ریز مغذیها

|+| نوشته شده توسط مونا همایی در چهارشنبه سیزدهم دی 1391  |
 ترجمه قسمت دوم مقاله کافئین(اثرات روانی)
موسسه ملی بهداشت و درمان ایالات متحده امریکا:استفاده بیش از حد کافئین میتواند شما را بیقرار،مضطرب و تحریک پذیر کند.همچنین ممکن است شما را از یک خواب خوب حفظ کند(موجب کم خوابی شما شود)و باعث سردرد،ریتم غیر طبیعی قلب و مشکلات دیگر باشد.اگر شما استفاده از کافئین را متوقف کنید شما نشانه هایی شبیه به ترک مصرف یک دارو را دریافت خواهید کرد(شبیه ترک اعتیاد).برخی از افراد حساسیت بیشتری نسبت به اثرات کافئین نسبت به دیگران دارند آنها باید مصرف کافئین خود را محدود کنند(خانمهای باردار و پرستار)  

4 اختلال روانپزشکی ناشی از مصرف کافئین در انجمن (APA)امریکا به رسمیت شناخته شده است.از جمله:مسمومیت با کافئین،اختلال خواب ناشی از کافئین،اختلال اضطرابی ناشی از کافئین و  اختلالات مربوط به کافئین که به یک روش خاص نیستند(NOS)(این اختلالات همه به یک روش نیستند. بروز این مشکلات متفاوت است.) در تعریف اختلال خواب ناشی از کافئین به عنوان مثال یک فرد که بطور منظم دوز بالایی از کافئین را مصرف میکند  موجب اختلال قابل توجهی در خواب خودش میشود که به لحاظ بالینی قابل توجه میباشد.تا سال2010 اثر کافئین بر افراد مبتلا بهADHDشناخته شده نبود.بعضی مطالعات نشان داده اند که بطور نسبی کافئین محافظی در برابر بیماری آلزایمر است اما این شواهد قطعی نمیباشد.

کافئین میتواند دو اثر مثبت و منفی بر اختلالات اضطرابی داشته باشد.تعدادی از مطالعات بالینی نشان دادهاند که ارتباط مثبتی بین کافئین و اثراتANXIOGENIC و یا اختلالات ناشی از ترس وجود دارد.در خوراک(دوز)بالامعمولا بیشتر از 300میلی گرم کافئین میتواند علت بدتر شدن اضطراب و به ندرت جنون(روان پریشی) باشد.کافئین در مصرفهای کمتر ممکن است علائم افسردگی و خطر خود کشی را کاهش دهد.بطور معمول بر یادگیری و حافظه تاثیر نمیگذارد و میتواند عملکردهای شناختی را بهبود بخشد بخصوص در افرادی که خسته هستند که احتمالا دلیل آن تاثیر بر هوشیاری است.با این حال در افراد مبتلا به اضطراب حساسیت به کافئین زیاد است و باید نسبت به مصرف آن پرهیز داشته باشند.برای برخی از مردم اضطراب زیاد میتواند با قطع مصرف کافئین کاهش یابد.بر خلاف باور رایج برخی از تحقیقات نشان میدهد که کافئین انگیزه ای را در انسان افزایش نمیدهد و حتی ممکن است انگیزه(اراده)را در بعضی افراد کاهش دهد.

|+| نوشته شده توسط مونا همایی در چهارشنبه سیزدهم دی 1391  |
 CAFEINE

Physical effects

Consumption of large amounts of caffeine – usually more than 250 mg per day – can lead to a condition known as caffeinism. Caffeinism usually combines caffeine dependency with a wide range of unpleasant physical and mental conditions including nervousness, irritability, restlessness, insomnia, headaches, and heart palpitations after caffeine use.[17]

Coffee consumption is associated with a lower overall risk of cancer.[18] This is primarily due to a decrease in the risks of hepatocellular and endometrial cancer, but it may also have a modest effect on colorectal cancer.[19] There does not appear to be a significant protective effect against other types of cancers, and heavy coffee consumption may increase the risk of bladder cancer.[19] On the other hand, caffeine has been shown to inhibit cellular DNA repair mechanisms.,[2] but only at extreme high concentrations (which would be lethal in humans).[20] There is little or no evidence that caffeine consumption increases the risk of cardiovascular disease, and it may somewhat reduce the risk of type 2 diabetes.[21] Drinking four or more cups of coffee per day does not affect the risk of hypertension compared to drinking little or no coffee. However those who drink 1–3 cups per day may be at a slightly increased risk.[22] Caffeine increases intraocular pressure in those with glaucoma but does not appear to affect normal individuals.[23] It may protect people from liver cirrhosis.[24] There is no evidence that coffee stunts a child's growth.[25] Caffeine may increase the effectiveness of some medications including ones used to treat headaches.[26]

