Kırmızı lahananın (Brassica oleracea var.capitata f.rubra) toplam fenolik madde ve antioksidan aktivitesi üzerinde pH ve ekstraksiyon süresinin etkisi
The effect of pH and extraction time on total phenolic and antioxidant activity of red cabbage (Brassica oleracea var.capitata f.rubra)
Yazar: AYE ŞEYHAHMET
Danışman: PROF. DR. MUSTAFA KÜÇÜKİSLAMOĞLU
Sakarya Üniversitesi / Fen Bilimleri Enstitüsü / Kimya Ana Bilim Dalı / Organik Kimya Bilim Dalı
Derece: Yüksek Lisans, 2023
Konu: Kimya = Chemistry

Özet:
Gıda ürünleri kabulünde önemli faktörlerden biri ve kalitesinin bir göstergesi olarak kullanılan renklerdir. Gıda rengi alıcının dikkatini çekmede ve gıda maddesine etkileyici bir görünüm kazandırmasında önemli bir özelliğe sahiptir. Gıdalara renk veren doğal maddeler, doğada yaygın olarak bulunan antosiyanin maddelerdir, antosiyaninler Sebze dünyasında Birçok bitkinin en mavi ve kırmızımsı renginden sorumludurlar ve suda çözünme özellikte renk pigmentleri olarak belirlenmektedir. antosiyanin içeren bazı sebzeler (üzüm, çilek, şeftali, patlıcan, kırmızı lahana, kırmızı pancar, turp .vb.), içeren bazı meyveler ise (kiraz , Elma ve Erik çeşitleri), ancak tüm hamurda bulunmazlar çoğunluğu iç hücrelerde ve deride bulunur. Bazı meyvelerde bir veya iki çeşit antosiyanin bulunur ve bazılarında 20 ve fazla türden oluşan karmaşık bir karışıma sahiptir. 
kırmızı lahana (Brassica oleracea var. capitata f. rubra) turpgiller famiylesinden yaprakları kat kat, geniş ve kalın bir sebze türüdür, Serin iklim sebzesi olan lahanagillerde en kaliteli üretim Sonbahar-kış döneminde gerçekleştirilir. Avrupa ülkelerinde bütün yıl boyunca yetiştirilen lahanalar ülkemizde genellikle kışlık olarak yetiştirilirler, kırmızı lahana antioksidan aktiviteye sahip olarak bilinen birçok biyoaktif bileşikleri içermektedir. Bu antioksidan aktivitesinin flavonoidler ve antosiyaninler gibi fenolik bileşiklerden ileri geldiği görülmektedir. yapraklarında Antosiyanin maddeleri içerdiğinden dolayı koyu kırmızı ve mor renkte olamaktadır, Düzenli tüketiminde mide, akciğer, deri ve kalınbağırsak kanserine yakalanma oranlarınını düşürdüğü ve kalp, damar hastalıkları, üst solunum yolu enfeksiyonları önleme gibi birçok etkisi bilinmektedir. 
Bu çalışmada farklı pH aralığında ve farklı zamanlarda kırmızı lahanadan elde edilen morumsu kırmızı ekstraktın toplam fenolik madde içeriği, antioksidan aktivite olarakta DPPH ve ABTS özellikleri karşılaştırıldı.
kırmızı lahana örnekleri temizlenip distile su ile ekstrakte edilmesi amacıyla karıştırıcı ile küçük parçalara parçalanmıştır bu şekilde ekstraksiyon işlemi yapılmış sonra Örneklerin ekstraksiyon koşulları farklı pH değerlerine (pH 4-10) ayarlanmıştır.
pH'ları ayarlanmış örneklerin distile su farklı konsantrasyonlar ( 1/40 , 1/80 , 1/120 , 1/180 , 1/240)
elde edilmiştir. Elde edilen konsantrasyonların Folin-Ciocalteu ayıracı yöntemiyle toplam fenolik içeriği, DPPH serbest radikal giderme aktivitesi, Troloks Eşiti Antioksidan kapasitesi spektrofotometrik ölçümleriyle antioksidan aktivitesi tayin edilmiş ve elde edilen sonuçlara göre Toplam fenolik maddenin içeriği sonuçlara göre 1saatlik ve 24saatlik ikisine aynı pH=4'te (6,48±0,77 mg GAE/g) ve (7,01±0,24b mg GAE/g ) olarak en yüksek antioksidan aktivite gösterilmiştir. DPPH serbest radikal giderme ölçümleriyle en yüksek aktivite 1saatlik pH=7'de (0,21±0,06 mg/ml) ve 24saatlik pH=4'te (0,34±0,01 mg/ml) belirlenmiştir. ABTS yöntemiyle en yüksek aktivite gösteren pH'ları 1saatlik (1sN) pH=5'te (0,29±0,01 mg/ml) ve pH=8'de (0,29±0,11 mg/ml) ve 24 saatlik (24sN) pH=5'te (0,33±0,01 mg/ml), pH=8'de (0,33±0,01mg/ml) olarak değerleri verilmiştir.

Abstract:
One of the important factors in the acceptance of food products is the colors used as an indicator of quality. Food color has an important feature in attracting the attention of the buyer and giving an impressive appearance to the food item.
Natural substances that give color to foods are anthocyanin substances that are commonly found in nature, anthocyanins are responsible for the bluest and reddish color of many plants in the vegetable world and are determined as water-soluble color pigments.
