Kuşburnundan C vitamini izolasyonu ve çekirdek yağlarının incelenmesi

Turan, Birol
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Fen Bilimleri Enstitüsü
Bu çalışmada, Kayseri yöresinden temin edilen kuşburnu meyva- larından, laboratuvar ölçekte çalışılarak, C vitamini izole edilmesi amaçlanmıştır. Bu amaçla önce, numunelerin C vitamini içeriği tayin edilmiş ve kuru meyvada ortalama 901 mg/100 g bulunmuştur. C vitaminini izole etmek için önce, literatürde yaş biberden C vitamini izolasyonu için verilen yöntem uygulanmıştır. Bu deney ler sonucunda, kuru baza göre ortalama %28.88 verimle C vitamini el de edilebilmiştir. Daha sonra bu yöntemin ekstraksiyon kademesi modifiye edilerek uygulanmış ve ekstraksiyon süresinin verime etkisi incelenmiştir. Ekstraksiyon süreleri 6-20 saat arasında değiştiri lerek bir seri deney yapılmış ve bu deneyler sonucunda 15. saatten sonra elde edilen verimde fazla değişme görülmemiş ve 18. saatten sonra da verimin sabitleştiği gözlenmiştir. 12 saatlik ekstraksiyon sonucunda, kuru baza göre %54.2 verimle C vitamini elde edilebilmiş tir. Her iki yöntemde de çözücü olarak su kullanılmıştır ve elde e- dilen C vitaminin saflığı, erime noktası tayini ile kontrol edilmiş tir. Kuşburnu çekirdeklerinin değerlendirilebilirliğini belirlemek amacıyla, standart yöntem olan Soxhlet ekstraksiyonu ile yağ tayin leri yapılmış ve yağ asitleri bileşimi gaz kromatografisi yöntemiy le belirlenmiştir. Kullanılan kuşburnunun teknolojik değerinin belirlenmesi için, numuneler üzerinde ayrıca, toplam kuru madde, mineral madde, kül, tane-et-çekirdek ağırlığı, rehidrasyon yüzdesi ve elek analizleri gerçekleştirilmiş ve sonuçlar literatür verileriyle mukayese edilmiş tir.
Ascorbic acid and vitamin C are the two names by which L-xylo- ascorbic acid is commonly known at present; however, during its his torical development, it has been called cevitamic acid, the astiscor- butic vitamin, hexuronic acid, soorbutamin, and Redoxon, the last because of its structural relationship to reductone, the enol of hydroxymethylglyoxal (CHOH:COH.CHO). Ascorbic acid is available commercially in various pharmaceuti cal forms and under numerous trade names such as Gebione, Cevalin, Cantaxin, Concemin, Cevimin, Scorbu-C, and Vitacee. In addition to some of these,. in Great Britain it is sold also under the trade names of Çantan, Celin,Davitamon C, and Planavit C. «o-i I _» 0j I HO-CH HÇ I H HC-OH HO-CH KC-OH H L-Ascorbic Acid Dehydroascorbic Acid When pure, the vitamin is a white crystalline substance with a formula weight of 176.12. It is related to sugar acids, and thus is derived from a carbohydrate from which the vitamin is probably synthe sized biologically. The most significant characteristic of ascorbic acid (I) lies in its reversible oxidation to dehydroascorbic acid (II). The latter is reversibly reduced in the body to the physiolo gically active ascorbic acid; therefore, estimation of the vitamin must provide means of determining both forms. With the exception of the primates and guinea pigs, all animals which have been studied have the capacity to synthesize ascorbic acid. Deprivation of vitamin C in human beings causes the deterioration of a number of physiological functions, finally ending in advanced VI scurvy and death following syncope. During the deficiency stages defective intercellular material is formed in connective tissue, while in bones the osteoid is replaced by collagenous material, and in teeth the dentin is supplanted by a substitute substance called "osteodentin". Further impairment of the teeth is brought about by lesions of the gums, which become swollen and bleed, and eventually the teeth loosen and fall out. Although there may be a long incubation period, the anatomic effects of human scurvy gradually give rise to weakness, rheumatic pains in the legs, lesions, bleeding gums, and hemorrhages in many organs. Patients become pale and