Caffeine consumption during pregnancy does not appear to increase the risk of congenital malformations, miscarriage or growth retardation even when consumed in moderate to high amounts.[27] However as the data supporting this conclusion is of poor quality some suggest limiting caffeine consumption during pregnancy.[28][29] For example the UK Food Standards Agency has recommended that pregnant women should limit their caffeine intake, out of prudence, to less than 200 mg of caffeine a day – the equivalent of two cups of instant coffee, or one and a half to two cups of fresh coffee.[30] Although the evidence that caffeine may be harmful during pregnancy is equivocal, there is clear evidence that the hormonal changes associated with pregnancy slow the metabolic clearance of caffeine from the system, causing a given dose to have longer-lasting effects (as long as 15 hours in the third trimester).[31]

On the positive side, caffeine is the primary treatment of the breathing disorders apnea of prematurity[32] and may also be effective in preventing bronchopulmonary dysplasia in premature infants.[33] The only short-term risk associated with caffeine citrate treatment is a temporary reduction in weight gain during the therapy,[34] and longer term studies (18 to 21 months) have shown lasting benefits of treatment of premature infants with caffeine.[35] However, the possibility of subtle long-term developmental problems cannot be ruled out fully.[36]

When doses of caffeine equivalent to 2–3 cups of coffee are administered to people who have not consumed caffeine during prior days, they produce a stimulation in urinary output.[37] Because of this diuretic effect, some authorities have recommended that athletes or airline passengers avoid caffeine in order to reduce the risk of dehydration.[37] Most people who consume caffeine, however, ingest it daily. Regular users of caffeine have been shown to develop a strong tolerance to the diuretic effect,[37] and studies have generally failed to support the notion that ordinary consumption of caffeinated beverages contributes significantly to dehydration, even in athletes.[38][39][40]

Psychological effects

The US National Institutes of Health states "too much caffeine can make you restless, anxious, and irritable. It may also keep you from sleeping well and cause headaches, abnormal heart rhythms, or other problems. If you stop using caffeine, you could get withdrawal symptoms. Some people are more sensitive to the effects of caffeine than others. They should limit their use of caffeine. So should pregnant and nursing women."[41]

Four caffeine-induced disorders are recognized by the American Psychiatric Association (APA) including: caffeine intoxication, caffeine-induced sleep disorder, caffeine-induced anxiety disorder and caffeine-related disorder not otherwise specified (NOS).[42] The DSM-IV defines caffeine-induced sleep disorder, as an individual who regularly ingests high doses of caffeine sufficient to induce a significant disturbance in his or her sleep, sufficiently severe to warrant clinical attention.[42] As of 2010 the effect of caffeine on people with ADHD is not known.[43] Some studies have however found a modest protective against Alzheimer disease, but the evidence is inconclusive.[44][45][46]

Caffeine can have both negative[47] and positive[citation needed] effects on anxiety disorders. A number of clinical studies have shown a positive association between caffeine and anxiogenic effects and/or panic disorder.[48][49][50] At high doses, typically greater than 300 mg, caffeine can both cause and worsen anxiety[51] and rarely trigger mania and psychosis. In moderate doses caffeine may reduce symptoms of depression and lower suicide risk.[43] In moderate doses caffeine typically does not affect learning or memory,[52] and can improve cognitive functions, especially in people who are fatigued, possibly due to its effect on alertness.[53] [54] [55] However anxiety sufferers can have high caffeine sensitivity.[56][57][58][59][60] For some people, anxiety can be very much reduced by discontinuing caffeine use.[61]

Contrary to popular belief, some research suggests that caffeine does not increase motivation in humans, and may even decrease motivation in some.[62]

Caffeine toxicity

Torso of a young man with overlaid text of main side-effects of caffeine overdose.
Primary symptoms of caffeine intoxication[63]

