Consuming diets with appreciable amounts of antioxidants from plant foods, such as tomatoes, to inhibit the oxidative process of low density lipoprotein may be one way to reduce the risk of cardiovascular atherosclerotic disease. One study in relatively healthy individuals and 2 studies in individuals with type 2 diabetes, who are in a relatively pro-oxidant state, showed decreased lipid peroxidation rates and decreased susceptibility of low-density lipoproteins to oxidation after daily consumption of tomatoes or tomato juice. Others have reported less susceptibility to oxidation of DNA and low density lipoprotein after tomato product consumption delivering approximately half of the lycopene dose typically used in lycopene supplementation studies. These data suggest that the health benefits of tomato/tomato product consumption are not solely because of lycopene content, but rather the result of the combination of nutrients and bioactive constituents delivered when the whole food is consumed. Tomatoes and tomato products are also being investigated for possible anti-inflammatory, antithrombotic, and lipid-lowering effects. Supplementation of a low tomato diet with tomato products produces mixed results as measured by changes in inflammatory markers such as C-reactive protein , interleukin-6, and tumor necrosis factor-a. Jacob et al. reported decreased CRP after a 2-week tomato juice supplementation containing approximately 21 mg lycopene and 2 levels of vitamin C . Both juices reduced CRP as well as total cholesterol concentration.
Natural antithrombotic agents that influence platelet function or fibrinolytic activity are of interest as primary and seconddary cardiopreventive strategies. Aqueous extracts from tomatoes have been shown to display antiplatelet activity in vitro. Subsequent research in humans shows significant reductions in ex vivo platelet aggregation 3 hours after supplementation with tomato extract from the yellowish membrane surrounding seeds in amounts equivalent to 2 or 6 fresh tomatoes. For skin protection,flood tray tomato intake for more than 8 weeks reduced ultraviolet light-induced erythema. Epidemiological studies suggest a beneficial relationship between dietary sources of lycopene and bone mass. Likewise, lower serum lycopene concentrations have been documented in osteoporotic women compared with controls. Rao et al. have also reported an inverse association between serum lycopene and markers of oxidative stress and bone turnover in 33 postmenopausal women aged 50 to 60 years. Research for a possible role of tomatoes in brain health has largely been limited to case-control studies investigating the relationship between plasma/ serum lycopene and oxidative stress markers in people with documented Alzheimer’s disease, Parkinson’s disease, vascular dementia, and mild cognitive impairment compared with control/noncognitively impaired individuals. In general, plasma/serum lycopene concentrations are lower in cognitively impaired compared with control individuals, and oxidative stress markers are elevated and inversely correlated with plasma carotenoids concentrations.Potatoes yield on average more food energy on a per-hectare and a per-day basis than either cereals or cassava. In general, potato is perceived only as a source of carbohydrates, but is also an excellent source of essential amino acids. The predominant form of this carbohydrate is starch. A small but significant portion of this starch is resistant to digestion by enzymes in the stomach and small intestine, and so reaches the large intestine essentially intact. This resistant starch is considered to have similar physiological effects and health benefits as dietary fiber: it provides bulk, offers protecttion against colon cancer, improves glucose tolerance and insulin sensitivity, lowers plasma cholesterol and triglyceride concentrations, increases satiety, and possibly even reduces fat storage.
The amount of resistant starch in potatoes depends much on preparation methods. Cooking and then cooling potatoes significantly increases resistant starch. For example, cooked potato starch contains about 7% resistant starch, which increases to about 13% upon cooling. Due to carbohydrate content, potatoes are considered to make a person obese if used in excess i.e. more than RDA of carbohydrates and fats. Recent research by the University of California, Davis and the National Center for Food Safety and Technology, Illinois Institute of Technology demonstrates that people can include potatoes in their diet and still lose weight. Potatoes are also often broadly classified as high on the glycemic index and so are often excluded from the diets of individuals trying to follow a low-GI diet. In fact, the GI of potatoes can vary considerably depending on type , origin , preparation methods , and with what it is consumed . Potato contains a small amount of protein , but the biological value of potato protein is the best among vegetable sources and comparable to cow’s milk. Human feeding trials suggested that potato proteins are of a very high quality, possibly because they are rich in essential amino acids, such as lysine, and other metabolites, which may enhance protein utilization. The lysine content of potato complements cereal-based diets, which are deficient in this amino acid. In addition to high quality proteins, potato tubers accumulate significant amounts of vitamins and minerals, as well as an assortment of phytochemicals including phenolics, phytoalexins,ebb and flow tray and protease inhibitors. Chlorogenic acid constitutes up to 90% of the potato tuber natural phenols. Others found in potatoes are 4-O-caffeoylquinic acid , 5-O-caffeoylquinic , 3,4-dicaffeoylquinic and 3,5-dicaffeoylquinic acids. A medium-size 150 g potato with the skin provides 27 mg of vitamin C , 620 mg of potassium , 0.2 mg vitamin B6 and trace amounts of thiamin, riboflavin, folate, niacin, magnesium, phosphorus, iron, and zinc. The fiber content of a potato with skin is equivalent to that of many whole grain breads, pastas, and cereals.
