Our body needs beta-carotene in very small quantities; moreover, excess beta-carotene can even have side effects.

What is beta-carotene - what is it for?

Beta carotene is classified as carotenoid, natural antioxidant, present in a variety of plants that perform important functions in our body.

An antioxidant is a molecule capable bind and therefore inactivate free radicals, are a type of chemically reactive molecules that can cause irreparable damage to cellular structure.

As an antioxidant, beta-carotene performs important functions in our body:

• together with other carotenes it is used for vitamin A synthesis, which is important for the growth and development of bones, for vision, for reproduction;
• along with protects skin from damage due to sun exposure such as dryness and aging skin.

Where to find beta-carotene - not just carrots

Beta-carotene is a pigment that gives food its orange-reddish color.

Most abundantly represented in the following products:

• carrot, from which it was first isolated, potatoes and peppers, as well as zucchini, apricots, peaches and grapefruits.
• some vegetables such as chard, spinach, lettuce and kale contain a lot of beta-carotene, but it is “hidden” behind the bright green chlorophyll.
• beta-carotene is also present in some grains (corn, barley) and algae.

Properties and Benefits of Beta Carotene

The beneficial effect of beta-carotene, as an antioxidant and precursor of vitamin A, is expressed in relation to various organs and systems:

• For skin: Beta-carotene protects the skin during sun exposure, preventing the appearance of erythema. The accumulation of beta-carotene in the skin gives it a yellow-orange color and enhances the action of melanin, which is responsible for natural tanning. Even in the case of vitiligo, beta-carotene helps avoid sunburn on the white areas of the skin and therefore more sensitive.
• For eyes: Some of the beta-carotene that enters the body is transferred to the retina, where it is converted into vitamin A. At this level, vitamin A is necessary in order, together with other pigments (for example, rhodopsin), to realize the ability to night vision. Consequently, beta-carotene deficiency can lead to decreased ability.
• For hair: Beta-carotene, like provitamin A, is important for the well-being of skin and scalp cells. Vitamin A is a component of the cell membrane and when deficient in it can lead to excessive production of keratin, and therefore dry scalp.
• Acne: Vitamin A is a component of scar tissue; beta-carotene, both internally and topically, may be helpful in restoring facial skin after acne.

Medicinal supplements with beta-carotene

Despite the fact that beta carotene is present in many foods, it can sometimes be deficient, especially in the presence of intestinal pathologies that limit the absorption of vitamin A and its precursors. Since vitamin A is part of many biological mechanisms, there may be several symptoms associated with its deficiency: dry skin and hair, frequent infections, decreased visual acuity, fatigue, poor appetite.

In these cases it is useful to resort to using beta-carotene based nutritional supplements. They may contain beta-carotene of natural origin, that is, extracts, or synthetic.

There are several benefits of additionally using beta-carotene:

• preventing breast and ovarian cancer in women during menopause, thanks to its antioxidant effect, which neutralizes free radicals responsible for damage to DNA and enzymes responsible for controlling cell replication;
• reducing the risk of sunburn, since beta-carotene is a pigment that can protect against damage caused by sun exposure, even in the case of pathologies such as protoporphyria, which predisposes to sunburn.

A pinch a day, and nothing more!

Beta-carotene enters the body through food, absorbed in the intestines and accumulates in the liver. When the body requires vitamin A, beta-carotene reserves from the liver are mobilized and converted into this vitamin.

How much beta-carotene do we need per day? In fact, very little: only 2 mg per day, which are contained in one carrot (30 g), 5-6 apricots (130 g) or 50 g of spinach or chard.

Regarding food additives based on beta-carotene, usually the dosage is one capsule per day.

Beta-carotene poisoning and side effects

In order to get all the benefits of beta carotene, it is enough to take, as we have seen, 2 mg per day, but what happens if you take it in excessive doses?

• Beta-carotene poisoning: In moderate doses, beta-carotene will give the skin a nice tan color, but if consumed in excess, the effect will be like jaundice. However, skin color will be restored if you avoid or reduce the dose of beta-carotene.
• Increased incidence of cancer in smokers: Some studies have shown that beta-carotene increases the likelihood of developing cancer in people who smoke. However, the mechanism by which beta-carotene promotes the occurrence of malignant tumors in smokers has not yet been elucidated.
• Liver and kidney fatigue: Excessive use of antioxidant supplements may be harmful to humans. Along with antioxidants, we have to ingest excipients - synthetic molecules that take away the resources of the liver and kidneys for their metabolism and excretion.

As we have seen, beta-carotene, being an antioxidant, can have side effects if taken in excess. A healthy and balanced diet, without excesses, will provide the body with everything it needs. You should seek the help of nutritional supplements only in cases of real need.

Finally, Beta-carotene does not make you fat: It is not used in our body to produce energy and has no effect on overall metabolism!

Today I will tell you how to get a golden, radiant and attractive skin tone without makeup and a solarium. Intrigued? In fact, everything is quite simple. Experts from the University of St. Andrews gathered a group of volunteers to analyze the effect of diet on skin color. They took photographs of people before and after the nutrition course. It turned out that fruits and vegetables led to an increase in the natural red and yellow undertones of the skin (in fact, it darkened). When assessing attractiveness, such skin is recognized as the healthiest and sexiest.

Vegetables (carotenes) are on the right!