Caffeine overdose can result in a state of central nervous system over-stimulation called caffeine intoxication (DSM-IV 305.90),[42] or colloquially the "caffeine jitters". The symptoms of caffeine intoxication are comparable to the symptoms of overdoses of other stimulants: they may include restlessness, fidgeting, anxiety, excitement, insomnia, flushing of the face, increased urination, gastrointestinal disturbance, muscle twitching, a rambling flow of thought and speech, irritability, irregular or rapid heart beat, and psychomotor agitation.[63] In cases of much larger overdoses, mania, depression, lapses in judgment, disorientation, disinhibition, delusions, hallucinations, or psychosis may occur, and rhabdomyolysis (breakdown of skeletal muscle tissue) can be provoked.[64][65]

Extreme overdose can result in death.[66][67] The median lethal dose (LD50) given orally, is 192 milligrams per kilogram in rats. The LD50 of caffeine in humans is dependent on individual sensitivity, but is estimated to be about 150 to 200 milligrams per kilogram of body mass or roughly 80 to 100 cups of coffee for an average adult.[4] Though achieving lethal dose with caffeine would be exceptionally difficult with regular coffee, there have been reported deaths from overdosing on caffeine pills, with serious symptoms of overdose requiring hospitalization occurring from as little as 2 grams of caffeine.[citation needed] An exception to this would be taking a drug such as fluvoxamine or levofloxacin, which blocks the liver enzyme responsible for the metabolism of caffeine, thus increasing the central effects and blood concentrations of caffeine five-fold.[65][66][67][68] Death typically occurs due to ventricular fibrillation caused by effects of caffeine on the cardiovascular system.

Treatment of severe caffeine intoxication is generally supportive, providing treatment of the immediate symptoms, but if the patient has very high serum levels of caffeine then peritoneal dialysis, hemodialysis, or hemofiltration may be required.[63]

Addiction and tolerance

With repetitive use, physical dependence or addiction are likely to occur. Also, the stimulatory effects of caffeine are substantially reduced over time, a phenomenon known as a tolerance. Tolerance develops quickly to some (but not all) effects of caffeine, especially among heavy coffee and energy drink consumers.[69] Some coffee drinkers develop tolerance to its sleep-disrupting effects, but others apparently do not.[31]

Withdrawal

Withdrawal symptoms – including headache, irritability, inability to concentrate, drowsiness, insomnia, and pain in the stomach, upper body, and joints – may appear within 12 to 24 hours after discontinuation of caffeine intake, peak at roughly 48 hours, and usually last from 2 to 9 days.[70] In prolonged caffeine drinkers, symptoms such as increased depression and anxiety, nausea, vomiting, physical pains and intense desire for caffeine containing beverages are also reported. Peer knowledge, support and interaction may aid withdrawal.[71
|+| نوشته شده توسط مونا همایی در یکشنبه دهم دی 1391  |
 برندهای معروف روغنهای خوراکی

 

  آفتاب!              جهان!

 

 تک!                اویلا!

 

 لادن!             محسن!

 

 ورامین!           نینا!

 

 دلپذیر!           قو!

 

 ورینا!             بهار!

 

 تبرک!            بهروز!

                         فامیلا!                             

 

 

|+| نوشته شده توسط مونا همایی در شنبه دوم دی 1391  |
 باکتریها در روغن
. This paper presents an overview of the microbiology of sulfate-reducing bacteria (SRB) and their detrimental effects in oil technology and summarizes a study on SRB in an oil field. SRB are a group of specialized microorganisms that occur in aqueous environments in the absence of oxygen. The main nutrients for SRB are simple organic acids and molecular hydrogen (H2) from decomposing natural organic matter. The nutrients are oxidized, with sulfate being reduced to sulfide (hydrogen sulfide, H2S). The formed H2S is the principal agent in the disastrous effects caused by SRB. It contaminates gas and stored oil, precipitates ferrous sulfide that plugs injection wells, and promotes precipitates ferrous sulfide that plugs injection wells, and promotes corrosion of iron and steel in the absence of oxygen (anaerobic corrosion). Another principal mechanism by which SRB are involved in corrosion is their ability to depolarize iron surfaces by consumption of cathodically formed hydrogen. The postulated mechanism in anaerobic corrosion are briefly explained. As an example for a microbiological study of SRB in oil technology, examination of an oil treater in a field in northern Germany is presented. On the basis of measured growth characteristics of the SRB, presented. On the basis of measured growth characteristics of the SRB, possibilities for controlling their activity are discussed. possibilities for controlling their activity are discussed.

