoparticles (PSPI11-LUTNPs) had smaller, more homogeneous sizes and larger negative charges than SPI7-LUTNPs. The combined treatment favored the unfolding of the SPI structure and could expose its interior hydrophobic groups to bind with lutein. Nanocomplexation with SPIs significantly improved the solubility and stability of lutein, with PSPI11 showing the greatest improvement. As a result, PEF combined with pH shifting pretreatment is an effective method for developing SPI nanoparticles loaded and protected with lutein.

Pulsed electric field-assisted esterification improves the freeze-thaw stability of corn starch gel by changing its molecular structure.

The influence of pulsed electric field (PEF) combined with octenyl succinic anhydride (OSA) on the freeze-thaw stability of corn starch gel was investigated. After five freeze-thaw cycles, the syneresis value of OSA starch treated with PEF-assisted esterification for 15 min was lower by 29.5 %, while that of OSA starch without PEF treatment was lower by 10.17 %, compared to that of native starch. Low-field nuclear magnetic resonance data showed that the introduction of OSA groups greatly increased the water-holding capacity of starch. Results from differential scanning calorimetry (DSC) and X-ray diffraction (XRD) showed that the PEF-assisted esterification markedly hindered the re-formation of the helical structure of starch during freeze-thaw cycles. Moreover, PEF-assisted esterification improved the viscoelastic properties of the starch gel. It is found that the freeze-thaw stability of the PEF-modified starch depends not only on the degree of substitution but also on the starch molecular fine structure. PEF-assisted OSA starch with a high degree of substitution, a low content of amylose, and a high content of short amylopectin chains were found to have high freeze-thaw stability. This study shows that PEF-assisted esterification is a promising technique that should be used for preserving the quality of frozen foods.

Succinylated whey protein isolate-chitosan core-shell composite particles as a novel carrier: Self-assembly mechanism and stability studies.

Single protein [whey protein isolate (WPI) or succinylated whey protein isolate (SWPI)] and composite particles of proteins with chitosan (CS) were tested for their ability to encapsulate and protect curcumin (CUR). Combining protein and CS resulted in changes in zeta-potential and surface hydrophobicity, particularly in the SWPI-H (high degree of succinylation, 90 %) and CS composite particle (H-CS). Furthermore, the secondary and tertiary structures were dramatically altered using Fourier transform infrared (FTIR), circular dichroism (CD), and X-ray diffraction (XRD). Scanning electron microscopy (SEM) and atomic force microscope (AFM) analyses revealed that H-CS exhibited a soft core-rigid shell morphology due to electrostatic interactions, hydrophobic interactions, and H-bond interactions. Fluorescence quenching results demonstrated that H-CS had a higher binding constant (K, 1.69 ×104 M-1) and encapsulation effectiveness (EE, 88.3 %) of CUR. Because of increased binding sites and steric hindrance, CUR was stabilized more effectively in H-CS in photostability and thermostability tests,. These results show that SWPI-CS composite particles can be utilized to build a protection system for water-insoluble nutritional supplements.

Binding affinity of curcumin to bovine serum albumin enhanced by pulsed electric field pretreatment.

The present study investigated the effect of pulsed electric field (PEF) pretreatment on the interaction between bovine serum albumin (BSA) and curcumin. Fluorescence quenching results showed that proper PEF pretreatment significantly increased the binding affinity of curcumin and BSA, the binding constant increased by 6.77 times under the conditions of 15 kV/cm for 0.51 ms. However, at higher PEF strength (≥25 kV/cm) and longer processing time (≥0.68 ms), the binding affinity was weakened. PEF pretreatment made the protein structure more disordered and induced partial unfolding of BSA, exposing more hydrophobic regions, thereby increasing the binding affinity to curcumin. PEF-treated BSA (PBSA) possessed better encapsulation efficiency (95.19%) and loading capacity (5.25 mg/g) for curcumin, and the storage stability of curcumin were enhanced by the formation of a complex with PBSA. This study provides new insights into the design of BSA-based delivery systems for curcumin and other hydrophobic nutrients.

Enhanced synthesis of succinylated whey protein isolate by pulsed electric field pretreatment.