Skin tone depends on the combination of pigments: melanin, hemoglobin and carotenes. Melanin depends on your genetics and the sun, but hemoglobin is found in blood vessels, so the redness of the skin depends on their tone and depth. If you get a bruise, it will change color due to the breakdown of hemoglobin into components of different colors. It is hemoglobin that makes cheeks pink and allows people to blush when excited, when blood vessels dilate under the influence of the release of hormones.

Dr Ross Whitehead, who led the study, believes that vegetables and fruits could be a (much healthier) replacement for tanning beds. A separate experiment was also conducted: scientists asked people to rate the attractiveness of several people. As a result, “people with a healthy complexion” most often received positive reviews.

It was previously known that some vegetables, such as carrots, can contribute to orange skin color, but this was not so significant. But now it has been experimentally proven that an increase in pigments in the skin can be noticeable to others. Using light sensors, the researchers showed that red and yellow hues were associated with carotenoid levels in the skin.

There are hundreds of different types of carotenoids. The main representatives of carotenoids in higher plants are two pigments - carotene (orange) and xanthophyll (yellow). But in this experiment, lycopene from tomatoes and red peppers, as well as beta-carotene contained in carrots, as well as broccoli, zucchini, and spinach, had the strongest effect on the skin. Skin color can also be affected by chemicals called polyphenols, found in apples, blueberries and cherries, which cause blood to flow to the surface of the skin.

Ross Whitehead, the experiment's lead scientist, published the research in the journal PLoS ONE. In his interview, he said that even experts did not expect such a diverse influence of vegetables and fruits, as the experiment showed.

The main source of carotenoids is greens and vegetables. The content of carotenoids in food correlates with their content in the skin, and carotenoids are found in all layers of the skin. These studies also found that the skin tone that carotenoids give to the skin is perceived as healthier and sexier than a tan obtained only from a solarium. Of course, both colors also interact effectively with each other.

Carotenoids and skin color

Carotenoids are a large group of pigments that have a very wide range of positive effects on our health. Of these, only beta-carotene can be toxic in high doses. However, natural sources of carotenes contain a mixture of them (lycopene, beta-carotene, alpha-carotene, lutein, zeaxanthin, etc.), which can be converted into each other, which makes them safe. Also among the carotenoids is the king of antioxidants - astaxanthin, which I recently wrote about.

Animals (including humans) cannot synthesize carotenoids de novo; their intake depends only on food sources. The absorption of carotenoids, like other lipids, occurs in the duodenal region of the small intestine. Under the influence of the gastrointestinal environment (for example, the acidity of gastric juice), the presence of specific protein receptors, carotenoids can be destroyed by oxidizing agents or enzymes or metabolized, such as b-carotene into vitamin A in the mucosa.

Sources of carotenoids:

Among the sources inherent in the middle latitudes, one can distinguish the fruits of carrots, pumpkins, tomatoes, sweet peppers, sea buckthorn, rose hips, and rowan. Dark green vegetables also contain carotenoids. The green chlorophyll masks the yellow-orange pigment they contain. The green leaves of some plants (for example, spinach), carrot roots, rose hips, currants, tomatoes, etc. are especially rich in carotenes. Alpha-carotene is present in carrots and pumpkin, lycopene is in red fruits (for example, watermelons, red grapefruits, and especially cooked tomatoes).

There is a lot of lutein and zeaxanthin in dark green vegetables, pumpkin and red peppers, and cryptoxanthin in mangoes, oranges and peaches. Some crops accumulate a predominant type of carotenoids: carrots and alfalfa - carotenes, tomatoes - lycopene, paprika - capxanthin and capsorubin, yellow corn - cryptoxanthin and zeaxanthin, annatto - bixin. As an option - tomato paste (one that contains only crushed tomatoes!)

Alpha carotene. Alpha-carotene, as well as beta-carotene and beta-cryptoxanthin, are provitamins that can be converted by the human body into vitamin A. Their dietary sources include orange foods such as pumpkin and carrots. Low levels of carotenoids in the blood are associated with the development of cardiovascular diseases. The daily recommended intake of alpha-carotene is 518 mcg/day. Among people 19 years of age and older, only 23% receive this standard.

Beta carotene. Beta-carotene is found in many orange and yellow fruits and vegetables - melon, carrots, sweet potatoes. Beta-carotene is a powerful antioxidant that protects body cells from damage caused by free radicals. This carotenoid is also thought to promote immune system function and may play a protective role in bone health. The intake rate for beta-carotene is 3787 mcg/day. Among adults 19 years and older, only 16% consume enough.

Beta-cryptoxanthin. Beta-cryptoxanthin is found in vegetables such as pumpkin, peppers, and fruits such as tangerines. Epidemiological studies suggest that the antioxidant potential of carotenoids may protect against oxidative processes that can lead to inflammation. Research shows that a small increase in beta-cryptoxanthin intake, equivalent to one glass of fresh orange juice per day, reduces the risk of developing inflammatory diseases such as rheumatoid arthritis. The norm for beta-cryptoxanthin is 223 mcg/day. Only 20% of people consume this amount.

Lutein/zeaxanthin. Lutein is found in green leafy vegetables and has high levels of antioxidant activity. High levels of lutein and zeaxanthin (a carotenoid closely related to and derived from lutein) reduce the risk of age-related macular degeneration, a leading cause of blindness in older adults. Lutein and zeaxanthin act as blue light filters and may help preserve vision. One study found that older adults with high levels of lutein/zeaxanthin in their diet had the lowest risk of age-related macular degeneration. The recommended intake for lutein/zeaxanthin is 2055 mcg/day. 17% of adults consume the norm.