Introduction

Biological sulfate reduction by SRB is the only known process by which, in aquatic environments of moderate process by which, in aquatic environments of moderate temperatures (O to 75 degrees C [32 to 167 degrees F]), H2S is formed from sulfate. In sediments of ponds, lakes, and marine environments, SRB are usually part of the indigenous community of microorganisms and are rather inconspicuous in nonpolluted waters. In oilfield water systems, however, SRB cause serious problems: (1) corrosion of iron in the absence of air (anaerobic corrosion), (2) precipitation of amorphous ferrous sulfide that, by precipitation of amorphous ferrous sulfide that, by plugging, diminishes the in injectivity of water injection wells, plugging, diminishes the in injectivity of water injection wells, (3) contamination of fuel gas with H2S, and (4) contamination of stored fuel oil with H2S. Furthermore, H2S is extremely toxic if inhaled: it easily escapes from contaminated waters and may accumulate under poorly ventilated conditions. It is usually recognized by its distinctive, unpleasant odor, but high concentrations anesthetize the sense of smell. The objective of this paper is to present an overview of" the biological features of SRB and of their activities in oil technology with emphasis on anaerobic corrosion. We also include results from our studies on SRB in an oil field in northern Germany.

Microbiology of SRB

SRB are an assemblage of specialized bacteria that thrive in the absence of oxygen and obtain energy for growth by, oxidation of organic nutrients, with sulfate being reduced to H2S. The biological significance of this form of life is best understood within the overall natural decomposition process carried out by living organisms.

Processes in Biological Decomposition. The natural Processes in Biological Decomposition. The natural decomposition of organic material in our biosphere through a food chain of oxygen-breathing (respiring) organisms-namely, animals, fungi, and bacteria-is a well-known process. Biochemically, respiration is a transport of reducing power (hydrogen, "electrons") from the organic nutrients (organic substrates, electron donors) being oxidized to oxygen (electron acceptor) being reduced (Fig. la). Respiration liberates the energy that has been originally conserved in the organic matter during photosynthesis by green plants and cyanobacteria photosynthesis by green plants and cyanobacteria (bluegreen algae). In the oxygen-breathing organisms, the liberated energy is used for maintenance of their living structures and for growth-i.e., a net synthesis of their own cell material from the nutrients. Thus every organic substrate of a respiring organism is partly decomposed for obtaining energy and partly converted into new cell material. These functionally distinctive reactions in living organisms are designated catabolism or dissimilation (energy metabolism) and anabolism or assimilation (cell synthesis), respectively. An amount of biomass initially synthesized by photosynthesis is diminished more and more by passing through the food chain because of respiratory losses. The final result is a reoxidation (mineralization) of the chemically complex biomass to CO7, H2O, and other minerals (Fig. 1a). These inorganic end products are used by green plants and cyanobacteria for products are used by green plants and cyanobacteria for photosynthesis of new organic substances (the natural cycle photosynthesis of new organic substances (the natural cycle of matter). The total reoxidation of biomass is possible only if the conditions are aerobic- i.e., if sufficient oxygen is present. If biomass gets into stagnant or rather closed water present. If biomass gets into stagnant or rather closed water systems where the gas exchange with the atmosphere is limited, dissolved oxygen may be completely consumed.

|+| نوشته شده توسط مونا همایی در سه شنبه بیست و هشتم آذر 1391  |
 انواع روغن

Types        

Organic oils

Organic oils are produced in remarkable diversity by plants, animals, and other organisms through natural metabolic processes. Lipid is the scientific term for the fatty acids, steroids and similar chemicals often found in the oils produced by living things, while oil refers to an overall mixture of chemicals. Organic oils may also contain chemicals other than lipids, including proteins, waxes and alkaloids.

Lipids can be classified by the way that they are made by an organism, their chemical structure and their limited solubility in water compared to oils. They have a high carbon and hydrogen content and are considerably lacking in oxygen compared to other organic compounds and minerals; they tend to be relatively nonpolar molecules, but may include both polar and nonpolar regions as in the case of phospholipids and steroids.[6]

Mineral oils

Crude oil, or petroleum, and its refined components, collectively termed petrochemicals, are crucial resources in the modern economy. Crude oil originates from ancient fossilized organic materials, such as zooplankton and algae, which geochemical processes convert into oil.[7] It is classified as a mineral oil because it does not have an organic origin on human timescales, but is instead obtained from rocks, underground traps, or sands. Mineral oil also refers to several specific distillates of crude oil.

Applications

A bottle of olive oil used in food

Cosmetics

Oils are applied to hair to give it a lustrous look, to prevent tangles and roughness and to stabilize the hair to promote growth.[8][9] See Hair conditioner.

