چای
1-1- پیدایش تندی اکسایشی در مواد غذایی
1-2- جلوگیری از اکسایش مواد غذایی
1-3- آنتی اکسیدانها
1-4- آنتی اکسیدانهای طبیعی و تغذیه
1-5- گیاه چای
1-6- برگ چای
1-7- ترکیبات شیمیایی چای
1-8- چایسازی
1-8-1- تولید چای سیاه
1-8-1-1- پلاس
1-8-1-2- مالش
1-8-1-3- تخمیر
1-8-1-4- خشک کردن و بسته بندی
1-9- تولید و مصرف چای در جهان
1-10- خواص آنتی اکسیدانی ترکیبات چای
1-11- ترکیبات عصاره چای به عنوان افزودنی غذایی
1-12- استخراج عصاره چای
2- مواد و روشها
2-1- مواد شیمیایی
2-2- تهیه و آماده سازی ماده اولیه
2-3- استخراج
2-3-1- استخراج با متانل
2-3-2- روش آگاروال
2-3-3- روش آبی
2-4- اندازه گیری قدرت احیاءکنندگی آهن
2-5- تعیین قدرت آنتی اکسیدانی در سیستم مدل اسید لینولئیک
2-6- اندازه گیری عدد پراکسید به روش تیوسیانات
2-6-1- ترسیم منحنی کالیبراسیون
2-6-2- محاسبه میزان پراکسید در نمونه
2-7- محاسبه شاخص اسید تیوباربیتوریک
2-8- تعیین قدرت آنتی اکسیدانی در روغن آفتابگردان
2-9- آزمون رنسیمت
2-10- روش آماری
3-1- بازده استخراج
3-1-1- اثر نوع روش بر بازده استخراج
3-1-2- اثر نوع ماده اولیه بر بازده استخراج
3-1-3- اثر متقابل نوع روش و نوع ماده اولیه بر بازده استخراج
3-2- قدرت احیاءکنندگی آهن عصاره های چای
3-2-1- اثر روش استخراج بر قدرت احیاءکنندگی آهن عصاره چای
3-2-2- اثر نوع ماده اولیه بر قدرت احیاءکنندگی آهن عصاره چای
3-2-3- اثر متقابل روش استخراج و نوع ماده اولیه بر قدرت احیاءکنندگی آهن عصاره چای
3-3- فعالیت آنتی اکسیدانی عصاره های چای در سیستم امولسیونی اسید لینولئیک
3-3-1- اثر روش استخراج بر فعالیت آنتیاکسیدانی عصاره چای
3-3-2- اثر نوع ماده اولیه بر فعالیت آنتیاکسیدانی عصاره چای
3-3-3- اثر متقابل روش استخراج و نوع ماده اولیه بر فعالیت آنتی اکسیدانی عصاره چای
3-4- آزمون رنسیمت
3-4-1- مقاومت حرارتی عصاره آبی برگ جدید چای در روش رنسیمت
3-4-2- اثر غلظت بر کارایی عصاره آبی برگ جدید چای در روش رنسیمت
3-5- اثر افزودن عصاره آبی برگ جدید چای بر اکسایش روغن آفتابگردان در دمای Cْ40
نتیجه گیری کلی
پیشنهادات
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: چکیده ی بخشهایی از متن:
1-1- پیدایش تندی اکسایشی در مواد غذایی
چربیها سوبسترای اصلی فساد اکسایشی و ایجاد طعمهای بد ناشی از آن محسوب میشوند. چربیها گروه ناهمگونی از ترکیبات شیمیایی هستند که ویژگی مشترک آنها حلالیت در سیستمهای غیر قطبی یا لیپوفیل است(3). تقریبا تمام مواد خامی که صرف تولید مواد غذایی میشوند حاوی چربی هستند. بخش عمده چربیها را تریگلیسیریدها و فسفوگلیسیریدها تشکیل میدهند. تریگلیسریدها در سلولهای ذخیرهای چربی گیاهان و جانوران تمرکز مییابند و فسفوگلیسریدها جزئی از غشاءهای بیولوژیکی هستند. ضمن تولید بسیاری از مواد غذایی، چربی به صورت بخشی از فرمولاسیون محصول به آنها اضافه میشود. چربی اضافه شده در برخی از مواد غذایی مثل مایونز و مارگارین جزء اصلی محسوب میشود. چربیها در مواد غذایی علاوه بر انرژیزایی، نقشهایی چون انتقال حرارت، ایجاد طعم و احساس دهانی و حمل ترکیبات مهمی نظیر ویتامینها و مولکولهای معطر محلول در چربی را بر عهده دارند(3،31،78).