Lycopene. Lycopene is extracted from tomatoes and is a powerful antioxidant. Epidemiological studies have shown that there is a correlation between increased tomato consumption and a reduced risk of prostate cancer. The norm for lycopene is 6332 mcg/day. Adult consumption 31%.

Not only shade, but also protection

Thanks to their antioxidant and anti-inflammatory properties, as well as their ability to influence cell growth and division, carotenoids protect the skin from photodamage and help prevent skin diseases. The systematic protective effect of beta-carotene on sunburn (erythema) has been widely studied. A meta-analysis of several studies found that target beta-carotene intake for at least 10 months is required for maximum protective effect. Clinical studies also examining increased lycopene intake from fruits and vegetables have shown positive results in the treatment of sunburn.

Not just skin.

Many studies have provided evidence of an association between regular consumption of foods high in carotenoids and a reduced risk of developing a number of diseases. It is believed that the basic mechanisms of protective action are due to the antioxidant activity of carotenoids and their biochemical ability to influence signal transduction in cells.

Therefore, sufficient intake of carotenoids to maintain the body's own antioxidant system prevents the development of diseases caused by oxidative damage to cell components. Since these micronutrients are fat-soluble substances, their action is primarily aimed at protecting cell membranes and lipoproteins from excess oxidation. Carotenoids help prevent cell mutation, and therefore the development of cancer. In addition, they prevent the formation of atherosclerosis, one of the causes of cardiovascular diseases.

Conclusion.

1. You can influence the tone and condition of your skin with diet. Vegetables will not only give you a healthy, glowing, attractive skin tone, but will also protect it from aging. Plus many other positive effects.

2. By varying the content of different carotenoids, you can achieve your ideal skin tone, while it actually comes from within, rather than being spread on like a cream.

3. At a minimum, this is six weeks and three to four doses of vegetables per day (can be eaten in one or two doses). Consuming at least three servings of vegetables and fruits a day, including carrots, cabbage and kiwi, gives your skin a healthy appearance and a golden glow. Moreover, to feel the effect, only six weeks are enough. In principle, even 30 mg of beta-carotene significantly slows down skin photoaging.

4. Carotenoids are fat-soluble compounds, so be sure to add fats (olive oil, butter) for better absorption.

5. Heat treatment and grinding increases the percentage of carotenoid absorption. It should be noted here that most carotenoids in plants, especially in vegetables, are associated with polysaccharides, lipids, and proteins. These complexes help preserve carotenoids, but prevent their absorption by the body. Therefore, the bioavailability of lutein, as well as zeaxanthin from natural raw materials, is 10–20% compared to the pure substance. The bioavailability of pure beta-carotene directly from carrots is no more than 20%, and from rutabaga - less than 1%. Blocks of carotenoids with complexing agents can be destroyed by cooking the raw materials containing them: grinding, steaming, gentle heating.

Sources:

The original study is freely available:

Attractive Skin Coloration: Harnessing Sexual Selection to Improve Diet and Health,

Fruit, Vegetable and Dietary Carotenoid Intakes Explain Variation in Skin-Color in Young Caucasian Women: a Cross-Sectional Study.

Carotenoids are present in many plant foods. Despite this, it is quite difficult to create a tasty and at the same time healthy diet. In addition to the fact that the diet should be as varied as possible, you need to know where carotene is found and in what form it is best absorbed, as well as have information about the symptoms of a deficiency or overdose of the substance.

What foods contain beta-carotene?

Of course, in carrots. And not only in it, but also in any vegetable colored red and yellow. In addition, beta-carotene is present in many leafy crops where chlorophyll covers up the orange hue. By autumn, the green pigment disintegrates and we see browned leaves and bushes.

This is interesting. The least amount of beta-carotene is found in yellow vegetables and fruits, a little more in orange ones and a record amount in deep red plants.

Foods rich in carotene:

• vegetables - green peas, tomatoes, sweet potatoes, broccoli, sweet peppers, zucchini, cabbage, spinach, pumpkin and carrots;
• fruits - persimmons, nectarines, plums, mangoes, cherries, peaches, apricots, melon;
• berries - black and red currants, blueberries, gooseberries, rose hips.

The amount of provitamin A in plants depends on the time of year and degree of maturity. Most of the substance is found in vegetables grown in the open sun on environmentally friendly and fertile soils.

Other foods that are sources of beta-carotene include green onions, various leaf lettuces, lettuce, sorrel, mustard, beet and carrot tops, and spinach. Natural sea salt also contains a lot of provitamin A.

It may seem surprising to many, but even cucumber contains beta-carotene. Of course, there is little β-isomer in greens, only 1% of the daily value. But the vegetable is rich in carotenoids lutein and zeaxanthin - 100 g of product contains 383% of the daily dose.

These substances, like beta-carotene, can accumulate in the tissues of the eye, providing protection and visual acuity.

This is interesting. A huge amount of provitamin A is found in green seaweed. In recent years, many successful attempts have been made to cultivate this amazing plant in limited water bodies. Thus, Orenburg scientists began growing healthy algae in one of the lakes in Sol-Iletsk back in 2010.

Which root vegetable contains more carotene?

Carrots have always been considered the champion in the amount of provitamin A. 100 grams of vegetables contain at least 6–7 mg of nutrients. To satisfy an adult's daily requirement for beta-carotene, you only need a couple of fresh and juicy root vegetables.

