Effects of preheat treatment and polyphenol grafting on the structural, emulsifying and rheological properties of protein isolate from Cinnamomum camphora seed kernel.

In this study, protein isolate (PI) and purified polyphenol extract (PPE) were prepared from Cinnamomum camphora seed kernel (CCSK). The effects of preheat treatment (50-90 °C) combined with polyphenol grafting (5 % PPE, w/w) on the structural, emulsifying and rheological properties of PI were investigated. Results demonstrated the preheat treatments at 80 and 90 °C significantly increased the extent of protein aggregation of PI. Fluorescence spectra and thermal behavior analysis revealed that preheat-treated PI exhibited more compact structure and higher thermal stability. Moreover, the emulsifying stability and apparent viscosity of PI were enhanced after preheat treatments at 50, 60 and 70 °C. After modification by PPE, the secondary structural changes of preheat-treated PI were confirmed by FTIR. PPE modification improved the thermal stability and antioxidant activities of preheat-treated PI. These results provide a novel way to combine the advantages of preheat treatment and polyphenol grafting in developing a novel protein ingredient.

Covalent modification by phenolic extract improves the structural properties and antioxidant activities of the protein isolate from Cinnamomum camphora seed kernel.

In this study, protein isolate (PI) and purified phenolic extract (PPE) were prepared from Cinnamomum camphora seed kernel (CCSK). The effects of covalent modification of PI by PPE at different concentrations (1, 2, 3, 4 and 5%, w/w) were investigated with respect to structural properties and antioxidant activities of protein. Fifteen bioactive compounds in PPE were tentatively identified by UPLC-ESI-MSn. With the increase of PPE concentration, the turbidity, covalent binding rate, phenolic content and color intensity of the PI-PPE complexes were gradually increased. Fourier transform infrared spectroscopy and circular dichroism spectroscopy analysis showed that the secondary and tertiary structures of the complexes were changed and became greater order than PI. Furthermore, the complexes exhibited stronger thermal stability and antioxidant activities than those of PI. These results suggested that the protein-phenolic covalent complexes obtained from CCSK may have great potential to be used in food formulations as functional ingredients.

Quality control and original discrimination of Ganoderma lucidum based on high-performance liquid chromatographic fingerprints and combined chemometrics methods.

In this paper, the feasibility and advantages of employing high-performance liquid chromatographic (HPLC) fingerprints combined with chemometrics methods for quality control of the cultured fruiting bodies of Ganoderma lucidum were investigated and demonstrated for the first time. In order to compare the HPLC fingerprints chromatograms between G. lucidum from different origins, the similarities of all the 60 samples and relative peak areas of 19 characteristic compounds were firstly calculated respectively. Then different pattern recognition procedures, including hierarchical cluster analysis (HCA), principal component analysis (PCA), partial least squares-discrimination analysis (PLS-DA) and soft independent modeling of class analogy (SIMCA) were applied to classify the G. lucidum samples according to their cultivated origins. Consistent results were obtained to show that G. lucidum samples could be successfully grouped in accordance with the province of origin. Furthermore, four marker constituents were screened out to be the most discriminant variables, which could be applied to accurate discrimination and quality control of G. lucidum by quantitative analysis. Finally, the chemical properties of those samples were also investigated to find out the differences of quality between them. Ranked in decreasing order, the quality of the G. lucidum can be arranged as Jinzhai/Huangshan, Shandong followed by Zhejiang samples. Our results revealed that the developed method has potential perspective for the original discrimination and quality control of G. lucidum.

Development of a chromatographic fingerprint for the chloroform extracts of Ganoderma lucidum by HPLC and LC-MS.

A new high-performance liquid chromatographic (HPLC) fingerprinting method was developed for the quality control of Ganoderma lucidum. Twenty-nine batches obtained from three different origins in China were used to establish the fingerprint. The constituents of these samples were separated with a Kromasil C(18) column (250 mm x 4.6 mm, 5 microm) by linear gradient elution using water-acetic acid (100:0.1, v/v) and acetonitrile as mobile phase components at a flow rate of 0.8 ml/min and detector wavelength at 254 nm. Mean chromatograms and correlation coefficients of samples were calculated by the software "Similarity Evaluation System for Chromatographic Fingerprint of TCM". There were 19 common peaks in this fingerprint. Eleven of these common peaks were tentatively identified with reference to literature data based on their liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS) and UV data. This profile was then successfully used to identify and assess the differences among samples from various origins with the aid of similarity analysis. The diverse similarities among different samples indicated that the quality of G. lucidum was not stable and the products from different areas were inconsistent. All results showed that the developed fingerprint assay was specific and could further serve for quality identification and comprehensive evaluation of G. lucidum.