Search

Abstract: A novel water-soluble heteropolysaccharide termed PBF2 was isolated from the fruiting bodies of Phellinus baumii Pilát using hot water extraction and purified on Sephacryl S-1000. PBF2 was shown to be composed of l-fucose, d-mannose and d-glucose. Its structural characteristics were further investigated by FT-IR spectroscopy, sugar analysis, methylation analysis and NMR spectroscopy. Based on the data obtained, PBF2 was found to be a heteropolysaccharide containing a β-(1→6)-d-glucopyranose backbone with a fucosyl unit on O-3 of the 3,6-di-O-substituted-d-glucosyl units and it also contained a minor (1→3, 6)-β-d-mannose residue and terminal glucose residues. [Copyright &y& Elsevier]

Abstract: Chitosan was prepared by alkaline N-deacetylation of β-chitin and hydroxypropyl derivatives with different degrees of substitution (DS) were synthesized. It was characterized by Fourier transform infrared (FT-IR) and elemental analysis. The DS of hydroxypropyl chitosan (HPCS) calculated by an element analyzer were 0.42, 0.75, 1.20, 1.82 and 2.25. HPCS showed better foam capacity and stability than that of chitosan, and the effectiveness correlated well with the DS of HPCS. The highest bile acid-binding capacity of all five HPCS reached 56.02mg/g, which was 4.0-fold higher than that of chitosan. The scavenging ability of HPCS against hydroxyl and ABTS radicals improved with increasing concentration. The correlation between the hydroxypropyl content (DS) of HPCS and scavenging ABTS radical ability was positive. The hydroxyl radicals scavenging activity of HPCS correlated well with its increasing concentration, and EC50 values were below 12.5mg/mL. These results indicated that hydroxypropylation is a possible approach to obtain chitosan derivatives with desirable physiochemical properties. [Copyright &y& Elsevier]

• Cold-pressed sesame cake protein removing lignans was obtained by ultrasonic pre-treatment (UPT). • UPT significantly increased protein yield. • UPT slightly reduced the solubility, foaming capacity and stability of protein. • UPT could disorder and loose protein molecular structure to some extent. • This work provides a guide for comprehensive utilization of lignans and proteins from sesame cake in separate. Sesame is an oil crop with high nutritional value. Protein is one of the main ingredients of sesame, however research on protein of cold-pressed sesame cake is limited. This study aimed to investigate the effects of ultrasonic pre-treatment (UPT) on physicochemical properties of proteins (yield, solubility, amino acid composition, surface properties, structural and thermal stability) extracted from the cold-pressed sesame cake, after removing lignans by ultrasonic-assisted extraction. By comparison, the extraction yield of protein was significantly (p ＜ 0.05) increased from 22.24% (without UPT) to 25.95% (with UPT), while the purity (54.08% without UPT, 55.43% with UPT), total amount of essential amino acids (22.48% without UPT, 23.10% with UPT) and non-essential amino acids (37.48% without UPT, 36.54% with UPT) were not significantly influenced. Besides, UPT slightly reduced the solubility, foaming capacity and stability (FC and FS) of protein. In addition, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermal stability (TG) analysis demonstrated that UPT could disorder and loose protein molecular structure, resulting in the change of morphology, secondary structure and thermal stability. In conclusion, this study provides a way for the separation and future application of sesame cake protein. UPT is a good option to remove the lignans from sesame cake proteins. [ABSTRACT FROM AUTHOR]