However, recent studies have found that pumpkin contains no less carotene than carrots. It turns out that 100 grams of melons contain 3100 mcg of plant pigment, which is 62% of the daily requirement. To get the maximum benefit from pumpkin, you should cook it in the oven or over low heat, adding milk or butter.

Beta-carotene: where is it found?

Carotene in food is one of the ways to compensate for vitamin A deficiency in the body. But to do this, you need to know not only what the plant pigment contains, but also in what quantities it is present.

With this information, you can create a very tasty and healthy diet for every day for both a child and an adult.

Let's create a table of beta-carotene content in foods.

Products	Provitamin A (mg/100 grams)
Carrot
Pumpkin
Sweet potato (sweet potato)
Sea ​​buckthorn
Sorrel
Parsley, greens
Rose hips
Spinach
Sweet pepper
Mango
Green onions, feather
Melon
Apricots, fresh
Tomatoes
Peaches
Persimmon
Green peas
Corn
Plum
Cherry
Fresh cucumber

The table below shows which foods contain the largest amount of beta-carotene. They should be included in your daily diet.

Attention. The level of provitamin A in carrots largely depends on the variety of root vegetable. This should be taken into account when planning your diet.

It is not recommended to keep vegetables, fruits and herbs in the light for a long time without packaging - this is fraught with the loss of a significant amount of nutrients and a decrease in the nutritional value of the products. Rapid freezing of plants, on the contrary, completely preserves their biological activity. Tocopherol and ascorbic acid enhance the effect of carotene.

As a supplement to food to increase the level of carotene in the body, you can use dietary supplements, for example, the Beta Carotene food supplement from Solgar. .

Daily value of beta-carotene

In some circumstances, significantly more beta-carotene is required:

• severe vitamin A deficiency;
• pregnancy and breastfeeding;
• serious sports and mental stress;
• stress or periods of illness;
• predisposition to cardiovascular diseases and atherosclerosis;
• cancer alertness;
• living in environmentally unfavorable areas or working in hazardous industries;
• increased eye strain, especially in children and students.

According to doctors, in the cases considered, exceeding the average daily norm of beta-carotene is quite justified. In addition, large portions of provitamin A are completely safe for the body and can only lead to temporary yellowing of the skin. You can get rid of this unpleasant phenomenon by simply adjusting your diet.

Carotene in carrots

Carrots are considered the leader in beta-carotene content. Its amount depends on the variety and increases noticeably in bright orange, sugary vegetables with a small core.

The sweet root vegetable is rich not only in β-carotene, but also in alpha-carotene (69% of the daily value), as well as other useful substances: folic acid, boron, vanadium, silicon, manganese, molybdenum, rubidium, cobalt, potassium.

Attention. Carrots are capable of accumulating the highly toxic trace element mercury, as well as arsenic and strontium. Therefore, it is better to eat root vegetables grown with your own hands.

The greening of the tops that sometimes occurs is due to the accumulation of chlorophyll in the tissues of the vegetable. These parts may taste bitter, but they are quite edible after boiling.

How is carotene from carrots absorbed?

The orange vegetable can be eaten raw or stewed. Oddly enough, in the latter case it turns out to be more useful - it is absorbed better and faster, and also contains 14% more carotene.

To avoid losing some of the beneficial vitamin during the cooking process, keep the pan closed. A dish cooked over low heat will have a richer color and a pleasant taste.

A vinaigrette is made from prepared carrots by adding vegetable oil, fried and added to soups or used as a side dish for meat and cutlets.

The stewed vegetable is especially indicated for gastrointestinal diseases - it does not cause flatulence, is easily digestible and does not irritate the mucous membranes.

For lovers of raw carrots, it is better to gnaw them whole, having first eaten 20–25 grams of butter. However, this method of consumption is not very comfortable, and not everyone likes the taste of a simple root vegetable. Alternatively, you can make a delicious salad from a fresh vegetable by adding sour cream, sugar or raisins to the dish, and pouring olive oil or milk.

Carrot juice is very rich in carotene, but only freshly prepared juice. It should not be used with flour products and delicacies, although for a better taste, sweet lovers can add a spoonful of honey.

Advice. The tops of the root crop can also be used for food. Greens contain a lot of carotene, so they are often added to salads or soups.

Carrot varieties with high carotene content

Scientists say that the amount of provitamin A depends on the degree of maturity of root crops, their storage and harvesting time. However, if the vegetable initially contained a lot of carotene, then more of it will remain after all the manipulations.

Therefore, for cultivation on your own plot, it is better to choose root vegetables with a high content of provitamin A.

Carrot variety	Description
Sweet tooth F1	An excellent hybrid, sweet and juicy. Suitable for making juices and baby food. Fruitful.
Crofton F1	The hybrid is distinguished by a very long root crop, excellent keeping quality and taste.
Leander	Nice old variety. It is stored for a long time, sweet and fruitful.
Major F1	Hybrid with long, bright roots. Very juicy.
Niagara F1	Beautiful, large, late ripening carrots.
Nebula F1	A medium-sized vegetable with a cylindrical shape. Fruitful and sweet.
Autumn King	A proven variety with a juicy, spindle-shaped root crop. Excellent storage.

This is not a complete list of carrots high in carotene. You can also note the Sentyabrina variety, the hybrids Romance F1, Santa Cruz F1, Siroko F1 and Tsetor F1.

