Study On The Nutritional And Functional Characteristics Of Quinoa(Chenopodium Quinoa Willd.)Sprouts

Quinoa(Chenopodium quinoa Willd.),an annual dicotyledonous plant belong to the Amaranthaceae family,originates from the Andean region of South America.Not only the grain is rich in nutrition,but also the leaves and sprouts of quinoa are rich in nutrition and functional substances,which have the functions of antioxidant and anti-inflammatory.However,there are few studies on the development of quinoa sprouts at present.The difference in harvest time will affect the chemical composition and nutritional value of vegetables.The quality of green leafy vegetables can be significantly improved in the optimal harvest stage.Therefore,the harvest time is very important for vegetable quality.In this study,three different quinoa genotypes were cultivated in greenhouse,and the nutritional functional components and antioxidant activities of five different growth periods of quinoa sprouts were measured,and the bioavailability and antioxidant activities of phenolic substances in quinoa sprouts were studied through in vitro simulated digestion,in order to find the most suitable picking period and variety resources for vegetable production.The research contents and main conclusions are as follows:(1)The results of the nutritional and functional components of quinoa sprouts in different periods showed that the quinoa sprouts had the highest fiber content and the lowest moisture content after 33 days cultivated,which was not suitable for consumption.Quinoa sprouts had the highest fat content on the 29 th day.The amino acid content of Yunnan red quinoa(RQ)and Mengli 1(Gray quinoa,GQ)was the highest on the 25 th day,while that of Yunnan white quinoa(WQ)was the highest on the 29 th day.The sugar content of RQ and GQ was the highest on the 29 th day,and WQ was the highest on the 17 th day,followed by the 25 th day.Quinoa sprouts are rich in vitamins,and its α-tocopherol is the main vitamin E.In terms of varieties,the highest content of fiber and protein was seen in GQ,which has the highest proportion of essential amino acids in amino acids,while RQ has the highest content of vitamin E.(2)The results of functional activity analysis of quinoa sprouts in different periods showed that the content of γ-aminobutyric acid,flavonoid and polyphenols was higher than that in quinoa grains,while the content of saponins was significantly lower than in quinoa grains(p<0.05).The contents of total polyphenols and flavonoids in quinoa sprouts were5.73-10.83mg/g and 18.48-30.38mg/g,respectively,which all dramatic decline after the 25 th day.The main phenolic acids in quinoa sprouts are ferulic acid,isoferulic acid and isoquercitrin.In terms of varieties,the highest total polyphenols and phenolic acid content were detected in RQ sprouts.The results showed that the antioxidant activity of quinoasprouts showed a significant downward trend on the 25 th day,and the polyphenol and flavonoid content of quinoa sprouts had a certain correlation with the antioxidant activity.(3)The results of in vitro simulated digestion showed that the phenolic compounds of quinoa sprouts were progressively released and made available for absorption during the digestion process,but the content of polyphenols and flavonoids that could be absorbed was relatively low,in the range of 7.4%-10.9% and 4.2%-12.4% respectively.The antioxidant activities showed that significantly increased(p<0.05)at gastric stage in comparison with oral stage;There was a positive correlation between the antioxidant activity and polyphenols or flavonoids released from different digestion steps.In terms of varieties,the lowest antioxidant activity of extracts and digestive solution was seen in WQ.(4)In summary,quinoa sprouts have a high comprehensive benefit during the harvest period from the 25 th day to the 29 th day.At this time,quinoa has better nutrition and taste.From the perspective of varieties,RQ is most suitable for development into sprouts for its low fiber,high level of vitamin E and phenolic substances.In vitro digestion results show that WQ is less suitable for development into sprouts because of the lowest antioxidant activity.