The objective of this study was to investigate the feasibility of pulse electric field (PEF) as a pretreatment for whey protein isolate (WPI) before its succinylation. The degree of succinylation (DS) of WPI increased from 88.31% for native WPI to 93.45% for PEF-pretreated WPI (PWPI, initial pH 10.0) for the same succinic anhydride (SA) to WPI ratio (1:1). Fourier transform infrared spectroscopy and scanning electron microscopy analysis proved the successful succinylation of WPI. For PWPIs, the surface hydrophobicity, exposed sulphydryl, and total sulphydryl decreased, which indicates the occurrence of changes in protein structures with more hydrophilic groups and better protein dispersion. Moreover, PEF may expose more amino acid residues binding sites that are present inside the protein, which is more suitable for succinylation. Therefore, the PEF pretreatment of proteins can improve their efficient use that is expected to play a critical role in succinylation industry.

Protective effect of baicalein on DNA oxidative damage and its binding mechanism with DNA: An in vitro and molecular docking study.

In this work, the protective effect of baicalein on DNA oxidative damage and its possible protection mechanisms were investigated. 2-thiobarbituric acid (TBA) colorimetry and agarose gel electrophoresis study found that baicalein protected the deoxyribose residue and double-stranded backbone of DNA from the damage of hydroxyl radicals. Antioxidant analysis results showed that baicalein has excellent radicals scavenging effects and Fe2+ chelating ability, which might be the mechanism of baicalein protecting DNA. DNA binding studies indicated that baicalein bound to the minor groove of DNA with moderate binding affinity (K = (7.35 ±â€¯0.91) × 103 M-1). Hydrogen bonding and van der Waals forces played a major role in driving the binding process. Molecular docking further confirmed the experimental results. This binding could stabilize DNA double helix structure, thereby protecting DNA from oxidative damage. This study may provide theoretical basis for designing new functional foods of baicalein for DNA damage protection.

Pulsed electric field assisted modification of octenyl succinylated potato starch and its influence on pasting properties.

The physicochemical properties and structural changes of potato starch esterified with octenyl succinic anhydride (OSA) assisted with pulsed electric field (PEF) were investigated. Results showed that PEF treatment during esterification resulted in a significant modification of pasting properties. The pasting temperature at 2-6 kV/cm reduced by 7.6-15.1 °C for PEF-assisted OSA starches but only by 3 °C for OSA modified starch without PEF treatment as compared to that of native starch. PEF-assisted esterification could reduce the reaction time and improve the reaction efficiency over the control by 6.1-39.1 %. A novel schematic model on structure-functionality relationship for PEF-assisted OSA modified starch was proposed. Structural disorganizations of starch induced lower pasting temperature and paste viscosity. The results suggest that PEF could be a potential eco-friendly and cost-effective physical technique to prepare starch products with desired paste behaviors and to broaden its application area especially in papermaking and textile industries.

Review of the application of pulsed electric fields (PEF) technology for food processing in China.

With the improvement of living standards, growing consumer demand for high-quality and natural foods has led to the development of new mild processes to enhance or replace conventional thermal and chemical methods for food processing. Pulsed electric fields (PEF) is an emerging and promising non-thermal food processing technology, which is ongoing from laboratory and pilot plant level to the industrial level. Chinese researchers have made tremendous advances in the potential applications of PEF for processing a wide range of food commodities over the last few years, which contributes to the current understanding and development of PEF technology. The objective of this paper is to conduct a systematic review on the achievements of PEF technology used for food processing in China and the corresponding processing principles. Research on the applicability of PEF in food processing suggests that PEF can be used alone or in combination with other methods, not only to inactivate microorganisms and extract active constituents, but also to modify biomacromolecules, enhance chemical reactions and accelerate the aging of fermented foods, which are mainly related to permeabilization of biomembranes, occurrence of electrochemical and electrolytic reactions, polarization and realignment of molecules, and reduction of activation energy of chemical reactions induced by PEF treatments. In addition, some of the most important challenges for the successful implementation of large-scale industrial applications of PEF technology in the food industry are discussed. The results bring out the benefits of both researchers and the industry.