Religion

Oils are commonly used in ritual anointments. As a particular example, holy anointing oil has been an important ritual liquid for Judaism and Christianity.

Painting

Color pigments are easily suspended in oil, making it suitable as a supporting medium for paints. The oldest known extant oil paintings date from 650 AD.[10]

Heat transfer

Oils are used as coolants in oil cooling, for instance in electric transformers. Oils are also used to enhance heating in other applications, such as cooking (especially in frying).

Lubrication

Oils are commonly used as lubricants. Mineral oils are more commonly used as machine lubricants than biological oils are. Whale oil is preferred for lubricating clocks, because it does not evaporate, leaving dust, although its use was banned in 1980.[11] As no suitable substitute is available, whale oil is still used in space (in small quantities).[12]

Fuel

Some oils burn in liquid or aerosol form, generating light, and heat which can be used directly or converted into other forms of energy such as electricity or mechanical work. To obtain many fuel oils, crude oil is pumped from the ground and is shipped via oil tanker to an oil refinery. There, it is converted from crude oil to diesel fuel (petrodiesel), ethane (and other short-chain alkanes), fuel oils (heaviest of commercial fuels, used in ships/furnaces), gasoline (petrol), jet fuel, kerosene, benzene (historically), and liquefied petroleum gas. A 42 gallon barrel (U.S.) of crude oil produces approximately 10 gallons of diesel, 4 gallons of jet fuel, 19 gallons of gasoline, 7 gallons of other products, 3 gallons split between heavy fuel oil and liquified petroleum gases,[13] and 2 gallons of heating oil. The total production of a barrel of crude into various products results in an increase to 45 gallons.[13] Not all oils used as fuels are mineral oils, see biodiesel and vegetable oil fuel.

In the 18th and 19th centuries, whale oil was commonly used for lamps, which was replaced with natural gas and then electricity.[14]

Chemical feedstock

Crude oil can be refined into a wide variety of component hydrocarbons. Petrochemicals are the refined components of crude oil and the chemical products made from them. They are used as detergents, fertilizers, medicines, paints, plastics, synthetic fibers, and synthetic rubber.

Organic oils are another important chemical feedstock, especially in green chemistry.

|+| نوشته شده توسط مونا همایی در سه شنبه بیست و هشتم آذر 1391  |
 بهترین و بدترین روغنهای خوراکی

بهترین و بدترین روغن های خوراکی

بهترین و بدترین روغن های خوراکی
برای ارزیابی انواع روغن های خوراکی و مقایسه ی آنها با هم، ویژگی های زیر را در نظر می گیریم:

 

1- میزان اسیدهای چرب ضروری موجود در روغن2- میزان چربی های غیر اشباع نسبت به چربی های اشباع در روغن (یعنی اینکه چقدر برای قلب مفید است)

3- تأثیر روغن بر کلسترول خون (یعنی آیا کلسترول خون را افزایش می دهد یا کاهش، مخصوصا در افراد دچار چربی خون بالا)

4- سایر فواید روغن

5- مزه آن

6- وجود بقایای آفت کش ها در روغن در طی فرآیند آن

7- تاثیر گذاری روش های فرآیند روی ارزش تغذیه ای روغن

البته باید گفت اینکه بعضی روغن ها بهتر از انواع دیگر هستند نباید باعث شود فقط یک یا دو تا از بهترین های آنها را همیشه مصرف کنیم و بقیه را نه. توجه داشته باشید رعایت اعتدال، نکته کلیدی در تغذیه مناسب است و تغذیه ی مناسب بر اساس تنوع و تعادل غذایی استوار است.

بهترین روغن ها:1- روغن بذر کتان:
روغن بذر کتان بهترین منبع اسیدهای چرب امگا- 3 است. برای قلب و روده ها مفید است. یبوست را کاهش می دهد. قدرت ایمنی بدن را تقویت می کند. سلامت پوست را ارتقا می بخشد. لیگنین (فیبر غذایی غیرمحلول) دارد که برای بدن مفید است. ولی اگر به طور صحیح نگهداری نشود، به سرعت فاسد می شود . برای پخت غذا مناسب نیست.

2- روغن کانولا:روغن کانولا منبع غنی اسیدهای چرب امگا- 3 و امگا- 6 است. مقدار چربی های اشباع در آن خیلی کم است، در نتیجه برای قلب مفید است.

