Research On Basic Nutritional Components Of Quinoa And The Biological Activity Of Their Flavonoids Extracts

Chenopodium quinoa willd,a traditional food crop in regions like Andean of South America,Chilean,etc,its history of cultivation can go back to thousands of years ago,it's the oldest food crop throughout the history.Quinoa seeds can be divided into three types according to their color,White quinoa?Red quinoa and Black quinoa.In terms of nutritional value,quinoa as a staple food can provide high protein content as same as meat?milk,and polyphenols,flavonoids,saponins and other functional active ingredients are more abundant than other traditional cereals,which has great development prospects and application value.To understand the nutritional quality of quinoa seeds of different colors and the differences in the content of flavonoids in quinoa,three kinds of quinoa from Shanxi Jingle been used as materials,its nutrients been analyzed and determined,the antioxidant,bacteriostatic and antitumor activities of flavonoid extracts from quinoa been pilot studied.The main results as followings:1.The basic nutrients?water,fat,protein,starch,ash and amino acid?in quinoa were determined by national standard method.The results showed that the proteins and flavonoids in BQ and RQ seeds were respectively 13.74%and 3.35 mg/100g,13.39%and 3.05 mg/100g,both higher than 11.81%,2.58 mg/100g of WQ.The results of amino acid analysis of quinoa showed that the amino acid composition of different varieties was slightly different and all have total 17 amino acids,which BQ was the highest.However,the ratio of essential amino acids in RQ is closer to the ratio of amino acid patterns proposed by FAO Food and Agriculture Organization,which is a good source of amino acids.The flavonoids in quinoa were analyzed by HPLC.The results showed that the compound type of flavonoids mainly were quercetin?15.06³5.25mg/100 g?and kaempferol?15.56²0.46 mg/100 g?.The above results showed that there was a slight difference between nutrient composition of quinoa with different colors,but BQ and RQ had higher contents of protein and flavonoids and there had significant differences.2.The antioxidant activity of quinoa flavonoids was determined by DPPH,hydroxyl radical scavenging and reduced power determination in vitro.The results showed that quinoa flavonoids had good antioxidant activity.The IC50 values of DPPH scavenging in three samples of BQ,RQ and WQ were respectively,0.08?0.09?0.14 mg/mL.The IC50 values of hydroxyl radical scavenging in three samples of BQ,RQ and WQ were respectively,0.08?0.10?0.15 mg/mL.The scavenging effects of BQ and RQ against free radicals and the reduction of Fe ³⁺ions were better than WQ.The comprehensive study showed that the flavonoids content of dark quinoa was higher and the antioxidant ability was stronger.The intracellular antioxidant CAA assay using HCT116 cells as model showed that quinoa flavonoids had obvious antioxidation ability on human colon cancer cells and could increase the dynamic numerical of Superoxide dismutase?SOD??Catalase?CAT?and Glutathione?GSH?in human colon cancer cells.3.Based on the above results,the BQ seeds who has the highest antioxidant activity and flavonoid content were selected for the study of antibacterial activity by Oxford cup method.The results showed that quinoa flavonoids had a killing effect on all been tested bacterial strains,especially on gram-negative bacteria Escherichia coli.we also found that the proliferation of Trichoderma koningii and Rhizopus sp were inhibited by quinoa flavonoids,and have a positive correlation with the concentration of flavonoids.4.MTT results showed that when the concentration was relatively high as 200³00?g/mL,quinoa could significantly inhibit the growth of HCT116 cells and dose-dependent relationship with flavonoid concentration.The cell morphology was observed with inversion and fluorescence microscope,compared with the control group,most of the cells were shrinkage and turned round after treatment with quinoa flavonoids,and the shape of nucleus changed from normal round to irregular.After Annexin V and PI double staining,it was been found by flow cytometry that quinoa flavonoids could induce apoptosis of HCT116cells,mainly in the late stage of apoptosis.Fluorescence probe DCFH-DA assay been used to detect intracellular ROS levels,the results showed that quinoa flavonoids could induce the production of ROS in HCT116cells.The above results initially showed that quinoa flavonoids had a certain anticancer effect.To sum up,quinoa has abundant nutrients such as protein,starch,fat and balanced amino acids,Dark seeds also contain more abundant flavonoids and has a good good antioxidant activity,antimicrobial activity and antitumor effect in vitro.