Comparative Study On Nutritional Ingredients And Antioxidant Activity Of Special Vegetables Between Categories And Varieties

Special vegetables refer to those different from the common varieties of vegetables, but also have special function. The results showed that special vegetables not only have high nutritional value, but also have certain medicinal value. In this study, 8 kinds of special vegetables and 6 varieties of yam in different areas were selected as the object of study. The physical and chemical analysis method, the high performance liquid chromatography(HPLC), UV and ICP-MS were used to determine the content of moisture, ash, protein, fat, amino acids, mineral elements and so on. The antioxidant activities of these methanol extracts were also determined. The main results are as follows:(1) The 8 kinds of experimental special vegetables were nutrient-rich,the content of ash were between 1.20 to 1.89%, which were rich in Dendranthema indicum, Begonia fimbristipula Hance and Lysimachia clethroides Duby, rich in K, Ca, Mg and so on. Dendranthema indicum and Lysimachia clethroides Duby contained rich protein, were 3.68% and 2.94% respectively, they were the ideal source of plant protein. The content of vitamin C in Abelmoschus esculentus was higher than that of other vegetables, was 34.78mg/100g. The content of 17 kinds of amino acids in the special vegetables were between 97.33mg/g to 165.35mg/g (except tryptophan), the content of essential amino acids in Coral dealbatus, Dendranthema indicum, Ablmoschus manihot and Begonia fimbristipula Hance were higher than other vegetables, in more than 160mg/g. The content of essential amino acids accounted for total amino acids from 0.29 to 0.35, Gynura formosana Kitam and Dendranthema indicum accounted for more than 0.35.(2) The contents of crude protein, crude fat, starch and carbohydrate, mineral elements of 6 different varieties of yam powder that of ripening treatment were more than that of drying treatment, But caused the loss of water and ash, the loss rate was 71.17 ～90.57% and 72.32 ～83.19%; the total amino acids content of ripening treatment was lower than that of the drying treatment, that is, ripening treatment will make most of the amino acids lost slightly, and the content of essential amino acids accounted for total amino acids was higher than that of drying treatment.(3) The total phenolics and total flavonoids in the samples were determined by the reducing power as the index to analyze and compare their antioxidant activities. The results showed that 8 kinds of special vegetables and 6 different varieties of yam all had phenolic acids, flavonoids, and the content of the active ingredients were different. Taken together, The antioxidant properties of Coral dealbatus and Dendranthema indicum were better than those of others; the antioxidant properties of Fujian purple yam was higher than that of other varieties. The results showed that there was a significant positive correlation between the active ingredients and antioxidant capacity of 8 kinds of special vegetables-the content of total phenols and the reducing power had a very significant positive correlation (P<0.01), the content of total flavonoids and the reducing power had a significant positive correlation (P<0.05). The results showed that phenolic acids was the main antioxidant substances probably.