Provitamin A, contained in plant foods, is very useful and completely safe for the body. Moreover, it is accessible and cheap. To cover the daily requirement of carotene, 1-2 carrots are enough, which can be eaten raw or boiled. There will be benefits in both cases.

All materials on the website are presented for informational purposes only. Before using any product, consultation with a doctor is MANDATORY!

Crimean sea salt includes beta-carotene and all biocomponents in its crystal lattice, thus preserving the living biology of the sea. The pink color of the water in the salt lakes of Crimea is due to the high concentration of unique hydroalgae in them, which is the only natural source in which the content of beta-carotene can reach 60-70% of its total content.

Beta-carotene provides the human body with provitamin A in an easily digestible form and in the required quantity.

OBTAINING CAROTENES FROM ALGAE DUNALIELLA SALINA

IN THE CONDITIONS OF THE CRIMEAN SALT FIELDS

Authors:
Davidovich Nikolay Aleksandrovich, Candidate of Biological Sciences, Senior Researcher
Styupan Andrey Vitalievich

Introductory part

Carotene (from the Latin carota - carrot) is a yellow-orange pigment synthesized by bacteria, fungi, algae, and higher plants. Its presence explains the yellow, orange, and red coloring of fruits, roots, and plant leaves.

By its chemical nature, carotene is an unsaturated hydrocarbon from the group of terpenoids. Empirical formula C40H56, molecular weight 536.9. The chemical synthesis of β-carotene was carried out in 1956. There are several isomeric forms of carotene, the most famous of which is β-carotene (beta-carotene). Structural formula of β-carotene:

Insoluble in water, but soluble in organic solvents; belong to lipophilic compounds, i.e. soluble in oils. In crystalline form it has a violet-red color, in an oil solution - from yellow to orange.

Solutions of carotenoids in organic solvents in spectrophotometric studies give characteristic absorption bands mainly in the visible region of the spectrum, and stereoisomers also show them in the ultraviolet region. This is one of the most accurate indicators used in identifying these substances. Another characteristic feature of carotenoids is that they are selectively absorbed on mineral and some organic absorbents, which makes it possible to separate them using chromatographic methods. Some specific reactions, including color reactions, are characteristic of individual carotenoids.

It should be taken into account that carotenoids in their pure form are highly labile - they are very sensitive to sunlight, atmospheric oxygen, heat, acids and alkalis. Under the influence of these unfavorable factors, they undergo oxidation and destruction. At the same time, being part of various complexes, they exhibit much greater stability.

Along with black-brown melanins, carotenes are the most common pigments in nature: about 100 million tons of them are synthesized annually on Earth (more than 3 tons per second). In nature, carotenoids can be found in different states: in free form they are more often found in plant plastids, muscle tissue of fish, bird eggs, in the form of fatty acid esters - in chromatophores and epidermal structures of plants, in the form of carotene proteins - in epidermal tissues of animals and etc.

Animals (including humans) are not able to synthesize carotenoids de novo; their intake depends only on food sources. The absorption of carotenoids, like other lipids, occurs in the duodenal region of the small intestine. Under the influence of the gastrointestinal environment (for example, the acidity of gastric juice), the presence of specific protein receptors, carotenoids can be destroyed by oxidizing agents or enzymes or metabolized, such as β-carotene into vitamin A. During digestion, vertebrates are able to split a β-carotene molecule into two molecules of vitamin A Therefore, β-carotene is also called provitamin A. The provitamin properties of β-carotene and its oxidative conversion to vitamin A are common to all animals.

Carotene, which is a provitamin of vitamin A, is extremely important in human nutrition; it is indispensable for vision, growth, reproduction, protection against various bacterial and fungal diseases, and the normal functioning of the skin and mucous membranes. Beta-carotene has the greatest ability to deactivate singlet oxygen known in nature. The latter has high chemical activity, affects processes associated with the destruction of various substances in light, is responsible for DNA damage in living organisms, affects the aging process of the skin, etc. The average natural (without biological additives) intake of carotene from food in different countries is 1.8-5.0 mg/day. According to the methodological recommendations on the norms of rational nutrition “NORMS of physiological needs for energy and nutrients for various groups of the population of the Russian Federation” dated December 18, 2008 (MR 2.3.1.2432 -08) 1 physiological need for beta-carotene for adults – 5 mg/ day (introduced for the first time). 6 mcg of beta-carotene is equivalent to 1 mcg of vitamin A. There is no established upper tolerable intake level for beta-carotene; Long-term use of beta-carotene is not accompanied by any side effects. With an excess of carotene in the body, a state of hypercarotenemia is observed - however, unlike excess vitamin A, carotene is low-toxic. Beta-carotene is registered as a food additive E160a.

The global market for carotenoids in 2000 was estimated at $786 million, including food use - $209 million, feed additives - $462 million, pharmaceutical and cosmetic products - $115 million. The carotenoid market is expected to grow to $919 million by 2015. 2 Beta-carotene makes up about a third of the total carotenoid market. The cost of synthetic β-carotene is about 500 US dollars/kg.

It should be noted that carotene obtained from natural sources is a natural product, the need for which is increasing every year.

Natural sources of carotenoids and their uses

Dyes can be naturally identical (synthetic) or natural (natural).

