Physicochemical properties of pectin-Fe(III) gained by HG-type hawthorn with different esterification degree.

In this study, the complexation ability of HG-type hawthorn pectin with trivalent iron ions after de-esterification was investigated. The moderate esterification reaction could significantly increase the iron content in HG-type hawthorn pectin. Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) experiments proved that -OH and -COOH in the pectin acted as a bridge connecting Fe leading to the formation of β-FeOOH structure, and the trivalent iron ions were successfully complexed into the HG-type hawthorn pectin.

Extraction methods and compositions of polyphenols in Shanxi aged vinegar.

The extraction, purification, qualification, and quantification of polyphenols (PPs) in vinegar are challenging owing to the complex matrix of vinegar and the specific physicochemical and structural properties of PPs. This study aimed to develop a simple, efficient, low-cost method for enriching and purifying vinegar PPs. The enrichment and purification effects of five solid phase extraction (SPE) columns and five macroporous adsorption resins (MARs) for PPs were compared.

The effect of ultrasound on the properties and conformation of glucoamylase.

In this study, the effects of ultrasonic treatment on the enzyme activity of glucoamylase were investigated and the mechanism of the effect was explored by determining their conformational changes. The enzyme activity was increased by 21.07% over the control with ultrasound at 420W for 10min at 60°C, and V and K values of glucoamylase were also increased.