Green leafy vegetables are very nutrient-dense and incredibly healthy. They are vital sources of antioxidants and they are the best which are very beneficial to providing weight loss and maintenance, because it keeps you feeling full and helps control your hunger. Also, leafy vegetables are full of fiber, vitamins; minerals and substances that help protect you from disease [1] [2]. For this we choose five types of vegetables which are lettuce, cabbage, parsley, spinach and arugula to estimate some nutritional values present on them such as: carbohydrate (sucrose, fructose, glucose and starch), protein, amino acids (lysine and phenyl alanine), vitamin C (ascorbic acid) and lipid. The results obtained were analyzed and the relative percentages of these compounds were tabulated. Among the five green leafy vegetables the glucose content was highest in lettuce and was least in arugula. Among the five green leafy vegetables the fructose content was highest in parsley and was least in cabbage. Among the five green leafy vegetables the sucrose content was highest in parsley and was least in cabbage. Among the five green leafy vegetables the starch content was highest in lettuce and was least in spinach. Among the five green leafy vegetables the ascorbic acid content was highest in lettuce and was least in parsley and arugula. Among the five green leafy vegetables the protein content was highest in parsley and was least in cabbage. Among the five green leafy vegetables the lysine content was highest in cabbage and was least in arugula. Among the five green leafy vegetables the phenyl alanine content was highest in cabbage and was least in spinach. Among the five green leafy vegetables the lipid content was highest in lettuce and was least in cabbage.
It has been known for a long time that green leafy vegetables are very rich sources of antioxidants. The extracts of green leafy vegetables have proved vital in curing diseases like asthma. These are highly essential for developing resistance by allowing the immune system to function in a systematic manner. Some plant chemicals are capable of treating inflammatory disorders and eliminate carcinogens, while many other leafy vegetables regulate the rate at which cells reproduce, get rid of old cells and maintain DNA. In a country like Oman there are a few farmers who cultivate such green leafy vegetables, and this evinces the interest in authors to focus on the present study. Another reason is that though most of the land is a desert and there is very little fertile land. Thus it is of significance to establish the nutritional parameters in these green leafy vegetables. This is because leafy vegetables are full of fiber (an important nutrient for weight loss which can also lower cholesterol and blood pressure, and help to temper blood-sugar swings by slowing the absorption of carbohydrates into your bloodstream after meals) along with vitamins, minerals, and plant-based substances that help protect you from heart disease, diabetes, and even cancer. This lowers your risk of cardiovascular disease and type 2 diabetes. Leafy greens also contain a lot of water, which helps keep you hydrated and contributes to beautiful skin and hair (one should consume a diet rich in B vitamins like salmon, sardines, legumes and whole grains, along with fortified cereals and breads, seeds and dark green leafy vegetables). Rich sources of omega-3 like flaxseed, canola oils, wheat germ and soya beans, along with nuts, citrus fruits, brightly coloured vegetables, mushrooms (rich in selenium), and magnesium-rich foods like spinach, dark green leafy vegetables should be preferred. Foods rich in sugar and hydrogenated fats loaded with empty calories should be avoided [
Cabbage is an excellent source of vitamin C and vitamin K, containing more than 20% of the daily value for each of these nutrients per serving [
Dark lettuces are rich in vitamins A, C and K; eating them regularly will improve your eyesight, bone health and skin elasticity while helping your blood to clot normally. On combining these dark leaves with tomatoes, onions, carrots and cucumbers, a colorful, healthy salad can be created [
Arugula is a cruciferous and leafy green vegetable with a peppery taste and is often used in salads. It is a good source of potassium, a mineral involved in managing blood pressure and preventing osteoporosis. Arugula may help boost memory due to phytochemicals―antioxidants found in all cruciferous vegetables. Like other salad greens, arugula is very low in calories, making it a great addition to any weight-loss plan.