Natural sources of carotenoids are very diverse, many of them are widely used to obtain carotenoid-containing products. In countries with tropical climates, red palm oil and sweet potato tubers are sources of carotenoid-containing products. Citrus fruits, apricots, and persimmons are quite rich in carotenoids. Among the sources inherent in the middle latitudes, including the climatic zones of Ukraine, we can distinguish the fruits of carrots, pumpkin, tomatoes, sweet peppers, sea buckthorn, rose hips, and rowan. At the same time, a number of carotenoid-containing preparations based on natural plant raw materials are produced by the Ukrainian pharmaceutical industry. In particular, rosehip oil is produced (contains at least 0.6 g/l of carotenoids), oil from sea buckthorn fruits (carotenoid content is at least 1.8 g/l).

Among natural dyes, the most popular is beta-carotene (E160a). According to the latest data, about 30% of the total amount of funds spent by food manufacturers on the purchase of natural dyes is spent on this pigment.

One of the most valuable sources of natural beta-carotene is the algae D. salina, from which a dye is obtained that contains 96% of this pigment. A mixture of carotenes from palm oil contains 35% alpha-carotene and 65% beta-carotene. By its nature, beta-carotene is a fat-soluble pigment. It is artificially brought to the form of a water-dispersed emulsion. Highly acid-resistant beta-carotene emulsions are required for beverages. If the emulsion breaks down during storage, a colored ring usually forms on the neck of the bottle. To avoid the manifestation of such a defect, it is necessary to use a dye with an emulsifying system selected in accordance with the characteristics of the production and composition of the drink. Polysorbate 80, sorbitan monooleate, gums, sucrose esters (individually or in various combinations) are used as emulsifiers. The light stability of beta-carotene is acceptable for drinks in clear packaging, but it is greatly reduced in the presence of oxygen and enhanced by the addition of ascorbic acid.

The next dye from the carotenoid group in terms of global consumption is paprika (E160c). Its market share in monetary terms is 20%. Paprika pigments are obtained from oleoresins of the sweet pepper Capsicum annum L.

Paprika pigments are fat soluble in nature. Their water-dispersed emulsions are available in forms suitable for obtaining both transparent and varying degrees of turbidity solutions. Paprika pigments are sensitive to light and oxygen, but not pH sensitive. Ascorbic acid, alphatocopherol and rosemary extract can be used to stabilize them. A well-purified dye at the dosages required for coloring does not impart noticeable foreign tastes and odors to products.

Also included in the group of carotenoids is the yellow-orange natural dye annatto (E160b), obtained from the seeds of the Bixa orellana plant. Annatto is native to Central and South America. Annatto is an easily cultivated tree that reaches a fruiting period of 4-5 years and produces a harvest for 20 years. Annatto is one of the most economically important natural dyes in the world. The largest producers of annatto seeds are Peru, Brazil and Kenya, and the largest importers are the USA, Japan and Europe.

The fat-soluble pigment bixin is extracted from annatto seeds with ethanol or oil. The water-soluble pigment norbixin is obtained by alkaline hydrolysis of bixin. Annatto water solution is produced as an alkaline solution with a pH of 10.5, so precautions must be taken when handling it. Recently, the conversion of the carotenoid lycopene (the red pigment of tomato) to bixin has been investigated. Currently, work is underway to breed bixin-producing tomatoes. Bixin is slightly soluble in oils – 0.1–0.3% (w/v). It is sensitive to pH, lowering which changes the color from yellow-orange to pink. Acidity does not affect the stability of this pigment. Bixin has good thermostable stability at temperatures not exceeding 100°C, but is quickly destroyed at temperatures above 125°C. Bixin is resistant to oxidation, but is sensitive to light, like other carotenoids. To increase stability, antioxidants are added to bixin-based dyes.

Bixin's share in the natural dyes market is 7%. Water-soluble norbixin is available in standard (stable at pH about 4) and special acid-resistant (up to pH 2.5) forms. Also, based on bixin, water-dispersed emulsions are produced, which make it possible to obtain cloudy solutions.

Methods for obtaining beta-carotene from natural raw materials

The oldest, but still used, is the method of production from carrots. The method is characterized by extremely high labor intensity and low profitability: to obtain 1 kg of crystalline carotene, it is necessary to process about 15 tons of carrots, i.e. this is equal to its collection from 1 hectare with an average yield.

In Ukraine, the predominant part of 80% of beta-carotene is now produced from the biomass of the mucor fungus Blakeslea trispora. The production uses waste from the flour milling, canning and meat and dairy industries. Carotene is extracted from the fungal biomass with an organic solvent in vegetable oil, or the resulting biomass is dried without extraction. In the first case, the degree of carotene extraction is higher, up to 50%. In the second case, a powder with a beta-carotene content of 6-7% is obtained. The cost of obtaining the product using this technology is high.

Benefits of using Dunaliella salina as a source of carotenoids

Dyes based on beta-carotene of natural origin have higher stability than naturally identical ones. In addition, in natural-identical and microbiological (bacterial and fungal) beta-carotene, part of the pigment is in the form of sparingly soluble crystals. Carotene has many isomeric forms; The synthetic version does not allow achieving the required ratio of isomers, which exactly replicates the natural complex. The same applies to accompanying carotenoids, including carotenes and xanthophylls.