اکسایش در مواد غذایی، تأثیر سوئی بر رنگ، بافت، طعم و بخصوص ارزش غذایی میگذارد(31،87). اکسایش لیپیدها پس از فساد میکروبی عامل اصلی کاهش کیفیت فرآوردههای گوشتی محسوب میشود(18،48). در این فراوردهها، اکسایش چربی علاوه بر اینکه باعث کاهش کیفیت حسی میشود، بر اثر واکنش محصولات اکسایشی با عوامل مغذی از قبیل پروتئینها باعث کاهش ارزش تغذیهای این محصولات نیز میگردد. واکنش محصولات اکسایشی با اسیدهای آمینه باعث نابودی آنها میشود که از این لحاظ اسیدهای آمینه ضروری اهمیت بیشتری دارند(50، 77). واکنشهای اکسایشی و پلیمری شدن بعدی پروتئینها موجب کاهش حلشوندگی پودر شیر خشک میشود(92). ...
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2- مواد و روشها
2-1- مواد شیمیایی
کلرید آهن III، تیوسیانات آمونیوم، پتاسیمدیهیدروژنفسفات، سدیمهیدروژنفسفات، فریسیانید پتاسیم، اسید کلریدریک، اسید تریکلرواستیک، متانل، اتانل، اتیلاستات و کلروفرم با خلوص بالا در حد آزمایشگاهی از شرکت مرک آلمان تهیه شد. اسید لینولئیک و کلرید آهنII نیز از شرکت سیگما (انگلستان) تهیه شد. روغن آفتابگردان تصفیه و بیرنگ شده عاری از آنتی اکسیدان از شرکت سه گل خراسان (نیشابور) تهیه گردید.
2-2- تهیه و آماده سازی ماده اولیه
برگ سبز چای در اوایل خردادماه سال 1382 از یکی از باغ های منطقه کوزه گر محله رامسر در شمال ایران برداشت شد. برگهای جدید و قدیمی به صورت جداگانه برداشت و نگهداری گردید. ضایعات چای سیاه از آخرین الک کارخانه چایسازی کتالم رامسر تهیه شد. برگها در درجه حرارت Cﹾ100 تا حصول وزن ثابت خشک گردید تا ضمن حذف رطوبت از فعالیت آنزیم پلیفنلاکسیداز بازداری شود. نمونه های خشک تا زمان انجام استخراج در دمای Cﹾ4 نگهداری گردید. نمونه ها قبل از استخراج آسیاب شدند.
2-3- استخراج
برای بررسی اثر روش استخراج و نوع ماده اولیه بر قدرت آنتی اکسیدانی عصاره چای از سه نوع ماده اولیه (برگ جدید، برگ قدیمی و ضایعات سیاه کارخانه چایسازی) با سه روشی که در ادامه تشریح شده اند عصارهگیری گردید. ....
تحقیق آنتی اکسیدان 9 ( Anti oxidant )
چکیده:
Description
This invention is directed to mercury vapor arc discharge lamps in which the arc discharge takes place in mercury vapor, including conventional phosphor fluorescent lamps and more particularly to avoidance of mercury pollution of landfills and groundwaters upon disposal of such lamps and during testing for leaching of toxic materials from such lamps and to compositions of matter useful in preventing the formation of leachable mercury in disposal and testing procedures. The lamps provided herein are characterized by reduced solubilization and leaching of mercury when the lamp is pulverized for testing or upon disposal.
