The L. barbarum fruit "Ke qi 608" was procured from the Institute of Chinese goji, Ningxia Yinchuan Academy of Agriculture and Forestry. For this, disease-free fresh fruit of Chinese goji were selected for processing. Sodium nitroprusside (SNP) reagent was provided by Shanghai Guangnuo Chemical Technology Co. (Shanghai, China)
Treatment of goji berriesAbout 2700 freshly ripened goji fruits with uniform size were selected. Three parallel groups of 50 fruits in each group were divided, with no SNP as control (CK). Soak them in 75% alcohol for 2 min to disinfect and air dry naturally. Subsequently, 200 mL SNP solutions of different concentrations (0.0, 0.2, 0.4, 0.6, 0.8,