Under conditions favorable for growth and reproduction, D. salina cells are green in color and contain only about 0.3% β-carotene by dry weight, i.e. as much as plant leaves and cells of other non-carotene-bearing algae. Only under conditions that inhibit cell growth and reproduction do β-carotene accumulate in the latter in the form of orange oil globules located in the interthylakoid spaces of the chloroplast. Among the parameters that regulate the processes of growth, reproduction and carotene formation, the light intensity, the concentration of osmotically active salts, temperature and the content of nutrients in the environment are of primary importance. The higher the illumination, the more intense the carotene formation. Excessive accumulation of β-carotene in its cells is also facilitated by an increased concentration of osmotically active salts in the habitat (up to 5 M NaCl), extreme temperatures (above or below the growth optimum), and a lack of nutrients in the nutrient medium (especially nitrogen starvation). Thus, the biosynthesis of β-carotene in the cells of the microscopic algae Dunaliella salina is an easily regulated process, which means that the cost of β-carotene obtained from algae grown in non-sterile conditions in the open air will decrease in the future based on further improvement of the technological process.

Biology and systematics of algae

Dunaliella salina Teod. (Dunaliella salina) is a unicellular flagellated microalgae (Fig. 1) from the department of Green algae.

Rice. 1 Dunaliella salina Teodoresco, seen under a microscope at different magnifications. The length of the scale bar is 20 µm.

Taxonomic position:

• Kingdom Plantae
• Class Chlorophyceae
• Division Chlorophycota
• Order Volvocales
• Family Dunaliellaceae
• Genus Dunaliella
• Species Dunaliella salina

The genus Dunaliella includes 29 brackish, marine, freshwater and soil species; 6 of them were found on the territory of Ukraine exclusively in salt water bodies. Dunaliella salina is well known - saltwater Dunaliella, which develops in hypersaline reservoirs of southern Ukraine, including the steppe Crimea. In large quantities, it causes a red “bloom”, especially pronounced during the period of summer evaporation of water from shallow lagoons. Sometimes a salt concentrate forms on the surface of such lagoons in the form of plates of salt crystals4. Thus, Dunaliella salina is able to live in brine, in which the saturation point has been reached and crystallization and precipitation of salts occurs.

Algae cells are of various shapes: oval, ellipsoidal, ovoid, pear-shaped, sometimes spherical, cylindrical or spindle-shaped; radially or bilaterally symmetrical, rarely dorsiventral or slightly asymmetrical. Cell sizes are very diverse. Length can be from 5 microns to 29 microns, width from 4 microns to 20 microns; cell volume from 70 cubic microns to 4500 cubic microns5. Chloroplast color is most often green, sometimes yellow or brown. The shape of the chloroplast is usually cup-shaped with a pyrenoid and an ocellus, less often without them.

Unlike many other algae, dunalielli cells lack a cellulose or pectin membrane and are surrounded only by a thin elastic protoplasmic membrane (plasmalemma). On either side of the papilla, at the convex apical end of the cell, two flagella are attached, with a normal microstructure (9 + 2 microtubules). Usually the flagella are of equal length, equal to or greater than the length of the cell. In young, newly divided cells, one of the flagella may be shorter than the other. Like the rest of the cell, flagella are covered with a protoplasmic membrane. Algae cells are able to move thanks to the paddle-like movements of their flagella. Dunaliella exhibits pronounced positive phototaxis.

Dunaliella salina is characterized by both asexual and sexual types of reproduction. The first one is predominant. Cell division is longitudinal. The sequence of organelle division is not strictly determined and is easily disrupted, especially in old cultures. This creates ugly shapes. Under unfavorable conditions, Dunaliella is capable of forming cysts of asexual origin. The cysts have a spherical shape, a thick double shell and granular contents, the release of which, upon germination, occurs through a gap in the shell. Before the cyst germinates, its red contents turn green and divide to form 2-4 cells. The sexual process in Dunaliella salina is of the hologamous type. Copulation can occur both in the light and in the dark. As a result of the fusion of two cells, a stationary zygote is formed, covered with a membrane (sometimes layered). Before germination, reduction division occurs with the formation of 2-32 cells. The number of the latter depends on the size of the zygote and the conditions in which it developed.

A study of the biology of D. salina and the environmental factors causing its transition to the active accumulation of β-carotene in natural conditions showed that the biosynthesis of this compound is an adaptive reaction of organisms in response to extreme growth conditions, which include changes in salinity and mineral composition of the environment, temperature and illumination, as well as a combination of a set of these parameters.

Assessment of carotenoid reserves in salt mine reservoirs of the Crimean Peninsula

We examined several reservoirs of the salt industries of the Crimean Peninsula and southern Ukraine, in particular the Saki (Fig. 2), Sivash and Kherson salt industries.

Rice. 2. Saki solprom. View of salt storage basins from a height of 2 km. White color – evaporated salt; The red-brown color of the pools is largely due to the high concentration of Dunaliella cells in the brine

Table 2 presents the average data for a number of observations for 2007. A total of 90 samples were processed. The most adequate for assessing the abundance of algae throughout the year are its modal values, which turned out to be in the range of 19 – 37 million cells/l.

Table 2. Average and modal abundance values ​​(million cells/l) of Dunaliella salina in the studied water bodies of the Kherson salt industry

The content of carotenes in a cell largely depends on the size of the cell and growth conditions. Across 80 determinations, we found that carotenes averaged 0.69 nanograms/cell, with a very wide variation from 0.03 to 31.26 ng/cell. Note that strong variations in the initial parameters do not allow us to estimate the content of carotenes per cell with a high probability of an event for each specific case. In addition, it is not entirely correct to use the obtained average value to estimate the content of carotenes per liter of water based on data on the number of cells in the studied reservoirs, also for the reason that the dependence of the concentration of carotenes (mg/l) on the concentration of cells (million cells/l) in water, as it turned out, is nonlinear in nature (Fig. 3) and is well described by the equation:

Rice. 3. Dependence of the concentration of carotenes (mg/l) on the concentration of cells (million cells/l) in the studied reservoirs.

where x is the concentration of cells, million cells/l; y – concentration of carotenes, mg/l.