3- روغن سویا:
روغن سویا دارای اسیدهای چرب امگا- 3 و امگا- 6 است، ولی اغلب خیلی تصفیه و هیدروژنه (جامد) می شود.

4- روغن زیتون (خالص یا خیلی خالص):
هنگام استخراج روغن زیتون از میوه ی آن، نیازی به حرارت بالا و فرآیند شیمیایی نیست. به کندی فاسد می شود. برای پخت غذا در درجه حرارت معمولی مناسب است. در صورت مصرف متعادل،LDL (چربی بد) را کاهش می دهد، بدون اینکه میزان HDL (چربی خوب) را تغییر دهد، در نتیجه نسبت HDL به LDL را بهبود می بخشد که برای سلامتی بدن مفید است.5- روغن تخم کدو حلوایی: روغن کدو حلوایی چربی اشباع کمی دارد. منبع غنی اسیدهای چرب امگا- 6 است. ممکن است بعضی اسیدهای چرب امگا- 3 را نیز داشته باشد. عمل تصفیه کردن و فرآیندهای شیمیایی در کارخانه، ارزش تغذیه ای آن را کاهش می دهد.

روغن های حد وسط:1- روغن گلرنگ: چربی اشباع کم و اسیدهای چرب امگا- 6 زیادی دارد.

2- روغن آفتابگردان: روغن آفتابگردان منبع غنی اسیدهای چرب امگا- 6 است.

3- روغن ذرت: روغن ذرت منبع غنی اسیدهای چرب امگا- 6 است. چربی اشباع آن کمی بیشتر از روغن های گروه اول (بهترین روغن ها) است. اغلب هیدروژنه (جامد) می شود.

4- روغن بادام زمینی: تا حدودی چربی اشباع روغن بادام زمینی بالاست، ولی کمتر از کره، چربی حیوانی و روغن پنبه دانه است. برای پخت و پز غذا در درجه حرارت بالا مناسب است.

بدترین روغن ها:1- روغن پنبه دانه: چربی اشباع زیادی دارد. دارای بقایای ضد آفت های گیاهی است. بیشتر اوقات هیدروژنه (جامد) می شود.

2- روغن هسته خرما (روغن پالم): روغن پالم دارای چربی اشباع بالایی است، در نتیجه کلسترول خون را افزایش می دهد.

3- روغن نارگیل: روغن نارگیل از تمام انواع روغن های گیاهی، چربی اشباع بیشتری دارد و برای سلامت قلب مضر است.
|+| نوشته شده توسط مونا همایی در سه شنبه بیست و هشتم آذر 1391  |
 تشخیص خلوص روغن(زیتون-بادام-کنجد)


تشخیص خلوص روغن زیتون:ابتدا 5ccروغن زیتون را داخل لوله آزمایش ریخته و به آن 6قطره H2SO4 و 9 قطره HNO3 اضافه کرده و آن را به مدت 5 دقیقه در بن ماری قرار داده و نتیجه آزمایش را مشاهده میکنیم.

تغییر رنگ در روغن زیتون خالص به رنگ زرد روشن یا زرد مایل به سبز است و در رئغن ناخالص به رنگ قهوه ای  میباشد.

نتیجه بدست آمده در آزمایش فوق طبق عکس نشان دهنده روغن زیتون ناخالص میباشد.(اولین لوله  سمت چپ در عکس)

تشخیص خلوص روغن بادام:ابتدا 5ccروغن  بادام را داخل لوله آزمایش ریخته و به آن 1ccمعرف بی بر اضافه کرده و بعد از 15 دقیقه تغییر رنگ را مشاهده میکنیم.

تغییر رنگ در روغن بادام خالص به رنگ قهوه ای روشن و در روغن ناخالص به رنگ صورتی میباشد.

نتیجه به دست آمده در آزمایش فوق طبق عکس نشان دهنده روغن بادام خالص میباشد(لوله دوم از سمت چپ در عکس)

تشخیص خلوص روغن کنجد:2ccروغن کنجد و 1cc HCLمساوی 1درصد ساکارزرا در لوله آزمایش ریخته و به مدت 5 دقیقه آن را ثابت میگذاریم.

