Defective coffee beans (DCB) are one of the main reasons for poor coffee quality. In the current research, chemical difference of three common DCB including sour beans (SCB), black beans (BCB), and mold beans (MCB) were clarified using 1 H qNMR method and compared with that of non-defective beans (NDCB). The results indicated that DCB has lower sugar and lipid content compared to NDCB, yet it boasts a higher acetate concentration. The 1 H NMR from water-soluble content was shown to be more effective than that of oil fraction for qualitative of DCB blends, regardless of whether partial least squares discriminant analysis (PLS-DA) or machine learning (ML) algorithms were used. Support vector machine (SVM) was proved to be excellent for distinguishing DCB blends. Finally, a partial least squares regression (PLS) model was built for quantitative analysis of DCB blends. In summary, current research will not only help to reveal the material basis of DCB and their impact on coffee flavor, but also provide feasible strategies for the identification of DCB.
Compound Danshen Dripping Pills (CDDPs) are a Chinese herbal medicinal preparation composed of Salviae miltiorrhizae Radix and two other Chinese medicines, Notoginseng Radix and Borneolum. The main components of CDDPs are protocatechuic aldehyde, danshensu, salvianolic acid A, rosmarinic acid, ginsenoside Rg1, ginsenoside Rb1, L-(−)-borneol and isoborneol. The complex composition of CDDPs, which contains phenolic acids, ginseng saponins and borneols, makes quantitative analysis by traditional methods difficult. Therefore, a fast and accurate 1H qNMR method was established that can simultaneously determine the eight main components of CDDPs. The qNMR method was well validated and successfully applied in the determination of ten sample batches. The vector cosine angle method was used for further analysis of the results to evaluate the sample quality. The results indicate that the qNMR method is suitable for the quality control of CDDPs and has potential as an easy alternative for the analysis of other complex Traditional Chinese Medicines (TCMs) that require two or more traditional instruments for comprehensive quantitative analysis.
Salvianolate Lyophilized Injection (SLI), a traditional Chinese medicinal (TCM) preparation which is used to treat stroke, is composed of multiple salvianolic acids from the aqueous extracts of Salvia miltiorrhiza , and includes mainly protocatechualdehyde, rosmarinic acid, salvianolic acid B, salvianolic acid D, salvianolic acid E, diastereomer of salvianolic acid E, salvianolic acid Y, lithospermic acid and diastereomer of lithospermic acid. It is difficult to quantitatively control the quality of SLI using traditional high performance liquid chromatography due to the highly similar structure of these constituents including three pairs of diastereomers and the lack of commercial resources for most of these constituents as standards. Thus, a highly reproducible, fast, accurate and simple 1 H quantitative nuclear magnetic resonance (qNMR) method without the need for calibration curves and complex computation was established by optimizing the solvent system and acquisition parameters to simultaneously determine the nine salvianolic acids and mannitol in SLI. This method was validated and successfully used to determine 10 batches of SLI and the qNMR data were further analyzed with a vector including angle cosine and the partial least squares method for the quality control of SLI. The results indicated that qNMR can be used as a routine method for the quality control of SLI and may have potential in the quantification of diastereomers in other TCM preparations.