anemic-looking and experience swelling of the ankles. Symptoms of advanced scurvy are accompanied by severe fragmentation and degeneration of the muscles, bloody tut.iors of eyes and eyelids, discoloration and lesions of the skin, fever, capillary weakness, brawny hematomata in the thighs, and optic prolapse. One gram of ascorbic acid dissolves in about 3 ml of water, 50 ml of absolute alcohol, or 100 ml of glycerin; it is insoluble in benzene, chloroform, ether, petroleum ether, and fats. Although the vitamin is quite stable in the dry form, on exposure to light it gradially darkens. Solutions of the vitamin are more sensitive to al kalies than to acids; the presence of propyl eneglycol further retards the inactivation. Heat alone, in the absence of oxygen, does not destroy the vitamin; however, if air is not excluded, it is readily oxidized, and the rate increases with a rise in temperature. Very rapid deterionation takes place in the presence of traces of copper or silver as catalyst. Ascorbic acid is a colorless, crystalline substance having a sour taste. It is melting point is 190-192°C. It can be obtained either by extraction of fruits and for plants or by semi-synthesis of glucose. The natural vitamin is widely distributed in animals and plants, where it is probably in equilibrium with dehydroascorbic acid. It accurs, for example, in comparatively large amounts in the adrenal cortex, in the suprarenal medulla, eye lens, etc., abundantly in vegetables, such as paprika, cabbage, spinach, peas, tomatoes, tur nips, beets, carrots, celery, lettuce, and in fruits such as grape fruit, lemons, oranges, tangerines, strawberries, bananas, peaches, pineapples, and apples. Fresh tea leaves are a rich source of vitamin C, for practical purposes citrus fruits "offer the best source of ascorbic acid, since appreciable amounts of the vitamin in other foods are testroyed in cooking in the presence of air, and in handling if they come in contact with traces of copper. Ascorbic acid is being produced at vii present on an industrial scale, especially in Sweden, by extraction from the flesh of ripe Rosa receptacles (rose hips). In view of the frequent occurrence of hypovitaminosis, charac terized by a partial vitamin deficiency, it is apparent that ascorbic acid is not stored in the body to any considerable extent. However, a minimum reserve supply most exist in the body because on a vitamin- deficient diet human scurvy takes about three to four months to develop. But, although the amount of ascorbic acid necessary to prevent scurvy is easily determined, it is a much more difficult task to establish the quantity necessary for good general health. It appears that ascorbic acid requirements depend upon the rate of energy metabolism and the size of the body. Table I shows the mini mum requirements as proposed by the Food and Drug Administration, while Table II gives the recommended dietary allowances published by the National Research Council. Table I- Minimum Daily Requirements as Established by the Food and Drug Administration. Infants 10 mg Children (1-12 years) 20 mg Adults (over 12 years) 30 mg Table II- Recommended Dietary Allowances Published by the National Research Council (1945) Man (moderately active) 75 mg Woman (moderately active) 70 mg (pregnancy, second half) 100 mg (lactation period) 150 mg Child (under 1 year) 30 mg (1-3 years) 35 mg (4-6 years) 50 mg (7-9 years) 60 mg (10-12 years) 75 mg Girls (13-20 years) 80 mg Boys (13-15 years) 90 mg (16-20 years) 100 mg In this study, Rose hip fruit growing in Kayseri region and the oil of its seeds were studied. In this respect, the subject can be divided into two main groups: 1. Analysis run on the rose hip fruit and vitamin C production. 