Parsley keeps your immune system strong, tones your bones and heals the nervous system, too. It helps flush out excess fluid from the body, thus supporting kidney function. Regular use of parsley can help control your blood pressure. Parsley essential oil, when massaged into the scalp, may reduce hair loss. Parsley is a source of flavonoid, antioxidants, apigenin, folic acid, vitamin K, vitamin C, and vitamin A [
After due calibration of the instrument, spectral and absorbance measurements were made using Thermo UV visible double beam spectrophotometer bearing model number UVA-144294 (Helios alpha) made in England.
5 g of (lettuce, cabbage, parsley, spinach and arugula) was weighed and cut into small pieces. By using pestle and mortar the 5 g of each vegetable was crushed with few drops of 70% ethanol. The crushed material was filtered first with cheese cloth then by filter paper. The filtered extract was transferred to 100 ml volumetric flask by using funnel. Finally the volume was made to 100 ml by 70% ethanol.
For methods 1, 2 and 3 di nitro salicylic acid reagent was used.
Preparation of the Reagent: NaOH solution: 20 mg of NaOH was added with 250 ml of distilled water.
DNS solution: 1.5 g of DNS was dissolved in 30 ml of NaOH with stir on hot plate and then was filtrated by filter paper in volumetric flask. DNS reagent: 75 ml of DNS solution was mixed with 30 ml of 1% sodium potassium tartarate solution
Method-1 Estimation of Glucose [
Method-2 Estimation of Fructose [
Method-3 Estimation of Sucrose [
Method-4 Estimation of Lysine: 0.2 g of ninhydrin was added to 100 ml of acetone. 100 mg of lysine was added to 100 ml of distilled water. From this 10 ml was taken with 100ml of distilled water. In tubes 2 ml of (lysine, blank, lettuce extraction, cabbage extraction, parsley extraction, arugula extraction and spinach extraction) was put one in each tube. Then 3 ml of ninhydrin reagent was added for each one. Finally optical density of each solution was read by using spectrophotometer.
Method-5 Estimation of Phenyl Alanine: 0.2 g of ninhydrin was added to 100 ml of acetone. 100 mg of phenyl alanine was added to 100 ml of distilled water. From this 10ml was taken with 100 ml of distilled water. In tubes 2 ml of (phenyl alanine, blank, lettuce extraction, cabbage extraction, parsley extraction, arugula extraction and spinach extraction) was put one in each tube. Then 3 ml of ninhydrin reagent was added for each one. Finally optical density of each solution was read by using spectrophotometer.
Method-6 Estimation of Protein [
Method-7 Estimation of Lipid [
Method-8 Estimation of Starch [
Method-9 Estimation of Ascorbic Acid [
The
Veg. | Sucrose | Glucose | Fructose | Starch | Ascorbic acid | Protein | Lysine | Phenyl alanine | Lipid |
---|---|---|---|---|---|---|---|---|---|
Lettuce | 18.41% | 1.66% | 0.99% | 50.83% | 2.687% | 0.251% | 0.945% | 1.595% | 89.3% |
Cabbage | 15.24% | 1.375% | 0.827% | 42.083% | 2.5% | 0.065% | 4.486% | 7.568% | 36.67% |
parsley | 22.59% | 1.226% | 2.038% | 6.25% | 0.875% | 3.331% | 3.261% | 4.105% | 49.33% |
spinach | 22.38% | 1.215% | 2.0197% | 4.17% | 2.125% | 2.627% | 2.433% | 1.215% | 71.67% |
Arugula | 20.198% | 1.097% | 1.823% | 12.92% | 0.875% | 2.391% | 0.922% | 1.55% | 54% |
The lipid, starch and sucrose were the most nutrient values in green leafy vegetables that were chosen (lettuce, cabbage, parsley, spinach and arugula) and the fructose, glucose and ascorbic acid were the least. The lettuce is the leafy vegetable that has most nutrient values and the least one is arugula.
The authors are grateful to the ministry of manpower for supporting the proposed research activity and to the higher management, faculty and technicians of Biology division of Department of Applied Sciences, Higher college of Technology for their continuous support and encouragement and for providing the necessary infrastructure facilities for executing this work.