Türkiye'de yetişen kocayemiş (Arbutus unedo) meyvesininproantosiyanidin temelli ultrasonik ekstraksiyonoptimizasyonunun HPLC ile incelenmesi
Turkey growing (Arbutus unedo) of fruitproantocianid based ultrasonic extractioninvestigation of optimization by HPLC
Yazar: TUGAY KESKİN
Danışman: PROF. DR. BİRSEN DEMİRATA ÖZTÜRK
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Kimya Ana Bilim Dalı / Kimya Bilim Dalı
Derece: Yüksek Lisans, 2020
Konu: Kimya = Chemistry

Özet:
Serbest radikal olarak yapılarında çiftleşmemiş bir veya daha fazla elektron
bulunduran ve bu saye de başka moleküllerle çok kolay elektron alışverişine
girebilen atom ve moleküllere denilmektedir. Serbest radikaller çok kolay
reaksiyona girebildikleri için hücreleri tahrip edebilir, enzimlerin ve DNA'nın
yapısını bozabilir. Gıdalar, kozmetik ürünler, ilaçlar, sigara dumanı gibi faktörler
serbest radikallerin oluşmasına sebebiyet verirler ve bu serbest radikaller zincir
reaksiyonunun başlangıcını oluştururlar. Serbest radikallerin vücutta artması direkt
olarak hastalığa sebep olmasa da dolayı olarak hastalıklara sebep olur.
Antioksidanlar bu tahribatı önlemek için kullanılır.
Çeşitli antioksidan kapasite tayin yöntemleri vardır. Genel olarak redoks
tepkimelerine dayalı olarak birçok testle tayin yapılabilmektedir. En sık kullanılanlar
ise CUPRAC, CERAC, ABTS, FOLİN gibi testler kullanılmaktadır. Bu çalışmada
da Türkiye''de yetişen Kocayemiş (Arbutus unedo) meyvesinin proantosiyanidin
temelli ultrasonik ekstraksiyon optimizasyonu ise yanıt yüzey yöntemi ile
belirlenmiştir. Genel tanım olarak, değişkenlerin deneysel uzayını araştırmak için
deneysel yöntemleri, sistemin durumlara ve değişkenlere karşı verdiği yanıtları ve
değişkenlerin birbiri üzerindeki etkisini belirlemek için kullanılan modelleme ve
değişkenlerin sistemin yanıtında istenilen etkiyi gösterdiği seviyelerin bulunması için
kullanılan tekniklerin tümüdür. 3 aşamadan oluşmaktadır. Eleme denemeleri, deneme
sayısını azaltarak daha verimli deneme yapılmasına olarak sağlanan aşamadır. Bölge
araştırması, bir önceki aşamada belirlenen bağımsız değişkenlerin araştırılan sistemin
yanıtında oluşturdukları değerlerin, sonuçların optimum noktaya yakın olup olmama
durumudur. Üçüncü aşama ise yorumlama kısmıdır. Gerçek yanıt fonksiyonun
optimum koşullar etrafında oluşturduğu eğriliği bazı lineer olmayan modellerden
genellikle 2. dereceden polinomiyal modeller kullanılır.
Optimizasyonu belirlerken ise optimizasyon çalışmalarında sistemi etkileyen bütün
değişkenlerin bir arada değerlendirilmesi gerekmektedir. Böyle bir durum pek
mümkün olmamaktadır. Bu problemleri çözmek için çeşitli yaklaşımlar ortaya
atılmıştır. Tek yanıtlı sistemlerde çözüm olarak durağan noktaların hesaplanması
şeklinde yapılır. Bunun için iki yol vardır. Birincisi tüm bağımsız değişkenler için
kısmi türev alınır, sıfıra eşitlenip ve denklem sistemi çözülür. İkinci bir yol ise matris
yöntemi kullanılarak durağan nokta hesaplanmasıdır. Son olarakta bir antioksidan
olan kateşin maddesi HPLC analizi ile incelenmiştir.

Abstract:
Free radicals are called atoms and molecules that contain one or more electrons that
do not mate in their structure and that can easily exchange electrons with other
molecules. Since free radicals can react very easily, it can destroy cells and disrupt
the structure of enzymes and DNA. Factors such as foods, cosmetics, medicines,
cigarette smoke cause the formation of free radicals and these free radicals form the
beginning of the chain reaction. Although the increase of free radicals in the body
does not directly cause disease, it causes diseases. Antioxidants are used to prevent
this damage. There are various antioxidant capacity determination methods.
