Assessment of flavonoids and volatile compounds in tea infusions of water lily flowers and their antioxidant activities.

Water lily, a member of the Nymphaeaceae family, can be made into tea on the basis of outstanding fragrance characteristics and health care functions. In this study, 16 flavonoids were identified and quantified in tea infusions prepared from the petals of 33 water lily cultivars using HPLC-DAD and HPLC-ESI-MS/MS. The infusions were analyzed with HS-SPME coupled with GC-MS; 29 volatile compounds were detected, of which nine were found to be scent components. The cultivars were clustered into three clusters characterized according to scent components. The 'Conqueror' and 'Virginia' cultivars had the highest antioxidant activities. The concentrations of polyphenols and flavonoids showed significant positive correlations with antioxidant activity as measured by DPPH, ABTS(+), and FRAP assays. This study is valuable for a fuller understanding of this important tea and can also be used for the development of water lily.

Systematic qualitative and quantitative assessment of fatty acids in the seeds of 60 tree peony (Paeonia section Moutan DC.) cultivars by GC-MS.

Seeds from Paeonia ostii and Paeoniarockii have been recently identified as novel resources of α-linolenic acid (ALA) in China. To assess whether tree peony cultivars can be used as oil resource, fatty acids (FAs) in 60 cultivars were monitored and evaluated in this study. The results indicated that the composition and content of FAs varied dramatically among different cultivars, in which ALA, linoleic acid, oleic acid, palmitic acid, and stearic acid were the dominant. The 60 cultivars were classified into six clusters by hierarchical cluster analysis, and they were quite distinct from each other. Finally, six cultivars with high yield and high quality were screened out, comprising of 'Liuliguanzhu', 'Hongguanyupei', 'LSS-2', 'LSS-1', 'Jingshenhuanfa' and 'LSS-11'. These cultivars were appropriately applied in practical oil production. Overall, tree peony oil with abundant unsaturated fatty acids especially ALA was proved to be a top-grade source for edible oil and nutritional supplements.

[Rapid detection of dichlorvos in chlorpyrifos by mid-infrared and near-infrared spectroscopy].

In the present study, the content of dichlorvos in chlorpyrifos was rapidly determined by mid-infrared and near-infrared spectroscopy. The quantitative models were established by partial least squares (PLS) method and optimized. The independent validation sets and 7 test samples were used to evaluate the model accuracy. The results showed that mid-infrared and near-infrared spectroscopy can accurately determine the content of dichlorvos in chlorpyrifos. The RMSEC (the root mean square error of calibration) of the mid-infrared model and near-infrared model was 0.013 and 0.020, respectively. R2 (determination coefficient) both were 1.000. For 7 test samples, RMSEP before model recalibration is 0.22 (MIRS) and 0.09 (NIRS). The adaptability of the near-infrared model was much better and model updating was unnecessary. To sum up, MIR and NIR are both rapid and easy-operation method with simple pretreatment.