Potato contributes a small but significant amount of phytochemicals. Several yellow, red, and purple fleshed types with high phytochemical content have recently been introduced into the market. The purple potato has purple skin and flesh, which becomes blue once cooked. A mutation in the varieties’ P locus causes production of the antioxidant anthocyanin. Total phenolics in potato tubers range in concentration from 0.5 to 1.7 g/kg. Al-Saikhan et al. reported significant differences in total phenolics among cultivars, with flesh color having no significant effect on total phenolics. Nearly 50% of the total phenolic compounds in potato are located in the peel and adjoining tissue, but decrease toward the center of the tuber, with chlorogenic acid representing about 90 percent of the total polyphenolic content. Potato tubers contain a moderate amount of vitamin C, in the range of about 10 to 104 mg/kg, depending on the cultivar and the growing season, but it declined rapidly during storage and cooking. Other antioxidants found in potato include 0.5 to 2.8 mg/kg α-tocopherol, 0.13 to 0.6 mg/kg lutein, and 1 mg/kg β-carotene. Cao et al. estimated the total antioxidant capacity of potato to be in the medium range among 22 commonly consumed vegetables. Potato also contributes a small amount of selenium and folate to the human diet. Peppers come in a beautiful array of colors and shapes. They add flavor, color, and crunch to many low-calorie dishes. All fresh peppers are excellent sources of vitamins C, K, carotenoids, and flavonoids. Antioxidant vitamins A and C help to prevent cell damage, cancer, and diseases related to aging, and they support immune function. They also reduce inflammation like that found in arthritis and asthma. Vitamin K promotes proper blood clotting, strengthens bones, and helps protect cells from oxidative damage. Red peppers are a good source of lycopene, which is earning a reputation for helping to prevent prostate cancer as well as cancer of the bladder, cervix, and pancreas. Beta-cryptoxanthin, another carotenoid in red peppers, is holding promise for helping to prevent lung cancer related to smoking and secondhand smoke. Besides being rich in phytochemicals, peppers provide a decent amount of fiber. Significant differences in vitamin C were observed between cultivars, but not between species. On average, fruits contain between 1 to 2 g/kg vitamin C, which is equivalent to 200% to 300% of the recommended daily allowance for adult men and women. The level of provitamin A carotenoids is cultivar specific. Some cultivars of hot pepper have as much as 12 mg/kg total carotenoids, while others are bellow the detectable level. Major flavonoids in the peppers are quercetin and luteolin. They are present in conjugated form and their content varies among cultivars ranging from not detectable to 800 mg/kg.
When comparing the nutrient values of the different bell peppers, studies have shown that red bell peppers have significantly higher levels of nutrients than green. Red bell peppers also contain lycopene, which helps to protect against cancer and heart disease. Possibly due to their vitamin C and beta carotene content, bell peppers have been shown to be protective against cataracts. Just like other nutrient-dense vegetables, bell peppers contain many different powerful phytochemicals. Bell peppers have also been shown to prevent blood clot formation and reduce the risk of heart attacks and strokes probably due to their content of substances such as vitamin C, capsaicin, and flavonoids. Although chili hot peppers contain a higher amount of those substances, bell peppers should still be promoted especially for individuals with elevated cholesterol levels. Hot peppers don’t have that spicy image for nothing. The major phytochemicals in hot peppers are capsaicinnoids. More than 20 capsaicinoids, belonging to two groups, capsaicin and dihydrocapsaicin, have been identified in pepper. Capsaicin was discovered in 1846 and its structure, as an acid amide, was elucidated by Nelson. Capsaicin constitutes about 70% of the pungent flavour in hot pepper, while its analogue dihydrocapsaicin represents 30%. The two groups differ in the presence or absence of double bonds in the fatty acid side-chain and within each group they differ in the length and branching point in the fatty acid side-chain. Significant variations in the profile of capsaicinoids are found between and within pepper species, ranging from about 220 ppm in Capsicum annum to 20,000 ppm in Capsicum chinense. Hot peppers’ fire comes from capsaicin, which acts on pain receptors, not taste buds, in our mouths. Capsaicin predominates in the white membranes of peppers, imparting its “heat” to seeds as well. The capsaicin in hot peppers has been shown to decrease blood cholesterol and triglycerides, boost immunity, and reduce the risk of stomach ulcers. It used to be thought that hot peppers aggravated ulcers. Instead, they may help kill bacteria in the stomach that can lead to ulcers. Capsaicin has also analgesic, anti-bacterial, and antidiabetic properties. Capsaicin is an ingredient in several commercial formulations formulation for the treatment of muscle pains, toothaches, burning-mouth syndrome, gastric ulceration, painful diabetic neuropathy, postmastectomy pain syndrome, and osteo- and rheumatoid-arthritis. It is also prescribed for bladder hypersensivity, vasomotor rhinitis, and hyperreflexia of spinal origin. Chilli hot peppers have amazingly high levels of vitamins and minerals. Just 100 g provides , 240% of vitamin C , 39% of vitamin B6 , 32% of vitamin A, 13% of iron, 14% of copper, 7% of potassium. Fresh chili hot peppers, red or green, are rich source of vitamin-C. 100 g fresh chilies provide about 143.7 μg or about 240% of recommended daily allowance. Chillies are also good in B-complex group of vitamins such as niacin, pyridoxine , riboflavin and thiamin . These vitamins are essential in the sense that body requires them from external sources to replenish. Chilli hot peppers contain good amount of minerals like potassium, manganese, iron, and magnesium. Potassium in an important component of cell and body fluids that helps controlling heart rate and blood pressure. Manganese is used by the body as a co-factor for the antioxidant enzyme superoxide dismutase. Both hot and sweet peppers contain substances that have been shown to increase the body’s heat production and oxygen consumption for about 20 minutes after eating. This is great news; it means our body is burning extra calories, which helps weight loss. The eggplant, known as aubergine in Europe and brinjal in south Asia, is a popular vegetable cop grown in many countries throughout the subtropics, tropics and Mediterranean area, since it requires a relatively long season of warm weather to give good yields. In addition to featuring a host of vitamins and minerals, eggplant also contains important phytochemicals which have antioxidant activity. Phytochemicals contained in eggplant include phenolic compounds, such caffeic and chlorogenic acid, and flavonoids, such as nasunin. Nasusin or delphinidin- 3–5-glucoside is the major phytochemical in eggplant.