Antioxidants are divided into two as naturally available or synthetically produced.
While some of the natural antioxidants can be found in our body, they are defined as
endogenous, and those that are taken by food from outside are known as exogenous
antioxidants. The production of endogenous antioxidants in the body decreases with
age. In addition, some compounds such as nitrate and nitrite added to synthetically
produced antioxidants to gain protective antimicrobial properties can form N radicals
later. Radical N causes diseases such as cancer rheumatism in humans. Therefore,
antioxidants which are naturally extractable from plants and tissues are more
preferred. The strongest examples of these are α-tocopherol acetate, β-carotene and
Vitamin C.
One of the most important natural antioxidants is flavonoids. It is a very important
natural antioxidant sample that is found in plants and cannot be synthesized in the
human body. It is diphenylpropanoid and has strong chelating properties. In general,
it is responsible for giving red yellow and purple colors to the flower and fruit of the
plant thanks to pigments. Apart from that, flavonoids are extremely important
because of their functions such as free radical repellant, antibiotic properties and
regulating enzyme activities. Flavonoids are divided into 5 subgroups:
anthocyanidins, flavones and catechins, flavanones, leucoanthocyanidins and
proanthocyanidins. Flavanones are found mainly in citrus fruits, catechins in black
tea, more green tea, red wine and onions, anthocyanins in strawberries and other
berries, isoflavones in soy flavones in celery and other vegetables.
Carotenoids are pigments that can be produced by plants and have 40 C atoms and
contain 9 or more conjugated double bonds. In addition, double bonds to this
conjections are unstable and easy to oxidize. It forms the yellow, red and orange
color pigments of the plant. For its variant hydrocarbon, α-, β- carotene and
lycopene; Another one is xanthophyll, for example lutein and capsentine containing
O in its structure in the form of epoxy, methoxy, carboxy.
Carotenoids constitute the precursor of fat-soluble vitamin A, which is important for
our body. Some studies have shown that excess carotenoids from fruits and
vegetables have led to decreased cardiovascular diseases, degeneration, and
cataracts. It also shows antioxidant properties by decreasing the rate of formation of
harmful ones such as hydrogen peroxide by participating in free radical reactions.
Phenolic acids are divided into two groups as hydrosynamic acid and
hydroxybenzoic acid. Caffeic acid esters, which are examples of phenolic acids and
found in nuts and oilseeds, have high antioxidant activity. Examples of
hydrosibenzoic acid in free form and in low amounts in vegetables and fruits are
salicylic acid, gallic acid, vanillic acid.
As a result of the researches, antioxidants, which are able to fulfill its functions
besides natural antioxidants, have been started to be synthesized. Many antioxidants
have been tried since 1940 but few have survived to the present day. Some of these
are those; BHA (Butylated hydroxy anisole), BHT (Butylated hydroxy toluene), PG
(Propyl gallate) and TBHQ (Tertiary butyl hydroquinone). Since it has been used for
many years, it has been thought that it may have side effects in recent years. In this
research, it has been observed that many of them have toxic effects and as a result,
there has been a tendency towards natural antioxidants.
In general, many tests can be determined based on redox reactions. The most
frequently used tests such as CUPRAC, CERAC, ABTS, FOLİN are used. This study
also grown in Turkey Arbutus (Arbutus unedo) fruits were determined based
ultrasonic extraction of proanthocyanidin with the response surface optimization
method. As a general definition, experimental methods to investigate the
experimental space of the variables are the modeling used to determine the responses
of the system to the states and variables, and the techniques used to find the levels at
which the variables show the desired effect in the system's response. It consists of 3
stages. Screening trials are the stage provided as a more efficient trial by reducing the
number of trials. Region research is whether the independent variables determined in
the previous stage are the values created by the response of the system investigated,
whether the results are close to the optimum point. The third stage is the
interpretation part. Polynomial models of the 2nd order are generally used from some
nonlinear models, the curvature of the real response function around optimum
conditions.
When determining optimization, all variables affecting the system should be
evaluated together in optimization studies. Such a situation is not possible. Various
approaches have been put forward to solve these problems. As a solution in single-
response systems, it is done by calculating stationary points. There are two ways to
do this. Firstly, partial derivatives are taken for all independent variables, they are
equal to zero and the system of equations is solved. A second way is to calculate a
static point using the matrix method. Finally, the catechin substance, an antioxidant,
was examined by HPLC analysis.