BACKGROUND OF THE INVENTION
Low pressure mercury arc discharge lamps are standard lighting means which include electrodes sealed in a glass envelope, the interior of which may be coated with a phosphor. The lamp also contains a small amount of mercury and an inert gas at low pressure, of about 1 to 5 torr. The term lamp, as used herein, means the complete unit including the glass envelope and the end pieces and plugs for mounting in a lamp fixture, and wires which connect the internal components of the envelope with the end pieces.
During manufacture of fluorescent or low pressure mercury arc lamps an amount of elemental mercury (HgO) is sealed in the lamp envelope. Most of the mercury adheres to the phosphor coating, a small amount being in the vapor phase. During operation, alkali metal carbonates from the electrodes decompose and form free oxygen in the lamp. The oxygen may react with a portion of the mercury to form soluble mercury oxide (HgO). Soluble mercury oxide is leachable from land fills and other disposal facilities. Soluble mercury oxides or other oxidized forms of mercury formed in the course of the test are detrimental to the accuracy and reliability of the standard test for determination of the leachability of toxic materials from lamp waste. This test is generally referred to as the Toxicity Leaching Characteristic Procedure or TLCP test. There is concern about the environmental impact of soluble mercury compounds which can leach into ground water sources, rivers, streams, and the like.
تحقیق آنتی اکسیدان 8 ( Anti oxidant )
چکیده:
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| ABSTRACT |
Background: Considerable scientific evidence suggests that whole grains, as commonly consumed in the United States and Europe, reduce risk for chronic disease including cancer and heart disease. Whole grains provide a wide range of nutrients and phytochemicals that may work synergistically to optimize human health. Fruits and vegetables provide protection against age related diseases. It is believed their high content of antioxidant compounds is key to such protection.
Objective: This research compares the antioxidant activity of whole grain, ready-to-eat (RTE) breakfast cereals to that of fruits and vegetables.
Method: Antioxidant activity was determined by dispersing finely ground samples in a 50% aqueous methanol solution of the stable free radical 2,2-diphenyl-l-picrylhydrazyl (DPPH). DPPH, which forms a deep purple solution, reacts with antioxidants and color loss at 515 nm correlates to antioxidant content, which is expressed as Trolox equivalents/100 grams (TE).
Results: Whole grain breakfast cereals analyzed in this study contained from 2200-3500 TE. By comparison, fruits generally ranged from 600-1700 TE, with a high of 2200 TE for red plums. Berries averaged 3700 TE and vegetables averaged 450 TE with a high of 1400 TE for red cabbage. A 41 gram average serving of RTE breakfast cereal provides 1120 TE, while an average 85 gram serving of vegetables or fruits provides 380 and 1020 TE, respectively.
Conclusion: Whole grain breakfast cereals, fruits and vegetables are all important dietary sources of antioxidants.
Key words: antioxidant, whole grain, breakfast cereal, fruit, vegetable, diphenylpicrylhydrazyl, DPPH
تحقیق آنتی اکسیدان 7 ( Anti oxidant )
چکیده:
Antioxidant Status of Vegetarians
While physicists since Einstein have been struggling to piece together a Grand Unified Theory to explain the underlying cause of forces like gravity and electromagnetism, medical scientists have been trying to piece together the underlying cause of aging and disease. Perhaps the leading contender is the Oxidant Stress Theory, which posits that free radicals cause the tissue damage that underlies most of our chronic disease states as well as the age-related deterioration in our bodies. Basically, the theory contends, we're rusting. Just like rust is the oxidation of metal, aging and disease can be thought of as the oxidation of our bodies.
The Oxidant Stress Theory explains why fruit and vegetable consumption seems to protect against almost every disease from Alzheimer's and cancer to heart disease and stroke. The antioxidants found in whole plant foods (fruits, vegetables, beans, nuts, seeds, and whole grains) play a role in squelching the free radicals we produce within our own bodies and are exposed to within our environment.
