Search

Citrus pectin (CP) and two pectins with distinct molecular weights (CP-1 and CP-2) were prepared using ultrasound-assisted H 2 O 2 /ascorbic acid reaction, and their structural, anticancer, and immunostimulatory properties were investigated. Based on the methylation and nuclear magnetic resonance analyses, the structure of CP-2 was determined to be composed of an α-1,4-linked homogalacturonan backbone that exhibited high levels of O-6 methylation. In addition, both CP-1 and CP-2 induced apoptosis in various cancer cell lines, while CP exhibited minimal impact. All tested CPs activated RAW264.7 cells, promoting the production of nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 by upregulating the expression of TNF-α, IL-6, and inducible NO synthase genes. Among them, CP-2 exhibited the highest immunostimulatory activity closely linked with its molecular weight. Furthermore, we found that CP-2 could activate RAW264.7 macrophages through NOD-like receptor (NLR) signaling pathways involving nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. In summary, the results of this investigation will enhance the comprehension of the structure-function correlation of CP, furthering its application within the functional food industry. • Citrus pectin (CP) and two molecular-weight pectins (CP-1 and CP-2) were prepared. • The structural and biological properties of the CPs were systematically examined. • The immunoregulatory mechanism of CP-2 was elucidated via proteomics analysis. • The findings contribute to revealing the structure-activity relationship of CPs. [ABSTRACT FROM AUTHOR]

Polyphenol-gelatin binary complex and polyphenol-gelatin-pectin ternary complex were synthesized. The differences in antioxidant activity between the binary complex and ternary complex were evaluated by using ABTS, DPPH, and reducing power assays. The differences in structural characterization between the binary complex and ternary complex were investigated by scanning electron microscopy (SEM), nuclear magnetic resonance (1H and 13C NMR), and Fourier transform infrared (FT-IR) spectroscopy. The reducing power assays of the ternary complex was greater than that of the binary complex. The maximum of ABTS•+ scavenging activity of the binary complex and the ternary complex was 98.1% and 99.3%, respectively, and the maximum DPPH• scavenging activity was 84.7% and 87.6%, respectively. The results of structural characterization showed that they were very similar in structure. Both complexes are mainly composed of hydrogen bonds and hydrophobic interactions, but the ternary complex is more tightly bound. In addition, the surface is smoother, and the gap is smaller. ► Ternary and binary complexes have excellent antioxidant properties. ► The addition of pectin increased the amount of hydroxyl groups, which improved antioxidant capacity. ► Due to the polyhydroxy structure, apple polyphenols can bind to gelatin and pectin tightly. ► Polyphenols can be used as natural and harmless cross-linking agents for macromolecules. [ABSTRACT FROM AUTHOR]

Radio frequency (RF) is an efficient uniformity heating method that can be used for pasteurization. Information on how RF heating influences the physicochemical properties of agricultural product is limited. In this study, the effect of RF heating treatment combined with hot-air (HA) drying (50 °C, 55 °C and 60 °C) on the physicochemical properties of Sichuan pepper was assessed. Sichuan pepper was subjected to RF treatment combined with HA drying, and the performance was compared with HA drying alone (50 °C, 55 °C and 60 °C) in terms of drying kinetics, volatile components, non-volatile components (OH-α-sanshool, polyphenols and flavonoids) and antioxidant activity (ABTS and ferric reducing antioxidant power). RF heating had no negative effects on OH-α-sanshool for the 50 RF-HA group but it could significantly reduce the loss of polyphenols (12.27% at 55 °C, RF-HA group) and flavonoids (15.08% at 60 °C, RF-HA group). Compared with fresh Sichuan pepper, the 50 RF-HA group retained a similar aroma profile. RF heating treatment followed by HA drying is a prospective technique for obtaining high-quality dried Sichuan pepper. • Radio frequency (RF) treatment did not change the drying kinetics or shorten total drying time. • The levels of d -limonene and linalool were not affected by RF treatment. • The OH-α-sanshool content reduced due to disruption of oil droplets and drying temperature. • RF treatment reduced the loss of polyphenols content and flavonoids content in the hot-air drying process. [ABSTRACT FROM AUTHOR]

The formation and characterization of conjugates of soybean protein isolate (SPI) and dextran with varying molecular weights (4, 10, and 70 kDa) and their effects on quality of glucono-δ-lactone (GDL)-induced tofu were investigated. The extent of glycosylation was negatively related to the molecular weight of dextran. Thus, the SPI-dextran4 conjugate exhibited a darker color and a biggest decrease in whiteness from 70.49 to 45.51. SPI-dextran70 conjugate exhibited an increased surface hydrophobicity and free sulfhydryl content. Volume-average diameter of SPI-dextran70 conjugate-added soymilk and gel strength of the corresponding tofu ranged from 10.34 to 11.24 μm and 0.068 to 0.083 N, respectively, which were lesser than those of the control (11.12 μm and 0.133 N). However, SPI-dextran10 conjugate incubated for 6 days and SPI-dextran4 conjugate incubated for 2 days increased the gel strength of tofu to 0.146 and 0.143 N, respectively. Conjugates-added tofu exhibited an increased water holding capacity and a discontinuous and loose microstructure, but a lowered whiteness and a color change to yellow. Results demonstrated that the selection of dextran with an appropriate molecular weight and controlling the glycosylation degree were capable of improving the quality of SPI-dextran conjugate-added GDL-induced tofu. • Soybean protein isolate (SPI)-dextran (4, 10, 70 kDa) conjugates were prepared. • Molecular weight of dextran affected the physicochemical properties of conjugates. • SPI-dextran70 conjugates reduced particle size of soymilk and gel strength of tofu. • Impact of SPI-dextran4/10 conjugates on gel strength of tofu depended on reaction time. • The addition of conjugates enhanced the water holding capacity of tofu. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the effects of different cooking methods (steaming, boiling, frying and microwaving) on nutrients and their bioaccessibility by an in vitro simulated digestion model. The result demonstrated that the degree of protein hydrolysis (42.84%) after digestion under microwaving was the highest. The fatty acid composition can influence the lipid digestion fate, and the stearic acid content of all samples was significantly increased, except for the methods of frying (only from 4.72 to 8.37 g/100 g). The highest bioaccessibility was discovered in Cu (83.35%, frying), and the lowest was in Fe (3.96%, frying), but Pb was not digested. Frying method caused severe losses of protein bioaccessibility but it has the highest amount of reducing sugar release and antioxidant activity. The scientific and in-depth nature of the above study provides a reference for the daily consumption of C. cornucopioides. Image 1 • The swallow and digestible particle size of C.cornucopioides is 4 mm. • The cooking methods had a great effect on nutrients value and bioaccessibility. • Cooking and digestion impact on the antioxidant capacity of C.cornucopioides. [ABSTRACT FROM AUTHOR]

