Low-temperature plasma modification, structural characterization and anti-diabetic activity of an apricot pectic polysaccharide.

To fully research the anti-diabetic activity of apricot polysaccharide, low temperature plasma (LTP) was used to modify apricot polysaccharide. The modified polysaccharide was isolated and purified using column chromatography. It was found that LTP modification can significantly improve the α-glucosidase glucosidase inhibition rate of apricot polysaccharides. The isolated fraction FAPP-2D with HG domain showed excellent anti-diabetic activity in insulin resistance model in L6 cell. We found that FAPP-2D increased the ADP/ATP ratio and inhibited PKA phosphorylation, activating the LKB1-AMPK pathway. Moreover, FAPP-2D activated AMPK-PGC1α pathway, which could stimulated mitochondrial production and regulate energy metabolism, promoting GLUT4 protein transport to achieve an anti-diabetic effect. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy data showed that the LTP modification could increase the CH bond content while decreasing the C-O-C/C-O bond content, indicating that LTP destroyed the C-O-C/C-O bond, which enhanced the anti-diabetes activity of the modified apricot pectin polysaccharide. Our findings could pave the way for the molecular exploitation of apricot polysaccharides and the application of low-temperature plasma.

Rheological properties, gel properties and 3D printing performance of soy protein isolate gel inks added with different types of apricot polysaccharides.

A soybean protein isolate (SPI)-apricot polysaccharide gel with hypolipidemic activity that can be used for 3D printing was prepared and the mechanism of its gel formation was studied in this work. The results demonstrated that adding apricot polysaccharide to SPI could effectively improve the bound water content, viscoelastic properties and rheological properties of the gels. Low-field NMR, FT-IR spectroscopy and surface hydrophobicity confirmed that the interactions between SPI and apricot polysaccharide were mainly realized by electrostatic interactions, hydrophobic and hydrogen bonding. Furthermore, adding modified polysaccharide treated by ultrasonic-assisted Fenton method to SPI on the basis of low-concentration apricot polysaccharide contributed to improving the 3D printing accuracy and stability of the gel. Consequently, the gel formed by adding apricot polysaccharide (0.5 %, m/v) and modified polysaccharide (0.1 %, m/v) to SPI had the best hypolipidemic activity (the binding rate of sodium taurocholate and sodium glycocholate were 75.33 % and 72.86 %, respectively) and 3D printing characteristics.

Preparation of anthocyanin-rich mulberry juice by microwave-ultrasonic combined pretreatment.

The work aims to study the process of microwave-ultrasonic combined treatment to obtain anthocyanin-rich mulberry juice. A Box-Behnken design was employed to analyze the effects of microwave time and citric acid content on the total phenol content, total anthocyanin content, hue, color intensity, DPPH and ABTS radical scavenging activities. Under the optimum conditions (microwave time of 46 s, citric acid addition of 273 mg/kg), the total phenol content, total anthocyanin content, the DPPH and ABTS radical scavenging activities reached 4.24 mg GAE/mL, 3.29 mg C3G/mL, 4.59 mg TE/mL and 11.90 mg TE/mL, respectively. Subsequently, the mulberry juice was processed with ultrasound of different frequencies. It was found that low-frequency ultrasonic treatment (25 kHz) could significantly reduce the loss of total phenolic and anthocyanin monomers and improve the antioxidant capacity of mulberry juice during storage for five weeks. Overall, mulberry juice with microwave-ultrasonic pretreatment is a natural antioxidant.