Some vegetables containing anthocyanins (grape, strawberry, peach, eggplant, red cabbage, red beet, radish, etc.), some fruits containing anthocyanins (cherry, apple and plum varieties), but they are not found in all pulp, most of them are found in the inner cells and skin.
Some fruits contain one or two types of anthocyanins, and some have a complex mix of 20 or more.
It grows 12.000 kinds of plants in Turkey, the number of endemic plants is 3778 taxa.
It is the Brassicaceae family, which is the fourth largest plant family in the country and attracts attention in terms of endemic plant members.
This family is spread all over the world and includes 3740 species belonging to 325 genera, while in Turkey there are 660 taxa belonging to 91 genera of this family.
Members of the family are most diverse in Southwest Asia, especially in Turkey and Iran-Turan region.
About 50 types of vegetables are grown in Turkey, and red cabbage (Brassica oleracea var. Capitata f. rubra) has an important place among the vegetables taken into culture.
Red cabbage production in Turkey is carried out in the southern and western regions, with a production of 605,218 tons, it is consumed in different ways throughout the year, except for two months of the year (Eşiyok et al, 2010).
Red cabbage (Brassica oleracea var. capitata f. rubra) is a broad and thick vegetable type from the cruciferous family, with many layers of leaves. The best quality production of cruciferous vegetables, which is a cool climate vegetable, is carried out in the autumn-winter period.
Cabbages, which are grown all year round in European countries, are generally grown in winter in our country, they are dark red and purple in color because they contain Anthocyanin substances in their leaves. showed that the ratio of anthocyanins in red cabbage was 90.5 mg/100g.
It has been noted to contain total phenols and flavonoids, and a greater amount of antioxidant activity than most fruits and vegetables. Red cabbage has minerals such as manganese, potassium, magnesium, calcium and iron.
For this reason, it is very useful for the circulatory system, having an important place in human body nutrition and helping to strengthen the heart and protect it from heart attacks, gains importance in protecting from various cancers, plays an important role in strengthening bones, improving digestive system and eye health.
Since it is rich in E, B6, K, its consumption helps to significantly reduce the risk of osteoporosis, and vitamin K increases the amount of protein needed to maintain Calcium in the bones.
Because it is rich in Vitamin C, which is a very powerful antioxidant, it creates white blood cells, which form the first line of defense against harmful microbes, protects the body from diseases and slows down aging by fighting harmful free radicals in the body and helps keep the skin young and smooth.
The polyphenol substances contained in red head cabbage are effective in preventing Alzheimer's disease. It protects brain cells and improves long-term memory and generally increases the energy level in the body and relaxes the blood circulation.
As we have seen, the human body is affected by the damage of free radicals, so human health and the working mechanisms of the body need many and different antioxidants.
As a result of the studies carried out in recent years, many and different (electrochemical and spectrophotometric measurements) methods have been determined to measure the antioxidant activity in a sample.
Each method has advantages and disadvantages, and it has been determined that the most common, fast and simple methods are DPPH and ABTS methods.
In our study, spectrophotometric measurements are made to measure the capacity of the sample (DPPH radical scavenging capacity and Trolox equivalent antioxidant capacity method), and at the same time, the amount of total phenolic substance of antioxidants is determined.
In order to examine the Antioxidant activity of the red cabbage plant, the plant is washed and broken into small pieces with a blender in order to dissolve it completely in pure water and the extraction process is done, then adjusted to different pH values (4, 5, 6, 7, 8, 9, 10 and original). Different concentrations ( 1/40 , 1/80 , 1/120 , 1/180 , 1/240) are obtained by taking a sample from the samples and adding distilled water.
DPPH free radical scavenging activity, total phenolic content with Folin-Ciocalteu reagent and Trolox Equal Antioxidant capacity are measured by spectrophotometric methods of each concentration obtained,
According to the results obtained (the IC50 value, which expresses the amount of antioxidant consumed for 50% of the % inhibition values to decrease), the greater the decrease in absorbance, the higher the antioxidant activity.
Accordingly, the antioxidant activity was measured by ABTS method and its absorbance (according to IC50) was measured, and pH=5 and pH=8, respectively, (0,29±0,01 mg/ml), (0.29±0.11 mg/ml)on the same day (1sN) the pH of which showed the highest activity, and after 24 hours of waiting (24sN) (0.33±0.01 mg/ml) (0.33±0.01 mg/ml). The lowest antioxidant activity was known as 1sN PH=10 (0.38±0.02 mg/ml) and 24sN PH= 4 (0.46±0.05 mg/ml).
According to the results, the highest antioxidant activity was shown when the total phenolic substance gave the lowest value as 1sN and 24sN both at the same pH value at 4 (6,48±0,77 mg GAE/g ),(7,01±0,24 mg GAE/g) However, when it gave high values at 1sN PH 4 (6.48±0.77 mg GAE/g) and 24sN PH 6 (7.59±1.22 mg GAE/g), it showed low antioxidant activity.
Finally, the antioxidant activity showed the highest activity at 1sN pH=7 (0.21±0.06 mg/ml) and pH=4 (0.34±0.01 mg/ml) for 24sN with DPPH free radical removal method. It showed the lowest antioxidant activity since it gave high absorbance values at 1sN PH 4 (0.32±0.08 mg/ml) and 24sN PH 9 (0.94±0.03 mg/ml).
As we know, red cabbage is rich in very strong antioxidants (vitamin c, k, potassium, etc.), it also contains a higher amount of antioxidant activity than most fruits and vegetables,  as it contains high levels of phenols and flavonoids. It is known as a source of antioxidant.