It is not surprising then that vegetarians have both higher levels of antioxidants in their blood and correspondingly lower rates of chronic disease. What few scientists have looked into, though, in terms of completing the chain of causation, is a demonstration that vegetarians have lower levels of the intermediate indicators of oxidized tissue damage. Recently, though, researchers in the Slovak Republic have closed the gap.
تحقیق آنتی اکسیدان 6 ( Anti oxidant )
چکیده:
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| Abstract |
Background Exposure to estrogens reduces the risk for coronary artery disease and associated clinical events; however, the mechanisms responsible for these observations are not clear. Supraphysiological levels of estrogens act as antioxidants in vitro, limiting oxidation of low-density lipoprotein (LDL), an event implicated in atherogenesis. We investigated the conditions under which physiological concentrations of 17ß-estradiol (E2) inhibit oxidative modification of LDL. Methods and Results Plasma incubated with E2 (0.1 to 100 nmol/L) for 4 hours yielded LDL that demonstrated a dose-related increase in resistance to oxidation by Cu2+ as measured by conjugated diene formation. This effect was dependent on plasma, because incubation of isolated LDL with E2 at these concentrations in buffered saline produced no effect on Cu2+-mediated oxidation. Incubation of plasma with E2 had no effect on LDL -tocopherol content or cholesteryl ester hydroperoxide formation during the 4-hour incubation. Plasma incubation with [3H]E2 was associated with dose-dependent association of 3H with LDL. High-performance liquid chromatographic analysis of LDL derived from plasma incubated with [3H]E2 indicated that the majority of the associated species were not detectable as authentic E2 but as nonpolar forms of E2 that were susceptible to base hydrolysis consistent with fatty acid esterification of E2. Plasma-mediated association of E2 and subsequent antioxidant protection was inhibited by 5,5'-dithio-bis(2-nitrobenzoic acid), an inhibitor of plasma acyltransferase activity. Conclusions Exposure of LDL to physiological levels of E2 in a plasma milieu is associated with enhanced resistance to Cu2+-mediated oxidation and incorporation of E2 derivatives into LDL. This antioxidant capacity may be another means by which E2 limits coronary artery disease in women.
تحقیق آنتی اکسیدان 5 ( Anti oxidant )
چکیده:
POLYPHENOL CONTENT AND ANTIOXIDANT ACTIVITY OF RYE BRAN EXTRUDATES PRODUCED AT VARYING PARAMETERS OF EXTRUSION PROCESS
ABSTRACT
Extrusion, a popular method of cereal processing, increases the amounts of phenolic acids in cereal grain. These compounds protect the human body from oxidation stress and prevent the development of chronic diseases. The present study determined the composition of phenolic acids in rye bran after extrusion and defined the antioxidant activity of the extrudates. The bran was obtained through the laboratory milling of the grain of three rye cultivars, namely Amilo, Rostockie and Agrikolo. Extrusion was performed in a single-screw laboratory extruder Brabender 20 DN equipped with a 3:1 screw and a 3 mm die. Screw speed was maintained at 190 rpm while two temperature profiles, 80-100-120°C and 120-160-180°C, were applied. Prior to extrusion, the moisture of the rye bran to be processed was equilibrated to 14 or 20%.
The main phenolic acid found in rye bran was ferulic acid. Irrespective of rye cultivar and the parameters of processing, the ferulic acid and diferulic acid contents increased two times, and the p-coumaric acid content increased by 70% due to extrusion. The levels of other phenolic acids and apigenin decreased or did not change. The exception was caffeic acid whose amount in extrudates was higher than in bran for the Amilo and Rostockie cultivars and was lower for Agrikolo. Using a 14% moisture of the original material and a temperature of 120 or 180°C as parameters of the extrusion process produced the highest antioxidant activity of rye bran extrudates. Key words: antioxidant activity, phenolic acids, rye bran extrudates.
تحقیق آنتی اکسیدان 4 ( Anti oxidant )
چکیده:
Energize Your Heart!*
Co-Enzyme Q-10 - 100 mg.