رنگ قرمز نشان دهنده حضور سزامول میباشد که انتی اکسیدان روغن کنجد است و رنگ قهوه ای ممکن است بوسیله برخی از روغنهای دیگر نیز ایجاد شود.

|+| نوشته شده توسط مونا همایی در سه شنبه بیست و هشتم آذر 1391  |
 اسیدهای چرب اشباع در مواد غذایی

Top 10 Foods Highest in Saturated Fat

160 24 17 11 Share2372

Saturated fat has long been associated with increased risk of heart disease, stroke, and even cancer. While such evidence is controversial, it still doesn't hurt to limit intake of saturated fats. The key word being limit and not eliminate. Don't substitute anything on this list with trans fats, or margarine, as they are now seen as being even worse for health than natural saturated fats. The DV for saturated fat is 20 grams per day. Below is a list of the top ten foods highest in saturated fat.

#1: Hydrogenated Oils (Palm, Coconut)
With every carbon bond saturated by a hydrogen atom, hydrogenated oils are, by definition, the food with the highest amount of saturated fat. Commercially processed palm kernel and coconut oils are 93% saturated fat, accounting for around 470% of the DV per 100 gram serving, 13g (65% DV) per tablespoon. Natural palm and or coconut oil contains slighty less saturated fat at 86.5g (433% DV) per 100g serving, and 12g (61% DV) of saturated fat per tablespoon.

#2: Dried Coconut
Coconut is often used in sweet confections like cakes and candy bars. Dried coconut can also be found in some Asian curries and soups. Dried unsweetened coconut contains 57 grams of saturated fat per 100 gram serving, or 286% of the DV. The sweetened flake variety of coconut contains half as much saturated fat at 26 grams or 132% DV. The raw coconut meat has 27 grams per 100 gram serving or 148% of the DV.

#3: Butter
Common in cakes, cookies, on bread, and vegetables, butter is everywhere. 100 grams of butter packs 51 grams (257% DV) of saturated fat, one stick has more with 58 grams (290% DV), and one table spoon contains 7 grams or 36% of the DV.

#4: Rendered Animal Fats (Tallow, Suet, Lard, Shortening (Includes vegetable)
These fats are typically used to make burgers, meatballs, sausages, gravy, or fried foods. In general these fats are around 40% saturated fat, with a 100 gram serving providing between 35-45 grams or 180-225% DV. Bacon grease is 40% saturated fat, 195% DV per 100 grams. Vegetable shortenings will also contain similar quantities of saturated fats. .

#5: Dark Chocolate
Dark chocolate is a nutrient and antioxidant packed food that is probably your best source of saturated fat, just remember, moderation! One hundred grams of pure baking chocolate (about a cup) will provide 32g saturated fat (162% DV). A bar of milk chocolate in contrast has 9.1 grams of saturated fat, or 46% of the DV. Pure cocoa powder contains hardly any saturated fat at all, less than 2% and can be used as a good substitute in baking, or in preparing Chocolate Banana Pudding. Some types of Cocoa powder may contain up to 25% saturated fat, so check nutrition labels to be sure of the saturated fat content. .

#6: Fish Oil (Menhaden and Sardine)
Even though fish and fish oils do carry good omega 3 fats their quantity of saturated fats should not be ignored. The fish with the most saturated fats are Menhaden and Sardine oils (30% saturated fat), Cod liver oil (23%), Herring oil (21%), and Salmon oil (20%).

#7: Cheese
A vegetarian source of protein, and also a good source of calcium, cheese is a tasty addition to most any dish. Hard goat cheese contains the most saturated fat at 24 grams per 100 gram serving, or 123% of the DV. It is followed by Cheddar (105% DV), Roquefort (96% DV), Fontina (96% DV), and Gjetost, Gruyere, Muenster, Monterey, and Parmesan all at 95% DV per 100 grams, or about 20% saturated fat.

#8: Nuts and Seeds (Pilinuts, Brazilnuts, Macadamia)
Packed with vitamins, minerals, and heart healthy fats and fibers, nuts and seeds are a great snack food, particularly if they are dry roasted unsalted. They do, however, also carry saturated fats, the highest being pilinuts at 31% saturated fat, or 156% DV per 100 grams. It is followed by Brazil nuts (15% saturated fat), Macadamia (12%), Watermelon seeds (10%), Cashews (10%), Pine nuts (10%), and Sesame Seeds (9%).

#9:Processed Meats (Sausage and Pâté)
Sausages and Pâté contain a lot of the animal fats that are #4 on this list, so it is no surprise that they appear here. Most sausages and pâtés are 15% saturated fat. A single serving of Bratwurst (84 grams) will have 12.5 grams of saturated fat for 63% of the DV.