This paper investigated the 3D printing feasibility of rice (waxy rice, japonica rice, indica rice) paste and the effect of sodium alginate (SA) added at concentrations (0, 0.25%, 0.50%, 0.75%, 1.00%, w/w, dry rice flour basis) on the physicochemical and structural characteristics of rice paste. Results showed that rice paste incorporated with SA exhibited shear-thinning behavior so that it can be used as ideal material for 3D printing. The viscosity, degree of bound water and mechanical strength of rice paste increased with increasing addition of SA. When SA concentration was 0.50%, the 3D printed japonica rice product (3DJP3) provided the best printability and highest precision, followed by waxy rice product (3DWP3) and indica rice product (3DIP3). Scanning electron microscopy (SEM) revealed that more convolutions were induced in the 3D printed rice products upon the addition of SA, which increased the products stability. It was a further proof that 3DJP3 and 3DIP3 still maintained good structure and precision after steaming. However, 3DWP3 has swollen after steaming due to the highest amylopectin content of waxy rice and showed the worst shape fidelity. Overall, SA could be functioned as proper additives for 3D rice products, and the food matrix of proper types of rice and SA could be promising materials for 3D printing. Image 1 • Sodium alginate (SA) functioned as structural modifier in 3D printing of rice foods. • Waxy, japonica and indica rice paste all achieved best printability at 0.50% SA. • 3D waxy rice products after steaming have swollen due to high amylopectin content. [ABSTRACT FROM AUTHOR]

The effects of mixed fermentation by lactic acid bacteria and Neurospora crassa, and microwave treatment on the composition, structure, and functional properties of okara dietary fiber (DF) were studied. The results of SEM and EDX showed that the honeycomb structure was more obvious and the content of elemental components was changed after fermentation and microwave treatment. The result of TGA-DSC showed that the thermal stability of the sample improved following microwave treatment. The FT-IR results showed that fermentation and microwave treatment effect the functional groups of cellulose and hemicellulose in a manner consistent with the composition of the samples, and the crystal structures of the samples were slightly damaged after modification. There was no obvious change in the adsorption effect of cholesterol and sodium cholate following mixed fermentation and microwave treatment. However, the inhibition ratio of fermented DF on α-amylase activity increased from 9.55% to 15.04%, while that of microwave-treated DF changed from 9.55% to 20.92%. The glucose dialysis retardation of fermented DF doubled at 30 min. Overall, both methods improve the availability of DF in okara. Modified DF from okara can be used as a functional ingredient in diverse food products. • The SDF was prepared by the mixed fermentation and microwave treatment. • The composition and structural characteristics of UFDF, FDF and MDF were compared. • The functional properties of UFDF, FDF and MDF were compared. • The modification mechanisms of mixed fermentation and microwave treatment were discussed preliminarily. [ABSTRACT FROM AUTHOR]

This study evaluated the feasibility of high-speed shearing (HSS) on the modification of okara fibers. Scanning electron microscope analysis suggested that HSS disintegrated and degraded the component cell layers at the cellular level. X-ray diffraction analysis showed that the reflection intensity of crystalline plane (I 002) and the amorphous contribution (I AM) declined after HSS, confirming that the degradation of okara fibers was accompanied with the disintegration of crystalline as well as amorphous area. Moreover, the reflection intensity of cellulose's triclinic structure went up after HSS, which might be attributed to the breakdown of β-1, 4-glycoside bond. The swelling capacity and water holding capacity extensively declined (p < 0.05) from 5.5 mL/g and 8.5 g/g to 2.2 mL/g and 4.9 g/g after shearing, which was caused by the degradation of porous structure and the decrease of pore volume. HSS empowered okara fiber better solubility as well, and it might be achieved by breaking the cellulose-cellulose hydrogen bonds and redistributing the fiber composition from the insoluble to the soluble fraction. Consequently, HSS provided a cost-efficient way to disintegrate substrates and modify hydration properties of okara fiber, which possessed considerable application prospects in soy industry. • High-speed shearing disintegrated component cell layers at the cellular level. • Better solubility of okara fibers was achieved by high-speed shearing. • High-speed shearing disintegrated the crystalline and amorphous domain of okara fibers. • High-speed shearing reduced the dimension of crystalline domain of okara fibers. [ABSTRACT FROM AUTHOR]