CoQ10 is essential for energy production in virtually all living organisms. This important nutrient is a vitamin-like substance that supports energy metabolism in the body, and plays a crucial role in helping cells reproduce. The beneficial effects of CoQ10 have been documented in many clinical trials.*
A study at the University of California suggested that CoQ10 is an effective antioxidant that helps protect against free radical damage. The heart, with its high energy demands, contains very high concentrations of CoQ10. Numerous studies indicate that CoQ10 benefits the cardiovascular system and may help improve healthy heart function. Some studies have also suggested that reduced levels of CoQ10 in the body may contribute to aging, while increasing those levels may actually slow down the process.* Because the body’s ability to synthesize CoQ10 slows down as we age, it is important to replenish this vital nutrient daily.
تحقیق آنتی اکسیدان 3 ( Anti oxidant )
چکیده:
Antioxidant Foods
Fruits and vegetables supply antioxidants other than those you can get from pills, say researchers at the USDA’s Jean Mayer Human Nutrition Research Center on Aging at Tufts University in Boston. Ron Prior and co-workers fed 36 men and women aged 20 to 40 or 60 to 80 a diet containing ten servings of fruits and vegetables a day. Then they measured the “antioxidant capacity” of the participants’ blood samples by seeing how well the blood deactivated damaging oxidized free radicals in a test tube. After two weeks, the antioxidant capacity of the participants’ blood rose in both groups, though more consistently in the older people. “Based on this and other studies, it appears that compounds other than vitamins C and E and carotenoids contribute a major portion of the increase in antioxidant capacity,” says Prior. Among the foods with the highest antioxidant capacity were oranges,cauliflower, and peas.
تحقیق آنتی اکسیدان 1 ( Anti oxidant )
چکیده:
The Power of Fruit, Green Tea and CoQ-10 High Potency Antioxidant and Cardiovascular Boosters
PomBerri™ & Green Tea with CoQ-10
High Potency Antioxidant Complex
What you and I think of as “aging” is actually caused by the never-ending barrage of free radicals on our body. Have you ever seen a peeled apple turn brown? Free radicals are the culprit. The same thing happens within our cells.
If you already notice unsightly age spots on your hands, fine lines and wrinkles, or less energy and vitality – that’s evidence of free radical damage in action.
Pomegranate Extract For Optimal Heart Health!
At the heart of this formula is PomElla®, a patent-pending pomegranate extract that not only is a potent antioxidant, but also supports healthy vascular function. This premium phytonutrient blend is the only extract standardized to punicaligins, the main polyphenol responsible for pomegranate’s superior bioactivity.*
Ongoing studies also show that PomElla® has been found to inhibit oxidation of LDL cholesterol five times better than Vitamin E.*
تحقیق آنتی اکسیدان2 (Anti oxidant)
چکیده:
Anti oxident – “Purple Corn Kernels (raw, organic)''
Organic Heirloom Purple Food!
Get your antioxidants, boost your immunity, eat like the ancients and much more. Rare, Raw, Purple Corn Kernels are now available to you!
Corn was the primary food of nearly all Native American tribes living in North, Central and South America! Purple corn, one of the sacred crops of the Incas, keeps surprising us. Most people don't even know that a purple variety of corn exists!
A RARE BREED
Purple Corn is a rare commodity. Peru is the only country that produces purple corn commercially. Annually, around 12,000 to 15,000 acres are planted with non-GMO/non-hybridized purple corn. While there are multiple varieties of purple corn, all of them originated from an ancestral line called "Kculli", still cultivated in Peru. The Kculli line is very old. Ancient objects in the shape of these particular ears of corn have been found in archeological sites at least 2,500 years old. The Purple Corn we offer is from this ORIGINAL LINE, which helps to explain it's great taste and nutrition levels.As interesting as it's history is Purple Corn's promise to your taste buds and health. For starters:
* Blueberries have gotten lots of press lately and are regarded by many as the top antioxidant food. Yet, it's a little known fact that Purple Corn has a higher antioxidant capacity and anti-free-radical effect than blueberries and higher or similar anthocyanine and phenolic contents.