BIOCHEMICAL STUDIES ON SOME LEAFY VEGETABLES

Abstract

Jews mellow (JM), Parsley (P), Rocket (R) and Leek (L) are the most important lea(y vegetables crops in Egypt. TI1ese plants are rich in protein, dietary fiber, elements, carotenoids, polyphenols, flavonoids, vitamin C and E. The protein and ash amounted to 25.89 and 14.09 in JM, 23.36 and 10.33 in P, 23.90 and 12.16 in R, and 21.40 and 13.52 in L, respectively. While, crude tiber contents were almost always the same as ash percentages. The values of soluble dietary fiber (SDF) and insoluble dietary tiber (IDF) were 16.69 and 8.37 in JM, 10.11 and 15.30 in P, 9.28 and 12.55 in R, and 11.57 and 15.05% in L, respectively. TI1e tirst limiting amino acid was cysteine and methionine except in L. A deticiency was also noticed in lvsine score It is noticed that arginine: lysine ratio increased, while methionine:glycine ratio decreased in all vegetables wmpared \\ith casein.

TI1e total phenolic compounds were almost the same in all vegetables, while total chlorophyll "-as slightlY higher in both (R) and (JM) than other vegetables. Carotenoids in (R) and (P) were relatively higher than other vegetables. Tannins content could be ascending arranged as follows: (P), (R), (L) and (JM). TI1e saponins contents were higher in (JM) followed by (L), but (R) was relatively higher in sterols and terpenes compared with other vegetables. The highest content of vitamin E was in (JM) followed by (R), (L) and (P). il1 contrast, (P) had a higher percent of vitamin C compared with other vegetables. Both polyphenols and t1avonoids contents were relatively high in ethanolic extract. (JM) contained relatively high amount of chlorogenic acid. rutin, 0-coumarin and kaempferol, while P had high content of apigenin. (R) contained high amounts of lerulic acid, salicylic acid and 0-coumaric acid, whereas (L) had a high amount of resroccnol, rutin, m\Ticetin. quercetin and kaempferol. TI1e degree of solubility of elements in ethanolic extract were compared with dried leafy vegetables, however these e:-.tracts still had high antioxidants and biological activities.

TI1e antioxidant activity increased with increasing the concentration of vegetable extracts !rom Still to IOOOppm in corn oil. Antioxidant efiectiveness was more obvious for both (R) and (L) extracts than (.1M) and (P). Whereas, BHT, BHA and rutin at lOOOppm were more e!Tective than other authentic antioxidants (tannic acid, catechin, quercetin and riboflavin) in preventing the oxidation process; however BHT and BHA had shown carcinogenic efiect

No efiect could be observed for (JM) and (P) extracts on G+ bacteria. However, a moderate elkct was exhibited at a concentration of lOOOppm for (R) extract against both Bacillus subtilis and Staphylococcus aw•eus. In case of(L) extract a both concentration 500ppm and lOOOppm had shO\m an inhibition zone against Staph. aureus. In respect toG' bacteria, (JM) and (P) extracts at IOOOppm showed a zone of inhibition against Ellterobacter aerogenes. Salmonella typhi was inhibited by both (R) and (L) extracts at concentration ot' SOil and lOOOppm. While, ditTerent extracts did not show any zone of inhibition against Sacclmromyces cen-'Jceae