Microwave pretreatment effects on the aroma precursors, sensory characteristics and flavor profiles of fragrant rapeseed oil.

Microwave technology offers a rapid and uniform heating method. This study investigated how microwave pretreatment affects the aroma precursors and flavor of fragrant rapeseed oils (FROs). Microwave pretreatment led to decreased levels of polyunsaturated fatty acids, sugars, protein-bound amino acids, and glucosinolates. Using gas chromatography-mass spectrometry, we identified 66 volatile compounds in the oil samples. Among these, based on odor activity values (OAV ≥ 1), we found 9 aldehydes, 1 ketone, 6 pyrazines, 1 isothiocyanate, and 7 nitriles as the key aroma-active compounds, contributing fatty-like, nutty-like, and pungent-like odors, respectively. The electronic nose results highlighted W5S and W1W as primary sensors for determining the flavor profiles of FROs. Notably, aroma-active pyrazines exhibited strong negative correlations with sucrose, cysteine, lysine, and isoleucine. This research provides essential insights for enhancing the aroma of FROs.

[Identification on Solanum lyratum by X-ray diffraction Fourier fingerprint and similarity analysis].

OBJECTIVE: To provide an X-ray diffraction (XRD) method for identifying different medicinal parts of Solanum lyratum. METHODS: Analyzed X-ray diffraction Fourier patterns of different parts of Solanum lyratum, and the similarity degree of different fingerprint was calculated and analyzed according to the position (2 theta value)of peaks searched. RESULTS: Different X-ray diffraction Fourier patterns of different medicinal parts of Solanum lyratum were obtained. CONCLUSION: This method can be used for identifying different medicinal parts of Solanum lyratum. The results of similarity calculation further proves the feasibility of this method.

[Identification on Spora Lygodii by X-ray diffraction fingerprint spectra method].

OBJECTIVE: To set up a new identification and analysis method of Spora Lygodii. METHOD: To get the extracts of Spora Lygodii using methanol, chloroform and petroleum ether as solvent and the extracts were identified, analyzed by X-ray diffraction Fourier fingerprint spectra. RESULTS: Experiments and analysis were carried out on three samples. The standard X-ray diffraction Fourier fingerprint spectra and characteristic diffraction peaks were obtained. There were some differences among the spectra of the extracts, but the characteristic diffraction peaks were obvious. CONCLUSION: The experimental result indicated that X-ray diffraction Fourier fingerprint spectra can be used to identify and analyze the Chinese traditional herb Lygodium japonicum (Thunb.) Sw.