Taking into account the modal concentrations of cells in water bodies and using the resulting equation, we find that the “usual” (most common) content of carotenes in these water bodies (according to the samples taken) is 3.42 – 4.51 mg/l.

The actual distribution of carotene content in 1 liter of water according to frequency of occurrence in 80 samples from the studied reservoirs, presented in Fig. 4 confirms the calculation made.

Rice. Fig. 4. Distribution of carotene content (mg/l) by frequency of occurrence in 80 samples from the studied water bodies.

Thus, on one square meter of pool with an average brine layer thickness of 25 cm, the current carotene content will be 855 – 1128 mg, which corresponds to 8.6 – 11.3 kg/ha. We emphasize that this carotene content is typical for salt production reservoirs in their “natural” state, aimed at obtaining and extracting salt, when the goal is not to obtain carotene as a production product. Sometimes (6% of cases) under natural conditions in water bodies very high concentrations of carotenes were reached, exceeding 50 mg/l, of which in two cases - more than 100 mg/l with a cell concentration of more than 3 billion/l.

Practice shows that the concentration of carotenes in brine can be increased tens and hundreds of times by using the following technological methods:

• controlled (in existing reservoirs) cultivation of algae using optimal salinity regimes, introduction of nutrients and regulation of salt composition;
• initiation of the accumulation of carotenes in algae cells when the salinity regimes, the illumination of the layer (regulation of the thickness of the water layer), and the concentration of nutrients (especially nitrogen) are changed properly;
• protecting the algae population from predators (the crustacean Artemia salina) by changing salinity;
• settling, using the phenomenon of algae phototaxis;
• flotation.

Further coprecipitation of carotene with magnesium hydroxide makes it possible to further increase the concentration of carotene and obtain a product (paste) that allows long-term storage of carotene without decomposition. This is very important if we take into account the seasonality of algae growing in natural bodies of water; opens up the possibility of subsequent processing of the paste and extraction of carotene from it in the winter, less busy months.

Previous experience in obtaining carotene in the salty estuaries of southern Ukraine

The method of mass cultivation of D. salina for the purpose of semi-industrial production of β-carotene was first used as the basis for the creation of an experimental carotene farm with an area of ​​0.5 hectares at the Saki Chemical Plant in Crimea in 1965-1968 (Fig. 56). To grow algae, cheap magnesium chloride brine and fertilizers (superphosphate, ammonium nitrate, potassium salt, etc.) were used. The experimental farm had fifteen 200-liter plastic trays, four one-cube and four five-cube concrete pools in which the seed was propagated, as well as a number of industrial pools with an earthen bottom (Fig. 5), in which the second stage took place - the accumulation of carotene. Experiments conducted on this farm in 1965-1968 showed the possibility of obtaining up to 120 kg of carotene/ha in the south of Ukraine during the growing season (7 months).

Leading manufacturers and examples of products containing carotene derived from Dunaliella salina algae

Mass cultivation of Dunaliella salina for the purpose of obtaining beta-carotene is carried out today in Australia, Israel, Spain, China, and the USA. The world's largest biotechnology firms: Betatene Pty Ltd in the south of Australia and Western Biotechnology Pty Ltd in the west of Australia, part of the international corporation Cognis7, have Dunaliella cultivation ponds covering an area of ​​more than 800 hectares (Fig. 6).

In the USA Cyanotech Inc. (Figure 7) and Microbio Resources, Inc. (San Diego, California, USA), each produce 1.5 tons of β-carotene per year from dunalielli biomass. There is evidence that the Microbio Resources company has invested over 15 million US dollars in the development of capacities for growing Dunaliella and obtaining carotene from it.

There are also large producers of beta-carotene in India (Arora aromatics, Uttar Pradesh) and China (Shandong Binzhou Tianjian Biotechnology Co., Ltd.)8. For example, Arora aromatics is ready to supply 5 tons of Dunaliella powder (dry biomass) monthly.

Mass production of carotene has been established in Israel (Nature Beta Technologies9).

In Ukraine and Russia, the only one today (according to the company itself) producer of natural carotenoids from the Blakeslea mushroom is the group "NPP "VITAN" 10. The company produces and sells such products as:

• Beta-carotene biomass with a beta-carotene content of 6-7%.
• Lycopene biomass with lycopene content of 3-5%.
• Oil solutions of beta-carotene in refined deodorized sunflower oil, which contain from 0.2 to 1.0% beta.
• Oil suspension of beta-carotene 2.5...30%
• Beta carotene crystals 95%
• Dietary supplement "Carenol+" contains a 0.2% solution of beta-carotene in sunflower oil.
• Carotene oil contains 0.015% beta-carotene dissolved in sunflower oil.

Conclusion

World experience in obtaining carotenes from the brackish unicellular algae Dunaliella salina shows not only the possibility, but also the promise of this biotechnological direction. The conditions of the reservoirs of Crimea and southern Ukraine provide a sufficient raw material base for the production of carotene. Properly used technological methods can significantly increase the yield of the final product. The previous, generally positive experience of growing algae on a pilot industrial scale indicates the feasibility of this project.