2. Analysis run on the oil of rose hip fruit seeds. First of all, it is advisable to introduce the wild rose's fruits. They are called Fructus Rosae which is a fruit of a cer tain rose. Roses have over 100 vari tries. The fruits are obtained vm from the wild rose which belongs to the Dog Rose group called Rosa Canına. Dog Rose is a tree 2-3 m of height. Theleaves have 5-7 leaflets. The size of fruit is about of a clichpea or of a sizable olive. The color changes first from green into yellow by time, then into orange and finally red and dark red. The fruit is but seeds though the cover and the flesh next to it can be eaten. The fruit is of a special importance for the public health because of vitamin C content. The fruit is also an important source for the carotenoids. The most important ones are B-caroten, y caroten, likopen, lutein, zeaksantin, rubik santin. Carotenoids, contained in the fruit prevents the vitamin C to be oxidised during preservation. The carotene contents of the different roses are given in Table III. (mg Total pigment) Pigments R.canina R.moyesi R.rufrifolia Fiton Fitofluen S-Caroten ^ -caroten Y-caroten Prolikopen Li kopen Mutatokram Kriptoksantin Zeaksantin Rubiksantin For drying the fruits, the temperature is adjusted to 80-90°C and for 3 hours, fruits are maintained in that temperature. By the end of the third hour, the temperature is lowered to 60°C and the process was completed at that point. This gives 1.5 kg of dried fruits obtained from 3 kg of fresh ones. The production of crystalline ascorbic acid (vitamin C) proceeds as follows: The fruits which were cleaned by removing leaves, skins, seeds and all the other impurities is extracted. Barium Acetate (25%) is added at controlled time intervals followed by. Lead Acetate (5%) addition to effect the precipitation of the by products. The liquid phase is separated and concentrated. Ammonia is addet to adjust the pH to 7.6 and the precipitate formed is discarded. Still more, sulphuric acid is added to adjust the pH to 2.0 and the ix precipitate formed discarded again. The concentrated part is extracted respectively by ethanol; ace- ton, and petroleum ether to effect the removal of the, by products. The remaining water phase set aside to effect the precipitation of crystalline vitamin C. In our studies, the yield obtained was 56%. The melting point of the products varied between 185-188°C which is quite satisfactory. The fruits growing in Kayseri region contain 900 mg of ascorbic acid/100 g of fruit. Many workers gave some data related to the ascorbic acid content in the fruits. Gadzieva (1968) gave the limits of 100-1450 mg/100 g fruit (dry basis). Other workers gave other limits, namely 100-2000 mg/100 g fruit (fresh basis). Gadzieva run some tests showing the depence of the amount of ascorbic acid on the altitude. As an example, tests run in Rosa Tomentosa, at 800 m, 1200 m and 1500 m; 1565 mg, 2060 mg, and 2352 mg/100 g of fruits (dry basis) were found. The emphasis also laid down on the importance of the differen ces among the species. Also were given was the amounts of some minerals found in the fruits: Ca: 140.28 mg/100 g; Mg: 56.48. 1*3/ 1 00 g; Na: 1.66 mg/100 g; Ka: 415.4 mg/100 g. According to Benk (1974), the literature on the minerals con tained in the fruit were of limited extent. The run some tests on the culture and wild fruits and found some results (respectively): Ca: 342, 397; Mg: 77, 82; Na: 0.1, 0.13; K: 572, 612 mg/100 g of fruits. The seeds of the i fruits contain about 10% of oil. Tests run on the oil by thin layer chromatography show only the existence of triglycerides. Tests run by gas chromatography reveal the precense of linoleic acid (52.3 %), stearic acid (16.9 %), linolenic acid (25.8 %), oleic acid (5.0 %). Other studies brought about some other data as follows: Acid value 2.12, free fatty acids percent 1.06, saponification value 173, Iodine valt/e 145.78.
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1991
Anahtar kelimeler
Kimya Mühendisliği, Askorbik asit, Kuşburnu = Rose hi, Chemical Engineering, Ascorbic acid, Rose hip