An Instant Beverage Rich in Nutrients and Secondary Metabolites Manufactured from Stems and Leaves of Panax Notoginseng

IntroductionRadix Notoginseng, one of the most famous Chinese traditional medicines, is the dried root of Panax notoginseng (Araliaceae). Stems and leaves of P. notoginseng (SLPN) are rich in secondary metabolites and nutrients, and authorized as a food resource, however, its utilization needs further research. MethodsA SLPN-instant beverage was manufactured from SLPN through optimization by response surface design with 21-fold of 48.50% ethanol for 39 h, and this extraction was repeated twice; the extraction solution was concentrated to 1/3 volume using a vacuum rotatory evaporator at 45 degrees C, and then spray dried at 110 degrees C. Nutritional components including 14 amino acids, ten mineral elements, 15 vitamins were detected in the SLPN-instant beverage; forty-three triterpenoid saponins, e.g., ginsenoside La, ginsenoside Rb3, notoginsenoside R1, and two flavonoid glycosides, as well as dencichine were identified by UPLC-MS. ResultsThe extraction rate of SLPN-instant beverage was 37.89 +/- 0.02%. The majority nutrients were Gly (2.10 +/- 0.63 mg/g), His (1.23 +/- 0.07 mg/g), alpha-VE (18.89 +/- 1.87 mu g/g), beta-VE (17.53 +/- 1.98 mu g/g), potassium (49.26 +/- 2.70 mg/g), calcium (6.73 +/- 0.27 mg/g). The total saponin of the SLPN-instant beverage was 403.05 +/- 34.98 mg/g, majority was notoginsenoside Fd and with contents of 227 +/- 2.02 mg/g. In addition, catechin and gamma-aminobutyric acid were detected with levels of 24.57 +/- 0.21 mg/g and 7.50 +/- 1.85 mg/g, respectively. The SLPN-instant beverage showed good antioxidant activities with half maximal inhibitory concentration (IC50) for scavenging hydroxyl (OH-) radicals, superoxide anion (O2-) radicals, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS+) radicals were 0.1954, 0.2314, 0.4083, and 0.3874 mg/mL, respectively. ConclusionWe optimized an analytical method for in depth analysis of the newly authorized food resource SLPN. Together, an instant beverage with antioxidant activity, rich in nutrients and secondary metabolites, was manufactured from SLPN, which may improve the utilization of SLPN.