Optimization Of Detection Conditions For Total Flavonoids Extraction And Antioxidant Activity And Its Distribution In Stems And Leaves In Quinoa

Quinoa(Chenopodium quinoa Willd),a natively pseudo-grain in Andean region of South America above 4,000 m,belonging to the family Chenopodium L.,Amaranthaceae,is an annually self-pollinated dicotyledonous plant.Quinoa,rich in nutritional value,not only containing protein,minerals,vitamins,starch,all essential amino acids which human body needs and other nutrients,but also rich in functional active component,such as polyphenols,flavonoids,saponins,is called "the mother of grains".The study on optimization of the detection conditions for total flavonoids extraction and antioxidant activity and its distribution in different organs of quinoa have an important role in the processing development and production of healthy foods in quinoa.In this study,The quinoa cultivar ?Longli 1? was used to perform single factor,s optimized experimently on total flavonoids extraction and antioxidant activity from quinoa by setting ethanol concentration,solid-liquid ratio,extraction time,extraction temperature and ultrasonic power.Subsequently,the process parameters were verified with three accessions of quinoa named ?Qingli 2?,White quinoa and Sherry.Finally,the total flavonoids content and antioxidant activity from different organs of quinoa in different periods were determined using the optimal process parameters.The main results are as follows:1.The optimal single factors process parameters on total flavonoids extraction from quinoa were extraction time of 60 min,solid-liquid ratio of 1:50,extraction temperature of 70 ?,and ethanol concentration of 80 %,as well as ultrasonic power of 320 W.According to these conditions,the total flavonoid content from quinoa amounted to 3.83 ± 0.03 mg/g.The maximum of total flavonoids in three quinoa cultivars Qingli 2,white quinoa and Sherry was consistent with the results which got by the CV Longli 1 process,indicating that the optimized single factor,s process parameters on total flavonoids extraction by using in quinoa is reliable in quinoa.2.The optimum single factor,s process parameters of DPPH AEAC from quinoa were ethanol concentration of 70 %,as well as solid-liquid ratio of 1:60,extraction time of 60 min,extraction temperature of 60 ?,as well as ultrasonic power of 200 W.Based on these conditions,DPPH AEAC from quinoa was 9.09 ± 4.5 mg/100 g.The optimum single factor,s process parameters of TAC AEAC from quinoa were ethanol concentration of 70 %,solid-liquid ratio of 1:60,extraction time of 20 min,and extraction temperature of 50 ?,as well as ultrasonic power of 240 W.Under these conditions,TAC AEAC from quinoa was 557.93 ± 15.82 mg/100 g.The maximum of DPPH AEAC and TAC AEAC in three quinoa cultivars Qingli 2,white quinoa and Sherry was consistent with in this experiment Longli 1,implying that the optimal single factor,s process parameters for DPPH and TAC AEAC are reliable in this experiment.3.In the stems and leaves collected quinoa,from appearing florescence to filling stage for detecting,the total flavonoids content and antioxidant activity were determined based on the optimum process parameters.The results showed that the content of total flavonoids and antioxidant capacity in leaves were much higher than them in stems.The content of total flavonoids in leaves was from 25.86±0.28 mg/g to 31.89±0.04 mg/g,while the content of total flavonoids in stems was from 3.08±0.02 mg/g to 3.57±0.1 mg/g.DPPH AEAC in leaves was from 595.03±8.71 mg/g to 760.69±3.17 mg/g,while the DPPH AEAC in the stems was from 86.33±5.62 mg/g to 102.84±5.77 mg/g.TAC AEAC in leaves was from 778.58 mg/g to 864.2±5.8 mg/g,while TAC AEAC in stems was from 284.16±2.51 mg/g to 363.24±6.7 mg/g.These results indicated that the content of total flavonoids and antioxidant activity in leaves are obviously different from stems of quinoa.