#10: Whipped Cream
The classic topping to cakes, pies, and coffees, whipped cream is about 14% saturated fat. One hundred grams provides 14 grams of saturated fat, or 69% of DV. One cup provides 41% DV, and a tablespoon(3g) provides 2% DV.

|+| نوشته شده توسط مونا همایی در شنبه بیست و پنجم آذر 1391  |
 کلسترول در مواد غذایی
Cholesterol is a steroid lipid (fat) found in the blood of all animals and is necessary for proper functioning of our cell membranes and production of hormones. While there can be negative health benefits associated with low cholesterol, cholesterol deficiency is rare. Our bodies already manufacture all the cholesterol we need, so it is not necessary to consume more. Excessive consumption of cholesterol has been shown to increase the risk of heart disease and stroke. Cholesterol is only found in animal food products, and thus, vegans are likely to have lower cholesterol than non-vegans. It is recommended that you buy a Cholesterol Test Kit, so you can monitor your cholesterol levels at home and see which diet works best for you. The current percent daily value (DV) for cholesterol is 300mg. Below is a list of high cholesterol foods, click here for an extended list of cholesterol rich foods. To lower your cholesterol, read the article on cholesterol lowering foods.


#1: Egg Yolk
The yolks of eggs have the most cholesterol of any food with 1234mg per 100 gram serving or 411% of the DV. A single egg yolk will provide 210mg (70% DV) of cholesterol, while a whole egg provides slightly more with 212mg (71% DV). Thus all the cholesterol in eggs is found in their yolks.

#2: Caviar (Fish Roe)
A common spread for breads in Northern and Eastern Europe, caviar is packed with cholesterol. 100 grams provides 588mg (196% DV), that is 94mg (31% DV) per tablespoon.


#3: Liver, Pate, Foie Gras
Cholesterol is manufactured by the liver, and therefore liver in cuisine contains a lot of cholesterol. The liver from most any meat will contain 564mg of cholesterol per 100 grams or 188% of the DV. Foie Gras (and most pâtés) contain 255mg (85% DV) per 100g serving,or 20mg (7% DV) per tablespoon.

#4: Butter
Common in cakes, cookies, on bread, and vegetables, butter is everywhere. 100 grams of butter packs 215mg (72% DV) of cholesterol, one stick has more with 243mg (81% DV), and one tablespoon contains 30mg (10% DV).
.

#5: Shrimp (Prawns, Camarones)
100 grams of shrimp will contain 195mg (65% DV) of cholesterol. A single large shrimp contains 11mg (4% DV), and an ounce of shrimp will provide around 55mg (18% DV).
.

#6: Fast Foods (Breakfasts)
Fast foods, the breakfasts in particular, are packed with cholesterol. A ham, egg, and cheese biscuit will provide 172mg (57% DV) per 100g serving, or 246mg (82% DV) of cholesterol per biscuit. An egg and sausage biscuit has even more with 261mg (87% DV).
.

#7: Oil Packed Fish
Although thought to be good for your heart, the oil of fish, and oil packed fish, does contain quite a bit of cholesterol. Oil packed Atlantic Sardines carry 142mg (47% DV) of cholesterol per 100g. That is 131mg (44% DV) per can, and 17mg (6% DV) in a single sardine.
.

#8: Cheese
A vegetarian source of protein, and also a good source of calcium, cheese is a tasty addition to most any dish. Port de Salut contains the most cholesterol with 123mg (41% DV) per 100 gram serving. That is 21mg (7% DV) per one inch cube. Other cheeses high in cholesterol include: Fontina (39% DV), Gouda (38%), Cream Cheese (37% DV), Gruyere (37%), and Cheddar (35% DV).
.

#9: Processed Meats (Sausage, Lamb, Duck)
The amount of cholesterol in any processed meat depends on the cut used, and the amount of fat added during processing. Liver sausage and bratwurst will contain around 158mg (50% DV) of cholesterol per 100 gram serving. That is 63mg (21% DV) per link. In terms of meats, lamb and duck will contain the most cholesterol all things being equal.

#10: Shellfish (Oysters, Clams, and Mussels)
Shellfish can be eaten raw, baked, steamed, fried, or made into chowder. Wild Eastern Oysters contain the most cholesterol with 105mg (35% DV) per 100g serving. That is 30mg (10% DV) per ounce, or 7mg (3% DV) per oyster.


|+| نوشته شده توسط مونا همایی در شنبه بیست و پنجم آذر 1391  |
 
 
 
بالا